Paul Vixie wrote:
aside from the corrosive nature of the salt and other minerals, there is an unbelievable maze of permits from various layers of government since there's a protected marshland as well as habitat restoration within a few miles. i think it's safe to say that Sun Quentin could not be built under current rules.
The ones I have are MDPE (Medium Density Polyethylene) and I haven't understood that the plastic would have corrosive features. Obviously it can come down to regulation depending on what you use as a cooling agent but water is very effective if there is no fear of freezing (I use ethanol for that reason). The whole system is closed circuit, I'm not pumping water out of the ground but circulating the ethanol in the vertical ground piping of approximately 360 meters. The amount of slurry that came out of the hole was in order of 5-6 cubic meters. Cannot remember exactly what the individual parts cost but the total investment was less than $10k. (drilling, piping, circulation, air chiller, fluids, etc.) for a system with somewhat over 4kW of cooling capacity. (I'm limited by the airflow, not by the ground hole if the calculations prove correct) Pete