内容摘要：Power demand spikes in the early morning and later evening, when solar arrays can't help. But resear

Power demand spikes in the early morning and later evening, when solar arrays can't help. But researchers in Scotland say orbital launch costs are getting so cheap that giant space-based reflectors could soon be a viable way to power these timeslots.

You could possibly look at this as a different way to do space solar – but instead of putting giant photovoltaic arrays in the sky and trying to beam the power down to Earth, you're just hanging big mirror structures in orbit, and using them to send more solar energy down to the surface for harvesting by terrestrial installations.

These orbital reflectors are a very old idea – indeed, Hermann Oberth proposed something very similar in his 1929 book Ways to Spaceflight, which he saw as a potential way of lighting cities, protecting crops from overnight frost, and maybe even keeping entire areas of the far North ice-free, making them more habitable through their gruelling dark winters.

Mind you, he also warned that such devices could be used to concentrate solar energy onto smaller areas for military purposes: "munitions factories can be exploded with it, tornadoes and thunderstorms produced, marching troops and their reserves destroyed, whole cities burned, and generally the greatest of damage done." But we'll leave that aside for the minute!