The only space I have available to pick up ground sourced heat is 14m x
2m which sounds too small to be of use with a conventional ground pipe array. Any rough ideas how many bore holes of what depth might be needed to recover 8Kw or so. I think my ground is surface gravel with clay beneath. We are on top of a hill but the playing field opposite floods in winter so possibly we have quite wet soil at eh time of year the heating will be needed.Any rough ideas of boring cost would be useful too.
TIA
Bob