Conclusions from the solar PV payback calculations
I hope this illustrates how using the energy at home makes more sense than selling it back to the grid – and remember too – if you don’t have an export meter you will be paid as if you are exporting 50% of the electricity, even if in fact you end up exporting zero!
The calculations also show the sort of payback you should be expecting once you install a solar PV system, potentially paying back in as little as 7 years.
This calculation above also doesn’t take into account electricity price increases going forward, and I am fairly confident these will be going up rather than down, so obviously the potentially savings are only going to increase.
Also as soon as you have paid back the initial installation costs of the solar, you then are getting free electricity and being paid for using it for a further 12 years or more and these payments are guaranteed.
It is also worth mentioning that once you have installed all the infrastructure required to run your solar PV system (i.e. inverters, meters) the actual panels themselves are relatively inexpensive, so it is worth trying to get as big a system as your roof will allow (based on size and its strength), since the more kWh you can squeeze out of your system the more money you will make the larger your return will be.
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Have you looked at the immerSUN and other such devices for PV/Wind generated energy storage?
fitted panels in june produced 1700 kwhrs but had immersun fitted and have put 400 plus kwh into hot water . hardly had gas onto heat water since then .
That is great Andy, how much are you making now the sun isn’t shinning so much? Enough to still heat the water? Also what size system do you have installed?
Interesting numbers – where does the 0.8 value come from?
Hi Jon,
The 0.8 is based on average industry SAP calculations for an optimum system in an average UK home and a south facing array at 30˚ pitch with no shading and subject to average UK weather conditions (You can find out more by googling ‘The Government’s Standard Assessment Procedure for Energy Rating of Dwellings 2009’). Hope that helps!
Conclusion is correct but the numbers are all wrong.
Price good, expectations way to low for good products and FiTs are no longer as stated.
Other than that, great promotional piece about Solar. Nice work.
Hi Solar Kev – thanks for the comments. This article was written as a blog about a year ago – so obviously the numbers were a bit out of date, however I have now updated them for you – hope that helps!
This is incredibly useful, especially finally understanding the difference between the generation tariff and the export tariff! I think for us, we might be able to get 20 odd panels on the roof (south facing), so hopefully that should produce a nice return!
The only figures I would take issue are those for the stay at home retired couple. It is most unlikely that you will ever reduce your electricity bill by as much as 80%.
The problem is still that daytime production will peak at about 3 – 3.2kW when demand is nothing like so high.
I have an EMMA fitted, to use surplus electricity for water heating, but that only utilises a maximum of 4 – 5kWh at best in the middle of Summer.
in winter the solar PV contribution is negligible, my south facing 4kW system produced just 90 kWh last December and I assume the mythical couple are at home with lights and T.V on.
The article is interesting though.
Hi Neil, thanks for your comment! Just a quick point, I was not meaning an energy bill reduction of 80% – I was saying that of all the electricity produced by solar PV, 20% would go back to the grid and 80% would be used in the home.
I take your point though – in the winter, solar PV doesn’t really contribute and so they are going to be pulling plenty of power from the grid!
Hello,
My experience is better than your example. My 3.84kw system on SW facing roof with a 55 degree pitch gave me 3,640 kW in the last 12 months. Plus the electricity company don’t actually measure the electricity that goes back to the grid but assumes half of what my panels make will go there and pays me the extra few pence on half of my generation figures. I would have installed panels even without the FIT but I am very happy to accept the generous payments every three months.
Our 3.9 kw PV system produced 3900 kwh last year. It is on a south facing barn roof with no significant shadowing. Production in the winter is low – between 10 and 40 kwh per week. We are all electric – heat pumps providing the heating – and also have 2 wind turbines. In total we make over 50,000 kwh per year and buy about 20,000 kwh.
‘as anyone who has done GCSE science will be able to tell you, it is not possible to store electricity’ LOL. Have you ever heard of batteries?!
LOL, you clearly haven’t done your GCSE’s
You can’t store electricity, batteries convert electricity into chemical potential energy, then when you discharge them, they convert it back – hence they are hugely inefficient…. Just saying 🙂
Rechargeable batteries only last a few years, so the cost to replace them every few years would be horrendous.
Hi Dave have you seen the new Power Wall from Tesla?
I think this is the start of batteries in the home becoming mainstream (and affordable)!
I am 70 years of age , we are both retired , and we were given a quote of £5000,200 for fitting solar panels , although the roof faces east , you do get the sun on there until about 4pm , we also spend about 80 days per year away from home , would solar panels be worth it for us ,
Hi Joseph, getting solar panels installed is definitely not a bad investment. You will benefit from both the feed-in tariff and free electricity. We have a case study showing you how the return is calculated which is worth having a read – take a look by clicking here.
If you coat the panels with nanoshellPV you can increase their efficiency by about 14% making these figures even better. The new coating acts as a self cleaning surface so everytime it rains it cleans the panel and increases its efficiency. We have proven results from an array in Exeter taken over the period of one year. Cheap,solution and last for about 5 years between re-coating
So basically with a feed in tariff of 15.44pence/kWhr or eve 14.9pence/kWhr these PV panels are effectively heavily subsidized either by the tax payer or at least other electricity customers,… ..not exactly the best indication that they’re good value for money,.. just that someone else is paying for it,. i.e. the poor subsidizing the better off who typically install these things.
A more honest approach would be to set the feed in tariff at a fraction of the standard electricity rates, as this would would take into account the fact that it’s the utility companies that carry the cost of line maintenance as well as the cost/inefficiencies of energy storage and/or ramping up and down power stations to accommodate intermittent renewables.
Hello i have had 4kW 16 panels fitted to my south facing roof foR five years my fit payback hAs totalled £8.500 to date i currently recieve 51.6 np per unit the cost of my units 5 years ago was £17.000 and was informed that i would have seen a return on this amount after 8 years.
I do not know how much i can assess that we use during the daytimeas both my wife and i are and have been at home daily since fitting
Is there a way we can estimate a rough guide on the possible savings we may have accrUded during this time.