How many kWh does a 500W solar panel produce per day?

It varies enormously by season. A well-sited 500W panel might produce 2–3 kWh on a bright summer day and only a few tenths of a kWh on a dull winter day, averaging out to roughly 400–475 kWh across a good UK year.

Is a 500W panel too big for an 800W system?

No. Two 500W panels give 1,000W of DC rating on an 800W microinverter, which caps AC output at 800W. Because panels seldom hit their rated output together, the extra DC mostly helps in weaker light rather than being wasted.

Panels & output

How much electricity does a 500W solar panel generate?

A 500W panel is one of the larger formats used in home solar, and a popular choice for two-panel plug-in kits. Its 500W rating is measured under standard test conditions, so the real question is how much energy it produces in everyday UK light.This guide gives realistic daily and yearly figures, explains what changes them, and shows how two 500W panels behave on an 800W microinverter. For the wider picture, start with our solar panel wattage guide.

Written and edited by Christopher Panteli

Last reviewed 21 June 2026

Christopher is the founder and editor of MyPlugInSolar. He oversees the site’s research standards, data tools and editorial process. He is not an electrician or solar installer, and specialist technical claims are sourced from official documentation or reviewed by appropriately qualified professionals.

Realistic 500W output in the UK

As a rough rule of thumb, a well-sited, unshaded, south-facing panel in the UK produces around 0.8–0.95 kWh per year for each watt of rating. For a 500W panel that is roughly 400–475 kWh per year in good conditions. Tilt it poorly, face it north, or place it vertically on a balcony railing and the figure falls — sometimes well below 350 kWh.

These are indicative ranges, not guarantees. For a figure based on your postcode and orientation, use our calculator.

Indicative 500W panel output (well-sited, south-facing).
Period	Indicative output	Notes
Bright summer day	2–3 kWh	Long days, high sun angle
Dull winter day	0.2–0.6 kWh	Short days, low sun
Full year	400–475 kWh	Falls with shade, tilt or north-facing

What changes the output

Direction and angle make a bigger difference than most people expect — see solar panel direction and angle and shading and plug-in solar.

Orientation and tilt: south-facing at roughly 30–40° is ideal; vertical balcony mounting gives less.
Shading: even partial shade from a railing, chimney or tree cuts output sharply.
Season and weather: UK output is concentrated in spring and summer.
Temperature and soiling: very hot panels and dirty glass both lose a little output.

Two 500W panels on an 800W microinverter

A common plug-in configuration is two large panels feeding a single 800W microinverter. Two 500W panels provide 1,000W of DC rating, but the microinverter caps AC output at 800W. This is not wasted capacity: panels rarely hit their rated figure at the same time, so the extra DC simply lifts output in weaker light. The component that sets this limit is explained in our microinverters guide.

Output is not the same as savings

Generating 450 kWh only saves money on the electricity you actually use while the panel is producing. Surplus you do not use is exported, and under current arrangements that export may earn nothing for a plug-in system. To turn output into a saving, match it to your daytime base load and read solar self-consumption.

Before you buy

Plug-in solar is not yet legal to sell, supply or use in the UK while a Government consultation runs. Check the current legal status first.

Frequently asked questions

How many kWh does a 500W solar panel produce per day?: It varies enormously by season. A well-sited 500W panel might produce 2–3 kWh on a bright summer day and only a few tenths of a kWh on a dull winter day, averaging out to roughly 400–475 kWh across a good UK year.
Is a 500W panel too big for an 800W system?: No. Two 500W panels give 1,000W of DC rating on an 800W microinverter, which caps AC output at 800W. Because panels seldom hit their rated output together, the extra DC mostly helps in weaker light rather than being wasted.

Sources

1. PVGIS (Photovoltaic Geographical Information System) — European Commission, Joint Research Centre

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