It is a full year since our solar generation system was installed. It consists of 20x400W panels (8kW total), 5kW inverter and 9.5kWh battery. I have just been trying to extract some data from the GivEnergy app, but it is not giving me the charts I want. I will have to look at extracting the data to do it myself. For now this is the total generation since it started operation on 23rd February 2024. Over half the power was exported with the rest equally split between charging the battery and powering the house. That may shift in the second year as the tariff changed so that I get paid more for exporting than I pay to charge the battery on cheap rate in the early morning. So instead of aiming to let the panels charge the battery I will aim to do it from the grid overnight to maximise my exporting.
I have mentioned before that we have had some minor issues with the system. One of the breakers has tripped a few times and that takes the system offline. The installers are investigating. It did it a couple of times in January, but not since.
The house consumed 5878kWh over the same period. I cannot do direct comparisons with previous years as we also started leasing an MG4 EV just over a year ago. That gets charged a couple of times each week and will make a substantial different to our consumption. That charging is mostly done on cheap rate.
I can generate a chart of exported power from the power company. Obviously it is low in winter, but we still generate something then. It may just not be enough to keep the battery totally full and we need a good charge to get through the long nights.
I have seen people say that a good solar setup would be generating 1MWh for each kW of panels. Mine falls a little short of that, but then it faces west. It would do better facing south, but I cannot move the house. Before we got solar we were paying over £130 per month for electricity and gas. We had built up some credit, so I reduced the payments to £30 from July and we still have some credit. Now that we get 15p/kWh to export rather than 8p we should earn a lot more in the sunny months, so I will be monitoring the situation to see how much we need to pay. I the summer we can earn more than we need to pay. We are with Octopus who installed the system. They are really promoting solar. I had a call asking if I was interested in getting a heat pump too. This is something we will consider as our gas boiler is quite old.
Overall I am happy with making this investment despite the glitches. We are saving money and the system will pay for itself eventually. With the better export tariff that time will have come down a bit.
You can see the days where the car was charged. We will use less than 10kWH on other days and some of that will come from solar, but the car will draw more than the inverter can supply and would easily drain the battery so we need the grid.
We had some sunny days late in the month, so were able to export a good amount.
You can see that not much solar went to charging up the battery. It would be fully charged by 05:30 on cheap rate from the grid and then get topped up if the sun was out. We hardly ever need to use peak rate power that costs over 2.5x as much.
I am happy to try and answer any questions you have about solar. It has been interesting to see reports from others around the world about their experiences. Power countries in some countries are not so encouraging of solar, but it can be such a benefit to those who have it. The UK is not the sunniest place, but even here it will save you money.
Shine on!
That is really cool to see the month to month comparison. Congrats on your first year with solar!
Cheers. I've been waiting for the year to roll around. I need to pull out more data for future comparisons. I ought to do some scripts for that.
Nice stats you have there!!! I find fumbling around with the cheap prices mid day and charging the car with the sun means that nearly all of our solar we use ourselves. This 5 year investment with the car use and no gas costs will make it go much faster than that.
Are you considering one of those home batteries? They seem a bit much to me at the moment honestly
We could charge the car on sunny days if you limit what current it takes. I think it works out cheaper than burning oil anyway.
We have the battery and it makes a big difference as we can use the cheaper power.
That's really interesting as I'm just considering a hybrid system here. May I ask how long you're hoping your battery to last for, please? It's a little bit of a wildcard in the calculations to work out my payback period.
Hope you're having a great, and sunny, weekend :-)
I would hope for a good 10 years from the battery. I think it could actually pay its way in less than that as it saves us so much by letting us use cheap power.
My dad got it installed last week for about 8k. He will be monitoring closely on the app but it should generate at least 75% of his use.
He didn't get a battery but can sell back to the grid, for a low rate.
I'm interested in doing the same as we have about 200 a month in electric bills so it should pay for itself.
I hope it goes well for him. If you can get it installed then I think it will be worth it if you are prepared to wait a few years. It was something we wanted to do 20 years ago when we built the house, but the cost would have been a lot more then.
I’d love to get solar, especially those that look like regular tiles so passes wife’s aesthetic criteria :)
Apparently there are higher efficiency composite solar panels coming that can generate more per square foot.
I hope they will improve, but we went with what was available. My other half wanted it too.