Ground source heat pump problems

[MR C A LYNCH]

I am involved in a project with design stage SBEM calculations that relied on gas powered ground source heat pumps delivering a seasonal performance of 4. The client decided not to have gas brought to site and the SBEM targets look difficult to meet now and we're half way through. Does anyone have any good ideas that don't cost much to help us out?

[David OLIVIER]

I can't see how gas heat pumps can easily give a COP of 4.

It's hard enough with elec ones in which the elec is generated from gas in CCGT power plants at only about 40% overall efficiency (generation and distribution losses, HCV.)