Solar Power Report: June 2025

June was quite productive for our 8kW of west-facing panels in central UK. There has been some cloud, but I think the system still maxes out the 5kW inverter anyway. The battery is 9.5kWh and helps save us money over the darker months when we can charge it on cheap rate to run the house all day.

So far this year the yield has been:

• January: 95kWh
• February: 228kWh
• March: 676kWh
• April: 927kWh
• May: 967kWh
• June: 1044kWh

You can see that not much of this power went to the battery. I charge that up on cheap electricity every morning so that I can export as much as possible. I pay 8.5p/kWh for that and get paid 15p to export, so it makes economic sense.

I have tweaked things a little to earn more. As the battery is full at the end of the day I have set the system to export some of that after the sun goes down. With this in addition the system has earned me about twice as much as I would have to pay for the electricity and gas I used, so I will build up more credit for the winter.

Compare that to last year. This was before I started scheduling the charging so I exported a lot less and also the export tariff only gave me 8p/kWh. My supplier

(referral link) are pretty good really. They are still looking into why my system sometimes trips out. It seems that others have experienced it, so they are looking to collect data to show the manufacturer. I have not lost too much from this issue, but it is annoying.

I saw some

about potential changes to allow plug-in solar panels. These are already a thing in some other countries where people can hang some from an apartment balcony to reduce their energy costs. I know has in Germany. Here there need to be rule changes as you cannot currently pump power into a standard domestic circuit. There is massive potential for domestic solar in the UK. With the current heat more people will be thinking about air conditioning and that can be expensive to run. You will need it most when the sun is out, so solar panels can provide at least some of the power.

I have wondered how much my panels contribute to keeping the house cooler. They are absorbing the sunshine and then there is an air gap under them. It may make a slight difference, but you have to be smart about things like ventilation and shading to keep the house cool. UK houses tend not to be designed for extreme heat as really hot summers have been rare, but they are becoming more common. We saw 40C a couple of years ago and that could become normal. In other parts of Europe

. This can be deadly for some people.

Solar is not perfect, but it gives people some agency in reducing their bills whilst contributing to cutting global emissions. The equipment prices have dropped massively in recent years whilst energy prices are likely to keep going up. I only wish we could have got solar earlier, but we are reaping the benefits now.

Shine on!