Solar panel output in the summer vs the winter
The sun has well and truly 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 around 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 and, of course, how sunny that particular summer is.
Between 1 April and 30 September 2024, Imogen’s (hello, it’s me) 12-panel, 4.2kW solar array generated an impressive 2966.95 kWh. That’s around 10% more than the average home’s annual electricity consumption and, by being used by Imogen’s family and shared with the grid, it helped save 668kg of carbon*, equivalent to taking one car off the road.
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 £214 by using their solar power at home in the summer months (compared with drawing that power from the grid at 24.8p / kWh).
They also earned a further £490 by exporting their excess power to the grid at 25p / kWh (Good Energy’s exclusive rate export tariff for install customers**). 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 £704 – not bad for 6 months ‘work’.
Solar panel output in the winter – how does it compare?
As you can see in this graph of 2024 Imogen’s 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 1,0006 kWh of electricity, earning Imogen and her family £251.50.
This brought the 2024 total savings up to £990.90.
🔴 Solar power exported to the grid. 🔵 Solar power stored in battery. 🟢 Solar power used directly.
With the longest day coming up, now’s the time to go solar.
*Compared with the UK’s electricity grid carbon intensity in 2024.
**Exclusive rate available for 12 months, after which you move onto Good Energy’s standard rate export tariff, currently paying 15p/kWh.