Today, let us take you back to a discovery that was made some 2229 years ago. Legend has it that Archimedes defended the city of Syracuse (Sicily) from the fleet of the Roman general Marcus Claudius Marcellus using rays of solar energy generated by hundreds of soldiers equipped with polished bronze shields. Deployed along the coast, they are said to have directed the rays of the Sun onto the Roman ships that besieged the city, concentrating them to such an extent that the ships eventually caught fire. A couple of millennia later, somebody had the bright idea of using the same trick to generate thermal energy…