Solar panels in Cowes: what they generate and what they cost

A 4 kWp array in Cowes should generate about 3,980 kWh a year on our modelling — 10% more than the median of the 1,356 places we model. Here is where that number comes from, and what it is worth.

About 3,980 kWh a year from a 4 kWp array, on our modelling for Cowes.

That is 995 kWh for every kWp installed — 10% more than the median of the 1,356 UK places we model, and 8% below the sunniest.

Cowes: a 4 kWp south-facing array at 35°
Output per kWp installed995 kWh a year
A 4 kWp system generates3,980 kWh a year
Rank for sunshine92 of 1356 places we model — see the league table
Installed cost, South East mean£7,436 (£1,859/kW)
Network operator areaCheck 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 (50.757, -1.306), 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. South-facing at 35° is a modelling convention, not a description of your roof.

Monthly output for 4 kWp in Cowes, kWh
MonthJanFebMarAprMayJunJulAugSepOctNovDec
kWh152208348452480488492432368256176132

What the number means

Cowes sits in South East, and the installed-cost figure below is the South East mean from the official statistics.

68% of the year’s output falls between April and September. April to September gives about 2,712 kWh; November to February gives about 668 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.

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

  1. Check the price per kW against the benchmark — divide any quote by the array’s kWp.
  2. Confirm the network position — G98 or G99 — and who your operator is.
  3. Check the planning position if you are in a conservation area or the building is listed — the planning cluster.
  4. Get three quotes and compare them properly — comparing quotes.

Sources

  1. PVGIS 5.3 European Commission, Joint Research Centre · Accessed 20 August 2026 We ran PVGIS for this place's own postcode centroid at 20% system losses. Contains modified Joint Research Centre data.
  2. ONS Postcode Directory Office for National Statistics · Accessed 20 August 2026 · OGL v3.0 Centroid and live postcode count for this area.
  3. Solar photovoltaic (PV) cost data Department for Energy Security and Net Zero · Accessed 20 August 2026 · OGL v3.0

Contains public sector information licensed under the Open Government Licence v3.0.

Last verified: How we research this Suggest a correction
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