That massive spike of 50c/kWh at the left looks tiny compared to today even though that’s already insanely expensive
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.
- There are times when it is windy and there is low demand, when prices actually go negative - fill your batteries and make money
- 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.
- 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.
The math has been done multiple times. The batteries don’t pay themselves back, and also need to be replaced from time to time.
Is that actually a widespread practice anywhere? I’m in Switzerland and I don’t think I’ve seen that anywhere (other than in one farm near me which is entirely covered in solar panels)
In the UK domestic solar panels are quite common and new installations usually come with batteries. Agile 30-minute pricing tariffs are still new and fairly experimental, but people are rapidly realising that their batteries can be really useful when used to force charge/discharge based on grid demand. Octopus is probably the leader: https://octopus.energy/blog/agile-pricing-explained/
I live in the northeast US and we looked into batteries. Unless you’re rolling your own and have a very specific home/garage layout installing them is really difficult. They have to be outside the living space, away from flamingo wall coatings and windows. And they need to be relatively climate controlled (not great in direct sunlight or frigid temps).
Until we start designing battery systems that can mount outside (away from the house, like propane tanks) within their own heat pumps to manage temps built in, it’s not going to be popular in climates like ours (which are very similar to Swiss and lower scandawegian climates).
They should probably be bigger metal boxes with sodium flow batteries and heat pumps, like we have now for utility boxes in some places. They could incorporate the smart/net meters required to pump back into the grid too.
