Space solar power has been studied in the US since the 1970s, and in Asia since the 1980s.
Unlike ground-based solar panels, space solar power will be unaffected by weather. Unlike nuclear power, there are no dangerous byproducts. And unlike the burning of fossil fuels, space solar power is kind to our environment.
And this could work in tandem with space mirrors which would reflect sun rays towards these panels.
It’s not science fiction
Caltech is planning to put solar panels in space that beam power directly to earth with the purpose to reach totally clean, renewable, and affordable energy.
In fact, it’s more than thinking. It has just received $100 million in funding for its Space Solar Power Project (SSPP).
The project is described by Caltech as: “Collecting solar power in space and transmitting the energy wirelessly to Earth through microwaves enables terrestrial power availability unaffected by weather or time of day. Solar power could be continuously available anywhere on earth.”
SSPP will conduct a test launch of multifunctional technology-demonstrator prototypes that collect sunlight and convert it to electrical energy.
The project is not without its current shortcomings. It needs to collect enough energy to make economic sense and make sure that energy is not dissipated on its way down.
“[Launch] is currently expected to be Q1 2023,” co-director of the project Ali Hajimiri told TechCrunch. “It involves several demonstrators for space verification of key technologies involved in the effort, namely, wireless power transfer at distance, lightweight flexible photovoltaics and flexible deployable space structures.”
“The final system is envisioned to consist of multiple deployable modules and each module is several tens of meters on the side and the system can be built up by adding more modules over time.”
Mirrors and sun beams
Space-based solar power (SBSP) is approaching a critical threshold as a practical means of transitioning the world to green energy sources.
One way of collecting energy from space involves using colossal mirror-like solar reflectors hoisted onto orbital satellites — to concentrate solar energy from the sun onto solar panels. This energy would then transform the energy into electromagnetic radiation, and beam it back to Earth via laser or microwave.
On the ground, a rectifying antenna could capture the waves or various electromagnetic radiation from lasers, and transform them back into electricity to be pumped into a larger electrical grid.
The concept of SBSP “evolved over a very long time and is probably a couple of generations away from being hooked into the terrestrial power grid,” said James Vedda, senior policy analyst of the Aerospace Corp. Center for Space Policy and Strategy, during an October 2020 briefing, Space News reports.
Energy from solar arrays in space could power drones, internet-of-things (IoT) devices, and charging stations for the rapidly-approaching new generation of electric vehicles.
The potential for space-based solar power is growing every year. China is planning to build a space-based solar power station by 2035.
SBSP could be a solution to the energy problem
Transitioning to clean sources of energy is perhaps the most pressing item on the agenda to limit global warming to the 1.5 °C target set by the Paris Agreement. The energy sector is the world’s number one pollutant, accounting for over 30% of global greenhouse gas (GHG) emissions, according to the Centre for Climate and Energy Solutions.
In an average winter month in Europe, only 3% of sunlight reaches Earth, while satellites in space could gather energy for 99% of the year.
Secondly, it bypasses the problem of energy storage as the continuous stream of power from the sun would allow the energy to be beamed down directly when needed. Finally, the light in space, unfiltered by the atmosphere, is much stronger. For this reason, according to energy matching service Greenmatch, SBSP could generate 40 times as much energy as Earth-based solar power.
Despite its many advantages, there is one major drawback to this alternative source of energy: the astronomical cost. Currently, it’s commercially unviable, despite technological advances made in recent years having significantly lowered launch costs and which raised hopes for the future.