With the effects of climate change on our planet becoming increasingly evident, scientists worldwide are making huge strides in designing new technologies to slow down global warming. Renewable energy sources are one of our best shots at achieving net-zero emissions. In the race to design breakthrough technologies to obtain electricity from natural resources, one innovative proposal seeks to be the solution that we have been waiting for. A Space-based Solar Power (SSP) station, experts argue, would have the potential to mitigate climate change through the provision of clean energy. What are the advantages and the challenges of building a solar power system in space and will this ever become a reality?
What is A Space-Based Solar Power Station?
As futuristic as it might sound, building a solar power station in space could soon become a reality. Russian-born scientist and mathematician Konstantin Tsiolkovsky first presented the concept of capturing solar power from space and then transferring it to Earth in the 1920s. Scientists have studied ways to turn his concept into reality ever since and it looks like we are finally nearing a turning point.
When it comes to building a space-based solar power station in space, you have to think big. It is estimated that for the satellite to efficiently capture the sunlight, it would have to be approximately 10 square kilometers in area – or the equivalent of 1,400 football pitches – and equipped with avant-garde solar arrays. The power accumulated on the satellite could be transferred to Earth through high-frequency radio waves, which a ground antenna would then convert into electricity and deliver almost instantly to power grids across different locations.
The global demand for energy is projected to increase by approximately 50% by 2050, paired with the urgency to find more sustainable energy sources, make looking into alternatives involving renewables a necessity. Climate change is the greatest challenge of our time and as we begin to understand the immense value of these unlimited energy sources in the race to stop global warming, new ideas to make groundbreaking SSP-project feasible could not come at a better time. But why exactly are we looking at building a solar power station in space?
What are the Advantages and Disadvantages of Space-Based Solar Energy?
No other renewable energy source is comparable to the sun in terms of availability. Indeed, solar energy is the most abundant energy source on the planet. Throughout the years, scientists have developed innovative technologies that could allow us to depend entirely on solar for the rest of our existence.
As opposed to solar panels on Earth, which capture sunlight that has been absorbed and filtered through the atmosphere before reaching the ground, panels in space would be continuously and directly exposed to more powerful sunlight. This would allow a SSP-station to continuously generate an enormous amount of electricity. Indeed, it is estimated that space-based solar panels can generate up to 2,000 gigawatts of power constantly, nearly 40 times more energy than a solar panel would generate on Earth annually. SSP is not only considered more efficient than ground-based solar stations but it is also immaculately clean, infinitely available, and it has no impact on landscapes as it does not require any land use.
While the advantages of solar energy are numerous, a few flaws in the concept of SSP remain. The biggest disadvantage of a space-based solar power station is the cost of its launch. Looking at the current price for sending rockets into space, experts estimate that the launch cost for a 20-foot by 20-foot (1.2 by 1.2 meters) solar panel would be around USD$ 1.56 million, and this is without taking into account the launch of other required parts such as a transmitter, satellite housing, and internal electronics. Another potential risk factor is the unknown safety hazards that may arise during the lifetime of a SSP-system. These, however, are impossible to predict in advance. Potential scenarios may include space debris that could damage solar arrays and a faster degradation of the panels as they are exposed to more intense solar radiations. As scientists cannot exactly predict if and when such events will occur, it is also difficult to estimate the maintenance costs of the massive station.
What are the Manufacturing Challenges of Space-Based Solar Power?
Building a solar power system in space does not come without challenges. While modern technological advances have made this prospect more achievable, there is a reason why a space-based solar power station is still not a reality. Not surprisingly, one of the most complex and challenging drawbacks is how to assemble, launch, and deploy such a large structure in space. This complicated process requires solving a number of technological bottlenecks that involve not only the manufacturing of the power station, but also the design of thermal, wireless power transmission, and control systems.
Despite nothing of this size has ever been sent to space before, scientists are not easily discouraged and many believe that there are ways to get around it. In 2017, researchers at the California Institute of Technology designed a modular power station. The idea is to produce thousands of smaller satellites that can be launched separately and that will come together once they are in space to form a single large solar power station. Simultaneously, scientists at the University of Liverpool are looking at ways to embed photovoltaic (PV) cells on a foldable and extremely lightweight solar sail. The sail, capable of harnessing the sun’s radiation pressure to propel a spacecraft forward fuel-free, could represent an affordable solution to create a large, space-based solar power station powered by the same source of energy it captures. Finally, to answer the question of how the system could transmit the power it absorbs back to Earth, researchers from the Japan Aerospace Exploration Agency studied a method to convert electricity from the solar cells into energy waves and transfer it to a ground antenna using electromagnetic fields.
Is This Ever Going to Happen?
In 2020 European Space Agency (ESA) launched a campaign to collect new innovative ideas for technologies to increase the feasibility of space-based solar power to support the provision of clean energy and is now looking to fund some of these projects. Meanwhile, some prototypes are already underway in some countries.
The United Kingdom, for example, is considering undertaking a USD$ 21 million project to build a solar power station in space as part of the government’s Net Zero Innovation Portfolio to help the UK achieve net zero by 2050. In the United States, the Space Solar Power Project is working on high-efficiency solar cells along with a conversion and transmission system optimised for use in space, while the US Naval Research Laboratory tested a solar module and power conversion system in space in 2020.
Considering the extremely high initial costs, governments will require the financial support of private companies for the implementation of some of these projects. Despite the challenges, space-based solar power is an innovative technology worth investing into and it opens the door to the possibility of a future in which renewables play a key role in the global energy supply.