The idea that humanity could find a backup ‘planet B’ has long stirred passions and controversy with some arguing that seeking colonies in space is dangerous or delusional or both. But could space provide solutions to some of the environmental challenges we face here on Earth?
China appears to think so. According to Chinese media, the country is working on plans to build a solar farm in space. The project is hugely ambitious with several key questions still unanswered, but it does showcase a pressing environmental challenge: how do we reduce emissions sufficiently to curb runaway temperature rise?
Energy production and use is the single biggest contributor to global warming, accounting for roughly two-thirds of human-induced greenhouse gas emissions. According to the 2018 UN Emissions Gap Report, nations must triple their emissions reduction efforts to meet the upper 2°C target for global warming set out in the 2015 Paris climate agreement. To limit warming to 1.5°C, efforts would have to increase fivefold.
One of the main ways to cut emissions is to increase our use of renewable energy sources, such as solar power. China is already a leader in this field.
In 2017, the world installed a record 98 gigawatts of new solar capacity with China adding some 53 gigawatts—more than half the global total. Falling costs for solar electricity, and to some extent wind power, are driving this trend, but to have any hope of reaching the Paris targets, more must be done, and fast.
“While the ambition and pace to decarbonize our economies need to increase fivefold, we are seeing unprecedented progress and incredible innovation to decarbonize human life on earth,” said UN Environment climate change expert Niklas Hagelberg.
UN Environment works to promote low-carbon lifestyles, improve energy efficiency, and increase the use of renewable energy. It also works with governments to collect data on fossil fuel subsidies, and is responsible for monitoring the progress of phasing them out.
Global investments in renewable energy of US$2.7 trillion from 2007 to 2017 have increased the proportion of electricity generated by wind, solar, biomass and waste-to-energy, geothermal, marine and small hydro from 5.2 per cent to 12.1 per cent. And, as the Emissions Gap Report noted, surging momentum from the private sector and untapped potential from innovation and green-financing offer further hope.
The urgent imperative to find new ways of living within our planet’s limits will dominate the fourth UN Environment Assembly to be held in Kenya from 11 to 15 March 2019. The motto for that meeting is to think beyond prevailing patterns and live within sustainable limits to secure our planet’s future and our own.
Emissions reduction is key and while harvesting solar power in space is still in the realm of the unproven, it offers intriguing potential.
According to media reports, China plans to have a solar power station orbiting the earth at 36,000 km, allowing it to tap the energy of the sun’s rays without interference from the atmosphere or loss of sunlight. Theoretically, the station could deliver power 99 per cent of the time at six times the intensity of solar farms on earth. The electricity would be transmitted to earth using a microwave or laser beam.
The state-backed online site China.org.cn said researchers from Chongqing University, the China Academy of Space Technology and Xidian University have started designing a test facility in the city of Chongqing.
Xie Gengxin, deputy head of the Chongqing Collaborative Innovation Research Institute for Civil-Military Integration, said the construction of the testing facility would take one to two years and once it began operations, scientists and engineers would build tethered balloons equipped with solar panels and use them to verify microwave transmission technologies.
"We plan to launch four to six tethered balloons from the testing base and connect them with each other to set up a network at an altitude of around 1,000 metres," he said. "These balloons will collect sunlight and convert solar energy to microwave before beaming it back to Earth. Receiving stations on the ground will convert such microwaves to electricity and distribute it to a grid."
If the tests are successful, researchers will launch new tethered balloons to the stratosphere for further tests, he said. He predicted the space solar power station could start generating power before 2040.
The Sydney Morning Herald reported that a major challenge would be posed by the weight of the station, estimated at around 1,000 tonnes—compared to 400 tonnes for the International Space Station. The Chinese scientists were looking at whether it could be built in space using robots and 3D printing, the newspaper reported.
China is not the only country interested in harvesting solar power in space—an idea first mooted in the late 1960s by space pioneer Peter Glaser. Scientists from the California Institute of Technology are working on a prototype capable of harnessing and transmitting solar energy from space using lightweight tiles.
In 2011, the International Academy of Astronautics said solar plants in space could be technically feasible within a decade or two based on technologies then in the laboratory, and could be economically viable in 30 years or less.
During the United Nations Environment Assembly, from 11 to 19 March 2019, UN Environment is urging people to Think Beyond and Live Within. Join the debate on social media using #SolveDifferent to share your stories and see what others are doing to ensure a sustainable future for our planet.