If anyones thinking of getting a heatpump its worth considering that RHI's will be along soon and heatpumps are included.
Get an approved heatpump with a certified installation (

) and you could be onto a nice little earner.
Looks like being paid around 9p a unit heat out.
COP of 3 then could presumably mean spend 10p a unit to run it get paid 27p for using it!
RHIs could well change the landscape for heatpumps dramatically.
Possibly the additional expense of a certified install will make it all a bit of a gamble until the details are finalised though.
ps. RHI = Renewable Heat Incentive, a scheme by which you can be paid for the heat you produce provided its from an approved source.
http://www.decc.gov.uk/en/content/cms/what_we_do/uk_supply/energy_mix/renewable/policy/renewable_heat/incentive/incentive.aspx