Geotermalne

Geotermalne (geothermal) energy is the heat derived from the Earth. It originates from residual formation heat and radioactive decay within the crust and mantle. Temperature increases with depth, creating reservoirs of hot water and steam in rocks and fractures. This energy can be accessed through wells or earth-contact heat exchangers and used directly for heating or converted into electricity.

Electricity generation relies on hydrothermal resources containing steam or hot water. Conventional plants use dry steam, flash steam, or binary cycle technologies to drive turbines. When natural resources are insufficient, enhanced geothermal systems engineer fractures in hot rock and circulate water to transfer heat to the surface.

Direct use includes district heating, space heating, greenhouses, aquaculture, and spa baths, often at shallower depths. Ground-source heat pumps exploit relatively stable near-surface temperatures to heat or cool buildings by circulating a fluid through loops buried underground.

Resources and deployment: Geothermal potential is highest in tectonically active regions, around volcanic zones and hotspots. Known locales include parts of Iceland, the western United States, Italy, New Zealand, and the Philippines. Environmental aspects are generally favorable compared with fossil fuels: low emissions, high reliability, and long plant lifetimes, but challenges include seismic considerations, water use, mineral scaling, land use, and the need for sustained reservoir management to avoid depletion.

Economics and outlook: High upfront costs and exploration risk limit early expansion, but operating costs are low and geothermal provides baseload power and direct heat. Advances in Enhanced Geothermal Systems aim to broaden geographic availability and reduce costs, increasing the role of geothermal in a low-carbon energy system.