The University of Southampton has produced a useful app that tells us the carbon intensity and real time production of different sources of electricity, see http://www.gridcarbon.uk/
Unsurprisingly, the carbon intensity per kWh falls with consumption, as baseload nuclear becomes a bigger proportion of generation at night.
Where does this leave the Wadebridge Sunshine Tariff experiment? For the sixty households involved, electricity is very cheap during summer daylight hours - this is to encourage use when solar PV is generating. But for much of that time, the sun is not shining in Cornwall, and people are being subsidised to use dirty coal and gas electricity.
What's my advice?
For non time-sensitive appliances:
- Use electricity when the sun is shining in summer
- Use electricity from midnight to 7am all year round
- Don't use much electricity between 3 and 8pm in winter