Tokyo (SCCIJ)—At the December Luncheon with more than 40 members and guests attending, Dr. Matteo Madi, Founder and Managing Director of the Swiss company Sirin Orbital Systems AG (SIRIN) from Zürich, discussed wireless power transfer as a resilient energy transfer method. His company was awarded the 2024 ‘Leading Innovation in Space’ Award by judges from Lockheed Martin, Viasat, and others among over 100 nominated companies within an international campaign led by the World Space Week Association. We summarize his talk in Q&A form.
Why should humanity go into space to harvest solar energy?
Mr. Matteo Madi: The sun supplies us consistently with clean energy. It is a stable and CO2-free energy source. However, ground-based photovoltaics only get less than 15% of the sun’s energy, while the energy availability factor of space-based photovoltaics is above 90%. As the Russian scholar Konstantin Tsiolkovsky, who came up with the concept of space-based solar plants, once jokingly said: Earth’s atmosphere and its clouds, fogs, and dust powders are bandits on the passage of solar energy to us on Earth.
One of the main problems is that the harvested sun energy has to be beamed from space to Earth. Are our technologies near that point?
M.M.: The idea of wirelessly sending energy had struck the inventor Nikola Tesla in the 1890s. He designed and built an early experimental wireless transmission station called “Wardenclyffe Tower” in New York in 1901-1902. Tesla convinced the financier J. P. Morgan to give him some money. Today, the wireless transfer of energy and electricity over long distances is feasible via the microwave spectrum. The main challenge is the construction of the giant infrastructure in space.
How would space-based solar energy plants work?
M.M.: Large Solar Power Satellites would harvest solar energy in space with solar panels, convert the harvested electricity to radiofrequency beams, and beam this energy to Earth into land-based receivers. Such systems can provide both baseload and dispatchable power at the Gigawatt (GW) scale essential for electricity grid balancing and stability. The generation of 1 GW power—the typical capacity of a nuclear power plant block— requires a surface of 2 square km solar cells, a 2 square km microwave antenna installed on the solar power satellite on-orbit, and a 2–4 square km receiving rectenna installed on the Earth surface. The Total Addressable Market represents the global energy market, with a total share of around 20% of the worldwide electricity demand.
Your company, SIRIN, has proposed a demonstration mission to European Space Agency. Could you explain more?
M.M.: The intended mission, “16U4SBSP”, would supply wireless electricity for space-to-ground or space-to-space commercial applications. In the proposed demonstration, a swarm of 16U CubeSats collaboratively supplies kilowatt-scale power to clients and end-users in different locations, for example, remote/strategic areas on Earth’s surface, for emergency operations in the blackout zones affected by natural or manmade hazards or in-orbit power supply to data centers or other in-orbit modules with auxiliary power requirements. This mission concept is a fundamental technology demonstration step for realizing GW-scale Space Based Solar Power, aimed to provide clean and limitless energy from space through wireless power transmission toward the middle of the 21st century.
What are other applications of this technology on Earth?
M.M.: One basic idea is to remove batteries from many devices and send them electricity wirelessly. Switzerland is a drone-country, Swiss start-ups are developing many drones for their use in inspection and monitoring of critical energy infrastructures. But they can only fly 28 minutes on average on a single battery charge. It would be easy to supply their energy from the ground, thus enabling their uninterrupted monitoring and inspection jobs. Similarly, many smart sensors attached to buildings could get their energy wirelessly. Then, nobody would be required to change the batteries regularly, which accounts for more than 114,000 tons of toxic environmental waste dumped into the environment yearly from dead batteries.
How feasible are currently large-scale solutions?
M.M.: One developing solution would be for off-shore wind power plants. Instead of enormous cable harnesses and floating substations, we would directly transmit the electricity from the plant to shore. Also, the inspection and monitoring drones used for such off-shore facilities (e.g., inspection of wind turbine blades) can continuously perform their operations by wirelessly receiving power from the wind power plant itself, rather than returning to the shore for recharging batteries. Furthermore, solar power plants in the deserts of the Sahara or the Middle East could upload their power to stratospheric balloons and transmit it to Europe; that would be a game-changing way of clean-energy generation and export. Another realistic application is from mobile operators working on supplying small smart devices directly with electricity because in the coming 6G networks, data and power transmission can be packaged together. The first successful test of this technology has been made in Japan.
Intense “electric beams” may harm human health and nature. How do you answer such concerns?
M.M.: Indeed, birds flying into a transmission channel between an offshore wind power plant and the coast would be fried as the radio frequency beam in such cases is well confined to enhance the end-to-end efficiency of wireless power transfer. We, at SIRIN, have invented a technology to warn birds about the existence of invisible high-power links, what makes them to refrain from crossing wireless beams. A prototype is currently being research researched and developed. Another problem still needs to be solved for the case of Space Based Solar Power. The warm area on the rectenna sites may attract birds that would stop their migration further South. But such issues are manageable. As for the human safety and when humans are exposed to radiation, our wireless power transfer systems shall always respect the International Commission on Non-Ionizing Radiation Protection’s guidelines on limiting exposure to Electromagnetic Fields.
What is your company, Sirin Orbital Systems AG, contributing to developing of this technology?
M.M.: We focus on high-efficiency transmitter and receiver technologies for wireless power beaming and receiving. Systems that are of high-performance and scalable for different smaller or bigger applications. In terms of use cases, we have already established quite a track record. For example, we use wireless transmission technology to support future lunar settlements and in-situ resource utilization (ISRU). The plan is to put a small nuclear reactor there, transmit the electricity produced with millimeter waves to receivers in ISRU sites or Moon villages, or relay this energy with a chain of transmitters/receivers to expletory rovers working in the shadowed craters. This setup makes transporting vast amounts of heavy cables to the moon unnecessary and enables continuous robotics operations.
About the speaker
Dr. Matteo Madi obtained his doctorate from the Swiss Federal Institute of Technology in Lausanne. He worked at the European Space Research and Technology Center (ESTEC), ESA. His company, Sirin Orbital Systems AG based in Zürich, specializes in developing advanced technologies for the diverse needs of the emerging space market. The company is also leading strategic cooperative projects with high-tech sectors in Japan.
Text and pictures: Martin Fritz for SCCIJ
