As we use more and more computers, power, or rather producing it, is becoming a big issue, with environmental and political angles, but more critically simple physical and mathematical ones.

I know in the US, West Coast especially, brownouts and power cuts are becoming quite common. We're not quite there yet in the UK, but there are rumours and issues bubbling up about where exactly we are going to get all the power we are demanding here in the UK.

Years ago, in New Scientist, I came across the idea of Combined Heat and Power (CHP) Boilers. These work pretty much like the boilers we have in nearly all homes here in the UK, and use Natural Gas to heat water which we use in our baths and showers and which provide the necessary hot water for our central heating system. I'm no expert on US heating systems, but I suspect the same basic idea is used in American homes.