How do you guys keep track of ROI on your panels / battery?

Raxiel

Mikeyboy01443 said:

Reading some peoples replies on here, does anyone do anything now without running it through a spreadsheet first? Is everyone a bean counter now? Would any of you buy a ferrari just because you want to, even if you would lose money on it?
I know my solar will pay for itself fairly soon so at that point it's moot anyway if you would have been "better off"

I can't speak for the others, but I'm a massive nerd. The spreadsheet is just for fun.

Magnitio

Raxiel said:

Mikeyboy01443 said:

Reading some peoples replies on here, does anyone do anything now without running it through a spreadsheet first? Is everyone a bean counter now? Would any of you buy a ferrari just because you want to, even if you would lose money on it?
I know my solar will pay for itself fairly soon so at that point it's moot anyway if you would have been "better off"

I can't speak for the others, but I'm a massive nerd. The spreadsheet is just for fun.

I spent pretty much all my working life with spreadsheets, so if I had a Ferrari, I would have a spreadsheet for it.

EricMears

Mikeyboy01443 said:

Reading some peoples replies on here, does anyone do anything now without running it through a spreadsheet first? 

Probably not - why would you when the tools are available ?

I've logged fuel consumption for every car I've owned in the last 30 years or more,  usually in a spreadsheet though older ones were less sophisticated.

But for electrical generation & consumption I tend to use an online database rather than a simple spreadsheet.

Mikeyboy01443

EricMears said:

Mikeyboy01443 said:

Reading some peoples replies on here, does anyone do anything now without running it through a spreadsheet first? 

Probably not - why would you when the tools are available ?

I've logged fuel consumption for every car I've owned in the last 30 years or more,  usually in a spreadsheet though older ones were less sophisticated.

But for electrical generation & consumption I tend to use an online database rather than a simple spreadsheet.

Because not every decision is based on a number in a spreadsheet? 
I'm not saying its not worth keeping a track on it of course (i do for various things) but to calculate everything to the Nth degree and then use that to make a decision, well thats just not for me....

Mikeyboy01443

Magnitio said:

Raxiel said:

Mikeyboy01443 said:

Reading some peoples replies on here, does anyone do anything now without running it through a spreadsheet first? Is everyone a bean counter now? Would any of you buy a ferrari just because you want to, even if you would lose money on it?
I know my solar will pay for itself fairly soon so at that point it's moot anyway if you would have been "better off"

I can't speak for the others, but I'm a massive nerd. The spreadsheet is just for fun.

I spent pretty much all my working life with spreadsheets, so if I had a Ferrari, I would have a spreadsheet for it.

And this did make me laugh, sorry for going off topic a bit here...

pensionpawn

Mikeyboy01443 said:

EricMears said:

Mikeyboy01443 said:

Reading some peoples replies on here, does anyone do anything now without running it through a spreadsheet first? 

Probably not - why would you when the tools are available ?

I've logged fuel consumption for every car I've owned in the last 30 years or more,  usually in a spreadsheet though older ones were less sophisticated.

But for electrical generation & consumption I tend to use an online database rather than a simple spreadsheet.

Because not every decision is based on a number in a spreadsheet? 
I'm not saying its not worth keeping a track on it of course (i do for various things) but to calculate everything to the Nth degree and then use that to make a decision, well thats just not for me....

Being a numerate person I also enjoy playing around with spreadsheets. Thinking of buying an EV, spreadsheet, buying a home energy battery, spreadsheet, renovating the kitchen / bathroom, quotes, going on holiday, quotes.... Numbers are integral (pun intended...) to our lives, whether we like it or not. Last October I swapped out my 26 year old Ideal Classic boiler for a new hydrogen ready condensing Viessmann. Solicited a few quotes, did some research on the companies and chose one. Besides having a much better efficiency, I changed because I needed a new boiler, not to reduce cost, although that was a very useful secondary reason. Now, since gas prices have been on the rise with the help of a spreadsheet I have learnt that even a new boiler has a RoI! 

pensionpawn

caprikid1 said:

Hi all, How long does a solar system last and what is the depreciation rate to be used ? 

Every time I see Solar system calcs I seem to see people comparing it to having the money in the bank, reality is these solutions I suspect have no value after 15-20 years.

Has anyone work out the return assuming the install is worthless in say 20 years time ? Would the interest on say £20K sat in the bank now make a solar system savings - depreciation struggle to make sense ?  ]

If I had £20,000 invested at 5% PA I would have £54,000 in 20 years time.

Typical cost of electricity is currently £1700 per annum if prices rise at 5% Year on year (They are high now). 

That would be a total spend of £64,000, so £10,000 worse off if the install cost £20K and the panels and batteries are worthless, how long to the batteries last ?

Anyone got the figures over 20 years as I assume there is positive revenue from the panels every year ? So I guess over 20 years you could be £10K better off ? Obviously no idea of the levels of FIT tarrif either ?

anyone done the 20 year maths ?

Around 10 million years? Lol.... Seriously though 8 years ago I did run the numbers against kicking the solar panels idea into touch and just popping the £10k into my pension. That would immediately increase to £12k5 and then hopefully grow until needed. That said I just had a hunch that we were due another energy crisis and that some level of energy independence in the future would be sensible after retiring. So almost 8 years in this thread has tempted me to revisit the calculation. My scheme is 20 years, so I have 12.5 years of post RoI FiT to enjoy, others more. Generation FiT and metered export are worth approximately £2k pa, so that means I'll be £25k up after 20 years, keeping the maths simple. So what would the pension fund annual growth rate have to be over 20 years on a starting value of £12k5 to match £25k? That works out to be around 3.5% So it's horses for courses. However 20 years is a long time to wait the see the benefit from the pension fund, and 75% of it is liable for tax. By installing solar panels the returns are spread out across the term and are 100% tax free. Solar panels was the right decision for me.

1961Nick

pensionpawn said:

caprikid1 said:

Hi all, How long does a solar system last and what is the depreciation rate to be used ? 

Every time I see Solar system calcs I seem to see people comparing it to having the money in the bank, reality is these solutions I suspect have no value after 15-20 years.

Has anyone work out the return assuming the install is worthless in say 20 years time ? Would the interest on say £20K sat in the bank now make a solar system savings - depreciation struggle to make sense ?  ]

If I had £20,000 invested at 5% PA I would have £54,000 in 20 years time.

Typical cost of electricity is currently £1700 per annum if prices rise at 5% Year on year (They are high now). 

That would be a total spend of £64,000, so £10,000 worse off if the install cost £20K and the panels and batteries are worthless, how long to the batteries last ?

Anyone got the figures over 20 years as I assume there is positive revenue from the panels every year ? So I guess over 20 years you could be £10K better off ? Obviously no idea of the levels of FIT tarrif either ?

anyone done the 20 year maths ?

Around 10 million years? Lol.... Seriously though 8 years ago I did run the numbers against kicking the solar panels idea into touch and just popping the £10k into my pension. That would immediately increase to £12k5 and then hopefully grow until needed. That said I just had a hunch that we were due another energy crisis and that some level of energy independence in the future would be sensible after retiring. So almost 8 years in this thread has tempted me to revisit the calculation. My scheme is 20 years, so I have 12.5 years of post RoI FiT to enjoy, others more. Generation FiT and metered export are worth approximately £2k pa, so that means I'll be £25k up after 20 years, keeping the maths simple. So what would the pension fund annual growth rate have to be over 20 years on a starting value of £12k5 to match £25k? That works out to be around 3.5% So it's horses for courses. However 20 years is a long time to wait the see the benefit from the pension fund, and 75% of it is liable for tax. By installing solar panels the returns are spread out across the term and are 100% tax free. Solar panels was the right decision for me.

The tax element if often overlooked & really shouldn't be especially for a higher rate tax payer.

arty688

If you are looking at PV in purely in money terms can be complicated as you need to consider how much you could of earned investing that money or how much interest you are paying if you loaned the money.

Also ROI usually means return on investment not return of investment.

so you spend £15k on solar and save £1.5k the ROI is 10%

Once installed the value of the equpment is i would say written off as probably not worth much second had as removing it would cost a fair amount.

The other unknown is how much it has added to the value of the house.

I did start of trying to calculate if it was worth it in money terms but in the end I just gave up and as the money was spent so am happy with just monitorng the generation these days.

What I do do is make sure I'm on the right tariff to save me as much money as I can which I think is more important. Just swopped to EON next drive as much cheaper for me than Octopus.

ecraig

arty688 said:

If you are looking at PV in purely in money terms can be complicated as you need to consider how much you could of earned investing that money or how much interest you are paying if you loaned the money.

Also ROI usually means return on investment not return of investment.

so you spend £15k on solar and save £1.5k the ROI is 10%

Once installed the value of the equpment is i would say written off as probably not worth much second had as removing it would cost a fair amount.

The other unknown is how much it has added to the value of the house.

I did start of trying to calculate if it was worth it in money terms but in the end I just gave up and as the money was spent so am happy with just monitorng the generation these days.

What I do do is make sure I'm on the right tariff to save me as much money as I can which I think is more important. Just swopped to EON next drive as much cheaper for me than Octopus.

9.5p off peak charging + 16p export on eon is currently looking quite attractive…