San Diego solar project stemming from a mixture of professors and students at San Diego State University (SDSU) is making headlines this week, as the SDSU research team has been able to successfully produce solar-powered electricity by only using sunlight and air. It may seem obvious that sun and air are required to generate solar power, but what many people do not know is that the current concentrated solar power (CSP) systems use water that is heated to produce superheated air. Using water - a nonrenewable natural resource - to generate solar power may not be the most efficient process. Solar power is a great alternative to using fossil fuels and can help reduce greenhouse gas emissions that can cause global warming.
Solar power is the conversion of sunlight into electricity. There are two ways that the light can be converted: 1) using photovoltaic (PV) solar panels that directly convert light into electric currents, or 2) indirectly using CSP systems that use lenses/mirrors and tracking systems to focus sunlight into a small beam that can then heat water or air to generate electricity.
The currently used CSP technology generates solar-powered electricity when the concentrated sunlight is converted to heat. This heat is then used to power a heat engine that is connected to an electrical power generator. A steam turbine is the engine that is most commonly used, which uses the sunlight-heated water to produce steam which then powers the generator.
The research team at SDSU, however, created a new solar technology to use in place of these water-based CSP systems. The alternative CSP technology is not only innovative, but a huge advancement in solar science as the ideal location for such systems are in the desert (where water is lacking and must be imported for use). The new CSP technology releases carbon nano particles into the air to make the thermal absorption process of sunlight more efficient.
The carbon nano particles absorb the beams of sunlight from a field of mirrors surrounding the system and transfer the energy to the surrounding gas. These particles then burn up in the hot gas, which is used to drive a combustion turbine. In laboratory tests, the new CSP technology has been successful in effectively generating solar-powered electricity. Many people would never believe that carbon particles would be able to be applied in the generation of solar power, and in fact enhance its production.
The lead researcher involved in the project, engineering professor Fletcher Miller, was awarded a grant of $3.9 million from the United States Department of Energy's SunShot Initiative for this project. Thanks to the SunShot Initiative, the national initiative to make solar energy costs more competitive with other forms of energy by 2020, Miller's team will now be able to test the non-water CSP system in real life. The CSP system will be scaled-up from it's current lab-sized version and put into use in the field at the National Solar Thermal Testing Facility, Sandia National Laboratory, in New Mexico. If trials are successful, the combustion turbine CSP may replace the current technology and make solar-power an even more efficient renewable energy source to replace fossil fuel consumption.