A solar Stirling Engine takes advantage of the fact that concentrated sunlight is a fantastic heat source, and as such can be used to generate electricity more efficiently than photovoltaic solar panels
The Stirling Engine was developed in 1816 by Robert Stirling in order to offer an alternative to the frequently explosive early steam engines. Basically a closed cylinder containing a piston and helium, nitrogen or hydrogen gas is heated at one end by concentrated sunlight, and cooled at the other end by air or water.
Solar energy, radiant light and heat from the sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation, along with secondary solar-powered resources such as wind and wave power, hydroelectricity and biomass, account for most of the available renewable energy on earth. Only a minuscule fraction of the available solar energy is used.