Solar panels 4 years on.

I’ve written about solar panels before about how to get them installed. But, how do they actually perform in South Wales? Well- read on.

The install

Happened in August 2016- scaffolding went up in the week preceding the actual installation. Then on the day itself- all the solar panels/mounts etc were pretty quickly attached to the roof. By the end (of a long day for the installers)- the system was completed.

Solar panels on a house
Not my install- but very similar


Now- just to be transparent, these are the costs that we paid for install in August 2016. But do note- that solar panel prices have fallen since, so the panel/investor costs have dropped considerably.


We also have the following 2 extras installed (listed in the above quote:

Consumer Unit. Wasn’t actually a requirement for solar- but the old unit came with the house, so was 25+ years old. I also wanted more space for garage/car charging in the future etc.

Solar immersion controller. This basically monitored the export to the grid, and if there was any- would then switch on the hot water immersion heater then re-monitor to check it wasn’t pulling any energy from the grid. This happened constantly (something like 5 times a second) so that only excess energy would be consumed by the hot water element. The reason for this is explained before (FIT Tariff). I haven’t linked to the one we had installed- as it’s been replaced by the manufacturer.

Solar Monitoring. This enabled us to locally/remotely monitor how much the solar panels were generating. Whilst this wasn’t really required- it would be easy to look and see if there were any obvious problems (eg. if it had tripped on the consumer unit). I do also love a graph:

2020 solar panel performance

Return – FIT tariff.

The return we got on our solar installation is no longer available for new installations. For that, you need to look into “smart export guarantee” which has rather different rules to the FIT tariff.

The basics of FIT are that you get paid a fixed rate per unit of electricity that you generate- it doesn’t matter if you use it in your home, charge your car, heat your water- or export it. You get paid exactly the same amount of money. This most definitely incentivises you to “keep” the electricity on site if at all possible. Hence the “extra” we paid for- the solar diverter.

Every quarter we submit a meter read (of the generation meter) to the company that we picked for paying our FIT payment (ecotricity), then sometime later, they produce a statement and bank transfer the amount to our bank account. Pretty simple. It’s also inflation linked- so goes up every year as well. Here is 2019 as example:

  • May 2019 – £100.46
  • August 2019- £90.82
  • November 2019- £112.46
  • Total – £303.74

So, basically approx a 5.3% return- without considering the “free” power that I used on site as well. With approx 4,000kWh generated- even if we suppose that I only used 25% onsite, then assuming these units costed just 15p- then that’s another saving of £150.

It also reduced our hot water (gas) bill substantially as well- we didn’t need to use gas for hot water from April > September. Saving at least another £40~.

Solar installation


5% return, guaranteed for 20 years- inflation linked, with additional electricity savings on top (and future electric car charging as well)- with no downside? I’d say, solar was a pretty sure thing- with no maintenance and very little to go wrong (panels warrantied for 20+ years now). As long as you don’t intend on moving out shortly after having the panels installed- you are quid’s in. Even if you do move- they could increase your house price as well (especially if your estate agent sells them properly, as fully owned panels- NOT leased).

Then you have future to think about as well. You are not only doing your bit for the environment, but electric cars are coming- quicker than most think (EV only from 2030 for new vehicles)

Future plans

Since we had this install- we had a further solar install on our garage & Tesla Powerwall unit installed as well. I’ll blog about this at some point- but the figures aren’t quite as simple as this solar install.

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