Solar energy is a cornerstone of renewable power. Photovoltaic (PV) technology, using semiconductor materials, directly converts photons from sunlight into electrical current. This DC current can be used directly, stored in batteries, or inverted to AC for grid connection or powering standard computing equipment. Concentrated Solar Power (CSP) systems use mirrors or lenses to concentrate sunlight onto a small area, generating high temperatures to produce steam that drives a turbine, similar to conventional power plants. The intermittent nature of sunlight (day/night cycles, weather) is a key challenge, often requiring energy storage solutions or hybrid systems.

Wind turbines are sophisticated machines designed to capture the energy of wind. The wind's force causes the rotor blades to spin, which in turn rotates a shaft connected to a generator. The generator converts this mechanical energy into electrical energy. The efficiency of a wind turbine is highly dependent on wind speed; there's a cut-in speed below which it won't operate, an optimal operating range, and a cut-out speed at which it shuts down to prevent damage. Like solar, wind is an intermittent resource, requiring grid integration, energy storage, or backup power sources for reliable computing operations.

Hydropower is one of the oldest and most established forms of renewable energy. The most common method involves a dam that creates a reservoir. Water is released from the reservoir and flows through penstocks to spin turbines. These turbines are connected to generators that produce electricity. The height of the water drop (head) and the volume of water flow determine the power output. Run-of-river hydropower systems generate electricity from the natural flow of a river, often with smaller diversions or channels, reducing the ecological footprint compared to large dams. While offering a consistent power source, the construction of large dams can alter ecosystems, displace communities, and impact fish migration.

Geothermal energy harnesses the thermal energy generated and stored within the Earth. In areas with accessible geothermal reservoirs, wells are drilled to bring hot water or steam to the surface. This steam can directly drive turbines, or hot water can be used to vaporize a secondary fluid with a lower boiling point, which then drives the turbine (binary cycle). Geothermal power plants are known for their high capacity factors and consistent output, providing a stable baseload power source. However, the availability of suitable geothermal resources is geographically restricted, and there are concerns about potential emissions of greenhouse gases trapped underground and the risk of induced seismicity.