Virkjunarorku

Virkjunarorka, or hydroelectric power, is electricity generated from the energy of moving water. It typically captures water’s potential energy by storing it in a reservoir behind a dam or by using a stream’s flow. Water is released through turbines connected to generators, converting kinetic and potential energy into electrical energy that is sent to the grid.

Virkjunarorku can be produced in different plant types. Dam-based plants use reservoirs to regulate flow and electricity output. Run-of-river plants rely on the natural flow of a river with little or no storage. Pumped-storage facilities move water between two reservoirs to store energy for use during high demand, effectively acting as a large battery.

Key components include an intake, penstock or pipeline to guide water, turbine and generator sets, transformers, and transmission lines. Plants vary in size from small, local installations to large-scale facilities that power cities or regions. Hydroelectric power is known for high efficiency and long plant lifespans and can respond quickly to changes in electricity demand, making it suitable for load-following and, in some designs, baseload supply.

Environmental and social considerations are important. Building dams can disrupt river ecosystems, affect fish migration, alter sediment transport, and displace communities. Modern projects attempt to mitigate impacts with environmental flow requirements, fish passage facilities, sediment management, and careful site selection and monitoring.

Globally, hydroelectric power is a major source of renewable electricity. In Iceland, hydropower is a central part of the electricity system, often combined with geothermal energy to provide a largely fossil-free grid.