Japan is planning to send solar energy from space to Earth next year using microwaves. This development comes two years after American engineers achieved a similar feat and represents a significant advancement towards the creation of a space-based solar power station that could help reduce reliance on fossil fuels in the fight against climate change. Koichi Ijichi, an advisor at the Japan Space Systems research institute, outlined plans to test small solar power plants in space and transmit wireless energy from low orbit to Earth.
The experiment will involve a small satellite weighing about 180 kg and transmitting approximately one kilowatt of electricity from an altitude of 400 km. The spacecraft will utilize a 2 m2 solar cell to charge a battery pack, which will then convert the accumulated energy into microwaves for transmission to a receiving antenna on Earth. Given the fast speed of the spacecraft, antennas will need to be spread out over a distance of 40 km, with each antenna 5 km apart to effectively transmit energy. The project, known as the OHISAMA project, is set to launch in 2025 and has already seen successful ground testing of wireless transmission of solar power.
The concept of producing solar power in space was first proposed in 1968 by former Apollo engineer Peter Glaser, offering a constant and weather-independent source of renewable energy. As technology advances, the feasibility of space-based solar power becomes more promising. Recent developments, including successful demonstrations of solar power transmission from space, indicate progress in this area. However, challenges remain in ensuring continuous and carbon-free electricity supply in the future.
Despite advancements in autonomous technology and wireless power transmission, the cost of manufacturing, launching, and assembling a space-based solar power station remains high, making it less competitive compared to wind and solar power on Earth. While the potential benefits of space-based solar power are significant
