I received a quote from the geothermal installer saying I need a 4 ton unit, 4 vertical wells (200 ft each), 2 circulator pumps @ 400 W each etc. So both pumps would be using 800 W while the geothermal unit would be using 2400W.

I asked the installer if it is possible to drill 8 wells @ 100 feet each which should require much less pumping power.

He said its hard to balance 8 wells connected in parallel.

If the loops are the same length I don't see a problem with balancing.

Another question, regarding the COP. Is there any theoretical limit for COP and how close are the manufacturers to reaching that limit? That is another important factor to consider . In the last 10 years COP have doubled. If they could double them in the next 10 years geothermal definitely will be much better than the natural gas or oil