Letters

The article about the Suffolk County Water Authority targeting geothermal systems [“Water Usage, Limited Leaf Blowing And An ER For East Hampton,” 27east.com, November 11] may lead readers to an inaccurate understanding of geothermal systems and which kind is good and which kind is bad.

A well-designed geothermal system has no negative impact on SCWA’s wells or infrastructure, or on groundwater. Instead, it is an extremely efficient way to heat and cool a home while radically reducing emissions and climate change.

Some people hook up their geothermal systems in an “open” loop format to SCWA’s public water to supply the water to the geothermal system. This does burden SCWA’s wells/infrastructure, is a bad design and should not be allowed.

However, it is important to note that in this design, 100 percent of the water taken from SCWA is deposited back into the ground through a “return” well on the property. Thus, while the use of SCWA’s water should be forbidden, it is not because it “consumes” groundwater. It is because it puts an unnecessary burden on SCWA to supply and deliver that water.

There is a second type of “open loop,” where a supply and a return well are located next to the home, and where 100 percent of the water taken up from the supply well is returned into a return well. This type of “open loop” has no negative impact on SCWA, as it does not involve them in any way.

This design also has no negative impact on groundwater. This type of “open loop” is a valid and environmentally responsible way to design and run a geothermal system and should not be restricted.

Another valid approach is to use a “closed loop” system, where a continuous fully closed loop of liquid flows from the geothermal system into the ground and back up through the system, over and over again. In this design, absolutely no water is consumed by the system, and clearly this has no impact on SCWA, or the water table.

This type of system does not require large amounts of land, as the closed loops can go vertically into the ground and return vertically. This type of system is a little more expensive than an “open loop” and is generally used where the quality of the groundwater is not compatible with the geothermal system requirements. Accordingly, there is no reason to limit or restrict these closed loop systems.

As the towns consider SCWA’s request to regulate geothermal systems, it is critical that they get the facts and understand the nuance between each design, so that they don’t reduce the use of geothermal in any way. A properly designed geothermal system is one of the best ways to make our homes consume radically less energy and be more environmentally responsible.

Marc Clejan

Partner

GreenLogic Energy and ModernNetZero.com

Southampton