Scientists have long proposed that solar electricity generation in space could be an integral component of the world’s carbon-free future. In the 1970s, a U.S. Navy experiment showed that it might be possible to capture solar power and wirelessly transmit it from outer space using microwave beams. Progress stalled after that early test—the models used were at such a massive scale that creating a real-world system felt like science fiction. Recently, amid growing concerns about power grid security and intensifying legislation around carbon emissions, renewed attention focused on a smaller, more lithe microwave transmission system. This time around, the military is not the only interested party. Scientists around the world are conducting similar research. As investors and governments stand at the edge of a fresh green power opportunity, we look at microwave power transmission and some of the projects in this emerging field.
