Geothermal is a lesser-known type of renewable energy that uses heat from the Earth’s molten core to produce electricity. While this unique feature gives it key benefits over solar and wind, it also suffers from high costs and geographic restrictions. Because of this, few countries have managed to produce geothermal energy at scale. In this infographic, we’ve used a combination of diagrams and charts to give you a high level overview of this sustainable energy source.
How Geothermal Works
Geothermal energy is produced by accessing reservoirs of hot water that are found several miles below the earth’s surface. In certain parts of the planet, this water naturally breaks through the surface, creating what’s known as a hot spring (or in some cases, a geyser). When accessed via a well, this pressurized water rises up and rapidly expands into steam. That steam is used to spin a turbine, which then drives an electric generator. Further along the process, excess steam is condensed back into water as it passes through a cooling tower. An injection well pumps this water back into the Earth to ensure sustainability.
Where Is Geothermal Energy Being Used?
As of 2021, global geothermal power generation amounted to 16 gigawatts (GW). Only a handful of countries have surpassed the 1GW milestone. To give these numbers context, consider the following datapoints:
America’s 3.7 GW capacity is split across 61 geothermal plants. The world’s largest solar plant, the Bhadla Solar Park, has a maximum output of 2.2 GW The world’s largest hydroelectric plant, the Three Gorges Dam, can produce up to 22.5 GW
While geothermal plants clearly produce less power, they do have benefits over other types of renewables. For example, geothermal energy is not impacted by day-night cycles, weather conditions, or seasons.
The Big Picture
We now look at a second dataset, which shows the global contribution of each type of renewable energy. These figures are as of April 2022, and were sourced from the International Renewable Energy Agency (IRENA). *Geothermal’s total capacity in this dataset differs from the previous value of 16GW. This is due to differing sources and rounding. One reason for the slow adoption of geothermal energy is that they can only be built in regions that have suitable geological features (such as places where there is volcanic activity). To expand on that point, consider the following data from Fitch Solutions, which shows the forecasted growth of geothermal energy capacity by region.
Fitch believes that over the next decade, the majority of new geothermal capacity will be installed in Asia. On the flipside, investment in North America and Western Europe (NAWE) is expected to decrease. The top markets for geothermal are expected to be Indonesia, the Philippines, and New Zealand, which all lie along the Pacific Ring of Fire. The Ring of Fire is a path along the Pacific Ocean where the majority of volcanic activity occurs. on
#1: High Reliability
Nuclear power plants run 24/7 and are the most reliable source of sustainable energy. Nuclear electricity generation remains steady around the clock throughout the day, week, and year. Meanwhile, daily solar generation peaks in the afternoon when electricity demand is usually lower, and wind generation depends on wind speeds.As the use of variable solar and wind power increases globally, nuclear offers a stable and reliable backbone for a clean electricity grid.
#2: Clean Electricity
Nuclear reactors use fission to generate electricity without any greenhouse gas (GHG) emissions.Consequently, nuclear power is the cleanest energy source on a lifecycle basis, measured in CO2-equivalent emissions per gigawatt-hour (GWh) of electricity produced by a power plant over its lifetime. The lifecycle emissions from a typical nuclear power plant are 273 times lower than coal and 163 times lower than natural gas. Furthermore, nuclear is relatively less resource-intensive, allowing for lower supply chain emissions than wind and solar plants.
#3: Stable Affordability
Although nuclear plants can be expensive to build, they are cost-competitive in the long run. Most nuclear plants have an initial lifetime of around 40 years, after which they can continue operating with approved lifetime extensions. Nuclear plants with lifetime extensions are the cheapest sources of electricity in the United States, and 88 of the country’s 92 reactors have received approvals for 20-year extensions. Additionally, according to the World Nuclear Association, nuclear plants are relatively less susceptible to fuel price volatility than natural gas plants, allowing for stable costs of electricity generation.
#4: Energy Efficiency
Nuclear’s high energy return on investment (EROI) exemplifies its exceptional efficiency. EROI measures how many units of energy are returned for every unit invested in building and running a power plant, over its lifetime. According to a 2018 study by Weissbach et al., nuclear’s EROI is 75 units, making it the most efficient energy source by some distance, with hydropower ranking second at 35 units.
#5: Sustainable Innovation
New, advanced reactor designs are bypassing many of the difficulties faced by traditional nuclear plants, making nuclear power more accessible.
Small Modular Reactors (SMRs) are much smaller than conventional reactors and are modular—meaning that their components can be transported and assembled in different locations. Microreactors are smaller than SMRs and are designed to provide electricity in remote and small market areas. They can also serve as backup power sources during emergencies.
These reactor designs offer several advantages, including lower initial capital costs, portability, and increased scalability.
A Nuclear-Powered Future
Nuclear power is making a remarkable comeback as countries work to achieve climate goals and ultimately, a state of energy utopia. Besides the 423 reactors in operation worldwide, another 56 reactors are under construction, and at least 69 more are planned for construction. Some nations, like Japan, have also reversed their attitudes toward nuclear power, embracing it as a clean and reliable energy source for the future. CanAlaska is a leading exploration company in the Athabasca Basin, the Earth’s richest uranium depository. Click here to learn more now. In part 3 of the Road to Energy Utopia series, we explore the unique properties of uranium, the fuel that powers nuclear reactors.
