that would create clean hydrogen from water using only sunlight. Not just ordinary sunlight, but the power of the sun focused on a single point by an array of mirrors, a technology known as
The basic idea behind CSP dates back to the 1800s when European inventors tinkered with sunlight concentration. In recent decades, several different concentrated solar thermal power technologies have evolved, ranging from a parabolic dish circled by mirrors to tower systems filled with molten salt. The problem with molten salt is that it cannot get hot enough to take full advantage of the power of concentrated sunlight.
The “falling” part of this method uses gravity to heat these tiny, dark colored ceramic particles less than half a millimeter in size. When dropped from a hopper at the top of the tower, they are heated as they pass through a beam of focused solar energy. As they fall, their temperature can increase quickly from 500° C to 800° C. With more advanced setups, temperatures of more than 1000° C. are possible.
“The power generation from CSP technology resembles a coal fired power plant without the coal. It uses the same turbine. Typical coal fired power plants use a steam turbine that operates at 540 degrees. Instead of using coal to create the heat to superheat the steam, we capture energy from the sun and store it for 10 to 15 hours,” Stein said.