Solar panel output in the summer vs the winter
When do solar panels produce the most power?
The sun has made an appearance in the UK this spring, and interest in solar panels is on the up again as a result. In this article, we explain how much homes can generate from solar panels in the summer, and how that might translate to your bills this time of year.
When do solar panels produce the most electricity?
It won’t come as a surprise that solar panels generate most of their electricity in the summer months.
Longer days and fairer weather bring more ‘sunshine hours’ – a measure that quantifies the amount of sun-exposure in a particular location each day.
Between 1st April and 30th September, you can expect to generate 65% – 75% of your annual electricity, with 25% – 35% of your annual electricity generated between October and March.
Whatever you don’t use or store at home, you can export to the grid, creating a credit on your energy account to pay for your energy in the winter months.
How much do solar panels generate in the summer?
People often ask ‘how much will my solar panels generate in the summer?’. This will vary depending on how many panels you have installed at your home, the type of system (ie string, optimised, micro-inverter), where in the UK you live, the direction the panels face, whether they are clean and, of course, how sunny that particular summer is.
Between 1 April and 30 September 2025, Imogen’s 12-panel, 4.2kW solar array generated an impressive 3213 kWh. That’s similar to the average home’s annual electricity consumption.
How much will I earn from my solar panels in the summer?
As well as the factors mentioned above, the other main factors influencing your solar panel earnings are how much energy you use while it’s being generated, and how much you are paid for your exported power. Living in a modern home with energy-efficient appliances, Imogen’s family-of-four are fairly low electricity users – consuming 17% less than the UK annual average.
They saved £256 by using their solar power at home in the summer months (compared with drawing that power from the grid at 26.35p / kWh).
They also earned a further £400 by exporting their excess power to the grid at 15p / kWh (Good Energy’s standard rate export tariff). These earnings were applied monthly to their Good Energy account, helping to build a large credit that led to a long energy payment holiday throughout the winter.
Together, their total savings from solar panels in the summer was £656 – not bad for 6 months ‘work’.
Solar panel output in the winter – how does it compare?
As you can see in this graph of Imogen’s 2025 solar generation data, there is a pronounced peak of generation in the summer months.
In comparison, solar panel output in the winter (in this example 1 January – 31 March and 1 October – 31 December) produced 979 kWh of electricity. This solar output, combined with storing off-peak power in their battery, earned Imogen and her family £326.44.
This brought the 2025 total savings up to £982.44
🔴 Solar power exported to the grid. 🔵 Solar power stored in battery. 🟢 Solar power used directly.
