Introduction to SBSP:

Figure 1: SSP concept

Space solar power (SSP) is the most efficient theoretical concept to generate and transmit solar-powered electricity to the earth. The beauty of the concept lies in the ‘never-ending’ delivery of clean renewable energy to terrestrial power grids. Some of the important benefits lie below:

  1. Geosynchronous satellites (GEO) contain mirrors which focus sunlight onto photovoltaic (PV) panels.
  2. Photons are converted into DC energy here.
  3. DC energy is then converted into radio frequency (RF) or microwave energy.
  4. On Earth's surface, a rectifying antenna ("rectenna") beams the RF ray from a wireless power transmitter.
  5. Rectennas convert RF beams into DC electricity that is transmitted via wire to the local power grid.

Figure 1 shows a diagram of the SSP concept.

History of Space Based Solar Power

"Reason" is a 1941 science fiction short story by Isaac Asimov, in which a space station uses microwave beams to transmit solar energy to various planets. In November 1968, SBSP, originally called SSPS, was first described. A U.S. patent number 3,781,647 was granted to Peter Glaser in 1973 for his method of transmission of power over long distances (e.g. from a satellite to Earth's surface) using microwaves from a large antenna (up to one square kilometre) on the satellite to a much larger antenna on the ground.


Some historical concepts from archives are below.

Concept 1 –

Concept 2 –

Concept 3 –

Concept 4 –

Some applications:

Application-based ideas backing the export of Renewable Energy generation technology to space are as follows:

  • Remote mining operations for fuels
  • Powering Infrastructures essential for life support including water, oxygen, etc.
  • Supply of energy to grow plant-based food
  • Providing auxiliary power to satellites, rovers, etc.
  • Generation of power for earth from space

THE FIRST 10,000 DAYS ON MARS (Timelapse

Why Space-based Solar Power (SBSP)?

Space-Based Solar Power offers a range of desirable characteristics:

Energy Generation

  • Continuous power generation, 24/7, 365 days/year 
  • Gigawatt levels of base-load energy generation
  • Green hydrogen generation for the transport sector

Security and Economics

  • Security and resilience to political or terrorist action
  • Affordable LCOE for homes and industry
  • Long term security of fuel supply

Grid Integration

  • Readily integrated with existing Grid infrastructure
  • Low intermittency, high predictability
  • Dispatchable, high load factor

Environmental Impact

  • Fully sustainable, renewable energy source
  • Low carbon payback period
  • Low environmental impact (footprint, land use)

Delivering Net Zero

  • Roadmap for orbital demonstrator by 2031
  • Operational system could be developed by 2040
  • Scalable to provide a substantial proportion of energy

Flexible Energy

  • Export opportunities for energy and technology
  • Power for humanitarian disaster relief
  • Power for spacecraft and lunar operations

See Also10 Strong Reasons – Why solar energy is important for the future

Are SBSP a feasible approach?

Yes, it is feasible. Most space agencies are developing several SBSP projects estimated to be completed by the year 2050. Let’s have a look at the risks involved as below:

What are the risks?

Development of Space-Based Solar Power would be a substantial undertaking, primarily because of the size of the system, and the need to assemble and integrate this in space. The solar power satellite would be an order of magnitude larger in mass and extent than any spacecraft currently in orbit.

One of the major considerations in achieving the necessary performance is the power-to-mass ratio (kW/ kg) of the solar power satellite. This requires a low system mass, and efficient power transfer through the energy chain from the solar photovoltaic panels in space, to the electricity grid.  The overall power-to-mass ratio is around 0.5 – 1.0 kW/kg, which is considered ambitious but feasible given a development programme.

The key risks and considerations are:


  • Integration with energy policy
  • Land use – rectenna sites
  • Development timescales
  • Integration with national infrastructure
  • Responsibility and security of operations
  • International collaboration


  • LCOE vs another renewable tech
  • Development funding / long ROI
  • Economics of space launch
  • Industrial capability


  • Public acceptance of technology
  • Demonstration and acceptance of Safety


  • In-orbit robotic assembly, maintenance
  • Lightweight sandwich panel modules
  • Size and scale of satellite
  • Wireless power transmission efficiency
  • Accurate energy beam pointing and control
  • Operational life in space environment


  • Development of regulations
  • ITU spectrum allocation for WPT
  • Orbit allocation for satellite

Environmental and safety

  • Rectenna site environmental impact
  • Through life carbon/sustainability
  • Proving long term operational safety
  • Decommissioning strategy / orbital debris

Why it is feasible now?

Long seen as an attractive but unaffordable source of clean energy, the proponents of Space-Based Solar Power suggest that over the last decade it has become both technically feasible and economically viable.

There are several reasons behind this renewed global interest in Space-Based Solar Power:

  • Net Zero: Both the urgency and technical challenges of decarbonising economies are driving nations to look at new technologies;
  • Commercial space launch: The cost of space launch has fallen dramatically in recent years and this trend is set to continue;
  • Modular satellite designs: New highly modular solid-state solar power satellite designs have been conceived which are designed for high volume commercial manufacture, and are thus far more affordable than previous concepts;
  • Technologies maturing:The underpinning technologies of high concentration solar photovoltaic panels, wireless power transmission and space robotics are rapidly maturing;
  • Strategic self-interest:Other nations may see the strategic advantage and global influence in being able to develop a source of abundant affordable energy which could potentially be beamed anywhere in the world.

SBSP launch costs:

To understand the launch cost scenario let us take a solar panel mass of 20kg per kilowatt (Exclusive of the mass of supporting components like structure, antenna, focusing mirrors, etc.), 80,000 metric tons can be the weight of a 4GW power station.

SBSP launching cost still thwarts the optimists, given the practical scenario of space payload launch technologies and the cost associated. However, as more and more commercial and cost-effective launching technologies are coming due time, we are optimistic that SBSP can be soon turned into reality towards a sustainable future, just as we at Waaree are growing towards the technological breakthrough of a PV module technology, having developed technologies like MBB, HJT, Merlin PV modules.

How Waaree can help?


Waaree Energies Ltd. is the flagship company of Waaree Group, founded in 1989 with headquarters in Mumbai, India. It has India's largest Solar panel manufacturing capacity of 5GWs at its plants in Surat and Umbergaon in Gujarat. Waaree Energies is amongst the top players in India in Solar Panel Manufacturing, EPC Services, Project Development, Rooftop Solutions, and Solar Water Pumps and is also an Independent Power Producer. Waaree has its presence in over 380 locations nationally and 20 countries internationally. Step on to your cleaner journey by contacting us at 18002121321or mail us at



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