Space race that could solve net-zero problem

Maddie Evans, Guildford.

Scientists and engineers agree that we can solve the whole issue of net zero by using our ability to develop technology to replace fossil fuels. Doing this right means we could avoid damaging our beloved landscapes and beauty spots with solar farms and wind turbines.

So, it’s a win-win if we can remove the big old polluting power stations like Didcot and Ratcliffe on Soar without causing damage elsewhere.

On this basis, it’s attractive to put the infrastructure in space because the visual impact is just a twinkle in the sky, causing no issues for anyone. It is becoming feasible too; the European Space Agency Solaris programme is studying spacebased power; the Chinese have a target to get a demo running by 2028; and a US Caltech prototype beamed the first energy back to Earth this year. Space-X are testing Starship, which is a ‘tipping point’ technology, capable of lifting 100 tonnes into space on a reusable rocket.

But getting satellites with solar panels several km wide (the scale needed) into space will need thousands of launches of Starship, over decades. It needs a fleet of rockets and a fleet of robotic orbital ships that haven’t been designed yet to assemble the satellites.

Back on Earth, the receivers to collect the energy that is beamed back will be 2-10km wide. Transmission losses may be 40 per cent or as high as 90 per cent, according to the University of Portsmouth, requiring 10 times as many satellites, we just don’t know.

A big argument for space power is the constant supply, day and night, compared to renewables that need to be stored overnight, for periods of bad weather and for winter use. For this nuclear fusion is the main competitor and interestingly, both have become credible in the last three years, but only one needs space ports.

A recent Nasa report on the pros and cons concluded it will take until 2050 for space power to be fully operational; it will require those thousands of launches and the robot space fleet, and while the greenhouse gas emissions for building it are comparable to land-based renewables, and the construction carbon emitted is paid back in six months to a year of operation, we don’t yet know the likely impact of the pollution from all the rocket launches in the upper atmosphere. Financial models also show the cost of the energy produced will be between 12 and 80 times the cost of land-based generation.

Considering all this, both space power and nuclear fusion may have an important role providing a small proportion of demand, as nuclear energy does today, but it’s not competitive with even the current range of alternative renewable technologies and storage, and these costs are still falling.

What’s more, while we wait until 2050 or later to get space energy up and running, we may have truly solved the terrestrial storage issue with better batteries, hydrogen and new types of energy stores.

The money needed to develop space energy now may be better spent on Earth. We could and should do more in the short term to replace fossil fuels with the currently available alternatives in the most acceptable way before the impacts of climate change get worse. After all, developing space power needs a functioning global economy to pay for it.