CMP470 proposes the Oversubscribed Technologies Commitment Fee (OTCF): a mandatory financial floor on grid connection queue positions for any technology class that has overshot its Clean Power 2030 (CP30) target for 2035 by more than 50%, with battery storage as the immediate target.

Over 90 GW of battery storage holds queue positions in Great Britain against a CP30 2035 target of 29 GW, a threefold overshoot. Under current rules, developers post a financial guarantee of just 10% of their cancellation charge once planning consent is in place, setting a low bar for holding a queue position without firm commitment to build.

Connections reform uncertainty is already weighing on buildout timelines. Projects with protected connection dates in 2026 and 2027 are still awaiting confirmation of their new dates under the reformed framework, hence this consultation has been granted urgency status by Ofgem.

The Workgroup Consultation runs until 30 April 2026 at 17:00.

Key takeaways

• The BESS grid connection queue holds 90 GW against a 29 GW CP30 2035 target, more than three times the requirement.
• Under CMP470, any technology exceeding its CP30 target by more than 50% faces a mandatory commitment fee, meaning BESS would be caught immediately at £10k/MW.
• The floor starts at £10k/MW and rises to £25k/MW if the queue does not shrink by 25% at each six-month review
• Ofgem must decide by 1 August 2026, ahead of Gate 2 Phase 1 acceptances expected in mid-August

The OTCF adds a financial floor on grid connection queue positions

The OTCF adds a mandatory minimum on top of the existing cancellation charge framework for any technology that exceeds the oversubscription threshold.

1. Bi-annual assessment. Every six months (January and July), NESO publishes security statements and assesses whether a technology remains oversubscribed.
2. Activation. If a technology's grid connection queue exceeds its CP30 2035 target by more than 50%, the OTCF activates. For BESS, the queue stands at 210% of the CP30 target, so it activates immediately. The initial floor is £10k/MW.
3. Calculating the top-up. For each project, NESO compares the required standard security to the active floor. If standard security falls below the floor, the developer tops up the difference. If it already exceeds the floor, no OTCF payment applies.
4. Six-month review. At each subsequent statement, if oversubscription has not fallen by at least 25%, the floor increases by £5k/MW, up to a maximum of £25k/MW. If the queue shrinks fast enough, the floor holds steady.
5. Deactivation. Once oversubscription drops below 25% higher than the capacity target, the OTCF switches off entirely.

The reference capacity can change. When Strategic Spatial Energy Planning (SSEP) is finalised, for instance, NESO could revise the 29 GW benchmark, shifting the activation and deactivation thresholds with it.

The assessment is national, not regional. A regional approach was considered but rejected: a single national threshold is simpler to administer.

The finer details

Does co-location provide an exemption?
Any project with a BESS component holding a Gate 2 Offer in the grid connection queue falls within scope, including distribution-connected and co-located schemes.

When does the fee stop?
The fee runs until energisation; planning consent, construction start and financial close are all non-events. Where standard security already exceeds the floor, no top-up is required.

Are smaller developers disproportionately exposed?
The fee scales per MW rather than per project, so exposure is proportionate to size. At £10k/MW, a 25 MW project posts £250k; a 500 MW project posts £5M.

When is the security returned?
The OTCF is a security, not a charge. On energisation it is released in full. If the OTCF deactivates before the project connects, any excess above the remaining standard security is returned. If the project cancels, NESO claims it against the cancellation charge.

Ofgem must decide by 1 August 2026

Ofgem granted CMP470 urgency status on 2 April 2026 and must decide by 1 August 2026, with implementation targeted for 1 January 2027. That gives developers clarity on their financial exposure in the grid connection queue before Gate 2 Phase 1 acceptances are expected in mid-August.

The consultation covers the 50% activation threshold, the £10k/MW initial floor, the ramp mechanism, and the scope of the fee through to energisation. NESO has rated CMP470 as High Impact for generation developers, particularly BESS, and Medium Impact for Transmission Owners. Responses are due by 30 April 2026 at 17:00 via the CMP470 Workgroup Consultation, or by emailing claire.goult@neso.energy directly.