How much does it cost to heat a school building with Geothermal Energy?

Geothermal Energy is free, isn’t it? It is, as long as it stays in the earth.

How much does it cost to pull it out of the ground? Pumps need to circulate the water through the “closed loop,” system. Even on days when we hardly need any heat, we still need to keep pumping it. At times, in the shoulder seasons the water will just loop through a bypass connection and go back to the wells. The HVAC systems have a specific range of water flow so the flow rate is automated and adjusted as needed.

How much does it cost to extract the BTU energy from the water and convert it to air so it can heat or cool a space? How much does it cost to pump it throughout a building? Well, first off, you need to know how many BTUs have been removed from the water and the gallons per minute flow rate. That can be derived from the difference in temperatures of the water going out, subtracted from the water coming in. Knowing how many BTUS are being used at a given time, and the usage of KWH at that given time, allows me to determine that actual cost per BTU of geothermal energy being consumed.

Facilities staff need to track and understand their energy costs so that they know what is working efficiently and what isn’t during various times of the year. When you have a gas or oil boiler you simply add the usage on the monthly or delivery invoices. How can you track all of the electrical energy if you do not have it metered separately?

I have asked the smarter than I, people at Onset if they help me design something. Long story short, they gave a list of parts and pieces and over the past few weeks I have turned my office into a workshop (Left photo). The next picture is what all of the components look like put together and in place. I have just started gathering data and I will be posting my findings as they accumulate. Ideally I will be posting the data alongside of my C.M.P. bill so that we can compare the percentage of power between geothermal and everyday power needs. I would like to know what others have done to track the electrical load needed to power their geothermal systems.