Japan is preparing to take a major step in space-based renewable energy with the upcoming launch of a 400-pound satellite in 2025 under the OHISAMA project. The initiative seeks to test the feasibility of wireless transmission of solar power collected in space and sent back to Earth.
The satellite will be equipped with a 22-square-foot solar panel, designed to capture sunlight continuously in orbit—uninterrupted by nighttime or weather conditions. The energy will then be converted into microwave signals and transmitted to multiple ground-based receiving antennas spread across 25 miles. The experiment will attempt to deliver about 1 kilowatt of power, enough to operate small household appliances, directly from space to Earth.
If successful, the project could validate a long-envisioned concept: harvesting limitless solar energy from space and transmitting it wirelessly to Earth, where it could be integrated into the grid as clean power. Unlike terrestrial solar farms, space-based solar power would not be affected by cloud cover or the day-night cycle, offering a constant and reliable energy source.
Japan has been a pioneer in this field, with its space agency JAXA studying space-based solar power (SBSP) for decades. The OHISAMA project will serve as a crucial proof-of-concept, paving the way for larger-scale demonstrations in the future. Experts believe that if scaled successfully, space solar power could become a game-changer in the global transition to renewable energy, potentially supplying power to cities and reducing dependence on fossil fuels.