I spent some time talking to someone the other day who considered my attitude to ground source heat pumps maddening. They were concerned mostly with the “green” angle. In most circumstances on cost grounds it can easily be shown that they make little sense unless you are using the most expensive form of heating, for example electricity or bottled gas, see below chart. A plumber friend , field trained by Worcester Bosch, thought them justifiable with fairly expensive LPG, but still the numbers just do not stack up.




For those who do not know if you put one unit (1kWh) of electrical energy into a ground source heat pump, you will be able to get 4 kWh of heat out of the ground. This is absolutely true, BUT the electrical energy used to power the pump costs 4 times the gas energy you might ordinarily heat your house with, so what have you gained? If you consider that they cost £12,000, or $20,000 to install, then you are unlikely to pay back the investment, ever! If you are electrically heated however they are worth it.

There is a “green angle” to this technology. You would be forgiven for thinking that by using a ground source heat pump you will emit 4 times less CO2 with this technology, but this is also untrue. The bigger picture has to be considered. This would only be true if your electrical power were 100% generated by non carbon emitting power stations, and this is certainly not the case. In fact by using a ground source heat pump you will emit about 2.2 times less CO2, which is environmentally good, but can you afford the investment and the slow payback.

I think the Grants from government need to be much better to help us financially justify installing this technology.