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Here [0] is a lead-acid storage battery, UK price £90 ($135) for 1.26kWh. That is $107/kWh. You do not use the whole 1.26kWh each cycle - you only want to use

Here [0] is a lead-acid storage battery, UK price £90 ($135) for 1.26kWh. That is $107/kWh. You do not use the whole 1.26kWh each cycle - you only want to use e.g. 50% of that, so that you get reasonable battery life (fully discharge your lead-acid batteries, and you won't have any electrodes left). So $208/kWh might be the 'actually usable' value. The harder number to find is battery lifetime - it depends on many factors (discharge depth, number of cycles per year, storage temperature, exact battery type, etc). And when you are doing cost-benefit analysis, this number is a vital part of your calculations. You also want to know 'if I wait x years, will the price of Tesla batteries have dropped so much that I would be better holding cash now, and buying Tesla batteries in the future). This headline number is not the total cost of course, you need charge controller, inverter, building to house the batteries, etc. [0] http://www.bimblesolar.com/27DC105-105AH-12V?search=battery http://www.bimblesolar.com/27DC105-105AH-12V?search=battery

ptaipale 11y ago
BTW that £90 clearly includes VAT, but is the VAT on home battery systems in UK 20 % or 5 %? Domestic fuel is 5% but that doesn't necessarily mean that the same reduced rate applies to replacement energy devices?
- bainsfather 11y ago
  For ballpark numbers, I am not worrying about 15%. e.g. will your batteries last 10yrs, 20yrs, or more, is a bigger unknown. But to try answering your question, here [0] the UK govt says it is 5% for battery banks for wind power, and for hydro power. Solar is not mentioned, my guess would be that the rate on the battery we are discussing is 5%. [0] https://www.gov.uk/government/publications/vat-notice-7086-energy-saving-materials/vat-notice-7086-energy-saving-materials https://www.gov.uk/government/publications/vat-notice-7086-e...
  - ptaipale 11y ago
    Yes, this is not at all relevant for ballpark numbers, I was just interested whether the VAT rules appreciate the fact that these batteries are for alternative energy and not just generic consumer goods. I'm afraid my country (Finland) taxes them with 24 % VAT just like almost everything else.

ptaipale 11y ago

BTW that £90 clearly includes VAT, but is the VAT on home battery systems in UK 20 % or 5 %? Domestic fuel is 5% but that doesn't necessarily mean that the same reduced rate applies to replacement energy devices?

bainsfather 11y ago
For ballpark numbers, I am not worrying about 15%. e.g. will your batteries last 10yrs, 20yrs, or more, is a bigger unknown. But to try answering your question, here [0] the UK govt says it is 5% for battery banks for wind power, and for hydro power. Solar is not mentioned, my guess would be that the rate on the battery we are discussing is 5%. [0] https://www.gov.uk/government/publications/vat-notice-7086-energy-saving-materials/vat-notice-7086-energy-saving-materials https://www.gov.uk/government/publications/vat-notice-7086-e...
- ptaipale 11y ago
  Yes, this is not at all relevant for ballpark numbers, I was just interested whether the VAT rules appreciate the fact that these batteries are for alternative energy and not just generic consumer goods. I'm afraid my country (Finland) taxes them with 24 % VAT just like almost everything else.