Closed loop geothermal wellfield sizing

[fengyuanfei]

Hi there, I was wondering if there was a limit to how big one can plan a closed loop geothermal wellfield used for heating and cooling,i.e. will the wells in the center become useless at some point if too many others are around it? I am talking a wellfield of perhaps 2,000 wells. Has a wellfield that size been built in North America and where?
Thanks

 

[EnergyProfessional]

rule of thumb is to space them at least 20'. Obviously if the field is that large and a square, you may go wider. You really should hire someone with lot of experience in geothermal and the proper simulation software for such a large system.

typically we do test-wells to determine the heat transfer coefficient based on soil values. for such field you may need multiple test wells (you can use the test wells as normal wells, so if you go through with the project it is not much more cost.