Could 24/7 solar power from orbit be the answer to the world's future energy challenges? KATE ARKLESS GRAY reports from the International Conference on Energy from Space 2024, held at RAeS HQ, on 17-19 April.
On 17-19 April, a high-level conference with UK Department for Energy Security and Net Zero, Royal Aeronautical Society (RAeS), UK Space Agency and ESA took place at RAeS HQ.
RAeS Past-President Howard Nye welcomed delegates to the conference. (Tim Robinson/RAeS)
With a schedule packed to bursting and a sense of energy and optimism in the room, the International Conference on Space-Based Solar Power brought international experts on the topic together to spend three days exploring the latest thinking, research and challenges. Representatives from government, industry and academia shared their passion and optimism about space-based solar power (SBSP), unveiling innovative new concepts – both for technology and funding - and considering the challenges that must be overcome to make it a reality.
Following a welcome from Howard Nye, Chair of the RAeS Space Specialist Group, the conference was opened by Anna Stephenson, Deputy Director for Engineering and Research at the UK Department for Energy Security and Net Zero (DESNZ). Anna cited the 2021 Frazer-Nash feasibility study that concluded that space-based solar power would be technologically and economically feasible by 2050, and spoke of the need to work internationally, share knowledge, and overcome challenges together.
“It doesn’t get much more exciting than sending solar-power satellites into space and getting near unlimited energy” said Amanda Solloway MP, Parliamentary Under Secretary of State (Minister for Affordability and Skills), also from DESNZ. In her keynote on the UK’s energy future, she acknowledged that the development of space-based solar power will take years, but said that the UK government wants to invest now, and highlighted the announcement of £1.1m funding for UK firm Space Solar.
“We need optimism and realism” she said, “progress doesn’t come overnight, it’s gradual”. She was positive that this conference was important for “turning an idea into a sector”.
Everyone at the conference agreed on the urgent need to take action on climate change, and there was a real buzz in the room about the potential that space-based solar power has to help us to reach net zero.
The idea of SBSP can be traced back to 1968 when it was first proposed by Czech-US engineer Dr Peter Glaser. Traditionally the term has referred to a system where energy from the Sun is collected by a solar farm in space, and then converted and beamed down to Earth (or other locations such as the Moon). At the conference, several concepts involving large mirrors to reflect sunlight down to existing solar farms on Earth were also presented.
When SBSP was first proposed, there was no economically feasible way to launch all the required elements into space, but as launch costs come down, and new heavy-lift rockets come on the market, this could be about to change.
No bucks, no Buck Rogers?
How many launches will construction of giant solar arrays need? (ESA)
This point was made by Dr Mamatha Maheshwarappa, Head of Research and Development at UKSA, as she talked about the growing energy needs of the global population vs the need to address climate change. Studies suggest that to reach net zero, around 90% of energy must come from renewable sources, and the UK is funding research into SBSP concepts and technology, both through the Space Agency, and the Department for Energy Security and Net Zero.
A limitation of terrestrial solar farms is that power creation is intermittent and interrupted by nightfall or cloud cover. A key benefit of SBSP is that not only is the intensity of light higher since it has not passed through Earth’s atmosphere, but with the correct choice of orbit, you have a continuous source of clean energy, unlimited by Earthly weather constraints. Using a microwave beam to send power back to Earth avoids the need to worry about cloud cover, since microwaves can pass through cloud. It sounds like an elegant solution to the energy crisis, so why don’t we already have SBSP?
One issue is that the structures required to make this work are truly enormous and will require tens, if not hundreds, of rocket launches. Satellites have been getting smaller and smaller, but a space-based solar farm is at the other end of the scale from a (10 x 10 x 10 cm) CubeSat, with a commercially viable solar farm spanning multiple square kilometres.
The sheer scale of SBSP elements was just one of many technical, financial, and regulatory challenges that was discussed at the conference. These will need to be overcome before SBSP moves from sci-fi, to something that powers your kettle for your morning cuppa.
Dr Paul Bate, CEO of the UK Space Agency, introduced us to the idea of “professional positivity” as he described the UK’s approach to SBSP. He also reminded us that while space is exciting, the Agency must always think about their activity in terms of how it benefits the UK on the ground. With SBSP he sees a “collective opportunity, but a fiscal challenge”. The UK wants to take the lead in SBSP and has already committed £5 million to ESA’s Solaris project. Investment in research is not coming solely from the space agency, but also from other parts of government such as the Department of Energy Security and Net Zero (DESNZ). A good example of what became a key theme of the conference, the reminder that SBSP is more than just a space issue, is an energy issue, and needs to be communicated as such.
Dr Sanjay Vijendran, Lead on ESA’s Solaris initiative on SBSP, commended the joined-up approach taken by the UK government. “The rest of Europe is not quite there yet” he said. Funding is still a big issue, and Sanjay spoke of the need to communicate the high value proposition of SBSP and look at how it can be de-risked to encourage further investment. ESA’s Solaris initiative, which began 18 months ago, is taking a holistic view of the work that is needed before a full development programme could begin. Research activities include looking at the impact of radio waves on Earth’s atmosphere, the environmental impact of launches, and life cycle analysis and sustainability. ESA is still inviting research proposals on how SBSP may impact human health and flora and fauna. Solaris looked at both traditional power beaming SBSP and direct Sun reflection with large scale mirrors. “At ESA we think that there is a place in the future for each of these concepts for getting energy from space to Earth” he said.
No matter which way you come at it, the issue of finance cannot be avoided, and while David Homfray of Space Solar joked that “with an infinite amount of money you can build anything” he added that “we’re looking at the economics of a 5 x 2 km spacecraft”. It’s impossible to ignore the huge need for investment if SBSP is to become a reality. As the old saying goes: “No bucks, no Buck Rogers”.
A variety of different funding mechanisms were put forward during the course of the conference. There appeared to be general agreement that initial research and development would require government backing, but also that government funding alone isn’t likely to be of the magnitude required to get to developing a fully functional SBSP plant. Estimates for the cost of an operational SBSP plant are in the multi-billions of pounds, although when you consider the global electricity market is worth approximately 4.1 trillion euros, and that in 2023 around 1.7 trillion euros was invested into clean energy, the costs don’t seem quite so astronomical.
SBSP as a green future
Dr Meganne Christian FRAeS spoke about the link between SBSP and climate change. (Kate Arkless Gray)
ESA reserve astronaut Dr Meganne Christian opened the proceedings on day two and counselled the audience on the need to ensure we position space as part of the solution, rather than part of the problem. “We have not been clear enough, loud enough, strident enough to show that using space for a green future is a guiding principle of our sector”.
There was a refreshing amount of discussion about the need for communication and engagement over the course of the conference. Raising awareness of SBSP within the energy sector is essential - not only to get them on board from an investment point of view, but also to figure out how best SBSP should be integrated into existing power networks. The need for engagement doesn’t end there, and the fact that this conference was co-organised by DESNZ, UKSA and ESA is testament to the work done by the Space Energy Initiative.
Mark Garnier MP, Chair of the All Party Parliamentary Group on Space, perfectly summed up the need for clear communication when he shared two personal experiences in parliament. When he began making the case for SBSP, the (then) Energy Minister “shrugged his shoulders and said, ‘it’s space, it’s not for me’”. Having pointed out nuclear power plant discussions are not directed to DEFRA just because the power plant is located in a field, he got the meeting he wanted. He also spoke about a fellow MP whose first question on SBSP was whether the power beam could be turned into a “military death ray”.
Engagement with industry, government, academia and the general public is vital and needs to be actively considered. Allowing robust challenges, and converting previously sceptical people into ambassadors for SBSP is something that Sam Adlen and Martin Soltau, co-CEOs of Space Solar discussed during their fireside chat with Sanjay Vijendran. A dedicated session on public engagement, chaired by ESA’s Dr Nicol Caplin, underlined the need to engage the public, being mindful that it is likely to be decades before SBSP comes to fruition. In an earlier session, David Homfray of Solar Space drew on his experience working in fusion power. “It’s about taking people on the journey, talking about net zero, jobs, regional growth, and innovation” he said. “If we can’t excite the general public, we’re failing at our jobs”.
Challenges
Societal approval of beaming power from space could be a challenge. (ESA)
Aside from financial and launch capacity issues, there are still lots of hurdles that need to be overcome to allow SBSP to progress. The conference was so info-packed that there is only space to give a flavour of the topics covered, which included technology, geopolitics, safety, and sustainability to name a few.
Industrial cyber security consultant Charlie Hall, from Frazer-Nash, gave an overview of strategic and security issues related to SBSP and its operational technology (i.e. the physical assets both in space and on the ground). Threat actors such as nation states and organised criminals have been known to attack energy infrastructure in the past, so this needs to be considered. He advised that security be built in to designs from the start, and said regulation could play an important part in ensuring system security standards.
The idea that SBSP hardware may be targeted by nation states ran somewhat against the positive sentiments and belief in international partnership and cooperation elsewhere in the conference. “Energy is a commodity. Nation states will all compete” said Maciej Bukowski, an energy policy expert at the Centre for European Policy Analysis. “I wouldn’t bet my money on there being an international SBSP project.”
The session on safety and security ended with a question to the panel about whether they considered any of the risks they identified to be ‘showstoppers’. For Maciej it wasn’t that a geo-political issue would be a showstopper in itself, but that if anything were to happen it would spook potential investors and put projects at risk. Charlie Hall from Frazer-Nash had warned of security threats to physical elements of an SBSP plant during his talk, but concluded that good regulation, and security built in from the start would prevent security being a showstopper. He was however concerned about societal approval of SBSP and warned that lessons needed to be learned from the roll-out of 5G and the disinformation and conspiracy theories that emerged. Peter Death from CGI raised the alarming idea of an intentional collision with a large solar farm structure in space, resulting in a debris field that could knock out an entire segment of orbit. Thankfully Stella Tkatchova from the European Innovation Council sounded a more positive note as she brought the session to a close. Acknowledging the need to think about space debris, signal jamming, and robotic assembly, she pointed out that “we do have experience as an industry in risk analysis and redundancy planning”.
In terms of technology, there were calls for Europe to develop its own reusable heavy lift vehicle, discussions around the use of AI, and the need for spacecraft to work autonomously in space. There was also discussion of the role of robotics for in-orbit assembly of mega structures, the need for a true demonstration of power-beaming from space (rather than the relatively short distances where it has been shown to work on Earth), manufacturing capability, the use of space-tugs to move structures to GEO, and improving the efficiency of photovoltaic cells, which would benefit both space and terrestrial solar farms.
Questions were asked about how SBSP could comply with existing regulations on space debris, ensuring that SBSP plants are built, and decommissioned, sustainably, and the need for clarity on which body would regulate and provide frequency licensing for power beaming was raised. The conference heard from Eric van Rongen from the International Commission on Non-ionising Radiation about the existing regulations to protect human safety and ensure that power-beams are not dangerous for health. While Dr Andrew Williams from the European Southern Observatory made the case for protecting dark and quiet skies for astronomers and called for the SBSP sector to collaborate with astronomers and satellite companies that have already developed measure to reduce their impact on astronomy.
Whatever the challenge area, be it policy and regulation, technology, insurance, skills, manufacturing, safety or sustainability, the repeated take away was that early consideration or risks and mitigation is the best, and cheapest solution. However, the call for additional analysis was energetically countered by Robert Smith of the Space Studies Institute, who showed images of the piles of studies undertaken over the years. He was hungry for hardware. “This is only going to happen if hardware is funded and built” he said, prompting a loud “amen” from someone in the audience.
A crucial takeaway was that government alone cannot fund SBSP, but that investors won’t put their money in until SBSP has been adequately de-risked. This could be through improving the technology readiness levels using government funding or preparing consistent international regulatory frameworks. “No-one wants to be alone on the dancefloor” commented Maciej Bukowski. “Government is the DJ, increasing trust and helping bring investors to the floor”.
How far away is SBSP?
Anna Stephenson from the UK Dep of Energy Security and Net Zero. (Tim Robinson/RAeS)
The question of how long until we see a full-scale commercial SBSP plant doesn’t come with a simple, or definitive answer. Opening the conference, Anna Stephenson, Deputy Director for Engineering and Research at the DESNZ, cited the 2021 Frazer-Nash feasibility study that concluded that space-based solar power would be technologically and economically feasible by 2050.
John Mankins is rather more bullish, confident his architecture, if funded, could be up and running in a decade, while UK company Space Solar has a 12-year roadmap to an industrial power plant in GEO, albeit with lower output than the 1-2 GW considered in other architectures. Panellists in the Commercialisation and Scaling session guessed we would see a commercial SBSP station in 2035, 2040, 2045, and “twenty years after the technology becomes feasible”.
Global progress
In January this year, NASA released a new study to examine the feasibility and potential impact of SBSP. (NASA)
Updates on SBSP research initiatives around the world show that progress is (albeit slowly) being made. The UK is funding research in areas such as wireless power transmission and mission architecture feasibility, with money coming both from UKSA and DESNZ. ESA’s Solaris initiative is looking at how SBSP can be de-risked to encourage further investment, while the president of the Italian Space Agency, Professor Teodoro Valente, said “the significance of SBSP cannot be overstated in an era of climate change” and was positive about their collaboration with the UK.
A video address from Charity Weedon, the Associate Administrator of NASA’s Office of Technology, Policy, and Strategy referenced a report they published earlier this year comparing SBSP to other renewable energy solutions. They concluded that SBSP needed reduced costs and emissions to make it competitive, and that there are still technology gaps that need to be bridged. Although NASA doesn’t have an active SBSP programme, Charity said work on projects on wireless power transmission, materials science and autonomous vehicles could help overcome some of the existing hurdles, and that they regularly re-evaluate their decisions. Presentations from DARPA and the US Air Force Research Laboratory confirm the US has an ongoing interest in SBSP outside of NASA.
Dr Koji Tanaka of JAXA introduced us to their OHISAMA project, a planned on-orbit experiment looking at precision beam control using a small satellite for microwave beam transmission. “Ohisama” means sunshine in Japanese and Japan’s activity is focussed on precision power beaming and how this might be used to deliver power to permanently shadowed craters on the Moon, which will be important for future lunar exploration. The Korean Aerospace Research Institute has been conducting wireless power transmission experiments and has successfully beamed power over a distance of 1.8 km on Earth. Their roadmap sees them validating technology in low-Earth orbit in the 2030s, creating a megawatt class platform in low-Earth orbit in the 2040s, and a gigawatt class plant in GEO in the 2050s.
China also has an active interest in SBSP. In a video address, Xinbin Hou, from the China Academy of Space Technology talked about their activities and shared a draft roadmap for planned technology demonstration missions. Starting with tests of a single module in space from 2026, to an array in low-Earth orbit that could deliver 500 kW in 2030-2035, and a whole solar array in GEO providing 200 MW in 2035-2040. They aim to build a full-scale solar array in in GEO which could deliver 2 GW in 2050. Hou spoke of the need for international cooperation and called for a formal international organisation to set the required regulations, policies and standards for SBSP.
Professor Paul Monks, Chief Scientific Advisor at DESNZ, observed that countries with the greatest need for clean energy, might not be the same as those who can afford SBSP. This raises the ethical question of how the world can reduce its reliance on fossil fuels without unfairly impacting developing nations who rely on them.
Conclusion
Are projects like this Cassiopeia SBSP now within reach? (Space Solar)
Over the course of the conference several things became clear. There is huge passion and energy in the SBSP community, which needs to further expand to include not just the space industry, but also energy, government, policymakers, and communicators. The current “coalition of the willing” will likely evolve into a more formal industry body, to begin to tackle the challenges around funding and investment, and begin chipping away at the barriers to progress.
There is certainly lots of work yet to be done, challenges to be overcome, both technically and financially, but if this conference was anything to go by there is plenty of desire to fast-track the sci-fi of the past into the reality of the future.
No-one can deny the impact of climate crisis, and action is urgently needed to cut down on use of fossil fuels, but whether SBSP will reach maturity in time to contribute to achieving net zero by 2050 is neither certain, nor out of the question.