Vatnsafl

Vatnsafl, or hydropower, is energy generated by using the kinetic and potential energy of water to drive turbines connected to electric generators. Common methods include damming rivers to create reservoirs (reservoir-based hydro) and diverting water over turbines with minimal storage (run-of-river). In pumped-storage schemes, water is pumped uphill for later use to balance supply and demand.

In Iceland, vatnsafl has been a central pillar of the electricity system since the mid-20th century, providing a large share of electrical energy, often together with geothermal sources. The combination supports a low-emission, reliable grid, underpinning households, transport, and industry, including energy-intensive processing such as aluminum smelting.

Technical aspects include dam structures, intakes, penstocks, turbines, and generators, with control systems to regulate flow and power output. Resource availability depends on rainfall and river flow, causing seasonal and interannual variation. Hydropower plants are long-lived facilities, with upgrades and maintenance extending asset life.

Environmental and social considerations include impacts on river ecosystems, fish passage, sediment transport, and land use. Mitigation strategies may include fish ladders, environmental impact assessments, and careful siting and flow management.

Economic and reliability factors include high initial capital costs but very low operating costs, long lifespans, and the ability to provide baseload and peaking power. Hydropower is vulnerable to drought, climate variability, and regulatory constraints.

Globally, vatnsafl is one of the most widespread forms of renewable energy and a key component of decarbonization efforts. Developments focus on efficiency, environmental performance, and integration with other renewables.