Returns on investing in solar panels

[hayfield]

This is a question that I have been wondering for some time, some look for how quickly they get their money back, I am in the group who look how much it saves me on my dual fuel bills, others may have other values.

 

My original quotation worked on quoting returns on year 1,5,10 and 20. the salesman did say it may over this period need servicing, repair or replacements. But is guaranteed for 10 years

 

My quandary is that the cost and benefits are shown for 20 years, though I expect maintenance costs after the first 10 tears, to cater for these added costs, perhaps I should divide the acquisition costs over the first 15 years and perhaps use the next 5+ years to recover the maintenance costs after the first 10 years

 

Given I paid £2688 for the system, divided by 15 gives me an annualized cost for my investment for the first 15 years.   £179.20

 

Year 1 realized a financial benefit** of £283.74. A return of 58%

 

Year 2 due to the energy crisis the benefit increased to £470.47. A return of  162%  

 

Year 3 is 10 months old and so far produced £328 with two of the best months to be added. Projecting a return of  £138% for the year

 

** value of own energy used plus export income

 

To a certain degree the figures were skewed by the energy crisis, plus I got a very good deal due to the covid recession. But had the salesman quoted these figures I would not have believed him. But after 34 months we have nearly reached the 5 year projected benefits on the sales illustration

 

For me the best thing is that my DDI monthly benefit has not changed in 4 years and is on target to cover the forthcoming winter period 

 

I expect others will differ on how to calculate the return on their investment, please let me know where I may be getting it wrong

[GrumpyPenguin]

All I  know is that I save money, the installation paid for itself some time ago, I do a rough calculation every so often to check but I'm really not inclined to bother with the real minute details.

 

If I'm bored I can see exactly what is happening through the app' that came with the system & don't need a so called smart meter to tell me.

[Ray H]

We're are currently benefitting from the battery we have connected to the system. Most days recently we have imported not much more than 0.02kWh. Today, it is fairly overcast and there's not too much happening by way of power consumption and yet we have a full battery, have so far consumed 2.43 kWh, generated 7.01kWh and exported 3.49kWh and those figures are with a rather high tree on the grass verge opposite that means we don't generate too much from direct sunlight before mid morning.

 

My biggest gripe is that we get circa 12p per kWh exported which is less than 50% of what we pay for imports from the grid.

 

The less we can import the better.

[Kris]

3 minutes ago, Ray H said:

My biggest gripe is that we get circa 12p per kWh exported which is less than 50% of what we pay for imports from the grid.

 

The less we can import the better.

You want to change suppliers. Our import / export price is equal. We were getting 28p per kWh until the end of June. Not checked not the prices have changed a little.

[Ray H]

4 minutes ago, Kris said:

You want to change suppliers. Our import / export price is equal. We were getting 28p per kWh until the end of June. Not checked not the prices have changed a little.

 

That's interesting. I do check from time to time to see what the best rate is and I've only ever found it to be around 12p.

 

Ours is a fairly recently installed system so not able to profit from some of the early government schemes.

 

Would you mind telling me your provider please?

[Kris]

9 minutes ago, Ray H said:

 

That's interesting. I do check from time to time to see what the best rate is and I've only ever found it to be around 12p.

 

Ours is a fairly recently installed system so not able to profit from some of the early government schemes.

 

Would you mind telling me your provider please?

We use intelligent octopus flux. Like you we have not had our system for very long (just over a year) so we also don't get any feed in tariff options that the earliest adapters got. 

 

This link will take you to the tariff and if you sign up I believe that both you and I would get £50 providing you stay with them for a certain length of time. 

 

https://share.octopus.energy/rainy-goat-5

 

This screenshot shows you the current tariff that we get. Yours might be a little different as they do vary a little by area. 

 

 

This link shows you the initial rates you can sign up for. Still seems better that your 12p per unit. 

 

https://octopus.energy/smart/outgoing/

 

 

[Ray H]

That looks very interesting.

 

Our system was initiated by & with a company that decided during the fuel crisis that they didn't wish to be a "supplier" any more and we were transferred to British Gas. A bit of research revealed that Scottish Power offered a better price for electricity exported from the panels so we swapped over to them. It took us over a year to get our first payment and we have to read our meter and pass that reading on to them. Power exported from the battery is still handled by the original company and, to be honest, I don't know what rate we get.

 

I check to see what penalties I'll have to pay to switch from our present supplier.

 

Thank you.

[PatB]

Perhaps not entirely relevant on a UK oriented forum, but my own rough figures, overall, after 6 years from an 8.8 kW system amount to:

 

Initial installation $4800

Maintenance so far $0

Energy costs saved ~$4000

Export income ~$2900

So overall "profit" ~$2100, or $350 pa.

 

Obviously, annual return will increase as the initial installation cost is amortised over a longer period.

 

We're not typical though. We run a big electric kiln which chews up roughly 100kWh per firing, which usually happens weekly. Normally that's overnight on cheap energy, but often spills over into the following morning, so everything off the roof goes into it for a few hours.

 

I'm also not sure how things will look longer term. We went over to all electric heating a couple of years ago (along with air-conditioning for summer), which will have increased our imports and reduced our exports somewhat. We've also gone to electric water heating (6 months ago) and are treating the tank as a thermal battery, running it on a timer only during peak solar generation hours. That too will have reduced our exports but shouldn't increase our imports very much, if at all.

 

Generation averages about 12kWh/day at this time of year and double that (or a bit more) in high summer. It's currently putting out about 3.4 kW on a sunny winter day with some light cloud around. Which reminds me. I'd better go and put a wash on.

[hayfield]

17 hours ago, Kris said:

We use intelligent octopus flux. Like you we have not had our system for very long (just over a year) so we also don't get any feed in tariff options that the earliest adapters got. 

 

This link will take you to the tariff and if you sign up I believe that both you and I would get £50 providing you stay with them for a certain length of time. 

 

https://share.octopus.energy/rainy-goat-5

 

This screenshot shows you the current tariff that we get. Yours might be a little different as they do vary a little by area. 

 

 

This link shows you the initial rates you can sign up for. Still seems better that your 12p per unit. 

 

https://octopus.energy/smart/outgoing/

 

 

 

 

I am with Octopus so I will explore whether this rate is wort it for us