Comment on Price of electricity in Finland peaks at 2.35€/kWh today. Keeping my tiny granny cottage warm costs me over 50 euros for a single day. It's negative 25C (77F) outside.

• Critical_Insight@feddit.uk ⁨10⁩ ⁨months⁩ ago

  Those batteries would never pay themselves back.

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  • HeartyBeast@kbin.social ⁨10⁩ ⁨months⁩ ago

    I'm in the UK on an agile tariff and I'm not quite so sure - it depends on a number of things. Sure my batteries were bought primarily to support my solar panels. but I've been making quite a lot of money this winter.

    1. There are times when it is windy and there is low demand, when prices actually go negative - fill your batteries and make money
    2. The differential between lowest and highest price per kWh is often 30p so filling up when it is 10p and using when it is 45p makes sense.
    3. The grid will sometimes pay you large amounts of money with a few hours notice that they will pay you a premium to discharge your batteries when demand is predicted to be extremely high - to avoid them cranking up coal power stations. In November and December I made £90 just from this - and I only have 5Kwh batteries.

    I haven't run the figures on payback times if the batteries were just for shifting and not solar - but they might just pay themselves back.

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    • red@sopuli.xyz ⁨10⁩ ⁨months⁩ ago

      The math has been done multiple times. The batteries don’t pay themselves back, and also need to be replaced from time to time.

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      • HeartyBeast@kbin.social ⁨10⁩ ⁨months⁩ ago

        Sure. But the math depends on electricity tariffs. And those change and therefore, so does the maths. it sounds like tariffs are pretty extreme currently

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      • psud@lemmy.world ⁨10⁩ ⁨months⁩ ago

        Batteries on a plan like that, where they’re part of a large virtual battery, do pay for themselves within warranty

        Solar batteries never do. To rationally buy a battery one needs to put high value on backup power

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