Geothermal Masterclass

Even more hot rocks. How exciting, right?! Let’s dive deeper into the characteristics of geothermal energy, and the future direction of the industry.

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The Characteristics of Geothermal

• Efficiency – In geothermal, efficiency is determined by how the process converts heat extracted from the Earth into electricity. Dry Steam Power Plants achieve conversion efficiency between 10-20%. Flash Steam Power Plants have conversion efficiencies of 10-20%, and Binary Cycle Power Plants have conversion efficiencies of 10-15% due to the lower-temperature secondary fluid. Other aspects that affect efficiency are plant design, maintenance, and operation. The reduced efficiency versus other renewable sources is contrasted with the constant source of power generation via geothermal.

• Environmental Impact – In terms of greenhouse gas emissions, they are drastically lower than fossil fuel power plants. Fossil fuels can be used in constructing, operating, and maintaining geothermal power plants rather than energy generation. Geothermal once established takes up a small land space and in newer cooling systems, there is very little water used. However, the environment can be damaged by the disposal of the geothermal fluid, and hydraulic fracking leads to increased occurrence of seismic events. Finally, the heat released from the geothermal process can leak into other groundwater sources, leading to potential damage to ecosystems.

  

  Photo by Chris LeBoutillier on Unsplash

• Affordability – Once geothermal power plants are established, they have a long lifespan, create many jobs, and have low operating costs. Since the fuel comes naturally from the heat of the Earth, there are no high fuel costs. Although, setting up the plant has a high investment cost. Exploration, locating a site for the plant that is suitable for geothermal energy production, and the cost of drilling are very large costs associated with geothermal. Advancing the industry to compete with other renewable sources, and obeying environmental regulations will increase costs. Currently, geothermal struggles to keep up with other energy production methods in terms of cost-effectiveness.

• Scalability – Geothermal can be purpose-built for deployment on different scales. Power generation can be implemented in local residential areas using geothermal heat pumps, and power plants can have capacities ranging from 100kW in MiniGeo systems to 900MW at Geysers Geothermal Complex in the United States. Again, power generation depends on the suitability of the area to build geothermal power plant sources, and the distance over which produced electricity has to be transmitted to population centres.