Old Solar Panels - is it worth getting a battery now?

mickyduck55

Reed_Richards said:

How do you make sure that your panels and your separate AC-coupled battery don't end up exporting more than the 3.68 kW most of us are limited to?

If that is a question for me.. I never export from my battery, I don't know that if I did it would exceed 3.68.

Exiled_Tyke

Before costs started soaring and using an electricity price of 15p per kWh I calculated that the 'raw' return on my battery was around 5%.  However at current electricity prices it's coming in at around 18%.  

Hexane

EricMears said:

Heedtheadvice said: There are probably few people who are not very glad they installed solar years ago when Which? the consumers association urged caution for financial reasons.

No idea why the CA were advising caution ! 

On this topic, as apparently on some other topics, the Consumers' Association has a tendency to produce poorly-researched clickbait garbage.

QrizB

Reed_Richards said:

How do you make sure that your panels and your separate AC-coupled battery don't end up exporting more than the 3.68 kW most of us are limited to?

Usually you don't, you (or your installer) make a G99 application.

Heedtheadvice

The caution was by comparing the capital expenditure on solar (and the returns that could be expected on the FIT system) with what could be reasonably expected from an investment both capital and 'income'.

Purely from memory I think there was not much in it financially -better investment return over the long term and a possibly smaller return and a cost to replace the inverter but some guarantee on the returns.

I think what swung it was that the capital was tied up after solar purchase but was able to be realised from investment so it was a balance of the two.

Markets and costs have certainly changed along the way and some of the population put their money into solar (yipee). I am happy I did but investments have certainly been significantly better even after recent falls. I too am happy with a return of capital (not any growth I might add) after 7 to 8 years and the prospect of another 14 or so as return on investment.

Green credentials have a big value in my book for me and my family and the future.

ispookie666

I always find the ROI fascinating when it comes to solar or batteries. No one talks about this for any other home improvements or transport improvements. 

Exiled_Tyke

Heedtheadvice said:

The caution was by comparing the capital expenditure on solar (and the returns that could be expected on the FIT system) with what could be reasonably expected from an investment both capital and 'income'.

This is accounted for with an Internal Rate of Return calculation (IRR). I didn't share this as I thought it would not be of interest. Using my numbers above it is still pretty high (17%).  With the pre-crisis numbers the IRR obviously comes out a lot lower and the investment decision is less clear. 

jimjames

Exiled_Tyke said:

Before costs started soaring and using an electricity price of 15p per kWh I calculated that the 'raw' return on my battery was around 5%.  However at current electricity prices it's coming in at around 18%.  

If the reports of an energy cap being implemented and then repaid via bills over 10 years or more then it's likely that bills will be higher for longer which I suppose will help the ROI for batteries.

Exiled_Tyke

ispookie666 said:

I always find the ROI fascinating when it comes to solar or batteries. No one talks about this for any other home improvements or transport improvements. 

True but most other home improvements aren't done for financial return (or at least shouldn't be) but to meet another need or pleasure.   Public sector transport improvements are subject to a business case employing The Five Case Model. This has to show that benefits outweigh costs.  These include intangible costs (e.g. disruption during construction) which are quantified using treasury guidance.  

QrizB

ispookie666 said:

I always find the ROI fascinating when it comes to solar or batteries. No one talks about this for any other home improvements or transport improvements. 

I'm sure I wrote a reply to this but I can't see it anywhere so I'll try to remember what I said!

Most home improvements - replacing a kitchen, adding a conservatory, doing some landscaping, even replacing a broken boiler - improve the livability of your home in some way, and have a direct impact on your quality of life. They might also increase the value of your home (although this benefit is only realised when you sell up and move out).

Bolting an electrical generation plant to your roof has no direct effect on either livability or life quality. It might even make your home uglier and more difficult to sell (depending on market forces and other factors). I doubt that many people would fit one without some sort of financial incentive. This is where ROI comes into it.

ROI is also commonly discussed for other home improvements like boiler replacements, and has started coming into the equation with white goods (there have been several posters on the main Energy forum who have replaced old-but-functional fridges & freezers with new ones principally for the reduced energy use, with payback periods of 2-3 years).

Exiled_Tyke said:

This is accounted for with an Internal Rate of Return calculation (IRR). I didn't share this as I thought it would not be of interest. Using my numbers above it is still pretty high (17%).  With the pre-crisis numbers the IRR obviously comes out a lot lower and the investment decision is less clear. 

I plugged some numbers into Excel and my FIT gave a 25-year IRR of 15% or so even without considering the saving in electricity use. I was quite surprised (and want to check my calcs again).