How Does the ISS Get Its Electricity in Space?

How Does the ISS Get Its Electricity in Space?

Space is always a curiously intriguing topic. Whether people wonder about extraterrestrials, how far the universe extends, or whether or not humans will colonize other planets, space topics always make for great conversation. One question that seems to be on some people’s minds is how the ISS gets its electricity in space. This short guide will explain the International Space Station’s current solar array system, which captures and converts solar energy into usable electricity for its onboard missions.

Solar-Powered Arrays

The International Space Station receives all its energy from the sun. Aerospace engineers created large solar converters that capture, harness, and process solar radiation into usable energy. These solar arrays use thousands of solar cells made up of purified silicon. Once in orbit, photovoltaics convert direct sunlight into energy. Currently, the ISS uses 8 solar arrays that open and rotate to face the sun based on the ISS’s location. Each solar array is 112 feet long and 39 feet wide.

Conducting Energy to the Space Station

In total, the 8 solar arrays generate between 84 and 120 kilowatts of electricity. Small appliances such as refrigerators or microwaves use only about 700 watts of electricity, so the solar arrays generate enough electricity to power over 40 homes—more power than the station uses, in fact. However, 60% of that energy goes directly to the ISS’s batteries. Connectors convert the solar energy into direct currents (DC), which flow at all times. On Earth, most homes and businesses require energy sourced from longer distances, which means they require alternating currents (AC) for power. However, since the ISS receives direct energy, it utilizes a direct current.

Powering Scientific Research

The process of how the ISS get its electricity from space also means astronauts can perform experiments or daily activities on the space station without issue. The American, Russian, Japanese, and European laboratories have enough energy to run simultaneous experiments without losing power. Since 2007, the station-to-shuttle power transfer system (SSPTS) has generated electricity to any docked space shuttles at the station. This enhanced docking times by four days, whereas previous power systems only allowed for short missions.