No.72 of 650 · approved, not built MP: Llinos Medi (Plaid Cymru) Wales

Ynys Môn

Ynys Môn has 95 MW of clean power (almost all solar) approved and still not built: enough to supply a year's electricity to 40,000 homes. When the wires are too full to carry the power, Britain pays wind farms to switch off instead. No wind farm here is paid that way — almost all of it goes to wind farms in Scotland. That cost is shared across every bill in Britain, so households here pay for it too: about £92 a year per household, £2.8m across the constituency's 30,822 homes. There is also 31 MW of wind running here on the local network. If that gets switched off, no national record shows it.

Not visible
here

31 MW of wind is running in this constituency, but it sits on the local network rather than the national grid — so if it is paid to switch off, no national record shows it. That is why this seat has no figure here: not because nothing happens, but because nobody publishes it. The £ figure for this seat is a floor, not a zero.

how we worked this out

95 MW

of clean power — almost all solar — approved and still not built, enough to supply a year's electricity to 40,000 homes — about as many homes as this constituency has. Approved at least two years ago; waiting on the grid, not on planning. That is 1.6× the renewable capacity actually running here.

4 projects · 85 MW solar, 9.9 MW onshore wind · planning database (REPD), July 2026 · how we worked this out

£2.8m

is what the grid gap costs this constituency's 30,822 households in a year between them — £92 each, about 51 days of one home's electricity.

The £92 per household is a national figure — identical in every GB seat. Only the seat total varies, with the number of households · NESO · how we worked this out

The waiting list

4 of 4 waiting projects · years since approval

Rhyd-y-Groes Wind Farm - repowering 9.9 MW

9.8 YRS

Porth Wen 50 MW

8.4 YRS

Parc Solar Traffwll 35 MW

3.4 YRS

Cyngor Sir Ynys Mon - Solar Photovoltaic Panels 0.5 MW

2.6 YRS

Every approved, unbuilt project

approved 24+ months ago, still not generating · planning database, July 2026

Site	Technology	Enough for	Capacity	Approved	Waiting
Porth Wen	Solar Photovoltaics	18,000 homes	49.9 MW	2018-03	8.4 yrs
Parc Solar Traffwll	Solar Photovoltaics	13,000 homes	35.0 MW	2023-03	3.4 yrs
Rhyd-y-Groes Wind Farm - repowering	Wind Onshore	8,700 homes	9.9 MW	2016-10	9.8 yrs
Cyngor Sir Ynys Mon - Solar Photovoltaic Panels	Solar Photovoltaics	200 homes	0.5 MW	2024-01	2.6 yrs

Plus 1 more approved within the last two years.

Batteries

projects of 10 MW and above · planning database, July 2026 · what batteries do →

Site	Size	Status	While discharging
Penrhos Works - Battery Energy Storage System	349 MW	approved, not built 2024	could supply ≈1,223,000 homes
Carrog Ganol, Rhosgoch - Battery Energy Storage System	300 MW	approved, not built 2024	could supply ≈1,051,000 homes

What this page does not show

Smaller wind farms on the local grid are also switched off; national data does not show it, so the £ figure here is a floor, not a zero. Offshore wind is counted nationally, never per seat. The planning database can run a quarter behind reality.

Electricity does not travel from a particular project to particular houses. Everything generated goes into the national grid and everyone draws from that shared pool, so "enough for X homes" is a way of sizing the electricity — not a claim that these homes would be powered by this site. Battery storage is counted separately from generation: it moves power in time rather than making it.

Planning statuses come from the government's planning database (REPD), which records what was decided and when, but not why. Where a project was refused we say so and name the authority; for the reasons, look up the planning reference on that council's own register. How to check any figure on this page →

Read the full method, including everything we cannot see →

What has Llinos Medi said about the grid in Parliament? Search Hansard →

See the full league table Data (JSON)