The letters following each Review Question refer to the corresponding Learning Objective from the Chapter Opener. What is geothermal energy? What limits its use? (F)

Geothermal energy is the heat energy produced and stored in the Earth's interior. It is derived from the radioactive decay of isotopes in the Earth's crust and the heat from Earth's core. Geothermal energy can be harnessed using different technologies, such as geothermal power plants and geothermal heat pumps. These technologies convert the heat energy into electricity or use it to provide direct heating for various applications.

There are several factors that limit the widespread use of geothermal energy: 1. Geographical constraints: Geothermal resources are not evenly distributed across the globe. They are typically found in areas with high volcanic activity or near tectonic plate boundaries. This means that countries or regions without such geological features may not have access to geothermal resources. 2. High initial investment: The upfront cost of building geothermal power plants and drilling wells to tap into the Earth's heat can be quite high. These expenses may deter potential investors or developers from investing in geothermal projects. 3. Limited lifespan of geothermal reservoirs: Over time, the amount of heat extracted from a geothermal reservoir may exceed the rate at which it is replenished, resulting in a decline in temperature and energy output. This means that geothermal power plants may have a limited lifespan, although this can be extended through sustainable management of the geothermal resources. 4. Environmental impact: Geothermal energy is generally considered an environmentally friendly energy source since it produces lower greenhouse gas emissions compared to fossil fuels. However, it can still have some negative environmental impacts, such as water pollution from the release of chemicals and gases found in the geothermal fluids, land subsidence, and induced seismic activity. By understanding both the concept of geothermal energy and the factors that limit its use, we can better assess its potential as a sustainable energy source and address the challenges associated with implementing this technology on a larger scale.