What Are The Advantages Of Geothermal Power Plant To The Environment?

Geothermal Energy is Renewable and Sustainable

Geothermal power generation utilizes heat derived from the Earth to produce electricity, making it incredibly sustainable. Geothermal energy is considered renewable since it comes from the natural heat flowing in the Earth’s crust, which is essentially limitless. As explained on the Microsoft Sustainability website, “Earth’s geothermal energy formed more than 4.5 billion years ago when the planet first solidified. It exists because as our planet formed, radioactive decay in the core and mantle generated heat at depths of up to 7,200 miles below the Earth’s crust.” [1] This heat will continue flowing for billions of years, constantly replenishing the source of geothermal power generation. Unlike fossil fuels which can be depleted, geothermal energy is sustainable and will be available for the foreseeable future.

Very Low Greenhouse Gas Emissions

One of the biggest environmental advantages of geothermal power plants is that they emit very minimal greenhouse gases like carbon dioxide (CO2). While fossil fuel power plants emit large quantities of greenhouse gases that contribute to climate change, the process of generating electricity from geothermal energy releases little to no emissions. This is because geothermal plants do not burn fossil fuels to generate power.

The steam used in geothermal power plants is naturally occurring from underground hydrothermal resources. This makes the process of harnessing geothermal energy much cleaner than traditional power plants that rely on the combustion of coal, natural gas or other fossil fuels. According to the U.S. Department of Energy, geothermal power plants emit on average just 4 grams of CO2 per kilowatt-hour of electricity generated. This is drastically less than coal (1,001 g/kWh) or natural gas (469 g/kWh) plants.

With rising concerns about greenhouse gas emissions and global climate change, geothermal energy stands out as an environmentally-friendly alternative. The minimal carbon footprint of geothermal power gives it a major sustainability advantage over conventional fossil fuel-burning plants. This makes geothermal energy an important renewable power source to help reduce greenhouse gas emissions and their environmental impacts.

Small Land Usage

Geothermal power plants have a very small footprint compared to conventional power plants. According to the U.S. Department of Energy, geothermal power plants use less land per gigawatt-hour than coal, wind, or solar photovoltaic power plants [1]. For example, a 50 MW geothermal power plant would use around 202 hectares of land whereas a 50 MW coal power plant would use over 1,818 hectares. This massive difference is because geothermal plants do not require large infrastructure for fuel transport and storage.

Think GeoEnergy reports that geothermal energy is the least land-use intense renewable energy technology, using only 7.5 square km per terrawatt-hour (TWh) produced [2]. In comparison, solar thermal power uses 15.2 square km per TWh and wind power uses 9.3 square km per TWh. The small land footprint makes geothermal an ideal energy source where land availability is limited.

Reliable Baseload Power

One of the key advantages of geothermal power plants is that they provide consistent, reliable baseload power that is unaffected by weather changes. Geothermal reservoirs produce steady streams of hot water and steam that can generate electricity 24/7, with capacity factors typically above 90% ^[1]. This gives geothermal power the ability to operate as baseload generation, meeting the minimum demand on an electrical grid.

Unlike wind and solar power, which fluctuate based on weather conditions, geothermal plants produce stable output regardless of external factors. This makes geothermal a highly reliable renewable energy source that can serve as a baseload replacement for coal or nuclear power ^[2]. Geothermal’s base load capacity gives grid operators the consistency needed to integrate higher levels of intermittent renewables without compromising reliability.

Low Maintenance Costs

One of the key advantages of geothermal power plants is that they require far less maintenance than traditional fossil fuel plants. According to Dandelion Energy, geothermal systems need little maintenance and can last much longer than conventional HVAC equipment. This dramatically reduces operating costs over the lifetime of the plant. The geothermal reservoir and wells have no moving parts and do not degrade over time like machinery in traditional plants. Pumps, heat exchangers and other equipment in the above-ground power plant also require less frequent maintenance and replacement compared to fossil fuel plants.

Maintenance on a geothermal plant averages just 1-2% of the original capital cost per year, according to industry estimates. This amounts to substantial savings over decades of operation. The reliability and durability of geothermal plants gives them very low maintenance costs compared to coal, natural gas, oil, and even nuclear power.

No Harmful Air or Water Pollution

Geothermal power plants emit little to no harmful air pollution because they do not burn fossil fuels like coal or natural gas. According to the U.S. Department of Energy, geothermal plants release less than 1% of the carbon dioxide emissions of a relatively clean natural gas-fueled power plant. They also emit negligible amounts of sulfur dioxide and nitrous oxides, which are major sources of air pollution from conventional power plants [1].

Geothermal energy also does not contribute to water pollution. The geothermal water or steam used to generate electricity is injected back into the reservoir after use. There have been no reported cases of groundwater contamination from geothermal sites in the United States [2]. Proper construction and maintenance helps ensure that geothermal installations do not leach any untreated fluids into freshwater sources.

Minimal Noise Pollution

Geothermal power plants produce minimal noise since most of the facility is located underground. The most significant noise comes from the cooling towers and pumps (Design Considerations for Geothermal Power Plants, 2016). However, the noise from geothermal plants is comparable to background noise and does not exceed 45 dBA at the site boundary, according to a noise study analyzing an operational geothermal power plant (Micallef, 2014). This noise level is significantly lower than conventional fossil fuel plants, which can reach 85-100 dBA (Noise Comparison Chart, 2022). Additionally, since geothermal plants don’t require any combustion, they eliminate the loud noise from burning fuels during operation. Overall, geothermal systems operate very quietly with little audible noise, especially when equipped with sound insulation around pumps and other equipment.

According to internet forums, homeowners report geothermal heat pumps used for residential heating and cooling also run very quietly. Most noise comes from the air handler fan circulating conditioned air, comparable to a furnace or AC system (Reddit, 2020). Proper installation and insulation can minimize this noise so that the system is barely noticeable inside the home (Houzz, 2019). Therefore, geothermal technology results in minimal noise pollution for both utility-scale power generation and residential applications.

Improved National Energy Security

Geothermal power plants utilize domestic resources, like heat beneath the Earth’s surface, to generate electricity. This reduces a nation’s reliance on imported fossil fuels like oil, coal, and natural gas. According to the National Renewable Energy Laboratory (NREL), geothermal energy improves national energy security by using indigenous resources. Geothermal power plants provide reliable baseload power without being subject to global price fluctuations or supply constraints of fossil fuels.

The geothermal resources used for power generation are available locally, often in remote areas far from population centers. Tapping into these resources with geothermal power plants can provide energy access to isolated communities. Utilizing local geothermal sources reinforces energy independence and security for nations.

Economic Benefits

Geothermal energy provides significant economic benefits at both the local and national level. According to a report by the National Renewable Energy Laboratory (NREL), geothermal power plants contribute substantial tax revenue to local counties and schools. In addition, royalties and rents are paid to federal and state governments for geothermal leases on public lands [1]. Geothermal plants also create jobs in drilling, power plant construction, operation and maintenance, and indirect services. The geothermal industry employs thousands of workers, often in rural areas with high unemployment rates. One analysis found geothermal job creation generates over $40 million in income annually in the western U.S. alone [2]. Overall, geothermal energy provides economic stimulus, tax revenue, and employment opportunities.

Compatible with Wildlife

Geothermal power has minimal impacts on wildlife habitats compared to other energy sources according to the Audubon Society. Since geothermal energy is inherently found in very hot, less habitable locations, geothermal power plants are unlikely to disrupt habitat.

In fact, geothermal development can actually create new habitats. The heated water from geothermal plants supports unique ecosystems of thermophilic (“heat-loving”) plants and animals. According to the Waikato Regional Council in New Zealand, geothermal areas are home to distinct collections of plants, animals and microorganisms, some of which are valuable to science and industry.

Proper siting of geothermal plants is still important though, according to the U.S. Fish & Wildlife Service, to avoid any potential impacts to surface water resources or native vegetation. Overall, geothermal power has a minimal footprint compared to other baseload energy sources.