NASA, the European Space Agency (ESA), and the British government are dusting off a decades old idea to beam space-based solar energy to Earth from an array of orbiting satellites beaming power by laser or microwave to help reach net-zero carbon emissions by 2050, and other nations including China, Japan, and South Korea are doing the same.
Once dismissed as technically impossible and far too expensive even if the technology existed, space-based solar power (SBSP) is again being assessed as a potential source of limitless clean energy as public and private sectors in space-faring nations are now seriously considering developing their own SBSP systems.
The UK government’s Department for Business, Energy, and Industrial Strategy commissioned a study by the UK-based Frazer-Nash Consultancy that was released in September 2021. Entitled Space Based Solar Power—De-Risking the Pathway to Net Zero, the study identified the following as drivers in renewed interest in SBSP.
- A new political will exists now as countries seek diverse technologies to decarbonize their economies and reach net zero by 2050.
- The costs of commercial space launches have dropped dramatically as private companies enter the market.
- New highly modular solid-state solar-power satellite designs such as SPS-Alpha and CASSIOPeiA have been conceived for high-volume commercial manufacture. This also lowers costs.
- Technologies required to make SBSP a reality have matured. These include high-concentration solar photovoltaic (PV) panels, wireless power transmission, and space robotics.
- Countries view their ability to provide unlimited affordable energy from space to any point on the planet as a way to leverage global influence, evidenced by the fact that not only Britain and Europe have recently renewed their interest but also the US, China, Japan, and South Korea.
At the end of May, Nikolai Joseph, a policy analyst for NASA’s Office of Technology, Policy, and Strategy, told the International Space Development Conference of the US National Space Society that NASA is re-evaluating the viability of SBSP after having abandoned the concept as unworkable decades ago.
Like the UK government, NASA has commissioned its own study to revisit past concepts for collecting solar energy in space and beaming it to earth to feed as electricity into local power grids. The study will compare Earth-based power systems and assess costs and policy issues related to implementing the concept, according to the industry media SpaceNews.
Studies that found costs prohibitive date as far back as the 1970s. Joseph told the conference that as part of its reboot, NASA has discussed SBSP with the US Space Force and other “technical agencies.” NASA plans to complete its study to present in September at the International Astronautical Congress in Paris.
US Defense Funding of SBSP Research
The UK’s Frazer-Nash study noted at the time of the study’s release that the US Department of Energy had no civilian energy policy with respect to SBSP.
But Washington, DC, was pursuing “a $180-million defense research program lead by Northrop Grumman and the US Air Force Research Lab (AFRL) to develop and demonstrate technology including lightweight sandwich panel PV/RF modules, and lightweight extendable mirrors, under the SSPIDR (Space Solar-Power Incremental Development and Research) Project,” Frazer-Nash noted.
The US Naval Research Lab was also conducting power collection and conversion experiments in space on the X-37B space plane.
The UK has evaluated two baseload solar-power satellite (SPS) designs and declared them feasible from an engineering standpoint to beam SBSP to the UK: the SPS-Alpha designed by Mankins Space Technology in the US, and CASSIOPeiA, developed by International Electric Company in the UK. Both are modular, solid-state designs that can be mass manufactured.
From a geo-synchronous orbit, CASSIOPeiA (constant aperture, solid-state, integrated, orbital phased array) would convert solar radiation into microwaves that are beamed to an Earth-based rectifying antenna that feeds into a local power grid. SPS-Alpha also works as a microwave transmitter.
China’s Chongqing Collaborative Innovation Research Institute for Civil-Military Integration has been conducting power-beaming experiments and is building an SBSP testing facility. The UK study noted that China established a new Committee for Space Solar Power in March 2021, an apparent followup to the SBSP roadmap announced in 2015 by the China Academy for Space Technology.
Together with several private organizations, the Korea Electrotechnology Research Institute is involved in power-beaming activities, and Japan’s Aerospace Exploitation Agency has conducted wireless power-transmission experiments in space, following its own roadmap for commercial development of SBSP.
ESA Seeks To Develop a Business Case for SBSP
In Q1 2022, ESA awarded contracts for two separate cost-benefit analysis studies, each based on a different technical solution to develop a business case for providing SBSP to Europe using orbiting solar-power stations and terrestrial renewable power plants. Frazer-Nash will complete one study; the Munich-based Roland Berger consultancy will develop the other, with both planned for release at the end of summer 2022, according to ESA.
In January, ESA said it would fund 13 of the 85 proposals it received after it put out a call for ideas related to SBSP over the agency’s Open Space Innovation Platform. As ESA explains on its website: By coming “close to the theoretical transmission efficiencies via electromagnetic waves (50–60%) … we could produce around 400 W electricity per square meter on Earth receivers, which is about two to three times the amount we could receive from the same area of terrestrial PV panel,” 24/7.
A recent article in Forbes noted that microwave-beaming systems could transmit up to 1 GW of energy to terrestrial receivers, enough to power a large city, whereas laser systems produce 1 to 10 MW per satellite and so would require a network of hundreds of satellites.