Borehole thermal energy storage (BTES) is one of the most common methods used for seasonal thermal energy storage around the world. By installing a BTES system, your facility can achieve double the performance of a conventional geothermal system and drastically lower heating and cooling costs.
How Does Borehole Thermal Energy Storage Work?
The ground heat exchanger (GHX) for a BTES system is designed and operated so heat is stored and abstracted seasonally as compared to a conventional geothermal heat pump system that is designed to simply dissipate heat or cold into the subsurface. In other words, borehole thermal energy storage uses the Earth as a thermal battery as opposed to a radiator.
BTES involves using the ground as the storage medium, allowing heat to be added to the ground during the summer months and extracted to meet the heating demands in the winter heating season. Borehole thermal energy storage can be used as a seasonal storage method for a wide variety of systems with a wide range of thermal capacities ranging from a residential home to a large-scale commercial building. According to ScienceDirect, the most common use of a borehole thermal energy storage system is for the heating and cooling of individual residential houses, although it is a great fit for commercial buildings as well. In most installations of a BTES system, it is paired with a ground source heat pump.
Benefits of a BTES System
1. Monetizes Heat More Efficiently
As described before, a borehole thermal energy storage system intentionally stores heat in the ground for use later and pulls the heat back up for later use. This process balances the geothermal borefield, resulting in a higher potential for energy savings.
2. Backed By New, Advanced Technology
BTES systems use a ground heat exchanger (GHX) array which stores heat differently in each season, using the earth like a thermal battery. Standard geothermal systems just pull heat from the ground and use it, whereas BTES systems store it for optimal use during each season. As a result, BTES systems are two times more powerful.
Is Borehole Thermal Energy Storage Right for your Organization?
Before investing in borehole thermal energy storage, ask yourselves these questions to see if this technology is right for your facility.
- Do you have high heating and cooling costs in the winter and summer respectively? In these seasons, costs reach their peaks, but with borehole thermal energy storage, those costs can be offset and reduced significantly.
- Do you have open land available for a pump system to be installed? This is a huge requirement, and it’s also worth noting that your company may need to get permission from your city or municipality to get them installed.
- Does your company already have a geothermal energy system? Is it failing or not performing as expected? If so, borehole thermal energy storage could solve that problem.
How Expensive is a BTES System?
The installation cost of a BTES is comparable to a conventional geothermal heat pump system although the capital cost of a large BTES system can be significant. This is due to a large number of geothermal boreholes needing to be drilled compared to just a few wells for an aquifer thermal energy storage system. But, don’t let this sway you from looking deeper into this new technology. At EnergyLink, we offer financing options that can help you afford an energy-efficient system like BTES. Especially paired with systems like an HVAC system, HVAC controls, and an automation system, this could be a perfect addition.
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