Electricity needs when the grids down.

[Lightspeed]

Hi Pete,

You're exactly right. Plan minimal consumption needs and scale PV array based on mid winter predicted output.

For me, a 3Kw array will be fractionally short of the 200w/h that my furnace and CH system will draw in mid-winter.

We're working on this basis as in the here and now, we'll be able to meet the shortfall from mains / backup generator. If a long term crisis were to unfold, the furnace and CH system would be shut down in order to conserve fuel, leaving a useful minimum 2.4kW/hr per day of off grid power.

Highlander's excellent real world advice a few years ago, was that in summer used excess generated power through time switches ( on while daylight and generating, off overnight) to feed immersion heaters, fridges and freezers etc. This uses self-generated power to directly replace mains consumption.