Soojusallika

Soojusallika is the Estonian term for a source of thermal energy used to heat a system or process. In thermodynamics, a heat source is a reservoir or device from which heat flows to a cooler system that requires heating.

Soojusallikas can be natural or artificial. Natural heat sources include geothermal reservoirs and solar thermal energy, while artificial sources include boilers powered by fossil fuels, electric heaters, and heat pumps. Renewable sources such as geothermal, solar thermal, and biomass are contrasted with non-renewable ones.

In practical energy systems, heat sources are used in district heating, residential space heating, hot water production, and industrial processes. The choice depends on temperature needs, reliability, operating costs, and environmental impact. Heat pumps, for example, can extract heat from air, ground, or water.

Performance is described by metrics such as the coefficient of performance (COP) for heat pumps and efficiency ratings for boilers. In Estonian building and energy policy, the concept of soojusallikas appears in energy performance certificates, audits, and planning of heating infrastructure.

Examples include a geothermal heat source supplying a heat pump, a solar thermal system feeding a hot-water circuit, or an air-source heat pump drawing heat from outside air.