Tel Aviv: Inspired by green hybrid cars driven by a mixture of gas and electricity, researchers have turned their attention to the greening of power plants too.
Most power plants, explains Avi Kribus professor at Tel Aviv University (TAU) School of Mechanical Engineering, create power using fuel.
And solar thermal power plants, which use high temperatures and pressure generated by sunlight to produce turbine movement, are currently the industry`s green alternative, but a prohibitively expensive option.
The technology developed by Kribus combines fuel with the lower pressures and temperatures of steam produced by solar power, allowing plants to become hybrid, replacing 25 to 50 percent of their fuel use with green energy, the Solar Energy Journal, reports.
In a solar thermal power plant, sunlight is harvested to create hot high-pressure steam, about 400 to 500 degrees centigrade. This steam is then used to rotate the turbines to generate power.
Though the environmental benefits over traditional power plants are undeniable, Kribus cautions that the "complex solar technology" is somewhat unrealistic economically for the current industry.
However Kribus, with his graduate student Maya Livshits, is developing an alternative technology, called a steam injection gas turbine. "We combine a gas turbine, which works on hot air and not steam, and inject the solar-produced steam into the process," he explains.
"We still need to burn fuel to heat the air, but we add steam from low-temperature solar energy, approximately 200 degrees centigrade," said Kribis.
This hybrid cycle is not only highly efficient in terms of energy production, but the lowered pressure and heat requirements allow the solar part of the technology to use more cost-effective material, such as common metals and low-cost solar collectors.