A University engineer believes that by developing hybrid solar panels, more useful energy can be obtained from sunlight. The hybrid system, in which sunlight heats a combination of water and methanol in glass tubes, can produce hydrogen which can be stored and used on demand in fuel cells.
Nico Hotz, Assistant Professor of Mechanical Engineering and Materials Science at Duke’s Pratt School of Engineering said the hybrid system absorbed more energy: “The hybrid system achieved exergetic efficiencies of 28.5% in the summer and 18.5% in the winter, compared to 5 to 15% for the conventional systems in the summer, and 2.5 to 5% in the winter.”
The hydrogen produced in the solar cells can be directed to a fuel cell to provide electricity to a building during the day, or compressed and stored in a tank to provide power later.
The team tested three systems in the analysis and found that the hybrid was more effective. Hotz said: “We performed a cost analysis and found that the hybrid solar-methanol is the least expensive solution, considering the total installation costs of $7,900 if designed to fulfill the requirements in summer, although this is still much more expensive than a conventional fossil fuel-fed generator.”
The research describing the results of Hotz’s analysis was named the top paper during the ASME Energy Sustainability Fuel Cell 2011 conference.