Our solar battery wasn't a great financial choice: although it yields some savings, the steep upfront cost means that it will probably never break even. Recently, however, I found out that the Pylontech US2000C modules that it's made up of have come down in price quite significantly - I could add 2.4 kWh of battery capacity for a little under £500. That's about a third of the price of the originals, which feels like an absolute bargain. Such a significant reduction in price would mean that a new module would break even much sooner. After that, any savings that it...