Thank you for the numbers, it gives a good inside view of the actual costs/profits of solar. I've only one small comment on the Payback Period. You didn;t adjust the payback period for the cost's of the investment! When you took a loan for the installation costs you've to pay interest on it, otherwise the 12.400 could be invested in anything. Suppose you'd bought 7.453 ounces of gold at Aug. 22 instead of investing in solar your current value would be 15.697. So you should correct the spreadsheet with a missed or paid interest, at least about 4% anually.
Hi, Thanks for the feedback. You raise a great point i.e. accounting for the 'lost opportunity cost'. Although I'd personally argue that buying gold is more speculation than investing, I wouldn't have minded grabbing some of the price rise that has occurred in the last few months ... But your general point is quite valid. In our case we were lucky enough not to have to take a loan to pay for the solar, but even so, we still 'lost' interest on that money had it stayed in a savings account, or been invested in stocks & shares. I think the problem is that - AFAIK - there is no standard payback model used throughout the solar industry, so some will account for lost interest and some won't, and thus it becomes difficult/impossible to compare. The spreadsheet wasn't mine, and I haven't had chance to look at any of the others on Gary's list, so for now I'd quite happily accept that the stated payback period should come with the caveat "Does not take account of lost interest". Cheers, Chris
thank you for sharing, doing my homework on solar and this is very useful. Here's hoping 2025 is a lot sunnier !
Cheers. Glad you found it helpful.
Thank you for the numbers, it gives a good inside view of the actual costs/profits of solar. I've only one small comment on the Payback Period.
You didn;t adjust the payback period for the cost's of the investment! When you took a loan for the installation costs you've to pay interest on it, otherwise the 12.400 could be invested in anything. Suppose you'd bought 7.453 ounces of gold at Aug. 22 instead of investing in solar your current value would be 15.697. So you should correct the spreadsheet with a missed or paid interest, at least about 4% anually.
Hi, Thanks for the feedback. You raise a great point i.e. accounting for the 'lost opportunity cost'. Although I'd personally argue that buying gold is more speculation than investing, I wouldn't have minded grabbing some of the price rise that has occurred in the last few months ... But your general point is quite valid. In our case we were lucky enough not to have to take a loan to pay for the solar, but even so, we still 'lost' interest on that money had it stayed in a savings account, or been invested in stocks & shares. I think the problem is that - AFAIK - there is no standard payback model used throughout the solar industry, so some will account for lost interest and some won't, and thus it becomes difficult/impossible to compare. The spreadsheet wasn't mine, and I haven't had chance to look at any of the others on Gary's list, so for now I'd quite happily accept that the stated payback period should come with the caveat "Does not take account of lost interest". Cheers, Chris