Renewable energy is energy that is collected from renewable resources, which are naturally replenished on a human timescale. Sources such as sunlight, wind, rain, tides, waves, and geothermal heat can all be used to produce energy. Renewable energy often provides energy in four important areas: electricity generation, air and water heating/cooling, transportation, and rural (off-grid) energy services. While many projects are large-scale, renewable technologies can as well be applied in rural and remote areas and developing countries. As most of green energy technologies provide electricity, renewable energy deployment is often applied in conjunction with further electrification initiatives.