geoenergi

Geoenergi, or geothermal energy, is heat recovered from the Earth that can be used for electricity generation, direct heating, and cooling. The heat originates from the planet’s formation, radioactive decay, and residual magma, and it exists at varying depths. Shallow resources are exploited with heat pumps for space heating and cooling, while deeper high-temperature resources can power turbines.

Geothermal electricity production uses three main plant types: dry steam plants, which drive a turbine directly with steam; flash steam plants, which depressurize hot water to produce steam for a turbine; and binary cycle plants, which transfer heat from moderate-temperature fluids to a secondary organic fluid that vaporizes at a lower temperature. Enhanced geothermal systems (EGS) expand access by creating artificial reservoirs through rock stimulation in otherwise dry formations.

Direct-use applications include district heating, greenhouse heating, aquaculture, and industrial processes, while ground-source heat pumps extract heat from the ground for building comfort and energy efficiency.

Advantages include relatively low greenhouse gas emissions, high capacity factors, and the ability to provide baseload power or heating. Challenges cover high upfront drilling and infrastructure costs, exploration and reservoir management risks, and, in some cases, induced seismicity. Environmental considerations include land use, water use, and emissions of trace gases from reservoirs.

Geothermal energy is most developed in geothermally favorable regions, with notable use in Iceland, parts of the United States, Indonesia, the Philippines, New Zealand, and Italy. Ongoing research aims to improve resource assessment, reduce costs, and mitigate environmental impacts.