Renewable energy encompasses methods of generating usable power from natural sources that are replenished over time. These sources include harnessing the kinetic force of moving air via wind turbines, capturing electromagnetic radiation from the sun through photovoltaic arrays, and utilizing the constant heat gradient within the Earth's crust through geothermal technology. Hydropower generates electricity by capturing the potential energy of falling or flowing water. The utilization of these sources minimizes the depletion of finite fuel stores and converts natural physical processes—such as solar incidence, atmospheric flow, and subsurface heat—into electrical or thermal energy for industrial and domestic use.