Launching mirror clusters helps increase solar power production on Earth

Reflect Orbital, a startup in California, wants to launch a cluster of mirrors into orbit to transmit sunlight to solar power plants to increase electricity production after dark.

Ben Nowack, founder and CEO of Reflect Orbital, introduced the company's plans at the International Conference on Energy from Space taking place at the end of April, according to Space . A prototype of Reflect Orbital's light-reflecting satellite could launch next year.

Simulate a satellite equipped with a mirror that reflects sunlight back to Earth. (Photo: Security Lab).

Reflect Orbital wants to develop a cluster of 57 small satellites orbiting the Earth in a Sun-synchronous polar orbit, at an altitude of 600km. In that orbit, the satellite will fly around the Earth from pole to pole. The satellites will fly over each point on Earth at the same time of day, twice within 24 hours. In total, the 57 satellites will provide an additional 30 minutes of sunlight to the power plant, when energy is needed most, according to Nowack.

The cost of solar cells has dropped 90% in the past 15 years, according to the International Renewable Energy Agency, and their efficiency continues to increase thanks to advances in photovoltaic technology. Thanks to that, solar power is currently the cheapest form of electricity available to humanity, according to Carbon Brief.

But the intermittent nature of solar energy production is a problem that experts are still struggling to solve. On a cloudy day, solar power plants produce less than when the sky is clear. At night, solar energy production stops completely. Battery systems and other forms of renewable energy can make up the difference. Up to now, nuclear power plants and thermal power plants still play a backup role.

Reflect Orbital's satellite weighs only 16kg and is equipped with a 9.9 x 9.9 m mylar mirror for deployment in orbit. Mylar is a plastic material used to make insulation and packaging in spaces. The mirrors will be adjusted to concentrate light into a narrow beam that can be redirected and focused based on the needs of the solar farm operator.

Last year, Reflect Orbital tested mirrors on a balloon floating 3 km above the Sun Farm. They can produce 500 watts of energy per square meter of solar cells. The company has called for enough investment capital to launch the first test satellite into space in 2025.