Connections
The access crisis
▶Briefing24 Mar 2026
In one line
Britain allocated grid connection capacity at cost instead of at value — a tragedy of the commons that produced 860GW of applications on a 60GW system, £1.7 billion per year in curtailment payments to generators who connected where the grid couldn't handle them, and a reform programme that responds with planning instead of pricing.
The thesis
Grid connection capacity is scarce. Scarce resources allocated without a price get oversubscribed. Scarce resources allocated with a price generate revenue — revenue that funds system expansion, creating capacity for the next wave of users. Pricing is not rationing. It is the mechanism by which the system grows.
Britain has never priced connection capacity at its value. Even before 2005, 'deep' connection charges reflected the engineering cost of reinforcement, not the market value of the capacity. If a connection is worth £100 million to a developer but the reinforcement costs £20 million, deep charging prices at £20 million. That is still a cost signal, not a price signal. A true price would be set by competitive bidding among developers, not by engineering cost estimates. The reforms now underway still do not price the underlying capacity.
How the generation queue was created
Three policy choices, each designed to support renewables, widened the gap between the cost of applying and the value of holding a position.
1. Shallow charging (2005). Ofgem moved from 'deep' to 'shallow' connection charges. Developers now paid only for the wire to their site. Reinforcement costs were socialised through TNUoS, spread across all consumers. This removed the last cost signal — imperfect as it was — that told developers what their connection cost the system.
2. Connect and Manage (2010). Generators could connect before the grid was reinforced to handle them. If constrained off, they received constraint payments. More accurately: Connect and Pay Them Off. A connection position became valuable even at a fully congested location. The cost falls entirely on consumers. In 2024/25, constraint payments reached £1.7 billion (NESO, Annual Balancing Costs Report 2025). NESO projects £8 billion per year by 2030 without network investment.
Constraint payments, 2018–2025 (NESO): - 2018/19: £300m - 2019/20: £350m - 2020/21: £500m - 2021/22: £1.05bn - 2022/23: £1.15bn - 2023/24: £1.05bn - 2024/25: £1.7bn
3. CfD (2014). A connection offer became a prerequisite for bidding into subsidy auctions. A connection position became a ticket to a guaranteed revenue stream.
4. The downstream effect. CfD-subsidised wind and solar created intermittent generation. Intermittent generation created price volatility. Price volatility made battery storage profitable — not because battery costs 'collapsed,' but because the subsidy regime created the market conditions batteries exploit. 236GW of battery storage then flooded the queue — more than all wind and solar combined.
How Connect and Pay Them Off actually works
The mechanics are worse than they appear. When NESO curtails a wind farm:
1. The generator has already sold power on the wholesale market at, say, £50/MWh. That trade stands. Under the ABSVD mechanism (Applicable Balancing Services Volume Data), the generator's imbalance is neutralised — they keep the wholesale revenue as if they had generated.
2. On top of that, NESO pays the generator a bid price via the Balancing Mechanism. This bid is supposed to cover lost CfD top-up and lost REGOs (renewable certificates). For a CfD wind farm with an £80 strike price, the cost-reflective bid should be roughly £31.50/MWh (£30 lost CfD top-up + £1.50 lost REGO).
3. Some generators were bidding £60–70/MWh — capturing the difference as profit from being curtailed. Beatrice Offshore accepted a £33.14 million fine for this (Ofgem, May 2024). Dorenell paid £5.53 million (March 2024). Moray East is under investigation — it received £136.8 million in constraint payments.
4. When the wholesale price exceeds the CfD strike price, being curtailed saves the generator from repaying the Low Carbon Contracts Company. A cost-reflective bid should reflect this benefit and go lower. Beatrice kept bidding high.
The government rejected locational pricing in July 2025 despite Ofgem analysis showing £48–49 billion in consumer benefits between 2025 and 2060. Under locational pricing, generators at congested locations would face lower local prices — bearing the cost of congestion directly instead of socialising it. Connect and Manage would become unnecessary. The government judged the investor confidence risk too high for Clean Power 2030.
What is in the generation queue
The pre-reform generation queue stood at approximately 722GW (NESO, December 2025):
- Battery storage: ~236GW — the largest single category. 153GW was removed in the 2025 reforms. Even the surviving 83GW exceeds the 23–27GW target range. - Solar: ~95GW - Offshore wind: ~74GW - Onshore wind: ~31GW - Gas (unabated): ~10GW - Nuclear: ~7GW
Batteries do not receive CfD. Their business case depends on price arbitrage and balancing services — revenue streams that exist because subsidised renewables create volatility. The battery queue is a second-order consequence of the CfD regime. 60–70% of projects holding connection agreements never ultimately connect (GOV.UK Connections Action Plan, November 2023).
The demand queue
The demand queue is the same failure, replayed faster. Demand connection applications carried a flat fee of roughly £40,000–£70,000 regardless of capacity — a 100MW project and a 2,000MW project paid the same. Unlike generation, demand faced no Progression Commitment Fee scaled to MW, and no requirement to demonstrate the project was 'needed' as well as 'ready.' The queue grew 460% in seven months, reaching 125GW by June 2025 when NESO closed it (DESNZ, March 2026). Data centres account for 50GW at transmission level.
NESO's Demand CFI (March 2026): 243 responses, over 90GW. Data centres are 55% (50.8GW, 152 projects). 68% have no secured off-taker. 81% would accept non-firm, ramped, or phased connections for an earlier date.
The demand side is easier to fix. The reforms are earlier-stage. And demand customers are demonstrably willing to pay — the 81% is direct evidence.
Why planning cannot fix this
All three reform programmes — Ofgem's 'Curate, Plan and Connect,' NESO's Strategic Spatial Energy Plan, DESNZ's capacity reservation — assume someone can determine where demand will materialise, when, and at what scale. This is a knowledge problem. The information required to allocate connection capacity efficiently — which locations developers value, at what price, and when — does not exist inside any planning body. It exists only in the willingness of developers to commit capital.
The 460% demand surge that no energy scenario predicted is direct evidence. The demand appeared in seven months, driven by decisions in boardrooms in California and Tokyo.
DESNZ proposes reserving capacity at specific substations for strategic demand without a developer attached. A reservation that nobody takes up is capacity a real project could have used.
What is being proposed
Ofgem — higher deposits and fees for demand applicants, especially data centres. Amounts being set by a Curate Advisory Group.
NESO — milestone-based queue management. Gate 2 offers carry a 90-day acceptance window and eight mandatory milestones (CMP434/435). Miss M1–M3 (planning consent, land rights): automatic termination. Miss M5–M8 (design, construction, FID): discretionary termination.
DESNZ — three interventions using PIA powers. Proposal 1: government backstop for Ofgem's Curate measures. Proposal 2: freed capacity reallocated to government-designated projects, placeholder reservations at substations, in-batch prioritisation. Proposal 3: a separate managed process for data centres, scored on economic value, clean energy alignment, and national security.
The generation reforms (Gate 2, TMO4+) are well advanced. The demand reforms are earlier-stage and more malleable.
The case for pricing
If connection capacity were priced — auctions at specific locations, tradeable rights, deposits scaled to locational scarcity — three things happen.
The queue clears. Developers who value a connection at the true cost of providing it pay. Speculative developers withdraw.
The system grows. A data centre that pays £50 million for early access to a constrained substation is funding the reinforcement that creates capacity for the factory, the school, and the hospital that cannot pay £50 million.
The bids reveal information. A developer bidding at a specific location is telling you where demand actually is — information no planning model possesses.
The Progression Commitment Fee prices process — the cost of holding a position — not scarcity. A fee that costs the same at a congested London substation and an empty node in rural Scotland allocates nothing.
Three tests
Does it price scarcity? Gate 2 milestones create a cost to holding a position. DESNZ allocates scarcity by priority list. Neither prices the underlying capacity. As such neither will prevent a new queue forming once this one clears.
Does it reduce transaction costs? The reform has produced three overlapping consultations, 26+ webinars, mandatory portal communications, eight milestones, a government nomination process, and a Curate Advisory Group. The firms that benefit from complexity can absorb it. New entrants cannot.
Does it let the market reveal what the planner cannot? DESNZ reserves capacity ahead of need. NESO plans where investment should go. The 460% surge nobody predicted, and the 68% without off-takers, suggest the relevant information does not sit inside any planning body.
The reform most likely to clear the queue — and fund the system growth that serves everyone — is priced, tradeable connection rights. The 81% who would accept alternative arrangements are ready to trade. The system is not yet ready to let them.
▶Timeline
▶Open consultations (10)
Ofgem sets out five options for redesigning transmission network charges to steer investment towards Strategic Spatial Energy Plan locations, ranging from tweaking existing TNUoS to auctioning connection capacity by zone. Charges would apply to new generators, demand, and storage. Responses by 26 May 2026, reforms targeted for 2029.
STC modification CM093 extends the CUSC Section 15 User Commitment Methodology principles to demand customers currently on Final Sums methodology, reducing their upfront security requirements by applying the Strategic Investment Factor (SIF) and Local Asset Reuse Factor (LARF). This is the STC-side consequential change required by CUSC modification CMP417, targeting the January 2027 securities run. The workgroup voted unanimously that the original proposal better facilitates STC objectives than the baseline.
STC modification CM097 mandates Transmission Owners to submit EMT and RMS models of their assets to NESO, enabling system-wide dynamic modelling as inverter-based resources replace synchronous generation. The workgroup unanimously supported the original solution. Implementation aligns with Grid Code modification GC0168.
NESO proposes replacing references to the Electricity Ten Year Statement (ETYS), Seven Year Statement, Network Options Assessment, and Offshore Development Information Statement in the STC with references to the new Centralised Strategic Network Plan (CSNP). This is a housekeeping modification under self-governance, updating code text to match licence changes already made by Ofgem. Parallel modifications are being raised for the Grid Code and CUSC.
Ofgem consults on the second preliminary Strategic Direction Statement, which sets binding priorities for how GB industry codes must develop under the Energy Act 2023 governance reforms. The SDS categorises policy areas requiring code changes and proposes converting from a preliminary to a hybrid document once BSC and REC are designated by end-2026. Responses due 28 May 2026.
DESNZ consults on siting and investment levers under Reformed National Pricing (RNP), the programme that replaces REMA after ministers rejected zonal pricing. Closes 2 June 2026. Ofgem runs a parallel Call for Input on network and connections charging to 26 May. Together these set how much new generation and storage pay, and where.
GC0168 would require legacy generators (completion before 1 September 2022) to provide Electromagnetic Transient models to NESO on request, enabling analysis of inverter instability, system oscillations, and transient overvoltage on a grid increasingly dominated by power electronics. The workgroup's preferred alternative (WAGCM1) defers the obligation for GB Code Users until a CUSC cost recovery mechanism is in place, while applying immediately to EU Code Users. Responses due by 8 June 2026.
NESO is consulting on GSR037, a housekeeping modification to the System Quality of Supply Standard (SQSS) that restructures the definitions section into a table, renumbers Section J, and applies consistent formatting throughout. No substantive requirements change; the Proposer flags sections 6.1, 11, and J for careful review to confirm restructuring has not inadvertently altered obligations. Standard Governance route, no Workgroup, no system or process impact.
Muirhall Energy has raised CMP471, a temporary CUSC amendment letting Users adjust connection dates and contract elements before the first CMP434 Gated Application Window and the 1 April 2027 liability trigger. The CUSC Panel unanimously recommended urgent treatment on 15 May 2026; if Ofgem agrees by 19 May, implementation lands 31 July 2026 instead of an undated 2027 slot. Without it, queue holders enter Gate 2 carrying contractual connection dates that no longer match deliverable programmes.
Ofgem proposes an early competition OFTO build model where transmission assets are competitively tendered before construction, rather than after. The consultation also updates the existing late competition model. Early competition would be mandatory in certain circumstances, with detailed proposals covering tender process, evaluation criteria, and commercial framework.
▶All publications (218)
NESO is consulting on GSR037, a housekeeping modification to the System Quality of Supply Standard (SQSS) that restructures the definitions section into a table, renumbers Section J, and applies consistent formatting throughout. No substantive requirements change; the Proposer flags sections 6.1, 11, and J for careful review to confirm restructuring has not inadvertently altered obligations. Standard Governance route, no Workgroup, no system or process impact.
NESO has raised SQSS modification GSR037 to reformat and tidy the System Quality of Supply Standard for readability. The proposal is administrative housekeeping with no change to technical security or planning standards. Standard Governance, proceeding to Code Administration Consultation.
CMP477 proposes a CUSC change to allow a single connection modification request to span more than one Transmission Owner area, rather than forcing developers to raise separate applications when their works touch the boundary between TO networks. Raised by Andrew Urquhart on 19 May 2026 as an Urgent modification under an Authority-agreed timetable, status Proposal Raised. NESO classifies the impact as Medium across generators, demand customers, TOs (including CATOs) and consumers.
Ofgem republishes the UK Competition Network's running list of Competition Act 1998 cases across all regulated sectors since 2014. The only energy entries are previously concluded matters: SGN gas connections (commitments accepted Dec 2025), wholesale trading (June 2019), PayPoint prepayment top-ups (Aug 2021), domestic supply Chapter I infringement (May 2019), and SSE connections (commitments accepted Nov 2016). No new investigation, decision, or rule.
NESO has raised GC0186, a Grid Code modification updating restoration requirements following GC0156's implementation of the Electricity System Restoration Standard. The proposal introduces Regional Restoration Plans, equal treatment of NGET, SPT and SHET during restoration, requirements for Network Operators to switch at sufficient speed, and tightened testing and data obligations. Currently at Workgroup Nominations stage, governance route still to be decided by the Panel.
Muirhall Energy has raised CMP471, a temporary CUSC amendment letting Users adjust connection dates and contract elements before the first CMP434 Gated Application Window and the 1 April 2027 liability trigger. The CUSC Panel unanimously recommended urgent treatment on 15 May 2026; if Ofgem agrees by 19 May, implementation lands 31 July 2026 instead of an undated 2027 slot. Without it, queue holders enter Gate 2 carrying contractual connection dates that no longer match deliverable programmes.
NESO has reissued STCP 11-1 (Outage Planning) as Issue 013, incorporating System Access Reform changes and a revised Emergency Return to Service (ERTS) profiling regime under modification PM0153. The procedure governs how the system operator and transmission owners (NGET, SPT, SHETL, offshore TOs, and Competitively Appointed Transmission Owners) coordinate outages from six years ahead down to day-ahead handover. The substantive change is to ERTS profiling; the rest is administrative consolidation of CATO inclusion already made in Issues 011 and 012.
NESO has raised PM0153 to revisit the criteria for recalling transmission circuits with longer Emergency Return to Service (ERTS) times during winter. The modification mandates use of a Winter Risk Policy Form to document system margins, constraints, mitigations, and recall plans, with the aim of clearing more winter outages without breaching security standards. It is self-assessed as low impact on Transmission Owners, Transmission Licensees, Generators, and System Operators, with a Panel Decision governance route.
The Secretary of State granted a development consent order for North Falls, a ~1 GW offshore wind farm of up to 57 turbines roughly 40km off the East Anglia coast. Consent covers construction, operation, maintenance, and decommissioning under the Planning Act 2008. This clears the principal planning barrier for a project led by North Falls Offshore Wind Farm Limited (an SSE Renewables / RWE joint venture vehicle).
DESNZ has granted development consent under the Planning Act 2008 for RWE's two Dogger Bank South offshore wind farms, each up to 1.5 GW, for a combined 3 GW across up to 200 turbines. The arrays sit 100 km (West) and 122 km (East) from shore in the North Sea, with onshore export cables and converter stations connecting to the National Grid.
Ofgem has endorsed five innovation challenges for the Strategic Innovation Fund covering RIIO-3 transmission (2026-2031) and electricity distribution (2028-2033): six-month industrial connections by 2033, 50% faster and 20% cheaper build by 2035, plug-and-play domestic device connections by 2032, near-zero outages via autonomous islanding by 2038, and decentralised local balancing by 2034. The challenges were recommended by the Energy Networks Innovation Taskforce and will be delivered through Innovation Delivery Groups and SIF-funded projects. This document sets the target framework; it does not allocate funding or change rules.
NESO publishes its forecasting strategy to 2030, committing to probabilistic forecasts, multiple weather data sources, and in-house cloud infrastructure (Platform for Energy Forecasting) to replace legacy systems. The headline number is an estimated £2.5m per month saving from dynamic reserve setting underpinned by probabilistic forecasts, reducing average reserve holding by 400MW. FES2025 anticipates 90-120GW of wind and solar installed capacity by 2030 and 12-16% demand growth from 2024 to 2030.
NESO's Constraint Management Intertrip Service (CMIS) page consolidates the three active constraint management programmes: EC5 East Anglia (enduring service starting mid-2026), B6 Anglo-Scottish boundary (15 generators contracted, now extended to September 2027), and a new CMIS Scotland consultation launched 13 April 2026. These are commercial alternatives to transmission build, paying generators to accept automatic disconnection post-fault so more power can flow on existing infrastructure pre-fault.
GC0164 rewrites Grid Code Operating Code 2 (Operational Planning and Data Provision) in plain English with diagrams and flowcharts, without changing any obligations on users. The Panel unanimously recommended the original proposal. It now awaits Ofgem decision, with implementation 10 business days after approval.
The CUSC Panel on 24 April 2026 progressed three new modifications and one workgroup report. CMP469 creates a one-year cost recovery mechanism for parties affected by Grid Code restoration obligations (GC0186). CMP472 allows NESO to share large embedded generators' red line boundaries with DNOs without customer consent, enabling Gate 2 distribution contract verification. CMP471, which proposed interim contract variations ahead of the first CMP434 gated application window, was sent back to the proposer for scope clarification.
STC modification CM093 extends the CUSC Section 15 User Commitment Methodology principles to demand customers currently on Final Sums methodology, reducing their upfront security requirements by applying the Strategic Investment Factor (SIF) and Local Asset Reuse Factor (LARF). This is the STC-side consequential change required by CUSC modification CMP417, targeting the January 2027 securities run. The workgroup voted unanimously that the original proposal better facilitates STC objectives than the baseline.
STC modification CM097 mandates Transmission Owners to submit EMT and RMS models of their assets to NESO, enabling system-wide dynamic modelling as inverter-based resources replace synchronous generation. The workgroup unanimously supported the original solution. Implementation aligns with Grid Code modification GC0168.
NESO proposes replacing references to the Electricity Ten Year Statement (ETYS), Seven Year Statement, Network Options Assessment, and Offshore Development Information Statement in the STC with references to the new Centralised Strategic Network Plan (CSNP). This is a housekeeping modification under self-governance, updating code text to match licence changes already made by Ofgem. Parallel modifications are being raised for the Grid Code and CUSC.
GC0168 would require legacy generators (completion before 1 September 2022) to provide Electromagnetic Transient models to NESO on request, enabling analysis of inverter instability, system oscillations, and transient overvoltage on a grid increasingly dominated by power electronics. The workgroup's preferred alternative (WAGCM1) defers the obligation for GB Code Users until a CUSC cost recovery mechanism is in place, while applying immediately to EU Code Users. Responses due by 8 June 2026.
Ofgem proposes an early competition OFTO build model where transmission assets are competitively tendered before construction, rather than after. The consultation also updates the existing late competition model. Early competition would be mandatory in certain circumstances, with detailed proposals covering tender process, evaluation criteria, and commercial framework.
Ofgem has accepted urgency for CMP470, a CUSC modification proposing a commitment fee for oversubscribed generation technologies in the grid connection queue. Raised by Field Energy Limited on 20 March 2026, the proposal would price queue positions for technologies that dominate the 700 GW backlog. Urgency was requested by the CUSC Panel on 27 March and accepted by Ofgem on 2 April, meaning this bypasses the standard modification timeline.
DESNZ publishes the Q1 2026 extract of the Renewable Energy Planning Database, tracking all UK renewable electricity projects above 150kW through planning, construction, operation, and decommissioning. The database is managed by Barbour ABI and covers project-level detail including capacity, technology type, CfD allocation round, planning status, and grid coordinates. It includes an interactive map and links to the equivalent heat network database.
DESNZ commissioned Baringa to update its 2024 assessment of supply chain constraints across renewable and network technologies to 2035. The study identifies bottlenecks that could delay deployment and recommends industry or policy interventions to address them.
DESNZ is reviewing Ofgem's mandate, statutory duties, regulatory remit, and enforcement powers. The call for evidence covers whether Ofgem's principal objective should shift from promoting competition to broader goals including innovation and consumer standards, whether its accumulating statutory duties should be streamlined, and whether it should gain FCA-style Consumer Duty and Senior Manager Regime powers. The consultation closed 28 February 2025; outcomes are now being considered.
DESNZ publishes the first comprehensive review of Ofgem in its 25-year history, proposing to rewrite its statutory duties, give it direct consumer law enforcement powers without court action, introduce individual executive accountability, and cap bonuses for rule-breaking. The review will produce a reformed Strategy and Policy Statement to separate government policy-setting from regulatory delivery, and commits to clarifying the boundary between DESNZ, NESO and Ofgem. Ofgem's workforce has grown from 890 FTE in 2014/15 to 2,110 in 2024/25.
CMP471 landing page. Interim contract-variation process ahead of CMP434 Gated Application Window.
CMP473 urgency request letter. RWE proposes clarifying which Existing Agreement updates are required with a Gate 2 Modification Offer.
CMP473 landing page. Clarification of contract updates required with a Gate 2 Modification Offer.
Ofgem's Jack Presley Abbott confirms that the battery pipeline emerging from connections reform may be oversupplied relative to Clean Power 2030 needs, and that many protected 2026 and 2027 projects will miss their original dates. Ofgem is considering intervention to prune the queue, and names demand-connection reform, including a data-centre levy, as the next front.
DESNZ consults on siting and investment levers under Reformed National Pricing (RNP), the programme that replaces REMA after ministers rejected zonal pricing. Closes 2 June 2026. Ofgem runs a parallel Call for Input on network and connections charging to 26 May. Together these set how much new generation and storage pay, and where.
Ofgem and DESNZ confirm 221 GW has been removed from the connection queue under the new Gate 2 / Phase 1 process, with self-selection into Gate 1 filtering out additional capacity. Battery storage has progressed to Gate 2 at a materially higher level than planned: 14.8 GW above the Clean Power 2030 Action Plan range and 61.7 GW above projected 2035 system need. Protection measures for projects with planning consent, Capacity Market agreements or near-term offers, combined with batteries' faster consenting speed, are named as the cause.
Ofgem calls for stakeholder input on NESO's Business Plan 3 performance for 1 April 2025 to 31 March 2026, the final year of RIIO-2. Assessment moves to a Below/Meets/Exceeds Expectations grading across two components: delivery of business plan aims (via Success Measures) and value for money. Responses due 18 May 2026; final decision summer 2026.
DESNZ and Ofgem signal they may intervene to remove battery storage projects from the reformed connection queue, where 14.8 GW above the Clean Power 2030 Action Plan range and 61.7 GW above projected 2035 system need have progressed to Gate 2. The surplus was caused by protection measures for projects with planning consent or Capacity Market agreements, which batteries secured faster than other technologies. NESO's annual consultation proposes disapplying protections so that only batteries with revenue support schemes qualify for future windows, and a code modification imposing financial attrition measures has been granted urgency.
Ofgem has published a call for input on the future regulatory framework for electricity interconnection, covering route to market, competition models, financing structures, and treatment of Offshore Hybrid Assets. This accompanies DESNZ's policy paper on interconnection's role in a strategically planned system. GB currently has 10.3 GW of operational interconnector capacity with 1.4 GW in construction and 8.9 GW in development under existing approvals.
Ofgem has approved NESO's methodology for refreshing the second transitional Centralised Strategic Network Plan (tCSNP2), which will reassess the transmission network build programme needed through the 2030s. The refresh will update cost estimates, delivery timescales, and network designs from the 2024 tCSNP2, incorporating connections reform outcomes and revised offshore network configurations. It also feeds into the pipeline for the full CSNP due by December 2028.
Ofgem has directed NESO to delay the first Centralised Strategic Network Plan by 12 months: submission moves from June 2027 to 15 September 2028, publication from December 2027 to 15 December 2028. The delay aligns CSNP with the revised Strategic Spatial Energy Plan timeline. NESO requested the derogation itself on 23 March 2026, and Ofgem granted it.
Ofgem has conditionally approved NESO's methodology for producing the Centralised Strategic Network Plan (CSNP), the first independent long-term plan covering electricity, gas transmission, and hydrogen transport and storage networks in GB. The methodology uses the Strategic Spatial Energy Plan as an input and describes how NESO will identify system needs, develop options, appraise them, and recommend delivery. Approval is subject to two conditions requiring further detail on unspecified areas.
DESNZ has published a revised Electricity Supply Emergency Code setting out how rota disconnections would be imposed during a prolonged electricity shortage. Non-protected demand is split into 18 Load Blocks of ~5% each, disconnected in three-hour rotations under NESO-issued Activation Schedules, with Protected Sites shielded via a four-tier list (Tier 0 energy infrastructure, Tier 1 hospitals, Tier 2 essential services, Tier 3 industrial sites facing >=10% asset damage). The update follows a 2023 review and reflects the split between the short-notice Demand Control Rotation Protocol and the prolonged-emergency ESEC route.
DESNZ has issued a screening decision that a single 132 kV tower, cable sealing end platforms, and two underground cables at Musty Haulgh Farm, Burnley do not require a statutory Environmental Impact Assessment. The works are a minor modification to Electricity North West's existing 'DR' overhead line to connect a 152 MWh battery storage site that already has planning consent (FUL/2021/0375, granted July 2023). Burnley Borough Council confirmed no EIA needed on 15 December 2025; no public representations were received by the 3 April 2026 deadline.
Ofgem grants urgency to CMP470, a CUSC modification that would introduce commitment fees for developers holding grid queue positions in oversubscribed technology categories — primarily battery storage, which exceeds CP2030 targets by 14.8GW (2030) and 61.7GW (2035). The fee mechanism would price queue occupation for the first time, giving non-viable projects a financial reason to exit before signing Gate 2 connection agreements. Decision needed before Phase 1 offers are accepted from mid-August 2026.
NESO reports that the 2026 CUSC Alternate Panel Member election concluded with four candidates nominated for five vacancies, meaning all candidates were elected unopposed under CUSC 8A.2.2.3. The four alternate members (Joseph Dunn, Kirsty Dawson, Nick Sillito, Paul Jones) serve from 24 April 2026 to 30 September 2027. One vacancy remains unfilled.
NESO consults on a roadmap to gain operational visibility and dispatch access to distributed energy resources (DERs) and consumer energy resources (CERs) — commercial batteries, small-scale wind, EVs, rooftop solar, and home batteries. The consultation closes 30 April 2026 and seeks feedback on ambition, practicality, and completeness of proposed capabilities and data requirements. This is the system operator's bid to extend its operational reach below the transmission-distribution boundary.
NESO's Early Competition events page consolidates webinar recordings, slides, and an active Expression of Interest questionnaire with a 30 April 2026 deadline. The EOI asks stakeholders to shape how transmission projects are packaged, sequenced, and brought to market under the Early Competition regime. This is the engagement layer around an already-decided policy, not a new rule.
NESO's Connections Portal landing page provides access to the online system where developers apply to connect projects to the National Electricity Transmission System. The page collects user guides, how-to videos, and webinar materials explaining portal functionality. No new rules, charges, or process changes are announced.
The SQSS Panel met on 24 March 2026 and progressed three modifications: GSR036 (voltage limit review for operational timescales) was sent back for further refinement, GSR037 (formatting housekeeping) was approved to proceed directly to Code Administrator Consultation without a workgroup, and GSR035 (beneficial outages) had its Terms of Reference approved. GSR034 (offshore DC converter infeed risk) was implemented on 13 March 2026.
The Grid Code Review Panel met on 26 March 2026. Two new modifications were presented: GC0185 proposing dynamic regulation as an alternative to mandatory frequency response was sent back for clearer scope, and GC0187 (legal text corrections) was deferred over a drafting query. GC0139 on enhanced planning-data exchange between network operators and NESO was unanimously recommended to Ofgem.
CUSC Panel granted urgent treatment to CMP470, which introduces a commitment fee for grid connection technologies oversubscribed relative to Clean Power 2030 targets — a pricing mechanism for queue capacity. CMP440, which removes the zero price floor on demand TNUoS locational tariffs to restore locational investment signals, was unanimously recommended to Ofgem. CMP445 (pro-rated first-year TNUoS for generators) proceeds to Code Administrator Consultation opening 7 April 2026.
TCMF slidepack covers five substantive items: a proposed CUSC clause to let NESO share Large Embedded Generator red line boundaries with DNOs without customer consent; a proposed urgent modification to allow connection date delays during the ~30-month freeze ahead of the first CMP434 gate window; RWE flagging significant errors and missing appendices in Gate 2 Offers where network companies delayed connection dates; and NESO's proposal to model Sea Link HVDC tariffs on a north-to-south (Sizewell-to-Richborough) flow direction based on power flow studies showing 75% southward flow. The code administrator update lists CMP470 (Oversubscribed Technologies Commitment Fee) as a new urgent modification with nominations closing 2 April.
NESO consults on guidance for secondary generators — those with Grid Code obligations but no restoration contract — on how to comply with the Electricity System Restoration Standard (ESRS). The ESRS requires 60% of national demand restored within 24 hours and 100% within five days of a total or partial shutdown, with a compliance deadline of 31 December 2026. The guidance codifies existing Grid Code obligations around 72-hour plant resilience, cold start time declarations, communications testing, and cyber security under the NIS Regulations.
Ofgem consults on the second preliminary Strategic Direction Statement, which sets binding priorities for how GB industry codes must develop under the Energy Act 2023 governance reforms. The SDS categorises policy areas requiring code changes and proposes converting from a preliminary to a hybrid document once BSC and REC are designated by end-2026. Responses due 28 May 2026.
CUSC Section 14 v1.48a is the updated standing methodology document for connection charges, TNUoS, and BSUoS, effective 1 April 2026. It sets out the formulas for calculating connection charges (GAV depreciation, WACC-based returns, site-specific maintenance, transmission running costs), the transport model for deriving zonal TNUoS tariffs, and daily BSUoS settlement. This is the reference text, not a reform proposal.
NESO published the consolidated Connection and Use of System Code (CUSC) as of 1 April 2026, version 1.19/1.22. This is the complete code text — sections on applicability, connection, use of system, balancing services, charging methodologies, queue management, and the Gates process — not a modification or reform proposal. No rules change; this is the standing reference document.
Ofgem publishes guidance on how NESO should interpret Condition C1 of its Electricity System Operator and Gas System Planner licences, which sets minimum performance outcomes. The document establishes expectations for compliance and requires NESO to produce remediation plans when material performance concerns arise. This is part of NESO's enduring regulatory framework, replacing the transitional arrangements since its separation from National Grid.
Ofgem publishes the governance document detailing how it will assess NESO's annual performance and apply financial incentives under the enduring regulatory framework. The document sets out the methodology for performance assessment, reporting requirements, and the mechanisms NESO must use to collect stakeholder feedback. This sits within the broader implementation of NESO's post-separation regulatory settlement.
CMP470 proposes a commitment fee for technologies oversubscribed relative to Clean Power 2030 targets, aimed at forcing speculative projects out of the connection queue. The CUSC Panel voted by majority to recommend urgent treatment to Ofgem, with a final modification report targeted for 30 June 2026 under the urgent timeline versus April 2027 under standard process. The proposal was raised by Field Energy on 20 March 2026 after Gate 2 capacity data revealed approximately 90 GW of battery storage projects seeking connection points when roughly one third will actually connect.
DCRP/MP/25/01 considers potential changes to Distribution Code Document 6 (DOC6) following Grid Code modification GC0176, which introduces a Demand Control Rotation Protocol. The joint workgroup reviews whether distribution code amendments are needed to align with new grid code provisions for demand control. This appears to be a procedural alignment exercise following grid code changes.
The Distribution Code proposes consolidating EREC G98 and EREC G99 distributed generation connection guides into a single document. This annual revision follows Distribution Code requirements with consultation planned for March 2025. The change streamlines guidance for generators connecting at different scales rather than altering connection rules themselves.
DCRP/MP/25/03 proposes modifications to Engineering Recommendation G87 Issue 3, a technical standard governing electrical connections to distribution networks. The modification has been reviewed by ENA's Technical Author Service and is now under consultation. G87 sets technical requirements for equipment connecting to distribution networks.
Distribution Network Operators must now follow standardised technical procedures when providing new connection points to premises that already have connections, or are adjacent to premises with existing connections, regardless of which DNO provided the original connection. The new EREC G94 standard addresses safety and technical risks from multiple connection points in close proximity. This responds to increased demand for additional connections driven by EV charging infrastructure.
The Distribution Code modification EREC G59 Issue 3 A8 adds supplementary sections to facilitate intentional islanding during system restoration processes. This builds on existing Engineering Recommendation G59 guidance for distributed energy resources. The modification enables controlled isolation of network sections while maintaining local supply during wider system recovery.
EREC G99 adds supplementary sections to facilitate intentional islanding during system restoration. This is a code modification to the distribution connection standard. The change enables grid-connected assets to operate in isolation when the grid is being restored after blackouts.
The Standard Application Form (SAF) v11 for EREC G99 connections updates the formal document used to apply for connecting power generating modules exceeding 16A per phase to distribution networks. The form covers solar, wind, battery storage, and other generation technologies connecting under G99 requirements. This appears to be a routine version update to existing connection application procedures.
Distribution network operators assess whether to create explanatory guidance supporting Engineering Recommendation P28 Issue 2, which sets technical standards for distributed generation connections. The proposed Engineering Report would provide additional technical application guidance but would not change P28 itself. No timeline or specific technical areas are identified.
CMP470 proposes introducing a commitment fee floor for all technologies that are oversubscribed relative to Clean Power 2030 capacity targets. The modification targets generation developers with high impact and transmission owners with medium impact. It is proceeding through urgent governance route to workgroup stage.
NESO publishes its codes administration landing page, consolidating information on the four electricity transmission codes it manages: CUSC, Grid Code, STC, and SQSS. The page includes a monthly modification tracker published on the 7th of each month and search functionality for current and concluded modifications. This serves as a reference portal for industry participants engaging with code modification processes.
NESO expands its Demand Flexibility Service to allow participants to be rewarded for increasing electricity consumption during periods of excess supply, alongside existing rewards for demand reduction. The service threshold drops from 1MW to 0.1MW, opening participation to smaller suppliers and businesses. Over 2.46 million businesses and consumers have already signed up.
NESO published guidance on its connections reform programme, including a new delivery pipeline prioritising 381.5GW of 'ready-to-build' capacity and announcing permanent leadership structure under new Director of Connections Colm Murphy from 13 April. The reform moves from a chronological queue to a delivery pipeline based on project readiness, with claims of unlocking £40bn annual investment.
NESO has decided not to implement a short-term day-ahead reactive power market after cost-benefit analysis showed no consumer benefits under current conditions. The decision will be reviewed in 2027 at the earliest. NESO continues work on Commercial Services Agreements for additional reactive power capability, with transmission-connected solutions progressing faster than distribution-connected ones.
Code modification GSR038 proposed to remove the requirement for two offshore AC transformers at grid entry points of 90MW or more has been withdrawn. The modification aimed to assess restrictions in Grid Code Clause 7.7.1.1 that effectively mandated dual transformer configurations. NESO classified it as having high impact on offshore transmission owners and generators.
Code modification CM0106 proposes to restore requirements for Transmission Owners to submit interface substation compliance information to NESO, addressing a gap created when NESO separated from National Grid. Previously, TOs and DNOs agreed Access Groups and Periods, with DNOs sharing schedules at week 24 to allow TOs to determine site compliance. The modification is under standard governance with workgroup assessment.
The BSC Panel is consulting on code changes to establish governance arrangements for the Smart Data Repository, scheduled to launch later in 2026. The repository will centralise smart meter data to support market operations and grid management. This is implementation detail for an already-decided policy rather than a new structural reform.
Ofgem sets out five options for redesigning transmission network charges to steer investment towards Strategic Spatial Energy Plan locations, ranging from tweaking existing TNUoS to auctioning connection capacity by zone. Charges would apply to new generators, demand, and storage. Responses by 26 May 2026, reforms targeted for 2029.
Ofgem approves NESO's amendments to balancing terms and conditions to incorporate service documentation for the Demand Flexibility Service. The changes update Article 18 requirements under electricity balancing guidelines to include DFS parameters within formal balancing arrangements. This represents administrative housekeeping rather than substantive reform of the service itself.
Ofgem approved NESO's request to extend and amend the derogation from Article 6(4) of the Electricity Regulation for its Demand Flexibility Service, a balancing energy product. The derogation allows NESO to operate DFS without full compliance with standard balancing market requirements. The decision was made on 25 March 2026 following NESO's proposal submitted on 30 January 2026.
Ofgem proposes strategic planning-led interconnector development where NESO identifies projects and government sets delivery and financing arrangements. The consultation closes 1 May 2026. This shifts from developer-led merchant models to centrally planned interconnection aligned with wider system needs.
DESNZ proposes a bill discount scheme offering households within 500 metres of new transmission infrastructure £250 annually for 10 years, funded by an obligation on all electricity suppliers who will pass costs to all customers via bills. The scheme covers new overhead lines and substations from 2027, with eligible households identified automatically via their MPAN, plus an opt-in route for those on commercial meters or off-grid. Administrative costs are socialised across all billpayers while benefits flow only to those hosting infrastructure.
Government introduces regulations requiring majority of new homes in England to have solar panels fitted as standard from 2028 under the Future Homes Standard, removes regulatory barriers for plug-in solar panels under 800W to connect via domestic sockets without electrician installation, and launches trial allowing suppliers to offer discounted electricity on windy days in constrained areas instead of paying wind farms to switch off. The Future Homes Standard also mandates low-carbon heating systems like heat pumps in new builds, while plug-in solar will be available in shops within months through retailers like Lidl and Amazon.
Market-Wide Half-Hourly Settlement systems went live in September 2025, with first Wave 1 participants completing qualification and beginning migration of 30 million supply points. The programme transitions from implementation to business-as-usual operation of settlement systems and the Data Integration Platform. Elexon served as Implementation Manager rather than Ofgem leading directly, coordinating industry delivery through working groups and volunteer early adopters.
Government and Ofgem establish a data domain model with four coordinators (NESO, RECCo, Elexon) to standardise energy system digitalisation, replacing the current fragmented initiative-led approach. The framework introduces a digitalisation coordination function and mandates interoperability between Data Sharing Infrastructure (DSI) and Consumer Consent Service (CCS). Implementation begins immediately with interim governance, moving to full coordination function by 2028-29.
NESO published updated Connections Reform methodologies in March 2026, extending the Evidence Submission Window closure beyond July 29, 2025 due to portal issues and query response delays. The methodologies cover the Gate 2 Two-way Queue (G2TWQ) process, including network design criteria, project designation rules, and gate progression requirements.
DESNZ publishes quarterly statistics on smart meter roll-out, covering domestic and smaller non-domestic installations and operations. Data includes meters installed and operating across Great Britain, with quarterly updates for large suppliers and annual whole-market data. Historical data prior to 2017 available on request.
Ofgem proposes removing distribution network operators' reporting requirements under Standard Licence Condition 31E, transferring responsibility to Elexon as Market Facilitator from April 2027. The modification eliminates DNO obligations to report flexibility service procurement data to Ofgem. Statutory consultation follows in June 2026 with final decision by August 2026.
DESNZ commissioned Lucy Yu to review AI deployment in electricity networks, examining applications across grid planning, operations, and management. The review will map current AI applications, identify deployment barriers, assess system benefits and risks, and provide recommendations by Summer 2026. The scope covers transmission and distribution applications, regulatory landscape, and enabling conditions like data access and testing environments.
Elexon has published draft governance frameworks for Smart Secure Electricity Systems (SSES) and extended the consultation deadline to 31 March 2026. The framework establishes enduring governance arrangements for smart secure electricity systems in Great Britain, including bilateral agreements with cross-references to BSC provisions.
The Chancellor announces £2.5 billion for AI and quantum computing technologies, including £500 million for a Sovereign AI Fund and £2 billion for quantum capabilities. The package includes up to £1 billion for procuring commercial-scale quantum computers and funding for quantum research hubs. This forms part of the government's Industrial Strategy identifying digital technologies as a growth sector.
NESO issues mandatory Information Request Notice to transmission-level demand customers and co-located generation projects to gather detailed project readiness data. The IRN requires complete responses by 13 April 2025, building on last year's voluntary Call for Input which saw 460% queue growth. NESO uses statutory information gathering powers to compile evidence for Ofgem's Demand Connections Reform programme.
NESO publishes methodology for calculating Net Transfer Capacity (NTC) restrictions on interconnectors and compensating affected capacity holders. The current consultation runs until 17 April 2026, updating commercial arrangements for capacity restrictions. This covers all GB interconnectors and applies to both day-ahead and intraday capacity calculations.
NESO schedules a customer connections webinar for 25 March 2026, focusing on Securities and Methodology Consultation. The one-hour Teams session provides updates on connections reform. Questions are pre-moderated through Slido.
Ofgem proposes demand connections reform structured around 'Curate, Plan and Connect' pillars to address queue viability, project progression delays, and lack of strategic prioritisation. The demand queue has grown substantially with many non-viable projects blocking viable ones from connecting. The reform builds on TMO4+ and involves NESO and network companies in developing prioritisation mechanisms for strategically important projects.
NESO launches a call for input targeting customers with existing transmission-level demand connection agreements and co-located generation-demand sites, seeking project data to address queue management challenges. The initiative follows a 460% surge in demand applications exceeding forecasts, creating connection delays for viable projects. Responses are due by 5pm on 5 December 2025.
NESO published results from its November 2025 Call for Input on demand connections, receiving 243 responses representing over 90GW of demand capability. Data centres dominate at 55% of total capacity (50.8GW), with 81% of all projects willing to accept alternative connection arrangements like phased or non-firm connections for earlier dates. Connection dates span 2027-2035, with 40% of projects seeking pre-2030 energisation.
Government accepts 47 recommendations from the Nuclear Regulatory Review to consolidate nuclear regulation, merge ONR and DNSR by 2028, and establish a Nuclear Commission to resolve regulatory conflicts. Implementation commits to delivery by end-2027 subject to legislative timelines, with a Nuclear Regulatory Implementation Panel to hold government and industry accountable.
Government proposes using new statutory powers to accelerate grid connections for strategic demand projects, including data centres and AI Growth Zones, through queue management reforms, capacity reservation, and reallocation mechanisms. The proposals would impose higher financial requirements on data centres to address speculation in the 125GW demand queue, while creating prioritisation systems for government-identified strategic projects. Consultation closes 15 April 2026.
DESNZ expands its heat pump statistics to include all UK heat pump installations, not just those supported by government schemes. The department shifts from policy-specific deployment tracking to total market coverage for hydronic heat pumps up to 45kW. Statistics remain 'in development' status with methodology still being refined.
DESNZ will enable government to prioritise strategically important demand projects (AI data centres, industrial sites) in transmission connection queues while requiring higher financial commitments from developers to tackle speculative applications. The demand connection queue grew 460% in six months to June 2025, creating waits up to 15 years. Ofgem will consult on increased deposits or fees for queue participants who miss milestones.
DESNZ proposes amending electricity connection rules to prioritise 'strategic demand' including data centres and address speculation in the connection queue. The consultation seeks to create a separate pathway for approved strategic projects. This follows the connection queue growing to over 700GW with significant speculative applications.
NESO updates queue management guidance with new milestone calculation methods and evidence requirements for transmission connections. The guidance incorporates recent code changes CMP434 and CMP435 that implement connections reform, establishing eight mandatory milestones that developers must meet or face termination. Projects must now demonstrate progression through planning, land rights, construction planning, financial commitment, and construction initiation phases with specific evidence requirements and timelines calculated backwards from completion dates.
NESO has created a customer area consolidating guidance and resources for the Connections Reform programme. The page provides quick access to webinars, timelines, FAQs, pipeline enquiry processes, and support for the new customer support model. It includes links to e-signing tools and guidance on Progression Commitment Fees (PCF).
NESO publishes BSUoS charging data including fixed tariffs, monthly forecasts, and payment calendars through March 2026. BSUoS charges recover balancing costs and are paid by final demand customers only since April 2023 reforms. Current fixed tariff structure replaced variable charges following CMP308 and CMP361 implementation.
NESO has published updated charging documentation including guidance materials, charging statements, and policy developments on its website. The documentation includes guidance on TNUoS, BSUoS, connection charges, and AAHEDC, plus current charging statements and methodology policy decisions. This consolidates existing materials rather than introducing new charges or methodologies.
NESO publishes detailed guidance for its Enduring Auction Capability (EAC) platform, which conducts co-optimised day-ahead procurement for frequency response and reserve services. The platform uses N-SIDE's algorithm to clear Dynamic Response, Quick Reserve, and Balancing Reserve services together at 14:00 daily, with Slow Reserve to be added in March 2026. Results are published via data portal with monthly archiving for sell orders and annual archiving for other datasets.
Ofgem consults on changes to RIIO-ED2 Load Related Expenditure (LRE) volume drivers: upward revision of Low Voltage Services Volume Driver unit rates, higher LVSVD ex-ante allowance for all DNOs, revision to the Secondary Reinforcement Volume Driver cap for one DNO, and reporting metric changes.
NESO has issued Gate 2 offers to transmission-connected projects under connections reform, with customers having 90 days to accept or reject offers. Projects that reject Gate 2 offers revert to Gate 1 agreements, triggering security release processes under CUSC Section 18. Technical queries must be submitted within 4 weeks of receiving offers, with transmission operators providing 2-4 week response times.
NESO publishes guidance on contacting them about connections reform, directing customers to use the connections portal for application-related enquiries. The portal has been upgraded to handle 99MB file uploads and allow case comment updates without requiring NESO responses first. Non-portal channels may result in delays or unprocessed requests.
NESO proposes removing outdated references to defunct planning documents (Seven Year Statement, Offshore Development Information Statement, Electricity Ten Year Statement) from the Connection and Use of System Code. The proposal will be presented to the CUSC Panel on 27 March 2026. Cross-code impacts affect the System Operator Transmission Owner Code.
NESO has raised a modification to assess whether offshore wind farms of 90MW or more should be required to have two AC transformers at their grid connection point. The current SQSS rule 7.7.1.1 effectively mandates dual transformers for these capacities. The proposal will go to SQSS Panel on 24 March 2026.
NESO has issued the Go-Live Notice for Slow Reserve service, opening the Enduring Auction Capability (EAC) auction on 17 March with the first auction on 31 March 2026. This triggers the end of STOR service at 05:00 on 1 April 2026. Slow Reserve provides frequency management through post-fault energy balancing, requiring units to respond within 15 minutes with minimum 1MW capability.
NESO introduces a centralised customer support model for transmission-connected projects receiving connection offers under connections reform, replacing individual contract managers with a dedicated team operating to defined service levels. Customers have 90 calendar days to accept offers, with specific processes for queries, changes, and rejections. The new model provides single-route access through a portal system with structured response times for allowable modifications.
NESO announces a Customer Connections Call webinar scheduled for 24 February 2026, focusing on transmission offers with NESO and Transmission Owner representatives. The session runs 1-2pm via Microsoft Teams as part of ongoing connections reform updates. Questions are moderated through a Slido platform to focus on transmission offers agenda.
NESO publishes the Connection and Use of System Code (CUSC), which sets the contractual framework for connecting to and using the National Electricity Transmission System. The webpage provides access to code documents, modifications process, and panel information for parties seeking to connect to the transmission system.
NESO publishes webinar schedules and archive materials for Connections Reform, including upcoming sessions on advancement fees and securities (25 March), plus archived recordings from 2025-2026 covering queue management, offer processes, and evidence submission guidance. The materials support customers navigating the reformed connections process with regular updates on timelines, portal functionality, and technical requirements.
NESO publishes standard weekly Operational Transparency Forum materials - presentation slides and recordings from system operations discussions. The forum runs every Wednesday at 11am, covering recent operational actions in the Electricity National Control Centre.
NESO launches a call for input on Reformed National Pricing (RNP) proposals to reform dispatch arrangements and electricity market design, with responses due 14 April 2026. The RNP programme aims to strengthen investment signals, improve operational efficiency, and reduce constraint costs within Great Britain's retained single national wholesale market. Government will provide legislation as required for timely delivery.
NESO proposes Grid Code changes to implement 'Regional Restoration Plans' following the previous GC0156 modification, standardising how transmission operators coordinate during system blackout recovery. The proposal affects all transmission system operators, transmission owners, network operators and generators, requiring workgroup development under standard governance. Cross-code impacts extend to STC and DCODE.
Ofgem update on delays to connection dates for some TMO4+ Protected Projects. Protected Projects are those that retain their existing queue positions through the Gate 2 to Whole Queue reform.
NESO proposes GSR037 to improve formatting and readability of the System Quality of Supply Standard (SQSS), a technical document governing grid planning standards. The proposal follows standard governance and goes directly to CAC approval. SQSS Panel will review on 24 March 2026.
NESO operates the CUSC Forum, which includes the Transmission Charging Methodologies Forum (TCMF) and CUSC Issues Steering Group (CISG). The forum provides a regular venue for industry to discuss transmission charging methodology developments and general CUSC issues. The next meeting is scheduled for 2 April 2026, with the last held on 5 March 2026.
NESO proposes extending User Commitment Methodology principles from CUSC section 15 to users under Final Sums methodology through STC modification CM093, following the approved CUSC change CMP417. The workgroup process is ongoing with meetings through March 2026. This affects how transmission users commit to infrastructure costs under different charging methodologies.
NESO publishes comprehensive guidance for its Dynamic Services suite — Dynamic Containment (DC), Dynamic Moderation (DM) and Dynamic Regulation (DR) — which provide frequency response to keep the grid within 50Hz ±1%. The services require response times from 0.5 seconds (DC/DM) to 2 seconds (DR), with delivery duration from 15 minutes (DC) to 60 minutes (DR). Procurement occurs via the EAC platform with results published on the NESO Data Portal.
CMP465 proposes to allow affected generators to reset their construction progression milestones (M5-M8) back to what they would have been without the G2tWQ (Gate 2 to the West Queue) extension granted until 2026. The modification follows NESO's decision to extend G2tWQ connection offers beyond their original 2025 deadline. It proceeds under urgent modification procedures with Authority decision pending.
Ofgem decision on CUSC modification CMP447: Removal of designated strategic works from cancellation charges and security requirements.
DESNZ proposes eight refinements to Contracts for Difference (CfD) terms ahead of Allocation Round 8, including permanent restrictions on re-bidding surrendered capacity, hybrid metering arrangements to reduce costs, and excluding applications with Gate 1 connection offers. The consultation runs until early 2025 with changes taking effect for AR8. Other proposals include extending floating offshore wind delivery timelines, strengthening enforcement against distribution-connected generators gaming merchant revenues, and creating a new deepwater offshore wind technology category.
DESNZ proposes creating a new Load Control Licence regime, making it illegal to control customer electricity loads without Ofgem authorisation from end-2026. The licence covers load controllers and Flexibility Service Providers, with cyber security requirements for the former and consumer protection rules for the latter. A 12-month transition period runs from licence applications opening to enforcement.
CMP466 enables generators to recover costs of providing Electromagnetic Transient (EMT) models required under Grid Code GC0168. The modification follows after CMP456 and addresses the financial burden placed on existing generators, particularly older plant with complex systems. CUSC Panel initially rejected urgency but assigned high priority status on 5 February 2026.
NESO proposes to correct minor errors and formatting issues in CUSC Section 14 through modification CMP464. The changes address legal text errors, cross-references, and numbering problems accumulated from multiple code implementations. The Panel approved fast-track self-governance route with implementation following appeal period closing 23 March 2026.
NESO proposes increasing minimum reactive power requirements for full converter technology Power Park Modules operating below maximum active power output through Grid Code modification GC0184. The Grid Code Review Panel rejected the proposal on 13 November 2025, stating it did not identify a clear defect. The proposer is considering next steps.
NESO proposes to align operational criteria for low probability, low impact secured events between England/Wales and Scotland through SQSS modification GSR035. The workgroup phase begins March 2026 following panel approval in February. This affects transmission security standards that determine when networks must be reinforced.
NESO proposes reviewing voltage limits that apply during operational timescales and introducing flexibility around these constraints. The modification affects transmission owners, NESO, distribution networks, generators, and directly connected customers. Cross-code changes to Grid Code and STC may be required.
Ofgem consults on additional guidance for determining disputes when connecting to the electricity grid, specifically for entities receiving a new connection offer as part of the unique Gate 2 to Whole Queue exercise under the TMO4+ Connections Reform package. 31 responses received.
Ofgem minded-to position to approve the Original Proposal of CUSC modification CMP448, which introduces a progression commitment fee in the connections process. 40 responses received (25 non-confidential).
OPRED consults on draft guidance for derogations from OSPAR Decision 98/3, which requires removal of offshore installations after use. The consultation, extended to 14 November 2025, covers how decommissioning proposals will be assessed and includes policy changes on offshore oil and gas decommissioning.
Ofgem decides to create a new pass-through mechanism in the RIIO-ED2 price control for DNOs to recover the one-off costs of implementing TMO4+ Connections Reform, specifically the Gate 2 to Whole Queue Exercise. A new Connections Reform Costs Governance Document defines what counts as recoverable. Licence modifications effective 27 January 2026.
NESO proposes to socialise transmission connection asset costs and cap customer contributions through CUSC modification CMP460. The modification seeks to create more certain charging by reducing direct customer charges for connection infrastructure. Workgroup consultation runs 28 January to 18 February 2026.
NESO is revising the Obligatory Reactive Power Service (ORPS) compensation methodology through CUSC modification CMP457, moving away from gas price-based rates. The Standard Governance workgroup process begins after 13 November 2025, following unanimous CUSC Panel approval in October. Current ORPS costs reflect gas prices despite the shift to low-carbon generation requiring grid stability services.
NESO introduces Grid Code modification GC0183 requiring generators and interconnectors to notify their intended availability during severe space weather events. Ofgem approved the modification on 20 November 2025 with implementation on 4 December. The modification proceeded through urgent procedures due to national security implications.
DESNZ consults on streamlining land rights and consents processes for electricity network infrastructure to enable faster deployment. The consultation follows a 2022 call for evidence and targets reducing costs, complexity and delays that currently hinder network projects. Minor changes to existing infrastructure will be fast-tracked to free resources for complex cases requiring detailed scrutiny.
NESO proposes standardising power flow metering polarity across all parties sending data to the system operator. The modification creates a unified diagram and description format for how power flow direction is reported. Workgroups begin March 2026 with transmission system owners, interconnectors and network operators most affected.
Grid Code modification GC0181 proposes to improve system incident reporting procedures to make technical requirement monitoring more effective. The modification follows standard governance with workgroups, currently seeking further development work before Panel determination. Low impact identified on Transmission System Owners.
CMP456 creates a cost recovery mechanism for generators required to produce Electro Magnetic Transient (EMT) models under GC0168, shifting the financial burden from plant operators to system users. The modification addresses 'significant' costs imposed on older generators with multiple discrete systems who gain no direct benefit from producing these grid stability models. Authority rejected urgent processing in December 2024, with the CUSC Panel designating this high priority in January 2025.
DESNZ and Ofgem propose standard licence conditions for code managers and update CMA appeals process following Energy Act 2023. Code managers will replace industry panels with licensed entities that set budgets, recommend modifications to Ofgem, and align codes with Ofgem's Strategic Direction Statement. Appeals trigger when Ofgem disagrees with code manager recommendations, replacing current panel-based triggers.
DESNZ and Ofgem propose licence conditions for code managers and an appeals process to the Competition and Markets Authority for code modification decisions. The consultation follows 2024 regulations that enable Ofgem to select code managers. Appeals would allow industry parties to challenge Ofgem's decisions on code modifications through the CMA.
Ofgem publishes the TM04+ Connections Reform decision: a suite of decisions and supporting documents enabling the connections reform package. Covers code modifications (CM095, CMP434, CMP435), connections methodologies (Gate 2 Criteria, Project Designation, Network Design), and licence changes following the February 2025 statutory consultation. Plus an Impact Assessment.
Ofgem consultation on regulatory arrangements for dedicated provision of network services. Examines how DNOs and other parties can provide dedicated services on behalf of large customers.
GC0178 seeks to specify limits on temporary overvoltage events and clarify generator obligations during such events. The modification is proceeding through Standard Governance and has been paused to allow appointment of a consultant to scope the work. High impact parties include generators, transmission owners, and interconnectors.
NESO proposes removing Balancing Codes 4 and 5 from the Grid Code, which cover TERRE cross-border balancing processes that became obsolete after Brexit. The modification eliminates administrative complexity from terminated EU market coupling arrangements. Final decision expected March 2026.
Ofgem consults on connection reform (TM04+) enablers, including a statutory consultation component for licence changes needed to implement the Connections Reform package.
NESO proposes Grid Code changes to replace Mandatory Frequency Response (MFR) with a new Real-time Dynamic Regulation service from 2026/27. The two products will run in parallel until 2029 before MFR is phased out. The Panel rejected the initial proposal in March 2026 for lacking clarity on defect and scope.
DESNZ launches a review of Ofgem's role and powers, citing consumer protection concerns and the need for higher standards in energy markets. The review will examine the regulator's functions and delivery mechanisms. No specific timeline or scope limitations are provided.
NESO releases a new dataset calculating skip rates per 30-minute period using methodology developed with LCP Delta. The data shows skip rates following each stage of exclusions as set out in their published methodology. The dataset is accompanied by an online dashboard for market participants.
Ofgem consults on amendments to the Electricity System Operator Licence, Transmission Licence and Distribution Licence to support implementation of NESO's TMO4+ Connections Reform target model.
Ofgem directs an extended timeline for the Long Term Development Statement (LTDS) deliverables, granting a one-year extension to stages 1.3, 2 and 3 of the Form of LTDS and to the Capacity Heatmap publication.
Ofgem consults on funding transmission owners to book supply-chain capacity (cables, transformers, HVDC converters) before final certainty on project need, to compress delivery timelines for the ASTI build-out. Consumers carry the cost of the optionality upfront, with the regulator setting eligibility criteria and claw-back arrangements if commitments do not convert into delivered assets.
NESO formalises a Demand Control Rotation Protocol allowing rolling blackouts for 3-24 hours during supply shortfalls, modifying Grid Code OC6. The modification affects Distribution Network Operators, NESO, and consumers, with cross-code impacts on the Distribution Code. Panel recommendation has been deferred to address Load Lock definition issues with the Energy Network Association.
CMP445 proposes to pro-rate first-year TNUoS charges for generators from their charging date rather than charging the full annual amount upfront. The modification was denied urgent treatment by the Authority in December 2024 and is proceeding through standard governance, with workgroup consultation closing 22 August 2025. The CUSC Panel placed this high on their prioritisation stack in March 2025.
DESNZ proposes reforms to Scotland's electricity infrastructure consenting under the Electricity Act 1989, targeting projects over 50MW onshore and 1MW offshore within 12 nautical miles. The consultation seeks to modernise consent processes and strengthen community involvement requirements. Both UK and Scottish governments agree that removing inefficiencies from the 1989 Act is the primary route to accelerating deployment for Clean Power 2030.
CMP442 allows generators to fix their TNUoS charges against NESO's forecasted tariffs, converting variable transmission charges into predictable costs. The modification follows standard governance through workgroup process, with first workgroup meeting planned for 16 December 2024. CUSC Panel initially prioritised this as high but downgraded to medium priority in February 2025 following Ofgem's transmission charging modification prioritisation guidance.
CMP441 proposes to align the timing for de-energising non-embedded hydrogen electrolysers with embedded ones, addressing a credit risk discrepancy. The modification was unanimously recommended by the CUSC Panel in December 2024 but was sent back by the Authority in July 2025 for reconsideration. The Panel has now deprioritised it to low priority status.
CUSC modification CMP440 removes the zero price floor from demand TNUoS locational tariffs, reintroducing negative prices as investment signals. Negative tariffs apply over extended consumption measurement periods to prevent gaming. Code Administration Consultation runs 9 February to 3 March 2026.
Ofgem finalises guidance requiring NESO to produce strategic 'Future Energy Pathways' instead of illustrative scenarios, with pathways showing what must happen to meet net zero by 2050. The guidance mandates whole-system modelling including gas constraints, network limitations in the short term, and granular regional data. NESO must publish major pathways every three years to inform the Centralised Strategic Network Plan, with methodology subject to Ofgem approval.
NESO publishes 0-14 day ahead wind forecasts for all wind farms providing real-time operational metering data. Forecasts use evaluated operational capacity based on recent actual production levels from SCADA telemetry rather than nameplate capacity. The dataset covers both national and individual wind farm level predictions.
Grid Code modification GC0173 aligns GB connection conditions with European standards and clarifies thermal storage technology data requirements in the Planning Code. The modification follows standard governance with a joint Grid Code/Distribution Code workgroup, receiving four consultation responses. Final modification report was submitted to the Authority in December 2025.
Ofgem open letter updating stakeholders on reform of the electricity connections process following NESO proposals. Predecessor to the TMO4+ consultation cycle.
NESO proposes requiring Transmission Owners to provide detailed Electromagnetic Transient (EMT) and Root Mean Square (RMS) models for grid stability analysis as inverter-based resources replace synchronous generation. The modification addresses control interaction risks and oscillation threats from the changing power system characteristics. Workgroups are paused pending approval of related CUSC modification GC0168.
Ofgem publishes its assessment outcome for the 2023 RIIO-ED1 Incentive on Connections Engagement (ICE), a performance incentive for DNOs on their handling of connection customers.
OpTIC replaces the Transport component of TNUoS with an economic market model that creates transmission charges based on assumed optimal network investment in a zonal market structure. The proposal aims to charge generators and suppliers as if they operated in a zonal wholesale market rather than the current uniform pricing system. Workgroup activity starts Spring 2025 after the CUSC Panel prioritised it as Medium.
Ofgem launched a call for input on AI use in the energy sector, seeking views on how AI should be deployed responsibly to encourage innovation while managing risks. The consultation closed on 17 May 2024 and forms part of Ofgem's response to government AI regulatory principles. This represents regulatory guidance development rather than rule-making.
Ofgem summarises stakeholder responses to its proposal for a Future Regulation Sandbox (FRS), a new policy instrument to test regulatory changes before implementation. The FRS would complement existing innovation tools including the Energy Regulation Sandbox, Fast Frank Feedback, and Strategic Innovation Fund. This is not a decision document but sets out next steps based on feedback received.
Ofgem retains the current target for the Major Connections Customer Satisfaction Survey beyond the first regulatory year of RIIO-ED2. The decision extends an existing customer satisfaction metric rather than changing any substantive connection processes or charges. This is a parameter adjustment within the existing regulatory framework.
Ofgem finalises revisions to the Operational Performance Regime (OPR) that financially incentivises the Data Communications Company's performance across system operations, customer engagement, and contract management for smart meters. The regime adjusts weighting methodologies and scoring systems rather than changing fundamental incentive structures. This affects smart meter deployment costs allocated across all energy consumers through supplier charges.
Ofgem and DESNZ propose new licences for the National Energy System Operator (NESO), which will combine electricity system operation and gas system planning functions. NESO will hold both an Electricity System Operator licence and a Gas System Planner licence when designated as the Independent System Operator and Planner (ISOP). The consultation also proposes modifications to transmission, distribution, generation, supply, interconnector, smart meter communication, and gas transporter licences to accommodate NESO's expanded role.
Ofgem approves CMP411, introducing Anticipatory Investment (AI) into Section 14 charging methodologies for offshore transmission. The mechanism allows Offshore Transmission Owners to build grid capacity ahead of confirmed customer demand and recover costs through charges. Decision takes effect immediately on 28 March 2024.
Ofgem consults on its minded-to position for Eastern Green Link 2 project assessment under the Accelerated Strategic Transmission Investment (ASTI) mechanism. EGL2 is a 2GW HVDC transmission link connecting Scotland to England. The consultation closed 27 April 2024 with a decision already published.
Ofgem rejected DCC's appeal against REC Technical Expert Panel's approval of R0093, which increases Central Switching Service maximum demand volumes during the MHHS migration period. The decision upholds the TEP's original approval, allowing R0093 to proceed to implementation. This affects data processing capacity during the transition to half-hourly settlement.
Ofgem consults on its minded-to position for Eastern Green Link 1 under the new Accelerated Strategic Transmission Investment (ASTI) mechanism. EGL1 is the first project assessed under ASTI, which allows pre-construction spending on strategic transmission projects before full needs case approval. The consultation closed on 18 April 2024 with a decision now made.
Ofgem has approved CMP427, introducing a landowner Letter of Authority requirement for new onshore transmission connection applications under the Connection and Use of System Code (CUSC). The change takes effect from 28 March 2024. This adds a documentation requirement to the application process rather than changing substantive connection terms or costs.
Ofgem approved a Grid Code modification requiring interconnectors to meet standardised ramping requirements under EU System Operator Guidelines Article 119. The decision implements the Workgroup alternative rather than the original proposal. This codifies technical requirements that interconnectors must already meet under retained EU law.
Ofgem mandates Data Best Practice (DBP) Guidance integration into industry codes, targeting Central System Delivery Bodies, Code Panels, Code Administrators, and licensed entities. The guidance aims to surface, share, and make interoperable data held across the energy sector. Entities handling significant data portions face specific implementation expectations.
DESNZ launches second REMA consultation with narrowed options for fundamental electricity market redesign. The consultation runs until May 2024 and follows the first consultation's identification of market failures in current arrangements. This represents the most significant potential reform to GB electricity markets since BETTA, with options including central dispatch, locational pricing, and enhanced market-based coordination.
DESNZ proposes licensing regime for energy code managers under the Energy Act 2023, requiring Ofgem approval for organisations managing industry codes like the Grid Code and Connection and Use of System Code. The consultation sets out standard licence conditions and selection processes for code managers, with updated text published 24 April 2024 correcting a question on funding mechanisms. This implements the code governance reform framework established in the Energy Act 2023.
GC0169 makes technical corrections to the Grid Code following implementation of EU Connection Codes under modification GC0136. The modification was split into two parts (GC0169 and GC0173) and processed through standard governance with a joint Grid Code/Distribution Code workgroup. Final modification report was sent to Ofgem on 7 October 2024.
Grid Code modification GC0168 will require certain generators and network operators to provide electromagnetic transient (EMT) models to NESO for analysis of system stability as inverter-based resources displace synchronous generation. The modification follows standard governance through a workgroup process, with high impact on generators, transmission operators, distribution networks, interconnectors and transmission owners. Timeline has been repeatedly delayed, with workgroup report submitted June 2025 but Panel requesting further legal text review.
Ofgem grants urgency for CMP428, which addresses user commitment liabilities for onshore transmission circuits in the HND (network design). Changes how generators connecting under the HND framework provide financial security for transmission investment.
Ofgem consultation on amendments to the Major Connections Governance Document. Proposes changes to how large connection projects are managed and governed within the transmission network.
CMP426 proposes changing how TNUoS charges are allocated for transmission circuits classified as 'boundary reinforcement' within NESO's Holistic Network Design. The modification has been prioritised as 'Medium to High' by the CUSC Panel following an Authority open letter on transmission charging prioritisation in January 2025. Workgroup analysis resumed in early 2024 after initial delays.
NESO proposes STC modification CM093 to extend User Commitment Methodology principles from transmission connection charges to Final Sums methodology users, following CUSC modification CMP417. The modification affects NESO and Transmission Owners, proceeding through standard governance with workgroups restarting in May 2025 after extended delays. This is a consequential change to align charging methodologies across different user categories.
CMP423 proposes switching from a demand-weighted to generation-weighted Reference Node for TNUoS charging calculations. The CUSC Panel has recommended approval by majority, with the Final Modification Report sent to Ofgem on 9 December 2025. This changes how transmission charges are calculated and allocated across the network.
NESO's Grid Code modification GC0164 simplifies Operating Code No.2 to make obligations clearer for grid users. The modification has been under development since October 2023, with workgroup consultations completed and a second code administrator consultation closing March 2026. This is administrative restructuring of existing obligations rather than substantive rule changes.
NESO publishes settlement-period data on the availability and utilisation of Stability Pathfinder contracts, the procured service that supplies synchronous inertia and short-circuit level to a grid losing thermal plant. The dataset records availability and dispatch for all contracted units except Grid Forming Batteries, which deliver stability continuously while connected and so receive no control-room instruction. Long-term stability contracts carry no utilisation payment, so the data is published roughly a week after delivery.
CMP419 proposes to revise generation transmission charging zones to include offshore wind farms connected under the Holistic Network Design, allowing these generators to pay wider transmission tariffs rather than local rates. The modification has been deprioritised from Medium-High to Low as of September 2025, with workgroup activity stalled since 2024. This follows Authority expectations from previous zoning decisions CMP324 and CMP325.
CMP417 proposes extending the User Commitment Methodology to all grid connection users, replacing the Final Sums methodology for transmission-connected demand, distribution-connected demand, and DNOs. This would standardise security requirements across user groups, with security amounts reflecting actual transmission liabilities rather than fixed sums. The modification affects high-impact parties including NESO, TOs, DNOs, and demand users currently on Final Sums.
CMP414 seeks to implement the workgroup solution from CMP330/CMP374 by updating CUSC transmission charging methodology. Ofgem rejected the initial proposal in July 2024 due to deficiencies, forcing reconvening of workgroups. The modification is now designated high priority with workgroups beginning October 2025.
CMP402 would modify CUSC Section 15 to implement Ofgem's October 2022 anticipatory investment principles for offshore generators connecting to shared transmission networks at different times. The modification has been deprioritised to low priority by the CUSC Panel as of September 2025, with no active workgroup meetings scheduled.
CMP405 proposes to separate TNUoS demand charges into year-round locational signals and peak security signals, charging storage that imports outside Triad periods while rewarding it during other times. The modification has been deprioritised as low priority by CUSC Panel despite proposer requests for urgency, with Ofgem rejecting urgent treatment in January 2025. Panel confirmed low priority status in March and September 2025, effectively stalling progress.
NESO proposes reviewing restrictions on loss of power infeed risk for offshore DC converter outages under SQSS modification GSR030. The modification has been in workgroup since October 2022, with the latest workgroup scheduled for March 2026. The proposal was split in November 2025, with defect 1 becoming separate modification GSR034.
NESO publishes its Net Transfer Capacity values for ElecLink interconnector, showing the maximum import and export flows NESO allows in MW per hour. These values feed into capacity calculation processes alongside connected system operator values and interconnector capability to determine final available capacity. Values are only published when NESO applies restrictions.
CMP397 makes technical changes to CUSC exhibits to support CMP316's co-located generation rules. The modification received unanimous panel support in May 2024 and awaits Ofgem decision by September 2025. This is administrative housekeeping required to implement the substantive co-location framework.
NESO proposes reviewing demand connection criteria in the transmission network security standards (NETS SQSS) to align with distribution network security standard EREC P2/7. The review covers how embedded generation, demand side response, storage and active network management contribute to demand security. The workgroup process has been running since June 2022 with next meeting scheduled for March 2026.
NESO publishes 24-month-ahead constraint limits in MW for the main boundaries on the GB transmission system on a weekly basis.
Grid Code modification GC0155 proposes to clarify fault ride through technical requirements for generators connecting to the transmission system. The modification has been in workgroup since February 2022 with multiple timeline extensions, now scheduled for early 2026. A cost-benefit analysis is required and the modification will be split into two parts, with a new modification on temporary over voltage expected in March 2025.
NESO publishes constraint breakdown data showing costs and volumes of transmission system actions taken by the ESO. The dataset provides transparency on why specific system actions were taken, with tags that can be retrospectively updated. Data covers transmission network constraints only.
NESO publishes the TEC register showing which projects hold transmission entry capacity contracts to connect to the grid. From November 2025, the register will add a 'Gate' column distinguishing between Gate 1 and Gate 2 agreements under updated CUSC provisions. The register covers existing connections and the pipeline of future projects seeking transmission access.
NESO publishes a register of interconnector projects holding connection contracts, listing active and future projects with their firm Transmission Entry Capacity (TEC). The register includes import/export capacity figures and contractual definitions under CUSC. From November 2025, the register will add a 'Gate' column distinguishing Gate 1 and Gate 2 agreements under Connections Reform.
NESO publishes a register of embedded generation projects in Scotland that are connected or contracted to connect. The register will add a 'Gate' column from 21 November 2025 to distinguish Gate 1 and Gate 2 agreements under the Connections Reform process. Capacity data currently shows aggregated figures across stages and technologies, creating potential duplicates.
NESO publishes data on interconnector trading auctions used to manage grid constraints and energy balancing across six links (IFA1, BritNed, NEMO, IFA2, ElecLink, Viking Link). Trading occurs ad hoc throughout the day with qualified counterparties who hold interconnector capacity and BSC registration. Data includes volumes secured, best price, volume-weighted average price, and clearing price for each requirement.
NESO publishes System Operating Plans (SOPs) — real-time operational plans produced at demand peaks and troughs that show how the system operator will balance electricity supply and demand. The SOPs reveal expected actions in the balancing mechanism, reserve requirements, interconnector flows, and transmission constraints for each cardinal point throughout the day. This data release makes operational decision-making transparent to market participants who can see NESO's anticipated balancing actions hours ahead of real time.
NESO publishes regional carbon intensity forecasts covering 17 GB regions up to 48 hours ahead, using machine learning to predict demand, generation by fuel type, and power flows between regions. The methodology accounts for transmission losses, interconnector imports, and embedded wind/solar generation within Distribution Network Operator boundaries. Forecasts update every 30 minutes using real-time weather data from the Met Office.
CMP341 would create a sandbox for parties to trial innovative technologies by being derogated from specific CUSC obligations on a small-scale, time-limited basis. The proposal has been parked at low priority since 2020 and remains stalled with no active work. The CUSC Panel confirmed in February 2025 it will not prioritise this modification.
GC0140 proposes a Grid Code sandbox allowing parties to be exempted from specific Grid Code obligations for small-scale, time-limited trials of innovative technologies and services. The modification has been in a workgroup since 2020 but remains deprioritised, with meetings subject to Panel prioritisation as of February 2022. It follows standard governance procedures and has cross-code implications through CUSC modification CMP341.
NESO published historical carbon intensity data from January 2009 onwards, measuring CO2 emissions per kilowatt hour of electricity generation. The dataset uses seasonal decomposition to correct for missing or irregular data points and remains subject to ongoing data cleansing.
Grid Code modification GC0139 expands data exchange requirements between distribution network operators and NESO for system planning. The modification has been under development since 2020, with workgroup consultation closing January 2025 and panel recommendation vote pending workgroup agreement on legal text changes. High impact parties include NESO, transmission owners and distribution network operators.
CMP328 would establish a process for triggering distribution impact assessments when transmission connections affect local networks. The modification has been deprioritised to low status by the CUSC Panel as of February 2025, with work suspended indefinitely. The proposal originated in 2019 but has been repeatedly delayed and sent back by Ofgem for revision.
CMP330/CMP374 proposes to allow transmission-connected parties to build their own connection assets longer than 2km, where previously only assets up to 2km could be built contestably. The modification removes the arbitrary 2km length restriction on contestable connection works, requiring only agreement between the transmission owner and connecting party. Decision expected but currently delayed pending resolution of related modifications CMP414 and CM079.
CMP316 establishes charging methodology for co-located generation sites combining multiple technologies at one power station. The modification has been through extensive industry review since 2019, with Panel unanimously recommending WACM1 for implementation in August 2025. The Second Final Modification Report was submitted to Ofgem on 8 August 2025.
CMP304 seeks to reform the Enhanced Reactive Power Service but has been repeatedly paused since 2018. The modification was de-prioritised while NESO conducted reactive power market feasibility studies, then moved from low to medium priority in February 2026 following completion of those studies and the raising of related modification CMP457.
NESO proposes removing the Enhanced Reactive Power Service (ERPS) from the CUSC, a tendered commercial service that has attracted no bids in 7.5 years and no contracts in 9 years. Ofgem has delayed decision pending alignment with related proposal CMP304. The removal affects balancing service providers but has low industry impact.
GC0117 seeks to harmonise GB power station connection requirements by implementing EU Connection Code obligations within the Grid Code. The modification has been under development since 2018, was sent back by Ofgem in July 2025, and workgroups are now reconsidering DNO feedback on the cost-benefit analysis. The next workgroup meeting is scheduled for March 19, 2026.
CMP288 proposes explicit charging arrangements to recover additional transmission costs when users delay grid connection works or require backfeed arrangements. The modification has been low priority since October 2024, with Panel confirming this status in February 2025. The proposal targets cost recovery from developers who cause transmission owners to undertake works early due to user-initiated delays.
GC0103 proposes harmonising UK electrical standards with EU Connection Codes within the Grid Code, affecting compliance obligations for generators and network operators. The modification has been in development since 2017 but repeatedly stalled due to low prioritisation, with the Panel requiring further work on Applicable Electrical Standards as of February 2026. It impacts transmission owners, generators, and network operators across medium-scale operations.