Laplace has warned that “space photovoltaics” — the idea of harvesting sunlight in orbit and beaming power to Earth — remains at the stage of technical exploration rather than commercial deployment. The comment underscores a growing gap between bold political ambitions for space-based energy and the engineering, economic and regulatory obstacles that still stand in the way.
Space photovoltaics, often discussed under the rubric of space‑based solar power (SBSP), promises a seductive set of advantages: near‑continuous exposure to sunlight, higher solar intensity without atmospheric losses and the prospect of supplying power to remote or strategically important locations on demand. That potential has drawn renewed interest from governments and private actors worldwide as terrestrial renewable deployment runs into land, transmission and intermittency constraints.
But the road from laboratory demonstrations to terawatt‑scale delivery is littered with hard problems. Engineers must solve safe and efficient long‑range power transmission (via microwaves or lasers), build ultra‑lightweight and highly efficient arrays that can survive the space environment, and develop reliable, low‑cost methods for in‑orbit assembly and maintenance. Each requirement interacts with the others: heavier, more robust hardware raises launch costs; lighter systems increase deployment complexity and susceptibility to degradation.
Economics remains the decisive barrier. Even as reusable rockets and automated in‑space manufacturing chip away at launch and assembly costs, space solar must compete with ever‑cheaper terrestrial photovoltaics paired with battery storage and demand‑management technologies. For space systems to become competitive they will need sustained reductions in launch price, breakthroughs in power‑beaming efficiency and credible long‑term maintenance models — a set of advances that together suggest commercialization is likely decades, not years, away.
The technology also carries strategic and governance implications. A functioning SBSP system would be dual‑use by design: its ability to deliver power anywhere could be valued for civilian resilience, disaster response and off‑grid supply, but it also raises questions about military utility, space traffic and the safety of high‑power beams crossing national airspace. International rules, frequency allocations and norms of behaviour in orbit will be as important as engineering milestones in determining whether space photovoltaics becomes an asset or a risk.
Laplace’s blunt assessment is a corrective to inflated expectations. It points policy makers and investors toward a sober, long‑term approach: fund incremental demonstrations of power transmission and on‑orbit assembly, build international safety and licensing frameworks, and treat large capital bets as contingent on demonstrable, narrowly scoped successes. Until those milestones are met, space photovoltaics will remain a compelling research agenda rather than a near‑term solution to the world’s energy challenges.