SOLARIS to Market: Europe’s Path from Concept Studies to a Fundable SBSP Programme
The direct sun reflection concept is ESA’s feasibility study to achieve commercial-scale space-based solar power (SBSP).
Credit: European Space Agency
What ESA’s work means for primes, utilities and investors eyeing space-based solar power
Europe is treating space-based solar power (SBSP) as more than a thought experiment. The European Space Agency’s SOLARIS initiative was set up to answer a commercial question: can Europe justify a full development programme, and on what terms? ESA’s brief is explicit—use 2023–2025 to prove technical, political and programmatic viability so that ministers can take an informed decision by the end of 2025. That clarity has pushed two parallel system studies and a raft of enabling activities rather than another open-ended roadmap.
The 2023 system studies (run by industrial consortia) are public enough to be useful. They frame end-to-end architectures—generation, in-space assembly, power beaming, rectenna reception—and lay out performance and mass budgets that move SBSP from render to spreadsheet. ESA has published the system study results and a Space-Based Solar Power overview that anchor key assumptions: microwave transmission, modular satellites built up by in-space assembly, and no need for exotic physics—just a lot of engineering at scale. For programme planners, that’s the difference between a moonshot and a managed risk.
Outside ESA, credible stakeholders are converging. The UK government commissioned Frazer-Nash in 2021 to assess feasibility and economics; the reports recommended a staged development and demonstration programme and later informed cost–benefit work used by developers. That policy signal turned into money: in 2024 London awarded multiple grants under the Space-Based Solar Power Innovation Competition (Net Zero Innovation Portfolio), and in 2025 backed follow-on studies (e.g., Space Solar) to mature commercial concepts. These aren’t guarantees of grid-scale deployment, but they do create a buyer–supplier conversation with real artefacts and deliverables, as opposed to a purely research-based scientific study.
A pragmatic feature of SOLARIS is its activity plan: parallel tracks in system design, in-space assembly (ISA), power-beaming, and stakeholder engagement. ESA has even issued calls to mature ISA capabilities because the satellites under consideration are too big to launch fully assembled. For primes and startups, that means a near-term market in robotics, modular structures and on-orbit integration tools—capabilities also valuable to commercial stations and lunar infrastructure. If SBSP scales, ISA suppliers will be the picks-and-shovels winners long before the first baseload contract.
What will energy buyers care about? Bankability more than elegance. Utilities and offtakers will want a line of sight to grid integration (rectenna footprints, interconnection, curtailment rules), spectrum coordination, and environmental assessments (e.g., sidelobe limits, land-use trade-offs). Here, ESA’s outreach matters: its summary of NASA’s 2024 SBSP assessment notes that if space access and key technologies continue to improve, SBSP could become cost-competitive on both price and emissions. That doesn’t close the business case by itself, but it gives CFOs and policymakers a reputable benchmark to cite when opening diligence.
For vendors, the go-to-market posture that lands with European buyers is service-centred and staged. Sell reference designs and simulation toolkits that let energy companies and regulators interrogate rectenna siting and grid impacts. Package in-orbit demos as availability services—clear SLAs on power-beaming duration, link stability and measured end-to-end efficiency—rather than one-off spacecraft sales. Tie ISA milestones to repeatable modules (docking nodes, truss segments, “sandwich” power-conversion tiles) so that learning compounds across flights. And create a credible regulatory pack in advance: spectrum filings, environmental templates and safety cases aligned to ESA’s published assumptions reduce administrative friction for customers and host nations. This is because ESA’s public study set is a shared reference the whole market can point at.
Risk needs to be narrated plainly. Programme volatility is real; ministerial decisions can slip or re-scope. Counter with customer mix (space agencies, defence users for austere-site power, early industrial pilots) and with partial-credit value—e.g., if a demo under-performs, the data still de-risks design and unlocks paid follow-ons. Insurance-backed terms (defined “delivered power” events; reflight rights) help procurement move from curiosity to contract. In parallel, keep publishing before/after deltas: what changed in beaming efficiency, assembly time, or thermal margins between demo A and B? Investors read that as progress they can price.
The market narrative, then, is less “Europe will beam gigawatts by 2035” and more “Europe is building the option”: a policy-anchored, industry-tested pathway that could yield a new clean-energy pillar if milestones keep falling. SOLARIS has done the unglamorous work—setting a decision date, funding parallel studies, and pushing enabling tech into the open—so that primes, utilities and financiers can debate SBSP on facts rather than fantasies. If that continues, future articles we write won’t focus entirely on feasibility; it will be about procurement.
