Via Ein Grym in Wales
We aim to provide affordable heat and power to community’s in the UK with no city fat cats or shareholders taking excessive profits from our communities.
Enter: ther World of Networked geothermal
The term “networked geothermal” describes both the technology—geothermal—and the mode of delivery—a network. For our purposes, geothermal means delivering heat (“thermal”) from the ground (“geo”) to heat a building using a heat pump. This type of heat pump is called a ground-source heat pump.
As a quick refresher, at the most basic level, heat pumps simply transfer heat between two places via liquid in a looped pipe system. For the type of heat pump we’re talking about today, heat is transferred between a building and the ground via the loop. In heating mode, a ground-source heat pump pulls heat from the ground and transfers it indoors. In cooling mode, a ground-source heat pump pulls heat from inside and transfers it outside and into the ground. Ground-source heat pumps are really efficient because the ground remains a relatively constant temperature throughout the year, about 55 degrees, at the depth most systems are installed. This temperature just happens to be optimal for maximising the efficiency of heat pumps.
Try this at home: the wall facing the back of my refrigerator was about 10 degrees warmer than the wall near the front of my refrigerator.
If this concept still seems incomprehensible, have no fear—just take a break from this blog post and walk to your refrigerator and grab a refreshing beverage or a snack. But before you walk back, take a moment to really think about your fridge. Ever notice the warm air coming out of the back of the fridge when it’s running? Your fridge is approximating a heat pump operating in cooling mode: it’s pulling heat energy from inside and transferring it outside, thereby cooling your tasty beverage and blowing warm air out the back. Think of a building as a giant refrigerator. A heat pump operating in cooling mode pulls out heat from indoors and transfers it outside. Boom—you understand heat pumps!
Ok, so we now understand the geothermal aspect of networked geothermal, but what about the network aspect? Networked geothermal, also called geogrids, describes the connection of a number of ground-source heat pumps to one another to form a shared loop network. In English, this means connecting nearby homes and businesses together to form a system or network of heat pumps. A networked geothermal system can achieve upwards of 500 to 600 percent efficiencies, which means that for every unit of energy that goes in, five or six units come out! Is this magic? No! Recall that heat pumps simply move heat from one place to another. Ground-source heat pumps move heat from the ground to a building, and vice versa (in cooling mode). A network of ground-source heat pumps can move heat from the ground to a building and between a building and another building. Sharing (heat) is caring!
In a geothermal network—as in life—having diversity in your network is a good thing. Studies have shown that having a diverse group of buildings with different heating and cooling needs can help balance out the system. For example, if you’ve ever looked at the roof of a hospital or grocery store, you will probably see large fans that work to remove the heat generated by cooling (think back to our refrigerator example). This type of heat is called “waste heat” and it has, as its name suggests, been seen as an undesirable byproduct. But for networked geothermal systems, one person’s trash is another person’s treasure: that waste heat can be captured and put back into the system and delivered to buildings that need it.
- Efficiency
First, this was mentioned above, but it bears repeating: networked geothermal systems are super efficient. Almost magically so (Editor: it’s not magic, it’s just engineering and science at work). Using less energy to heat and cool our buildings is a no regrets approach. - Cost
Second, networked geothermal systems can be cost-effective. Today, your gas bill has two components: the distribution rate and the cost of the gas. Over time, as a result of utility rate cases driven by investments in the existing gas system, distribution rates have increased year-over-year. More recently, the cost of gas has increased and the gas market has shown volatility. Both of these factors hit consumers’ pocketbooks all the same. Networked geothermal systems take the cost of gas out of the equation as they rely only on electricity to operate the heat pumps, but pull energy out of the ground. - Air Quality
Third, removing appliances that combust fossil gas inside of homes will increase health outcomes. Let’s face it, indoor air quality has long been a neglected topic of consideration, but studies have shown the detrimental health impacts of burning gas inside our homes. Transitioning away from burning gas in our buildings will help improve health outcomes everywhere, but especially in traditionally under-resourced communities that bear the brunt of air pollution impacts from a variety of sources (US MDH/MPCA report on air pollution impacts). - Jobs
Fourth, networked geothermal systems can provide jobs for skilled labor, possibly the same folks who installed that vast network of gas pipes that crisscross our neighborhoods. At its core, networked geothermal systems and gas distribution systems are not so different. Both require infrastructure to be installed in the ground and that requires a legion of skilled, local workers who know the ins and outs of installing pipes and operating networks. - The Net Zero energy transition
Fifth, networked geothermal can serve as way for traditional gas utilities to begin the transition away from gas delivery companies and toward thermal/heat companies. This one is important. If we can find a solution that supports labor, allows utilities to transition their business model, and combat climate change, we should focus on finding ways to implement this solution equitably and rapidly. Gas utilities across the country have begun to install networked geothermal systems.