Since the 1948 construction of the Commonwealth Building, facilities have been steadily adopting geothermal solutions to save money on HVAC. The Portland, OR building was the first commercial facility to install ground source heat pumps (GSHP) for cooling and heating, proving that large-scale applications were feasible.
In addition to its geothermal capabilities, the Commonwealth Building was ahead of its time in including features like double glazing, heat recovery from ventilation exhaust air and aluminum sheathing. While the 15-story, 215,000-square-foot office building stands today, the geothermal system was decommissioned in 1992. The building is designated as a National Historic Mechanical Engineering Landmark by ASME and is on the National Register of Historic Places for its notable achievement in geothermal history.
Despite being a relic of sorts, the Commonwealth Building is nevertheless remembered for ushering in a new era of sustainable facilities, as the number of geothermal applications has increased, as 50,000 geothermal heat pumps are installed in the U.S each year. But with all of the other sustainable energy solutions out there, what is so appealing about geothermal energy?
Perhaps most importantly, geothermal provides steady ROI and savings on energy spend. Energy generation is one way geothermal can make an impact on a facility. In especially rich geothermal areas, water found below the Earth’s surface can be hot enough to turn steam turbines in electric generators. Some facilities have adopted systems like these to achieve net zero status.
Also, with HVAC consuming 44% of the energy in commercial buildings, geothermal heat pumps provide a cost-saving alternative. Geothermal heat pumps can heat and cool buildings with very low electricity demand and can reduce emissions, returning costs to users in 5-10 years.
Not only is it a more efficient energy source, but geothermal is also versatile. Many renewable energy sources require specific climate conditions, but geothermal can be installed in nearly any climate. As the DOE explains, “Ground temperature is warmer than the air above it during the winter and cooler than the air in the summer. The geothermal heat pump takes advantage of this by exchanging heat with the earth through a ground heat exchanger.” Thus, geothermal can stabilize air temperature in a building because of its consistency.
Unlike other energy sources, geothermal does not rely on any finite quantity of resources – it merely requires the Earth’s interior to maintain its temperature as it’s done for billions of years. Furthermore, the reliability of geothermal systems themselves provide stability. The low-maintenance system has a 50-year life span for ground loops and 20 years and up for pumps and compressors.
Reliability extends beyond simply the physical nature of geothermal. Energy costs after installation stay steady, which provide a distinct advantage over other renewable energy sources because that considerably reduces price volatility. Those who invest in geothermal are not at the same mercy of price spikes and energy crises as those who invest in other energy systems – renewable or otherwise.
After the installation of a system, geothermal solutions do not take up much space because the system works underground. Therefore, you can easily cover it, which can save space and give aesthetic freedom to design above the system.
Moreover, heat pumps are versatile and allow more options for installation. “Geothermal heat pumps circulate water or other liquids through pipes buried in a continuous loop, either horizontally or vertically, under a landscaped area, parking lot or any number of areas around the building,” says the Geothermal Energy Association.
Of course, as with any technology, geothermal has its limitations. The capital required to install a system can be higher than many FMs can even consider managing. However, it is mostly a one-time investment that pays dividends through its expected energy savings. Either way, it is a major decision to make for a facility.
To sway that decision towards the more affirmative option, the federal government has implemented a series of programs and incentives for installation. In addition to tax breaks that have aided those looking towards renewable energy like geothermal, projects like the Small Business Vouchers Pilot provide businesses with more opportunity for renewable energy, including geothermal.
However, researchers at the Insitute of Political Economy at Utah State University point to indicators outside of government programs, tax breaks and policies to predict the future of geothermal applications.
“Although policymakers favor geothermal power through mandates and subsidies, markets, not government policies, are best equipped to determine the true economic viability of geothermal power,” the researchers explain.
“New technology and increased market demand will likely decrease the need for subsidies and make geothermal more economically viable,” explain the researchers. As geothermal systems increase to the tune of 50,000 per year, the feasibility of more affordable implementation might also increase.
Whether you are ready for geothermal now or are considering it for the future, the nine geothermal projects presented in this issue range widely in their applications. These projects all exemplify innovation in geothermal and have paid dividends for their facilities with this clean power source.
Jennie Morton is a contributing editor for BUILDINGS. Justin Feit firstname.lastname@example.org is assistant editor of BUILDINGS.
Types of Geothermal Heat Pumps
Based on your location and building’s property, you will need a specific type of geothermal heat pump system. They are classified into three main categories:
Closed-loop systems typically circulate an antifreeze solution through a closed loop often made of plastic tubing that is buried underground or submerged in water. The system exchanges heat between the heat pump’s refrigerant and the antifreeze solution in the closed loop. Loops can be oriented horizontally, vertically, or in a pond or lake, but vertical is most commonly used in commercial buildings, schools and other larger facilities because it can be implemented in locations with land area restraints.
Open-loop systems use well or surface body water as the conduit for heat exchange to circulate through the system. Once the water is cycled through the system, the water returns to the ground through the well, a recharge well or surface discharge. Open-loop systems only work where there is a ready supply of clean water and the system meets groundwater discharge codes and regulations.
Hybrid systems will use multiple geothermal resources or a geothermal resource with outdoor air through the use of a cooling tower, for example. These systems are most effective when a building needs more cooling power than heating.