Harvesting solar energy in orbit and beaming it down to Earth is a decades-old idea. Now, a raft of companies say they could finally make it a reality.

At an American football stadium in Florida last March, an unusual test took place. Here, it wasn't footballs being thrown, but beams of light across the length of the pitch. The concentrated streaks of light lasted for a few minutes, fired from an emitter on one side of the field in the Jacksonville Jaguars' stadium and collected on a screen on the other.

The light was collected from the Sun and them beamed out by large lenses on the field like a magnifying glass, each about 1.2m (4ft) tall. "We had to get up a ladder to pull the cover off," says Andrew Rush, president and chief executive of the Florida-based company Star Catcher that carried out the test.