Every day, thousands of passengers heading south west on trains leaving Aldershot station pass a cluster of solar panels nestled by the tracks. Few, if any, may notice the installation. But the train they are on is drawing power from it. "On a sunny afternoon, if you are catching a train through Aldershot, a little bit of the energy for that train will come from those solar panels," says Leo Murray, co-founder and chief executive of Riding Sunbeams, a start-up aiming to use renewable energy