Space Solar Power Art: Image Source: Website of the British "New Scientist" Magazine
From constructing massive solar power stations in space to stabilizing melting glaciers, from building a series of energy islands to directly capturing carbon dioxide from the air, scientists have proposed some ambitious projects to tackle climate change.
According to a recent report on the website of the British "New Scientist" magazine, each of these projects would require billions of dollars in investment and carries high risks. However, once successful, they could have transformative impacts on human efforts to conserve energy and reduce emissions, potentially even reversing the current trend of climate warming.
Building Solar Power Stations in Space
For decades, engineers have entertained the idea of building solar power stations in space. This is because a solar power station placed in a geostationary orbit around Earth would be continuously bathed in sunlight, allowing for maximum energy generation.
Ian Cash from International Power Corp. explains that a solar panel 10 kilometers wide in geostationary orbit could generate 570 terawatt-hours of energy per year, while the total electricity demand in the UK in 2022 was 320 terawatt-hours.
The main obstacle to this idea is cost. Launching satellites carrying kilometers-wide solar equipment into space requires significant investment. However, with the advent of reusable rocket technology, the cost of delivering payloads to space has plummeted.
It is estimated that SpaceX's Starship launch system could reduce the cost of delivering materials to geostationary orbit to $5000 per kilogram, about half the cost of the cheapest rockets currently available. Martin Soltow, co-CEO of the British Space Solar Power Company, believes that the emergence of reusable launch vehicles could fundamentally change the fate of space-based solar power stations.
While building massive solar power stations in space is a challenge, another difficulty lies in transmitting the power back to Earth. In February of this year, scientists at the California Institute of Technology demonstrated the feasibility of this by successfully transmitting solar power in the form of microwaves from space to Earth using a satellite they had previously launched.
Soltow suggests that if the UK supports such projects, by the early 2040s, space-based solar power could account for 30% of the country's annual electricity consumption.
Developing Energy Islands
European countries have already constructed many offshore wind turbines, but there are two major drawbacks: wind power is intermittent, and electricity must be transmitted to land via cables, making the necessary infrastructure very expensive. To address these challenges, the concept of energy islands has emerged.
Energy islands are typically built on an island, either artificial or natural, serving as collection points for electricity generated by wind farms on the island and in the surrounding area, which can then be distributed to different countries and regions.
Denmark has partnered with several European countries to advance two energy island projects. One is the Bornholm Energy Island project, covering an area of 588 square kilometers. Initially, the offshore wind farm here was planned to have a capacity of 1 GW, with plans to expand to 3-5 GW.
Another energy island, Vindo Island, is located in the North Sea and is approximately the size of 18 standard football fields, with plans for future expansion to "double its size." It will host a control center for 200 offshore wind turbines, with a capacity of around 3 GW, meeting half of the country's annual electricity consumption, and potentially expanding to 10 GW in the future.
Similar energy island projects are planned in the Netherlands, Germany, and Belgium. It is reported that all planned energy islands could collectively generate 56 GW of electricity, equivalent to the total power output of 30 nuclear power plants.
Another attraction of energy islands is their potential to produce clean fuels. Industries with high energy consumption, such as aviation, steel, and cement, are difficult to power with electricity but can be powered by hydrogen. Energy islands can serve as hydrogen production centers, using green electricity generated from wind power to electrolyze water into hydrogen, which can then be transported to land by ships or pipelines.
Stabilizing "Doomsday Glaciers"
The Thwaites Glacier in Antarctica, often referred to as the "Doomsday Glacier," has lost over a trillion tons of ice since 2000, and its drift speed has doubled in 30 years, indicating a significant increase in the ice flowing into the ocean. This trend suggests it may be becoming unstable.
What's even more worrying is that this glacier supports most of the ice sheet covering West Antarctica. If it were to collapse, it would lead to widespread melting of the ice sheet, resulting in a significant rise in global sea levels. Anders Levermann from the Potsdam Institute for Climate Impact Research in Germany warns that this would pose a serious threat to cities like New York, Shanghai, Kolkata, and Hamburg.
One key threat to glaciers is the increasing intrusion of warmer seawater, causing melting at their base.
John Moore from the University of Lapland in Finland believes there may be a solution to this: deploying an 80-kilometer-long buoyancy seabed "curtain" near the glacier. Scientists from the University of Cambridge are conducting small-scale tests on this idea.
Moore estimates that the cost of this "curtain" could range from $50 billion to $100 billion. Compared to the hundreds of billions of dollars that cities like New York invest in flood prevention, this may be a worthwhile investment.
Capturing 80 Million Tons of CO2 Annually
To address climate change, it is not enough to simply avoid emitting more greenhouse gases; aggressively removing carbon dioxide from the air is imperative. Direct air capture is a reliable option, but it is costly.
Data from the International Energy Agency shows that by 2030, it will be necessary to remove 80 million tons of carbon dioxide from the air annually to achieve net zero emissions by 2050.
Currently, there are 18 pilot direct air capture plants operating globally, with a combined capacity to absorb only 10,000 tons of carbon dioxide per year. The largest of these plants can absorb 4000 tons of carbon dioxide per year.
Katie Leung, an environmental analyst at the World Resources Institute in Washington, D.C., points out that to meet the goal of capturing 80 million tons of carbon dioxide annually by 2030, approximately 10 million-ton-per-year plants would need to be built each year.
However, water and energy consumption are significant concerns. According to estimates from the International Energy Agency, achieving net-zero emissions by 2050 may require factories to annually consume 500 billion tons of water, equivalent to 1% of the current global water usage. Additionally, they would need to consume 6 exajoules (1 exajoule equals 100 quintillion joules) of energy, which is also around 1% of the current global electricity consumption.
