Heating when the power is off.

[Joe]

So we are faced with the potential of 3hr long power cuts, unlikely but just in case it's worth planning for. Afterall the grid will be maxed out with all the electric cars.
I think I might have a very simple method of providing heating. My central heating boiler transfers water to a storage tank upstairs, this tank is very well insulated and behind a wooden panel in the cupboard but if the door is left open and the panel plus insulating jacket removed it can heat the area for a while, it's a bit like a giant radiator with lots of water.
This is a very cheap option if you just want to provide a few degrees for a few hours.
(It's worth pointing out the central heating won't work without mains power driving the pump.)