A solar power station in space? Here’s how it would work - and help us get to net zero
来源:World Economic Forum;发表于:2022-04-01;人气指数:359
A solar
power station in space? Here’s how it would work - and help us get to net zero
https://www.weforum.org/agenda/2022/03/a-solar-power-station-in-space-here-s-how-it-would-work-and-the-benefits-it-could-bring/
Could there be a
solar power station in space?
Image: Unsplash/ NASA
23 Mar 2022
Jovana Radulovic
Head of School of
Mechanical and Design Engineering, University of Portsmouth
*The UK government is
considering building a solar power station in space.
*The multi-billion
pound project would contribute to the UK's goal of reaching net-zero emissions
by 2050.
*Recent technological
developments have made the concept of space-based solar power more achievable.
*Here, an engineer
weighs up the pros and cons of the project.
The UK government
is reportedly considering a £16 billion proposal to build a solar
power station in space.
Yes, you read that
right. Space-based solar power is one of the technologies to feature in the
government’s Net Zero Innovation Portfolio. It has been identified as a
potential solution, alongside others, to enable the UK to achieve net zero by
2050.
But how would a solar
power station in space work? What are the advantages and drawbacks to this technology?
Space-based solar
power involves collecting solar energy in space and transferring it to
Earth. While the idea itself is not new, recent technological advances have
made this prospect more achievable.
The space-based solar
power system involves a solar power satellite – an enormous spacecraft equipped
with solar panels. These panels generate electricity, which is then wirelessly
transmitted to Earth through high-frequency radio waves. A ground antenna,
called a rectenna, is used to convert the radio waves into electricity, which
is then delivered to the power grid.
A space-based solar
power station in orbit is illuminated by the Sun 24 hours a day and could
therefore generate electricity continuously. This represents an advantage over
terrestrial solar power systems (systems on Earth), which can produce
electricity only during the day and depend on the weather.
With global energy
demand projected to increase by nearly 50% by 2050, space-based solar
power could be key to helping meet the growing demand on the world’s energy
sector and tackling global temperature rise.
Some challenges
A space-based solar
power station is based on a modular design, where a large number of solar
modules are assembled by robots in orbit. Transporting all these elements into
space is difficult, costly, and will take a toll on the environment.
The weight of
solar panels was identified as an early challenge. But this has been
addressed through the development of ultra-light solar cells (a solar
panel comprises smaller solar cells).
Space-based solar
power is deemed to be technically feasible primarily because of advances in key
technologies, including lightweight solar cells, wireless power transmission
and space robotics.
Importantly,
assembling even just one space-based solar power station will require many
space shuttle launches. Although space-based solar power is designed to reduce
carbon emissions in the long run, there are significant emissions associated
with space launches, as well as costs.
Space shuttles are
not currently reusable, though companies like Space X are working on
changing this. Being able to reuse launch systems would significantly reduce
the overall cost of space-based solar power.
If we manage to
successfully build a space-based solar power station, its operation faces
several practical challenges, too. Solar panels could be damaged by space
debris. Further, panels in space are not shielded by Earth’s atmosphere. Being
exposed to more intense solar radiation means they will degrade faster
than those on Earth, which will reduce the power they are able to generate.
The efficiency of
wireless power transmission is another issue. Transmitting energy across large
distances – in this case from a solar satellite in space to the ground – is
difficult. Based on the current technology, only a small fraction of collected
solar energy would reach the Earth.
Pilot projects are
already underway
The Space Solar
Power Project in the US is developing high-efficiency solar cells as well
as a conversion and transmission system optimised for use in space. The
US Naval Research Laboratory tested a solar module and power
conversion system in space in 2020. Meanwhile, China has announced progress on
their Bishan space solar energy station, with the aim to have a
functioning system by 2035.
In the UK, a £17
billion space-based solar power development is deemed to be a viable concept
based on the recent Frazer-Nash Consultancy report. The project is
expected to start with small trials, leading to an operational solar power
station in 2040.
The solar power satellite
would be 1.7km in diameter, weighing around 2,000 tonnes. The terrestrial
antenna takes up a lot of space – roughly 6.7km by 13km. Given the use of land
across the UK, it’s more likely to be placed offshore.
This satellite would
deliver 2GW of power to the UK. While this is a substantial amount of power, it
is a small contribution to the UK’s generation capacity, which is around
76GW.
With extremely high
initial costs and slow return on investment, the project would need substantial
governmental resources as well as investments from private companies.
But as technology
advances, the cost of space launch and manufacturing will steadily decrease.
And the scale of the project will allow for mass manufacturing, which should
drive the cost down somewhat.
Whether space-based
solar power can help us meet net zero by 2050 remains to be seen. Other
technologies, like diverse and flexible energy storage, hydrogen and growth in
renewable energy systems are better understood and can be more readily applied.
Despite the
challenges, space-based solar power is a precursor for exciting research and development
opportunities. In the future, the technology is likely to play an important
role in the global energy supply.