In a race to harness the potential of space-based solar power transmission, a pioneering Japanese public-private partnership is gearing up to conduct a groundbreaking space-based solar power trial around 2025. This ambitious initiative aims to revolutionize the way we generate electricity by beaming solar power collected in space down to Earth.
The concept of space-based solar power was first introduced by an American physicist in 1968, proposing the deployment of solar panels into space to generate electricity at an astonishing altitude of 36,000 kilometers. The technology operates by converting solar power into microwaves, the same electromagnetic radiation used in microwave ovens, which are then transmitted to ground-based receiving stations for conversion into electrical energy.
One of the driving forces behind this remarkable endeavor is a consortium led by former Kyoto University President Hiroshi Matsumoto. The group, which has been involved in space-based power research since the 1980s, has successfully pioneered the transmission of power via microwaves in space. Continuing their advancements, the team achieved a significant milestone in 2009, transmitting power from an altitude of 30 meters to a mobile phone on the ground using an airship.
Collaborating with the Ministry of Economy, Trade and Industry, the consortium embarked on a comprehensive industry-government-academia project in 2009, with Kyoto University professor Naoki Shinohara at the helm of the technology committee. Notably, the team achieved successful horizontal microwave power transmission experiments in 2015 and vertical transmission experiments in 2018, both covering distances of 50 meters. Looking ahead, the consortium has its sights set on vertical transmission over distances ranging from 1 km to 5 km.
Shinohara’s vision extends beyond technical achievements; he envisions this technology as a catalyst for international cooperation in space development. “If we can demonstrate our technology ahead of the rest of the world, it will also be a bargaining tool for space development with other countries,” he asserted, emphasizing the potential diplomatic implications of their pioneering efforts.
The consortium’s grand experiment, slated for fiscal 2025, will put their innovation to the ultimate test: transmitting power from outer space to the Earth’s surface. Employing small satellites, the team aims to send power to ground-based receiving stations situated hundreds of kilometers away, showcasing the feasibility of this revolutionary technology.
Japan’s endeavor is not taking place in isolation, as international competition in the field is heating up. The U.S. Air Force Research Laboratory and the California Institute of Technology are leading sizeable projects, while other players like Chongqing University in China and the European Space Agency are actively developing their own approaches to space-based solar power.
The renewed interest in space-based solar power comes as governments and businesses worldwide intensify their efforts to achieve net-zero carbon dioxide emissions. However, the formidable obstacle of cost remains a significant challenge. The generation of approximately 1 gigawatt of power using space-based solar would necessitate solar panels covering an area equivalent to a square measuring 2 km on each side. Despite technological advancements, the installation of this capacity is projected to exceed a staggering 1 trillion yen ($7.1 billion).
As the world watches with anticipation, the Japanese consortium’s upcoming experiment holds the promise of ushering in a new era of sustainable energy generation. With implications reaching beyond technology and into diplomacy, the pursuit of space-based solar power has the potential to reshape the energy landscape and contribute to the global fight against climate change.
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