What Happened
- Space-Based Solar Power (SBSP) has emerged as a major frontier in clean energy research, with multiple countries accelerating development in 2026
- Japan's JAXA is pursuing an ambitious programme to become the first nation to harness commercial solar energy from space
- China has announced plans to launch a 1-kilometre-wide solar panel array into orbit by 2028, capable of generating power equivalent to large oil reserves annually
- The UK government released updated studies in February 2026, with government-backed CASSIOPeiA architecture targeting commercial deployment within six years
- The United States demonstrated partial SBSP capability — Caltech's MAPLE project successfully beamed power to Earth in 2023
- India, alongside the US, UK, Japan, China, Russia and the European Space Agency, is among countries actively researching SBSP
Static Topic Bridges
Space-Based Solar Power: The Technology
SBSP involves placing large solar panel arrays on satellites in space — typically geostationary orbit (GEO) at approximately 36,000 km altitude — where sunlight is available 24 hours a day, 365 days a year without atmospheric absorption, cloud cover, or night cycles. The harvested energy is then converted into microwaves or laser beams and transmitted to receiving stations (rectennas) on Earth.
- Solar panels in GEO receive roughly 8 times more solar energy than equivalent panels on Earth's surface (no atmosphere, no weather, 24/7 sunlight)
- The most common transmission method uses microwaves (2.45 GHz or 5.8 GHz frequency) — microwaves can pass through clouds and rain with minimal loss
- Rectenna (rectifying antenna) arrays on Earth convert the microwave beam back into electricity
- The energy transfer efficiency across the full system (space to ground) is estimated at 20–30% currently, but improving
- Key technical challenges: high launch costs, assembling massive structures in orbit, thermal management of large solar arrays, beam accuracy/safety
Connection to this news: As nations race to deploy SBSP, the technology's promise of continuous, weather-independent clean energy makes it strategically significant — especially for energy-deficient regions. India's research interest aligns with its national solar mission goals.
India's Space Technology and Solar Energy Programmes
India's SBSP interest sits at the intersection of two national priorities — space capability (through ISRO) and renewable energy (through the National Solar Mission under the Ministry of New and Renewable Energy).
- ISRO (Indian Space Research Organisation) has been researching SBSP as part of its future mission roadmap
- India's National Solar Mission (part of NAPCC — National Action Plan on Climate Change) targets 500 GW of renewable energy by 2030
- India currently receives some of the highest solar irradiance in the world (5–7 kWh/m²/day in most regions), making ground solar attractive, but SBSP could supplement intermittency
- The Space Activities Bill (under development) seeks to regulate commercial space activities and could provide a framework for private SBSP ventures
- IN-SPACe (Indian National Space Promotion and Authorisation Centre) was established in 2020 to facilitate private sector participation in India's space economy
Connection to this news: As Japan, China, and the UK move toward deployment, India's strategic calculus must weigh entry into SBSP — both for energy security and for maintaining technological parity in the emerging space economy.
Geostationary Earth Orbit (GEO) and Its Strategic Importance
GEO is the orbital regime at approximately 35,786 km altitude where a satellite completes one orbit in exactly 24 hours, appearing stationary relative to Earth. It is the preferred orbit for SBSP due to near-continuous solar exposure.
- GEO is governed by the Outer Space Treaty, 1967, which declares space a "global commons" — no nation can claim sovereignty over orbital slots
- The ITU (International Telecommunication Union) allocates GEO orbital slots and frequency bands — demand for slots is increasing sharply
- GEO is also used for communication satellites (INSAT series in India), weather satellites (Meteosat, INSAT-3D), and early warning military satellites
- A 1-km-wide SBSP array at GEO would have a mass of several thousand tonnes, requiring heavy-lift launch vehicles or in-orbit construction using robotics
- Low Earth Orbit (LEO) alternatives for SBSP are also being explored to reduce transmission losses but require satellite constellations
Connection to this news: The race to deploy SBSP arrays at GEO also has geopolitical dimensions — orbital slots are limited, and early movers (China, Japan, US, UK) will gain first access to prime positions, making timely national SBSP programmes strategically important.
Microwave Wireless Power Transmission (WPT) and Safety
Wireless Power Transmission (WPT) using microwaves is the leading technology for transmitting solar energy from space to Earth. Safety concerns — particularly about high-intensity microwave beams — are a subject of ongoing research.
- The proposed microwave beam intensity at the rectenna site is designed to be lower than current safety standards for microwave exposure (typically 1 mW/cm² at the perimeter)
- Microwave beams at 2.45 GHz can be deflected/redirected in case of off-target pointing errors using pilot signal-based guidance
- The diffuse nature of microwave transmission means the beam spreads significantly over 36,000 km — reducing intensity but requiring very large rectenna arrays (typically several km wide)
- Laser-based WPT is more precise but is affected by atmospheric absorption and cloud cover
- The International Academy of Astronautics and IEEE have published safety standards for WPT systems
Connection to this news: As SBSP moves from concept to prototype, WPT safety standards will require international coordination — making this a topic relevant to both technology governance and international space law.
Key Facts & Data
- Optimal orbit for SBSP: Geostationary Earth Orbit (GEO) at ~36,000 km altitude
- Energy advantage: GEO satellites receive ~8× more solar energy than Earth-surface panels
- Energy transmission method: Microwaves (2.45 GHz or 5.8 GHz) or lasers
- China's plan: Launch 1-km-wide solar array into orbit by 2028
- US milestone: Caltech's MAPLE project demonstrated space-to-Earth power beaming in 2023
- UK's CASSIOPeiA architecture: targeting commercial SBSP within 6 years
- India is among the countries (with US, UK, Japan, China, Russia, ESA) actively researching SBSP
- India's solar target: 500 GW renewable energy by 2030 (National Solar Mission)
- SBSP governed by: Outer Space Treaty, 1967; orbital slot allocation by ITU