I feel this question gets asked a lot and is not often answered. Solar panel salesmen will often give some impressive figures to make a sale, but talking to ordinary people most people don’t know how much their array actually saves them. So I have made an effort to compare a year without solar and a year with solar as scientifically as possible (but there were catches.)
To answer the question – straight off the bat- yes, they can be. But there are catches. To find out more, read on.
The test
We bought a house in August 2018 and I wanted to run it for a year without solar panels and a year with, to compare the two like for like to give an accurate comparison. However, the UK Government decided to close the Feed in Tariff (FIT) scheme to new installations after March 2019, so we decided to take the plunge and go solar early in order to qualify for the scheme and get 20 years of free money. So my comparison is between a 2 bedroom early 1900’s terrace and a 3 bedroom 1960’s ex-council semi-detached house. There are a few differences. The old house had an electric ceramic hob whereas the new one has a gas hob – however, the new house has a dishwasher and LED lights throughout, whereas the old house had halogen lights in the kitchen. I have no scientific way of comparing these differences, so for arguments sake lets say each difference cancels the other out.
So here is my calculations on how much I have saved on electricity by making some of my own. However, I noticed my old supplier was charging more than my new supplier, so I have also done a set of figures at the rates of the new supplier using the old usage in KwH.
(NB- if you are looking at my bill for this year and think it’s cheap and want to switch to Bulb, use this link and we both get £50 credit.)
So after 1 year, adjusting for the different pricing, the solar panels have saved me £154.92 on my electricity bill. Again, there are some caveats here:
The invertor died and I didn’t realize for a while, and it took a while to get it replaced under warranty. As such, I missed out on 3-4 weeks of generation in August which is peak solar season! The weather has also been SHOCKINGLY BAD over the last 12 months, so I fully expect most years to be a lot better than this one for solar production.
The system
I have a 10 panel solar array, with a solar edge invertor. Solar panels will perform at the capacity of the lowest performing panel, so if one is in shade, they will all perform at this level. Solar edge works around this and each panel performs at it’s actual level.
At time of installation, a typical 10 panel array with a standard invertor with a 10 year warranty, and panels with an 8 year warranty and 25 year performance guarantee would cost about £4,400 inc VAT. My array has panels with a 20 year warranty and a 25 year performance guarantee, with a 25 year warranty on the solar edge invertor and cost £5,500 inc VAT. This was needed due to a large tree casting shade on part of the roof. The 25 year warranty on the invertor is also nice.
Will it make me money?
Running the numbers through, if electricity costs remained the same and if the sunlight was the same, the system will cost £1,627 more than it saves. With the FIT scheme payments, it will make me £711.60 over the guaranteed lifetime of the invertor (more if the system keeps going after the warranty expires.) However, if you are looking at getting solar panels now, the FIT scheme is closed to new applicants, and I really don’t expect the Conservative Government (who don’t seem to care about the environment) to replace it, or replace it with anything good.
So should I not get solar panels then?
If you are reading this, you are probably thinking of going solar to help the environment, but obviously you don’t want to be out of pocket. Like I said at the beginning, there are catches. My installation is sub-optimal:
- I live in the North of England. The further South you go, the better performance you will get. Further North and in Scotland it will be worse
- My roof doesn’t face South (which is the ideal in the Northern hemisphere), the corner of the roof faces the South, so I have 6 panels on a South-West facing slope and 4 on a South-East facing slope. The 4 on the South-East perform better and I wish they’d put the 6 on there
- I have a big tree in my garden, which casts shade on the South-West panels in summer when I should be getting the best performance from my panels. This is a big factor, and this is why I had to get the solar edge invertor (see above)
- The panels were installed part way through Q1 2019 and there is still some of Q1 2020 to go, so I’m probably due another £10-£20 worth of FIT payment on the figures above
- As I mentioned before, the invertor was down for 3-4 weeks in August which has cost me some savings and some feed-in-tariff
There are also factors where we could save more money
- My partner and I both work full time. We set the washing machine off before we leave for work, but to get it to run 100% on solar it needs be after 11am in winter when there is more sun which we can only do on a weekend
- We don’t use a lot of electricity so we don’t have a lot to save on! During a weekday a lot of it goes back to the grid as surplus, but if we had children we’d obviously be using it in the school holidays for example and seeing some savings there
- These calculations don’t take into account inflation. As the price of electric goes up (which it does nearly every year), then the amount of money we save for not using electricity from the grid goes up, as does the amount we get paid on the Feed in Tarrif as it is linked to the market price. It’s nice to know they are there keeping our electric bill down. I do believe the panels are going to make me more than £711.60, and inflation will be a big part of that
So in conclusion, I would recommend solar panels if the following applies to you:
- You have a decent sized South-facing roof with nothing causing shade on it. This would allow you to have a cheaper invertor and there will be less money to recoup
- Consider how far down South you are in the Country. The further South you are, the more likely you are to recoup your investment
- Try and get a decent amount of panels on your roof. The invertor is a big chunk of the cost and you need it whether you buy 1 or 111 panels. Since you’ve laid out for it, try and cover your roof with panels to maximise on that investment
- With the Feed-in tariff gone, try and sign up for an export scheme as one comes available. Bulb are currently trailing one and will hopefully open to new customers soon
- Add another £500 to the cost for pigeon guards if you don’t want to be woken up by them walking underneath your panels!
If you have a traditional hot water system with a tank in the ceiling and are looking to make an investment to save money and the environment, consider a solar hot water system to help power your heating system instead
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