It’s μCHP’s turn. So the prime reason to use μCHP is not to generate electricity, but to generate heat. That’s right, it’s a boiler. But it’s a boiler that generates electricity, how cool! So what happens when it’s not cold, you turn the boiler off, and off goes the electricity as well. So you need a grid, and when you turn your boiler off, you are as efficient as the grid.

The fact that you are connected to the grid however is quite useful, because it means that if in course of generating enough heat for your house you generated too much electricity, it’s won’t go to waste. You just pump it into the grid and maybe make some money out of it.

So the efficiency here really comes from generating electricity as you generate heat and not the other way round, as in normal large CHPs. So μCHPs are useless in the summer (just like your boiler). Again the massive efficiency goes down the drain. It’s still better than those old central massive power plants though, so don’t get me wrong.

There are two problems I can think of right now about μCHP. First the poor people at the massive power plant. Not only are they being attacked for something that’s not their fault, (the fact that they have to dump 2/3 of the energy into the sea to give us 1/3, in reality the numbers are better, but still) but now they have to be ready to offset any electricity coming out of our μCHPs in case we feel like switching it off. Because they can’t control us, and we don’t have to even tell them when we are switching off our boilers, no one knows how much μCHP electricity there will be at any one time to count on. So they should always have backup capacity installed, and they have to be very responsive to our whims. Sounds very expensive and difficult.

This is not a big deal if there are a few units installed here and there, but it could be an issue if you have them everywhere.

Second problem, how much money do you give the people for their electricity. Give me too much money and I will have my heating on all the time. Hey you’re the one who’s paying me to heat my house. In summer, I’ll just open all the windows. The cash is worth it. Pay me too little and I won’t care. Why would I pay more for a fancy boiler and then donate my electricity to you. No thank you, I think I will stick with the old system.

So frankly, if you have the right policy in place you will find that indeed μCHPs are useful. But of course they are no where near as useful as some (Greenpeace) want us to believe. No they won’t save the world, but they’ll help bring us one step closer.