Geothermal heat pumps are widely recognized as one of the most popular renewable technologies in HVAC. Accordingly, the geothermal heat pump industry has seen growth on both the residential and commercial sides over the past few years. And, as advances in technology continue to improve the efficiency and controls of these units, the industry is concurrently investigating ways to make geothermal an affordable option for all.
HIGHLY EFFICIENT COMFORT
Because it uses the earth as a free heat source or heat sink, geothermal is inherently a highly efficient technology that can help homeowners and building owners save a significant amount of energy and money.
“Geothermal is an energy-efficient, cost-effective, and comfortable way to heat a home or building,” said Tim Litton, director of marketing and communications, WaterFurnace Intl. Inc. “Geothermal heat pumps use the energy stored in the ground to provide dramatic savings on heating, cooling, and hot water, which make up the majority of the average home’s or building’s energy usage.”
Tony Landers, vice president of sales and marketing, The Whalen Co., agreed. “The ability to use the ground as a storage tank reduces the amount of energy required to heat and cool commercial buildings. Rather than dissipating heat into the atmosphere via a cooling tower, the heat is simply stored in the ground during the cooling season and then utilized during the heating season.”
“Geothermal energy is a renewable resource that is a solid alternative to conventional energy sources,” added Shilai Xie, manager, product marketing, Bosch Thermotechnology Corp. “An Idaho National Laboratory [INL] report titled ‘The Future of Geothermal Energy’ states that ‘many attributes of geothermal energy, namely its widespread distribution, base-load dispatchability without storage, small footprint, and low emissions are desirable for reaching a sustainable energy future for the U.S.’ The technology reduces greenhouse gas emissions by as much as 40 percent more than traditional HVAC systems, according to the U.S. Environmental Protection Agency [EPA], and also offers considerable water savings potential — by replacing cooling towers with geothermal heat pumps, building owners can conserve potable water that is otherwise evaporated into the air during a cooling cycle or used to blow down the system to clean away mineral buildup. The systems can save 30-50 percent in heating and cooling costs, as well, making them good for the wallet as well as the planet.”
A GROWING MARKET
Consumers’ desire for increased efficiency and smaller energy bills, the end of the Great Recession, and the availability of federal income tax credits and other incentives for geothermal heat pump installations have all encouraged recent growth in the market over the past several years.
“Adoption of geothermal in terms of numbers of units is much faster in the commercial marketplace,” said Jeffrey Miller, president and CEO, EarthLinked Technologies Inc. “However, in number of customers, residential is leading the way. Our focus is on residential because our product’s small footprint is suited for contractors whose focus is on residential markets.”
Commercial buildings and institutions have been especially quick to adopt geothermal technology, Xie said.
“Schools across the country have tapped into the energy they already own to deliver a comfortable learning environment for their students while reducing their energy bills,” he said. “Don Penn of Image Engineering has installed geothermal heat pumps in more than 250 schools in Texas, and other firms have designed numerous schools in Pennsylvania and New Jersey. … We also have a project involving a water utility using geothermal as the vehicle for delivering heating and cooling to a school in New York.”
Darcy Lee, product portfolio leader, Trane, also pointed to educational facilities as the fastest-growing adopters of geothermal in the commercial market. “One of the main reasons for this growth is that school budgets are set annually, and with geothermal systems, the school pays a higher upfront cost but mitigates that with lower monthly bills. This growth can also be attributed to the fact that when a school is about to start new construction or a renovation project, it is looking for building systems that provide efficiency and use green technology, and, oftentimes, geothermal is the right fit.”
The commercial geothermal industry “is anticipated to continue growing with the commercial construction market,” said Naveen Halbhavi, director of marketing, ClimateMaster Inc. “However, the industry is expecting that there may be a decline in residential sales if the 30 percent federal tax credit is not renewed.” (For more information on the expiring federal tax credits, turn to Page 9.)
IMPROVED EFFICIENCY
Already an innately efficient technology, geothermal heat pumps have continued to improve in efficiency over the past few years thanks to advances in motor technology that have enabled part-load operation.
“In the geothermal market, there is a move toward higher efficiencies, which has led to the market adopting high-end motors and compressors,” Lee said. “Electronically commutated motors [ECMs] use a programmable motor speed that provides performance and efficiency advantages. When used in variable-speed applications, the high and low speeds are set, which allows the motor to run at the speed necessary to meet the heating or cooling load requirements. Variable-speed compressors provide very high part-load efficiencies and allow the compressor to run at the speed required by the building load. Both ECMs and variable-speed compressors are technologies used by Trane to provide the highest level of efficiency to customers.”
Halbhavi also pointed to improved part-load efficiency as a continuing trend.
“High-efficiency systems utilize variable-speed compressors to maintain high levels of efficiency, regardless of load,” he said. “Zoning and potable hot water generation that eliminates heating using fossil fuels are also popular options.”
SMART CONTROLS AND THE IOT
Perhaps the fastest-evolving component in geothermal heat pumps is the unit’s controls, which make it possible for the units to operate wirelessly, analyze operational data, diagnose issues with the equipment, and more.
“The market is seeing a move toward the integration of controls,” Lee said. “Wireless technology eliminates the need to worry about wiring, which is especially beneficial for older buildings located in the city. Wireless technology also provides building owners and managers with the flexibility of placing controllers where they are needed and moving or adding more controllers as building spaces change.”
All of EarthLinked’s Prime Series units come standard with the EarthLinked Diagnostic and Monitoring (EDM) system, which provides real-time monitoring of every installed unit. The EDM system measures and verifies pressures, temperatures, and currents and compares the measurements to the ideal conditions in that geographical location.
“Contractors never have to wonder about getting a service call again by staying connected,” Miller said. “The EDM comes with Ethernet and Bluetooth connectivity, a USB port, and an SD card to keep contractors in the loop 24/7. The real-time monitoring and history can be accessed through the EDM mobile app or the EDM online portal. The interface also lets a user see the system schematic in real time for more simple, efficient, and effective day-to-day operations.
“By using the online portal of the EDM, service personnel can set personalized reminders for each installed unit that regularly alerts both the residents and the service personnel that air filters need to be checked/cleaned/changed. The alerts can be in the form of an email, text message, or both. All these features and more allow the contractor, EarthLinked, and regulatory stakeholders the opportunity to see the actual performance of the unit.”
Landers also pointed to remote monitoring as an up-and-coming feature in geothermal heat pumps. “The trend is toward more controls to allow remote monitoring through mobile applications,” he said. “End users are driving the trend. In the constantly connected world in which we live, more and more consumers are connected via the internet and Wi-Fi to their homes. The ability to control the HVAC system from a mobile device has become expected in higher-end applications, and The Whalen Co. is working with several suppliers to ensure a wide variety of options to meet the growing demand.”
User-friendly, connected controls are a growing consumer expectation, Litton added. “Homeowners generally know very little about their heating and cooling systems and rely on contractors to be the experts. Those technologies, however, are being required more and more to fit into home automation and smart-home environments. While homeowners can’t tell you what brand of HVAC equipment they have in the basement, they do know they want to be able to control it from their phones or have it communicate with the rest of their connected appliances and devices.”
Litton said he expects all devices will become more connected through what’s known as a “device mesh” that shares data through Internet of Things (IoT) platforms. “Geothermal products will have to become part of this mesh,” he said. “Also, new innovative companies, like Tesla, will provide a halo effect on energy-efficient, electricity-based products and will drive adoption of all-electric homes with solar power and battery backup that offer the perfect environment for geothermal.”
MITIGATING LOOP COSTS
Perhaps the biggest barrier to the widespread adoption of geothermal technology in both the residential and commercial markets is the high first cost associated with putting the ground loops in place. To remove that roadblock, industry leaders are coming up with innovative ways to offset those costs through things like leasing and financing.
“One of the most important trends in the renewables market is financing,” said Mark Ladd, residential geothermal platform manager, Carrier Corp. “Typically, renewables require large upfront investments and may have longer paybacks. A number of unique financing options are available to make renewable investments more realistic for more customers.”
“A few more financing options are becoming available for both residential and commercial as well as start-up companies that are becoming loop-owning energy companies similar to Solar City,” Urlaub said. “It is all driven by first cost. If we can reduce the first cost of the geothermal loop system, the option to purchase has a much better chance of moving forward.”
EarthLinked is committed to improving loop performance, price, and installation time. “We understand that continued growth of the geothermal industry is the loop,” Miller said.
Three new kinds of partnerships have emerged to give more options for the widespread adoption of geothermal technologies, Xie said. “Contractors can now partner with utility providers, third parties, or both, opening the door for cost-effective ways to install this energy-efficient, environmentally sensitive heating and cooling system. These solutions provide the developer and builder with lower up-front costs and the end user with predictable energy costs over time without having to pay the price of installing a ground loop.”
Geothermal heat pumps have improved significantly in efficiency and connectivity over the past few years. As they continue to evolve, as more financing options emerge, and as the industry continues to find innovative ways to offset the higher first cost of a geothermal loop installation, the geothermal market is poised to continue enjoying success for years to come.
