The UK government is now examining a plan that would reshape the entire foundation of national power delivery. It involves placing solar collection satellites in high orbit and transmitting the energy to Earth using precisely controlled microwave beams. The proposal is contained inside a recent government report that outlines a series of steps toward a future power system that operates far above the atmosphere. It is not a theoretical exercise. It is positioned as a possible path toward real output in the 2030s and a significant new energy platform by 2040.
At the core of the proposal is the use of satellites that remain in continuous sunlight. These platforms capture solar energy, convert it into electrical power, and transmit that power to Earth through a microwave beam aimed at what is known as a rectenna. The rectenna is a massive ground based receiver. The study sets that size at more than thirteen square kilometres for reliable operation. It is not a small array. It is a structure larger than many towns, built to absorb focused microwave energy and convert it into electricity that flows directly into the national grid.
The system requires perfect coordination between orbit and ground. The satellites move through a three hour path around the planet. During that time, the microwave beam must remain locked onto the rectenna footprint with extreme precision. The power arriving at the ground is stated at two hundred and thirty watts per square metre. This is within established safety ranges for public exposure, but only if the beam remains inside the controlled zone and only if the equipment performs exactly as designed. There is no full scale demonstration of this technology. The report depends entirely on modelling and laboratory scale tests.
The satellites cannot remain in stable sunlight without crossing through regions of intense radiation. These zones contain charged particles that degrade electronics and structural components rapidly. The report acknowledges this risk and states that the spacecraft must manoeuvre with consistent accuracy to remain operational. Each orbit requires the satellite to pass in and out of these zones, exposing it to conditions that shorten component life. In the event of damage or loss of attitude control, the transmission must be shut down immediately. The study does not provide tested shutdown times, nor does it show verified responses to real world hardware failure.
Early deployment is forecast to produce thirty one megawatts of power. This is an output level that falls below most terrestrial power stations. The justification for such a small initial yield rests on a scaling plan. Later generations rise to larger modules, higher efficiency, and heavier beams. The final stage of the projected system moves toward hundreds of megawatts and aims for baseload performance. The idea is to develop a system that can run through the night, in all weather, with consistent delivery and no interruptions. It replaces the variability of wind and solar with an orbital platform that is always in sunlight.
The most significant dependency in the plan is launch cost. The economic model is built on the assumption that heavy lift vehicles will reach launch prices far below current market rates. The study uses future projections that have not yet been achieved. The chosen rocket for the analysis is still under development and has not demonstrated the commercial performance required. Without dramatic reductions in launch cost, the system remains too expensive to operate at scale. The entire case stands on this requirement. If launch prices remain high or if development slows, the timeline collapses and the output targets fall with it.
The ground installation carries its own challenges. Building a thirteen square kilometre receiving field in the United Kingdom presents real demands on land use, planning, public acceptance, and grid routing. The rectenna cannot be placed just anywhere. It must be built in a region that supports the power pathway and allows transmission into the national network without large losses. It must also be located in a zone where microwave exposure limits can be maintained with confidence. The report lists Aberdeen as an early candidate site, but that location is only an example. Any real deployment will require extensive groundwork and regulatory clearance.
The transmission itself is based on microwave frequencies that pass through the atmosphere with minimal attenuation. These frequencies are used because they can operate reliably in heavy rain, fog, and cloud cover. They do not create the hazards associated with laser based systems. They are also easier to convert into electricity at ground level. The drawback is the requirement for extreme precision in beam control. A deviation of only a few degrees can reduce performance dramatically. The satellites must maintain accuracy while moving at orbital speed and while compensating for gravitational shifts, radiation pressure, and thermal deformation. These are solved only through engineering and continuous correction.
The long term picture presented by the study is a system that could operate as a renewable power source independent of weather and time. It removes the instability of intermittent output and replaces it with a controlled orbital supply. It is a bold concept. It is also one that comes with technical risks that have not been resolved. The microwave transmission has never been tested at full scale. The land requirements are vast. The orbital environment is hostile. The economic model depends on future launch performance that has not yet been achieved.
The UK is considering a future in which solar power is collected in space and delivered through directed microwave beams to ground structures the size of entire districts. The ambition is significant. The operational demands are intense. The report outlines a system with the potential to alter the structure of national electricity delivery while relying on hardware and conditions that remain unproven. The scale, cost, and technical risk place this project in territory unlike any other energy plan currently under discussion in the United Kingdom.
Source:
UK Department for Energy Security and Net Zero.
SBSP-Enabled Pathways to Net Zero: Final Report (RAF036).
Published January 2025.
Available at:
https://assets.publishing.service.gov.uk/media/698f167c7da91680ad7f43ad/SBSP-enabled-pathways-to-net-zero-final-report-raf036-2425.pdf
