Solar - real-life experience of investment vs return

Martyn1981

roadweary said:

Reed_Richards said:

roadweary said:
... it's really our super high usage in the winter where I think the solar panels....and possibly the batteries too would come into their own.  

Lots of people think this when first contemplating getting solar panels but it's completely wrong.  Think about why it's cold in winter.  It's because we have short days with weak sunshine.  There isn't much solar energy to warm things up and there isn't much solar energy for your panels.  So you'll get the least electricity when you need it the most.

So based on the majority of my usage being in the winter months, isn't that massively reducing the likelihood of solar being a viable option for me in terms of ROI?

Hiya. Yes and no. If you think of the solar purely as a way of reducing winter costs, then yes, in Northern climes it will have a very low ROI. But if you consider the wider role of PV (as Nick has laid out), then it works fine, and will help a bit with winter costs, but the biggest gains will be outside of the winter.

Reed_Richards

1961Nick said:

 The good news is that you can get 15p/kWh for your export which helps the ROI.

But the bad news is that only one company, Octopus, pays 15p per kWh and all the rest don't come close.  If electricity prices ever fall in future then it's very likely this amount will fall too, so that would be a double whammy for your ROI.    

Alnat1

With decent Octopus rates, you can earn from your summer export to help cover the winter bills. 

Having the solar PV also tends to focus your mind on energy saving in general and you'll find many other small ways to use less.

ispookie666

I had a smart meter installed just before solar panels went up.  My Total(Day and Night) reading is 2100 for 11 months, I have had solar only for 6 months and batteries + solar for 5 months.  Our Electric consumption is on the uptrend as we have moved to use an A2A Heat pump to heat instead of Oil.  Total consumption is a pain to work out.  

System size - 6.6 KWh, multi-roof with significant shading 
Generation - 5295 KWh 
Consumption - 4402KWh 
Total Import - 2100KWh ()
Total Export - 2233KWh (I'm hoping this will be coming down due to the battery, the majority of the export was before the batteries went up/offline)
iBoost - 760KWh 

Estimating around £900 saving this year as roughly 350 of that is coming from buying electricity at cheap rate.  I'm not sure I'll break even but having had Solar in my previous house (2015) it was a no-brainer for me.  The only niggle was not having a battery and managed to fix it this time.  

Martyn1981

Reed_Richards said:

1961Nick said:

 The good news is that you can get 15p/kWh for your export which helps the ROI.

But the bad news is that only one company, Octopus, pays 15p per kWh and all the rest don't come close.  If electricity prices ever fall in future then it's very likely this amount will fall too, so that would be a double whammy for your ROI.    

But a reduction in your imported leccy costs. So as a whole things are good, with the PV working as a hedge.

But, yes if leccy costs fall fast and soon, then the higher PV and battery costs we are currently seeing would mean a longer time for ROI. But I can't see a swift reversal now. It was possible at the start of the invasion of Ukraine, but now it would be foolish for Europe to drop sanctions on Russian FF's until an acceptable peace is achieved, and possibly reperations are paid to Ukraine, so that's going to be years.

The alternative is to reduce European gas demand by an amount equivalent to the Russia contribution (30%?) to get supply and demand back in balance, which will also takes years, perhaps 5(?) as we see an acceleration of RE, energy efficiency focus, and heatpumps.

Not sure this works, but perhaps a way of looking at the current higher install prices, is to think of the early and higher savings costs as repaying that 'extra' cost, then in the medium to long term, the ROI of the PV against lower leccy prices is back to normal?


Edit - Or I'm talking absolute BS, and prices will fall sooner and faster. Doh!

European gas prices fall to pre-Ukraine war level

Exiled_Tyke

Apologies if this has been said before on this thread but just wanted to make sure.   On the subject of batteries:

1. Getting them with the PV install is a lot cheaper because there is VAT saving which you don't get if you add them later.

2. If you are eligible for a cheap night time tariff then the battery can provide benefit in Winter.  I'm currently generating around 1kWh a day (East and West system with  a very shallow pitch on some panels) but I import around 5kWh each night at 7.5p a unit.   Having that tariff also means that I can time the dishwasher and washing machine for the cheap electricy too.

3. During the shoulder months I often found it difficult to time my major appliances to the times of maximum sun and I seemed to always put one of them on just as clouds came over. Not having to play that game anymore while still getting maximum benefit from the PV is a big big plus for me.   In summer I pay for very little  electricity. May be the odd kWh or so each day.

I didn't expect my battery to realisitically pay for itself but at current rates it is doing very well.   I wouldn't necessarily recommend a battery as a good investment but more as a hedge against electricity prices. 

new_owner

I am on the other fence. 

My current batteries without solar, for me they are looking to have a payback of 3 years using an off-peak tariff (at current prices - I suspect this will be even shorter in 2023. I am now looking to add another two inverters and more batteries to run the planned heat pump with the idea of running my heating completely from batteries.

The issue I have found is that solar would only give me a saving of around £60 per month in the middle of summer and the payback would be so long, to not make it worth while. This is because I am using batteries first and so have to base the return off my off-peak rate.

This might change in the future but at this point batteries without solar make perfect sense for me.

1961Nick

Martyn1981 said:

Reed_Richards said:

1961Nick said:

 The good news is that you can get 15p/kWh for your export which helps the ROI.

But the bad news is that only one company, Octopus, pays 15p per kWh and all the rest don't come close.  If electricity prices ever fall in future then it's very likely this amount will fall too, so that would be a double whammy for your ROI.    

But a reduction in your imported leccy costs. So as a whole things are good, with the PV working as a hedge.

But, yes if leccy costs fall fast and soon, then the higher PV and battery costs we are currently seeing would mean a longer time for ROI. But I can't see a swift reversal now. It was possible at the start of the invasion of Ukraine, but now it would be foolish for Europe to drop sanctions on Russian FF's until an acceptable peace is achieved, and possibly reperations are paid to Ukraine, so that's going to be years.

The alternative is to reduce European gas demand by an amount equivalent to the Russia contribution (30%?) to get supply and demand back in balance, which will also takes years, perhaps 5(?) as we see an acceleration of RE, energy efficiency focus, and heatpumps.

Not sure this works, but perhaps a way of looking at the current higher install prices, is to think of the early and higher savings costs as repaying that 'extra' cost, then in the medium to long term, the ROI of the PV against lower leccy prices is back to normal?


Edit - Or I'm talking absolute BS, and prices will fall sooner and faster. Doh!

European gas prices fall to pre-Ukraine war level

I think what we're seeing at the moment is a falling demand for LNG due to Chinese lockdowns followed by rapid infections when restrictions were relaxed. China should have 2 big Covid spikes before summer after which the population will have immunity levels matching the rest of the world. Once economic activity returns to normal in autumn, demand for LNG will accelerate just as Europe is looking to fill up storage. The combination of those two things is likely to put significant upward pressure on gas prices after a relatively cheap summer.

Any reduction in wholesale energy costs in the UK will obviously reduce the Government's energy subsidy first before it feeds down to the consumer.

silverwhistle

I wouldn't assume too high a price per kwh to justify any investment. If you look at the half hour variable price tariffs you will see that at times recently that they have been negative (they pay you!) and whilst this has only been over the holiday period there will be another 2.5GW (? from memory) of more wind installed in the UK by next winter and more to come in the subsequent years. The same in Europe with similar impacts. All of this will reduce the impact of expensive gas on the price of electricity as its use declines. There doesn't appear to be a great shortage of LNG on the free market but the uncertainty has boosted the price as has the availability of gasification (e.g. Freeport in the US) and de-gasification (in Europe).

If you can justify your investment with lower electricity prices then so much the better!

Spies

My system has generated 3307kWh over the year, of which I used 42% of it (no battery).

I 'saved' £361 vs importing that same energy from the grid and earned £457 from SEG.

This leaves 5 years before I 'break even' assuming that prices stay the same but we are going to be looking at moving house before then most likely.

If we do, the new house will need to have panels and a battery installed from day one.

As others have said in the past, treat it as more of a home improvement rather than trying to justify it based on payback period, you don't buy new windows and then work out when they will payback for themselves do you?