Solar panels in Vale of Glamorgan: what they generate and what they cost
A 4 kWp array in Vale of Glamorgan should generate about 3,856 kWh a year on our modelling — 6% more than the median of the 1,356 places we model. Here is where that number comes from, and what it is worth.
About 3,856 kWh a year from a 4 kWp array, on our modelling for Vale of Glamorgan.
That is 964 kWh for every kWp installed — 6% more than the median of the 1,356 UK places we model, and 11% below the sunniest.
| Output per kWp installed | 964 kWh a year |
|---|---|
| A 4 kWp system generates | 3,856 kWh a year |
| Rank for sunshine | 168 of 1356 places we model — see the league table |
| Installed cost, UK median | £6,380 (£1,595/kW) |
| Network operator area | Check yours from your bill — licence areas follow cables, not council boundaries |
Generation modelled by us from PVGIS 5.3 for this place's postcode centroid (51.425, -3.303), at 20% system losses. Contains modified Joint Research Centre data. Cost from Solar photovoltaic (PV) cost data, Department for Energy Security and Net Zero, 2025/26 — no regional figure is published for this area, so the UK median is shown. South-facing at 35° is a modelling convention, not a description of your roof.
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| kWh | 136 | 204 | 332 | 444 | 492 | 480 | 476 | 420 | 352 | 240 | 156 | 120 |
What the number means
69% of the year’s output falls between April and September. April to September gives about 2,664 kWh; November to February gives about 616 kWh. That seasonal shape, not the annual total, is why solar cuts summer bills far more than winter ones.
The honest headline for anyone comparing towns: where you are matters much less than how your roof faces. Across every place we model, the spread from best to worst is about 54%. Turning a roof from south to north costs far more than that — see roof orientation and pitch and north-facing roofs.
Grants
Vale of Glamorgan does not appear on the department’s Warm Homes: Local Grant award list — not as a lead authority, not as a named consortium member, and not through a county council where that applies.
That is what the list says today rather than a statement about your eligibility. Councils join schemes, lists are updated, and other routes exist: see what actually pays for solar, and ask the council directly before concluding anything.
What it is worth
Generation is not saving. What decides the money is how much of it you use as it is produced rather than export:
- at 14% to 23% self-consumption — MCS’s figures for a household without storage — most of this output is exported
- exported units earn your export tariff, which ranges from about 4p to about 12p
- units you use instead avoid buying at about 26p
Put your own consumption in at the calculator, or read self-consumption for why it is the number that decides everything.
Before you get quotes
- Check the price per kW against the benchmark — divide any quote by the array’s kWp.
- Confirm the network position — G98 or G99 — and who your operator is.
- Check the planning position if you are in a conservation area or the building is listed — the planning cluster.
- Get three quotes and compare them properly — comparing quotes.
Sources
- PVGIS 5.3 We ran PVGIS for this place's own postcode centroid at 20% system losses. Contains modified Joint Research Centre data.
- ONS Postcode Directory Centroid and live postcode count for this area.
- Solar photovoltaic (PV) cost data
Contains public sector information licensed under the Open Government Licence v3.0.
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