http://bentasker.i2p/posts/blog/house-stuff/correcting-my-battery-saving-grid-charge-calculations.html
Without this credit, the calculations effectively levy an opportunity cost of £0.15 on each kilo-watt hour charged from the grid which, as we saw in my earlier post, does not lead to a happy result: (Red line is where I first enabled grid charging) Finding The Bug The earlier results, whilst unwelcome, are unfortunately quite plausible: Buying electricity from the grid in the hopes that we can consume at a higher equivalent value is a gamble - it's betting that enough of the energy will be...