SOLARIS: ESA'S PLAN TO GENERATE POWER IN SPACE

Could building a network of orbital power stations help us solve the energy crisis?

- DR STUART CLARK

Some of Europe's science ministers met in Paris in late November 2022, to decide on the priority list for the European Space Agency (ESA) for the next three years. One of the decisions they took could help wean Europe off fossil fuels and provide ESA's member states, which includes the UK, with their own secure source of energy. The decision was to green-light Solaris, a bold project to investigate the feasibility of building commercial power stations in orbit.

These power stations would run on sunlight. They would be equipped with extraordinarily large solar panels to soak up the Sun's energy and convert it into electrical power that would be beamed down to Earth as microwaves. On the ground, huge antennas would receive these microwaves and feed the resulting power directly into the electricity grid.

It sounds like science fiction but, as ESA's Dr Sanjay Vijendran points out, we've been doing something very similar for the past 60 years. "Every telecommunication satellite since the 1960s is basically a space-based solar-power satellite in a small format," he says.

That's because such satellites generate electricity with their solar panels and use it to transmit data to Earth. The transmissions are then converted back into electricity so that the data can be read. "The physics involved in that whole chain is exactly the same for space-based solar power, but the scale of it is completely different," says Vijendran.