No.352 of 650 · approved, not built MP: Liz Saville Roberts (Plaid Cymru) Wales

Dwyfor Meirionnydd

Dwyfor Meirionnydd has 1.9 MW of clean power (all solar) approved and still not built: enough to supply a year's electricity to 700 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, £3.9m across the constituency's 42,488 homes. A 100 MW battery was refused planning here in 2026; while discharging it could have supplied about 350,000 homes.

Not visible
here

No big wind farm on the national grid is mapped to this constituency, so no switch-off payments show here in national data. Smaller wind farms on the local grid can still be paid to switch off — invisibly. The £ figure for this seat is a floor, not a zero.

how we worked this out

1.9 MW

of clean power — all solar — approved and still not built, enough to supply a year's electricity to 700 homes. Approved at least two years ago; waiting on the grid, not on planning.

3 projects · planning database (REPD), July 2026 · how we worked this out

£3.9m

is what the grid gap costs this constituency's 42,488 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

3 of 3 waiting projects · years since approval

Nanhoron Home Farm, Nanhoron - Solar Panels 0.2 MW

4.0 YRS

Tyfos, Pen Y Geulan - Solar Array 0.6 MW

3.0 YRS

Rehau Plastics, Pencefn Road - Solar Panels 1 MW

2.4 YRS

Every approved, unbuilt project

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

Site	Technology	Enough for	Capacity	Approved	Waiting
Rehau Plastics, Pencefn Road - Solar Panels	Solar Photovoltaics	400 homes	1.0 MW	2024-03	2.4 yrs
Tyfos, Pen Y Geulan - Solar Array	Solar Photovoltaics	200 homes	0.6 MW	2023-08	3.0 yrs
Nanhoron Home Farm, Nanhoron - Solar Panels	Solar Photovoltaics	100 homes	0.2 MW	2022-08	4.0 yrs

Batteries

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

Site	Size	Status	While discharging
Tyddyn Forgan, Llanddeiniolen - Energy Storage System	100 MW	approved, not built 2026	could supply ≈350,000 homes
Seion, Pentir - Battery Energy Storage System	100 MW	refused 2026	could supply ≈350,000 homes
Pentir Substation, Pentir - Battery Energy Storage	57 MW	approved, not built 2024	could supply ≈200,000 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 Liz Saville Roberts said about the grid in Parliament? Search Hansard →

See the full league table Data (JSON)