Solar radiation from space used to be considered science fiction. But in recent years, space agencies around the world have launched studies into the feasibility of building real power plants in orbit.
Such projects would be difficult to pull off, stakeholders agree, but as global attempts to curb climate change continue to fail, such moonshot efforts may be necessary.
According to the United Nations Panel on Climate Change (opens in a new tab), the world is on track to warm by 4.5 degrees Fahrenheit (2.5 degrees Celsius) by the end of the century. That’s 1.8 degrees F (1 degree C) above the threshold considered safe by the international climate science community to avoid disastrous consequences of climate change.
In fact, to limit warming to anywhere near this threshold, the world’s economies would have to cut their greenhouse gas emissions by 45% by 2030. This would mean eliminating a huge amount of technology that consumes fossil fuels in a very short period. of time
For example, the UK would need at least 30-40 gigawatts of new sustainable on-demand power generation to get rid of all fossil fuel power generation (according to a 2019 statement (opens in a new tab )). This is the equivalent of building more than 30 new blocks of nuclear power plants.
Solar power plants in space, exposed to constant sun without clouds or air limiting the efficiency of their photovoltaic arrays, could have a place in this future emissions-free infrastructure. But these structures, which transmit energy to Earth in the form of microwaves, would be quite difficult to build and maintain.
Here are the main pros and cons of this technology.
Related: A solar power plant in space? The UK wants to build one by 2035.
The pros
The technology is less science fiction than you might think
Ian Cash is a British engineer, the CASSIOPeiA solar energy satellite concept has been adopted by a UK government-backed space energy initiative as a starting point for a potential future demonstrator of solar power plants based on the space A staunch supporter of the technology, Cash thinks developing and building a solar farm in space presents fewer challenges than cracking nuclear fusion. This may interest you : Roanoke is partnering with a solar energy nonprofit to bring affordable, renewable energy to the city.
When it comes to space-based solar power, “there’s no science to solve,” Cash told Space.com. “We’ve had it all working pretty much since the 1970s, when NASA with the US Department of Energy did a large-scale study. We’ve been demonstrating the physics behind it since we first launched a satellite of communication in geostationary orbit. You have solar wings, which face the sun. And you have the body of the satellite, either with a dish or a phased array antenna, which faces Earth. All the principles they’re the same; you’re converting solar energy into electricity, turning it into microwaves, and beaming it back to Earth. The only thing that’s different is the scale of the apertures.”
Andrew Wilson, a researcher at the Advanced Space Concepts Lab at the University of Strathclyde in Scotland, who led a study on the feasibility of space-based solar power, agrees: “I don’t think there is technology that “it has to develop as opposed to just advancing technological readiness levels,” Wilson told Space.com. “There is nothing that needs to be invented.”
However, as detailed later in this piece, the necessary “technological advance” is quite considerable.
It would provide 13 times more energy than an identical ground-based plant
Building solar power plants in space is certainly not an easy task, but it appears to have advantages, at least for some countries. On the same subject : San diego solar install. Proponents of the technology claim that a solar power plant in Earth’s orbit would produce 13 times more energy than an equivalent installation located in the notoriously cloudy UK.
Space-based solar plants would easily produce gigawatts of energy, matching the electricity output of nuclear power plants. In contrast, the UK’s largest solar power plant, Shotwick Solar Park (opens in a new tab) in North Wales, produces a paltry 72.2 megawatts during peak sunshine hours. Only the world’s largest solar plants, sprawling installations in some of the sunniest countries, reach the gigawatt mark. For example, the Bhadla Solar Farm in India generates up to 2.7 gigawatts and covers 52 square miles (160 square kilometers) of land, which is more than twice the size of Manhattan, according to Ecoexperts.
Building a solar power plant in space would have a huge price tag. Once built, however, the plant would pay for itself much faster than any Earth-based renewable energy generation technology, according to Wilson.
Ian Cash is a British electronic engineer and director of the International Electric Company. His concept for an orbiting solar power plant called CASSIOPeiA (Constant Aperture, Solid State, Integrated, Orbital Phased Array) has been adopted by the U.K. Space Energy Initiative as a starting point for a possible future space-based solar power plant demonstration. The initiative believes this demonstrator could be in orbit by the mid-2030s.
It provides perfectly clean electricity 24/7
Space-based solar energy does not suffer from the main drawback that affects most major renewable energy generation technologies. In space, the sun always shines. No cloud ever prevents the sun’s rays from reaching the photovoltaic arrays. And if you choose your orbit wisely, you can even avoid the night. A solar power plant in space, unlike its equivalent on Earth, or an offshore wind farm, would provide a constant amount of energy 24 hours a day throughout the year. This power would feed Earth-based electrical grids at a constant rate without operators having to worry about annoying blackouts or sudden overloads.
Proponents of space-based solar power, however, don’t expect celestial electricity to power humbler terrestrial renewables. They believe that space-based solar power should replace the power plants currently used to meet energy needs when the sun doesn’t shine and the wind doesn’t blow. In the UK, this so-called dispatchable energy comes mainly from oil and gas power stations, the kind of carbon-producing facilities that add to the world’s growing climate change problem.
“The thing about space-based solar power is that very high levels of power can be delivered, similar to nuclear power plants,” Wilson said. “Most other renewable energy options can’t provide these amounts at once. Without space-based solar, we’d probably be looking at building a lot more nuclear power plants, for sure.”
Of course, renewable energy could be fed into giant batteries in times of surplus generation for use in times of need. But energy storage technology on this scale is only slightly more settled than nuclear fusion.
It could be beamed anywhere without wires and power lines
Space-based solar energy does not suffer from the main drawback that affects most major renewable energy generation technologies. In space, the sun always shines. No cloud ever prevents the sun’s rays from reaching the photovoltaic arrays. And if you choose your orbit wisely, you can even avoid the night. A solar power plant in space, unlike its equivalent on Earth, or an offshore wind farm, would provide a constant amount of energy 24 hours a day throughout the year. This power would feed Earth-based electrical grids at a constant rate without operators having to worry about annoying blackouts or sudden overloads.
Proponents of space-based solar power, however, don’t expect celestial electricity to power humbler terrestrial renewables. They believe that space-based solar power should replace the power plants currently used to meet energy needs when the sun doesn’t shine and the wind doesn’t blow. In the UK, this so-called dispatchable energy comes mainly from oil and gas power stations, the kind of carbon-producing facilities that add to the world’s growing climate change problem.
“The thing about space-based solar power is that very high levels of power can be delivered, similar to nuclear power plants,” Wilson said. “Most other renewable energy options can’t provide these amounts at once. Without space-based solar, we’d probably be looking at building a lot more nuclear power plants, for sure.”
Of course, renewable energy could be fed into giant batteries in times of surplus generation for use in times of need. But energy storage technology on this scale is only slightly more settled than nuclear fusion.
It is theoretically safe from Earth-based conflict
The apparent sabotage of the Nord Stream gas pipelines in the Baltic Sea that shocked the world in September 2022 showed that in the politically unstable world we live in, relying on foreign energy is quite unsafe.
Space-based solar power, advocates say, is safer from international conflict than Russia’s gas supply, and also safer than traditional solar plants here on Earth.
“Some people say that if you strategically placed solar panels in certain unpopulated regions, say the Sahara desert, you could power all of humanity’s energy needs,” Wilson said. “But the same thing that we’ve seen happen with Russia could happen to our energy security if a war broke out in the Sahara region.”
Some opponents argue that a space-based solar power plant could easily be attacked by anti-satellite missiles. Cash, however, disagrees. Shooting down a platform in geostationary orbit, he says, is beyond the current capabilities of most states. Furthermore, while stealthily disrupting underwater pipelines with submarines allows for plausible deniability, an adversary launching a missile to destroy a rival’s space solar plant would be easily identified.
“There is certainly a risk, but it is no greater than hostile players who want to attack nuclear power plants, gas pipelines or high-voltage cables between continents,” Cash said. “Many of these things can be attacked covertly, and the attacking nation can easily deny responsibility. But in space, any attack involves a launch that is sure to be detected.”
Wilson added that since any space-based solar power plant project will likely be an international effort, the international nature provides an additional layer of protection against political upheaval.
The infrastructure on the ground will be allegedly less obtrusive than that of other renewables
Ground PV plants gobble up large tracts of land to harvest any reasonable amount of energy. The wind farms in the landscape are also not to be missed. The rectifier antennas (or rectennas) needed to receive microwave beams that carry solar-generated energy into space would also require a large footprint. These rectennas, however, will be much less intrusive, Cash said, and will allow other uses of the land or sea on which they will be built.
“The rectennas will be a fine mesh construction; they will let sunlight through and be almost invisible when viewed from a distance,” Cash said. “We envision a future where we could have a rectenna raised several meters above the ground by poles and reuse the land below for, say, robotic farming or even human farming, as the land will be under a shield of microwaves, so there will not be exposed to microwave radiation.”
Andrew Wilson is a Research Associate at the Advanced Space Concepts Lab at the University of Strathclyde, Scotland. His main research interest is life cycle assessment, carbon accounting, cost analysis and energy systems, with a special focus on the space sector.
It could power flying airplanes
According to Airbus’ idea of the future, solar energy produced in space could help clean up aviation’s difficult carbon footprint. Not that it will wean airplanes off fossil fuels entirely, but it could slightly affect the amount of greenhouse gases that the world’s planes dump into the Earth’s atmosphere.
“In the future, as we move toward hydrogen and battery-powered aircraft, we could use space-based solar power to extend the range of aircraft,” Coste said. “We could use it in liftoff assistance, because liftoff is when most of the fuel is used. You could have a beam that provides power during liftoff and then also to recharge the airplane while flying.”
Cons
A space solar power plant would have to be much larger than anything flown in space before
The solar power plant in orbit will have to be huge, and not just to collect enough sunlight to make it worthwhile. The main factor in the enormous size is not the amount of power, but the need to focus the microwaves which will carry the energy through the earth’s atmosphere into a reasonably sized beam that could be received on the ground by a rectenna reasonably sized. Those focusing antennas, Cash said, would have to be 1 mile (1.6 kilometers) or more wide, simply because of the “physics you’re dealing with.”
Compare that to the International Space Station, at 357 feet (108 meters) long, the largest space structure built in orbit to date. All proponents of space-based solar energy agree that exactly how these plants could be mounted is still a question.
Cash says his CASSIOPeiA concept would also work with multiple smaller plants in some types of lower Earth orbits. Having a plant closer to Earth would allow the antenna to be smaller in size, potentially reducing the scale to one-tenth of what would be needed in geostationary orbit. On the other hand, a plant closer to Earth would be an easier target for anti-satellite missiles and could also annoy astronomers as it would be too visible from the ground.
In all cases, building a space solar power plant would require hundreds of rocket launches (which would pollute the atmosphere depending on the type of rocket used) and advanced robotics systems capable of joining all the constituent modules to the space
This robotic construction is probably the biggest obstacle to making this sci-fi vision a reality, Cash said.
“If we can demonstrate that we can assemble smaller CASSIOPeiA satellites, 12 meters [40 feet] in diameter, using robots, we can gradually expand to 100 meters [330 feet], 1 kilometer [0.6 miles ] or 2 kilometers [1.2]. miles],” Cash said. “We should just apply more robots working in parallel. But it’s certainly one of the key challenges.”
Converting electricity into microwaves and back is currently awfully inefficient
Airbus, which recently performed a small-scale demonstration of converting electricity generated by photovoltaic panels into microwaves and transmitting it wirelessly to a receiving station 118 feet (36 m) away, says one of the biggest hurdles for space-based solar feasibility. Power is the efficiency of the conversion process.
According to Airbus calculations, microwaves glide through Earth’s atmosphere almost undisturbed, losing barely 5% of their energy during their journey from geostationary orbit. Enormous amounts of energy, however, are already lost in the plant and then in the grid when the electricity produced by the photovoltaic panels is converted into microwaves and then back into electricity.
“The system we used in our demo had an end-to-end efficiency of about 5 percent,” Coste said. “This is not something that would be operationally viable, even though sunlight is free. For a space-based solar plant to make sense, the efficiency would have to be around 20% at least.”
Jean-Dominique Coste is senior director of Airbus Blue Sky, a department of the European aerospace company that researches innovative concepts. Airbus Blue SKy focuses on innovative technologies with the potential to push boundaries and have broad social impact.
It might be turned into a weapon of mass destruction
Some worry that microwave beams in space could be turned into weapons of mass destruction and used by evil actors to fry humans on Earth with invisible radiation.
Coste admitted that if someone wanted to develop such a weapon, they could possibly do so. Microwave beams carrying space solar energy, however, would be designed from the start to be safe.
How dangerous the beam is to human health, he said, depends on the power density it carries, and that could be limited by design.
“You could design the beam to be so safe that you could take a nap with your child and not get hit,” Coste said. “That would be at a power density level of about 10 watts per square meter. But that would require an extremely large area to collect [the energy], so we would want to have a narrower beam with a higher density and some security system around it.”
The company, he says, is investigating methods of “traffic management around the beam,” using radar and lasers to search for objects in the vicinity of the beam to stop the flow of energy in the event of a safety risk.
“We can design a system that’s designed to target only one receiver and that would never work if it was aimed anywhere else,” Coste said. “We work on this concept with some large energy companies in Europe, and they don’t see it as too much of a problem, as they are used to dealing with security issues around high-voltage power lines or gas pipelines.”
It would get damaged by micrometeorites
The vast orbiting structure of interlocking planar photovoltaic panels would be constantly struck by micrometeorites, risking not only substantial damage during operations, but also generating large amounts of space debris in the process.
The James Webb Space Telescope, with its 21.6-foot-wide (6.5 m) mirror, took quite a beating early in its operations, prompting its ground control team to adjust the observation plans to avoid looking towards the direction where most of the rocks. I come from.
Engineers designing a possible future space-based solar power plant would certainly need to build their structure with this constant influx of micrometeoroids in mind.
“For the life cycle of the station, it is necessary to design it in such a way that it can be maintained and repaired continuously”, said Coste. “Because it’s such a large structure, you’re going to have some defects in some panels. The ideal antenna design will be modular so you can replace tiles and panels.”
Cash added that by making the panels from the thinnest material possible, engineers can almost eliminate the generation of debris from the affected panels.
“If we do it with some kind of polymer materials, things like micrometeorites would just make a hole,” Cash said. “We hope to be able to reduce the risk of generating debris but also the effects on the plant. If we build each of the modules to be independent of other modules, then the only thing that happens is that a strike takes out a few elements.”
It would create a huge amount of debris at end of life
But what about the end of life? What would happen to faulty modules that needed to be replaced? And what happens to everything once it reaches the end of its useful life, perhaps after a few decades of power generation? Will an object 1 mile (1.6 km) in diameter in geostationary orbit be left to slowly decay?
Wilson envisions a more sophisticated removal procedure, which assumes that by the time we have solar power plants in space, we’ll most likely see some permanent infrastructure on the Moon. Space tugs that don’t yet exist could move the aging plant to the Moon, where its materials could be recycled and reused for another use.
“One of the ideas for the future use of the moon is to use it for space launches into deeper space,” Wilson said. “We could also have some sort of recycling center there to process some of the material.”
It could contribute to light pollution
Some astronomers are concerned about the impact of these giant orbiting structures on the night sky. SpaceX’s Starlink constellation has been provoking a reaction from the astronomy community since the company’s first batch of satellites streaked across the sky in the form of trains of light.
The International Astronomical Union denounced Starlink as a worse threat to astronomy than urban light pollution, with large-scale survey telescopes scanning large swathes of the sky particularly affected.
But Coste thinks that a plant in geostationary orbit, 22,000 miles away from Earth, would hardly be noticed.
“From Earth, you would perceive it as a single star,” he said. “The only part of the plant that will face Earth is the antenna, and that doesn’t have to reflect light. We could probably do something in the system to reduce the amount of light that reaches [Earth]. I don’t think it’s as big a problem as the megaconstellations.”
Cash agrees: “The whole concept [of a space-based solar power plant] is to collect and absorb as much sunlight as possible. We maintain this constant attitude, always facing the sun. And any part that don’t absorb that sunlight, we can in principle arrange them to deflect sunlight away from Earth.”
So what do you think? Should space-based solar become a thing? Airbus seems serious about its plans, expecting to launch a small-scale demonstrator with an aerial platform within the next two years. A small-scale energy satellite could be in orbit by the end of this decade.
“We don’t see a show,” Coste concluded.
Follow Tereza Pultarova on Twitter @TerezaPultarova. Follow us on Twitter @Spacedotcom and on Facebook.
Join our space forums to keep talking space about the latest missions, the night sky and more! And if you have a news, correction, or comment, let us know at: community@space.com.
Tereza is a London-based science and technology journalist, aspiring fiction writer and amateur gymnast. A native of Prague, Czech Republic, she spent the first seven years of her career working as a reporter, scriptwriter and presenter for various television programs of the Czech Public Service Television. Later, he took a break from his career to pursue studies and added a Master of Science from the University of International Space, France, to his BA in Journalism and MA in Cultural Anthropology from Charles University in Prague. She worked as a reporter for Engineering and Technology magazine, freelanced for a variety of publications including Live Science, Space.com, Professional Engineering, Via Satellite, and Space News, and served as the cover science editor for maternity at the European Space Agency.
What are 3 benefits of solar?
Financial returns and lower monthly utility bills are major incentives to go solar… Cost Savings
- Electricity consumption.
- Solar energy system size.
- Whether you buy or lease your system.
- Direct hours of daily sunlight.
- Roof size and angle.
- Local electricity rates.
What are the 3 pros and cons of solar energy?
What is the biggest benefit of solar energy? Solar energy has the least negative impact on the environment compared to any other energy source. It does not produce greenhouse gases and does not pollute water. It also requires very little water for its maintenance, unlike nuclear power plants for example, which need 20 times more water.
What are the 4 benefits of solar energy that they explain? Clean renewable energy that is available every day of the year, even cloudy days produce some energy. Return on investment unlike paying utility bills. Virtually maintenance-free, as the solar panels last more than 30 years. Create jobs by employing solar panel manufacturers, solar installers, etc.
Can a house run 100% on solar?
With a modern solar power system, including energy storage, you can definitely run an entire house on solar energy. Today’s highly efficient solar panels and solar batteries make it cheaper than ever to power an entire house using solely solar energy.
Can a house be self-sufficient with solar energy? During certain hours of the day, the owner of a building using a solar array can be completely energy self-sufficient. Sometimes your solar PV system can even produce more energy than the building consumes.
How many solar panels would it take to fully power a house? How many solar panels does it take to power my home? The average US home uses 10,400 kWh of electricity per year. If you install the average 250 watt solar panel, you will need about 28-34 solar panels to generate enough energy to power your entire home.
Can solar panels power an entire house off the grid? An off-grid solar system uses solar panels, battery storage, and related equipment to power a location independent of the power grid. It has many uses; it can power campsites, RVs, boats, remote cabins and even family homes. Before you buy an off-grid system, you’ll need to figure out what size system you want.
Can you go a 100 percent solar?
If your goal is a 100% solar-powered home, you can achieve that with an off-grid or grid-connected solar system. The difference between these is what happens to excess electricity and how you access electricity when your system is not generating power.
Why can’t we get 100% solar energy from solar cell? Average Silicon Solar Panel Cells Are Not Very Efficient Semiconductors that convert sunlight into electrical energy are considered inefficient because they only capture a portion of the light they receive.
Is it possible to go solar completely? Frequently asked questions about solar panels at home It is possible to run a house on solar energy alone. However, going completely off the grid requires a considerable financial and time investment. The greater your energy needs, the more solar panels you will need.
Is it possible to have 100% clean energy?
Research on this topic is fairly new, with very few studies published before 2009, but it has gained increasing attention in recent years. Most studies show that a global transition to 100% renewable energy in all sectors (electricity, heat, transport and desalination) is feasible and economically viable.
Which countries have 100% clean energy? Iceland is a country that runs on 100% renewable energy. It gets 75% of its electricity from hydropower and 25% from geothermal energy. The country then takes advantage of its volcanic activity to access geothermal energy, with 87% of its hot water and heating coming from this source.
Is 100% renewable feasible? And, the great news is that it is technically feasible to meet 100 percent of the USCA states’ electricity needs with renewable energy, even as we clean up other sectors of the economy as well.
What are the 2 main disadvantages of solar energy?
High initial costs of material and installation and long return on investment (however, with the reduction in the cost of solar energy in the last 10 years, solar is becoming more feasible every day) Needs a lot of space as the ‘efficiency is still not 100%.
What is the biggest problem with solar energy? One of the biggest problems with solar energy technology is that energy is only generated while the sun is shining. This means that the night and cloudy days can interrupt the supply.
Do solar panels work better in outer space?
Solar panels are much more effective in space than on Earth because they can take advantage of the sun’s almost constant light. Space has no night or day cycles, so solar panels only spend a maximum of 72 minutes in Earth’s shadow, and even that time is unusual.
Do solar panels work better closer to the equator? Latitude is a factor According to NASA, the sun’s rays are 40 percent as intense there as at the equator. The closer a solar panel’s location is to the equator, the greater its electrical output.
Do solar panels work better closer to the sun? Therefore, the more solar exposure the solar panels receive, the more output they generate. Although panels can generate power from any sunlight, direct sunlight has more photons than indirect sunlight. Therefore, solar panels facing directly into the sun will generate more electricity than those in the shade.
Do solar panels work better in space? Space-based solar panels can generate 2,000 gigawatts of power constantly. This is 40 times more energy than a solar panel on Earth would generate annually. This is also several times higher than the efficiency of current solar panels.
Where is the best place on Earth for solar panels?
One of the best places on the planet for solar energy, due to its exceptional conditions, is the Atacama desert in Chile. It is located near the equator and at a high altitude, which gives it high levels of solar radiation, which refers to light energy from the sun. As the driest area in the world, it has limited cloud cover.
Which location will benefit the most from the use of solar panels? The main factor in the benefits of solar energy is solar radiation. The earth is round, so there are some parts that are a little closer to the sun; areas near the tropics are generally more favorable than locations closer to the poles.
What would be an ideal location for a solar farm?
In addition to plenty of sun and moderate temperatures, solar works best in regions with light winds and low humidity.
What area of land is best suited for solar energy? Solar developers look for clear, flat land with little or no wetlands and a minimal slope (5 degrees maximum).
Does location matter for solar farm? Geographical location is an important factor. Because the earth rotates around the sun on a tilted axis, higher latitudes, areas farther from the equator, will produce lower levels of production. This is why systems installed in the southwest produce greater amounts of energy than those installed in the northeast.