Long Term Solar Generation History.

Solar LogoThe information on this page about the monthly generation we have achieved over a full 10 year period from our 22 panel SolarPv Array on our East facing roof in Northumberland UK .

It is a personally compiled history with our own thoughts and conclusions on the viability of SolarPv and is totally unbiased.

The 1st chart below shows how variable the sunshine (and actual Solar Generation that has been achieved) in South East Northumberland (55.10' N - 1.34' W), season to season, year by year since May 2010 when we paid £15,000 to have it installed (installation costs have reduced significantly since then though)

Annual Genration Graph

That graph does show how variable actual generation is (and weather dependent), plus from July 2016 when a battery storage system was installed overall generation output to the system meter fell. Now was that because the systems charges the battery packs 1st before sending the power out to the Home and Grid, or was it simply down to a reduced amount of generation because of a lack of sunshine? You can decide for yourself looking at the data in the graph.

The next graph below does show that comparing the 48 months before the Storage Battery was fitted compared to the 48 months after it started being used, 1,478 Kw less SolarPv went to the generation meter.

Annual Storage Battery Graph

Given that the generated power that comes from the Inverter goes 1st to the Battery Pack, then on to the recording meter to our home supply and any unused power then goes to the National Grid it does look like the Storage Battery does reduce overall generation output.

For us it doesn't matter as we are no longer claiming the FITS payments. As of July 25th 2016 we sold the system to a 3rd party, Solar Equity Release, for a cash lump sum plus a 4.8kw battery Storage pack.

Why did we sell? Well we have recouped more than our initial outlay when you add in the Fits payments paid to the cash sum we received on sale. Plus there was the value of the 4kw battery storage pack and we still retain the reduction in electricity bills the Solar PV system gives.

We will reduce our future bills by still using generation from the SolarPv system on our roof, plus the power supplied via the battery storage system which is setup to charge the batteries 1st, then power the house, then export to the grid any unused energy.

It's still a 'win win' situation as far as we are concerned as we have no ongoing maintenance or repair costs, no administration work supplying output figures or claiming FITS payments as generation readings are all sent via a new 'smart meter' which was installed when the battery storage system went live.

Over the 72 months that the system had been installed from May 2010, working and owned by us, we had received a total of £9,189.62 in Fits Payments, which equates to 59.3% of the installation costs tax free, plus we had savings on our monthly Electricity bills so yes, it had been a very worthwhile investment.

Looking at the graph above it does clearly demonstrate that the amount of electricity generated varies considerably over the seasons, but what does that actually mean for us?

Solar Pv power versus Power bought depending on the season

Whilst the 1st chart shows the monthly seasonal variations in generation achieved, it is useful to look at what that actually means in practice. The 3rd chart above covering 2019 shows how much generation we recorded versus the electricity we have had to buy over the individual months.

In the Winter Months Especially Solar Power alone is simply not enough for our household needs and we still have to pay for electricity (and that is likely to apply to most private installations in the UK). In the summer there is still a small amount of electricity to pay for to the suppliers, in this case OVO Energy, but overall our electricity bill over the 10 years is lower by £4,093 (at current rates) than it would have been without the Free Solar Electricity produced.

Would things be better if we had a South facing roof installation or we had split the panels on the East and West sides? that we do not know but when the system was installed having maximum generation in the morning was most beneficial to us and the costs of altering the system don't make financial sense..

We can't draw any firm conclusions on that point unfortunately.

So should you install SolarPv on your roof?

Today's average 'commercial' solar panel converts 17-19% of the light energy hitting it to electricity. This is an increase from 12% just 10 years ago when our 'domestic' system was installed. Newer, more efficient solar cells mean you could get more of your electricity supply from the sun but......

There are numerous factors involved in deciding whether to proceed including installation costs, roof direction and location so please do your own research and don't rely on some smooth talking 'salesman's' advice and beware of people advising you to take out a loan to cover the cost of installation which is rarely good advice. Plus if your getting solar panels installed, get a battery storage pack as well to maximise the benefits.

Please Note: Subsequent system installations qualified for a smaller FIT payment, but cost less to install as prices reduced considerably and from 2016, incentives for new Domestic Installations ceased to be paid.

From 2020 New SolarPv Installations that meet certain requirements may qualify for a Smart Income Guarantee

Last Update: 19th May 2020