Scientists Developing More Efficient Solar Energy Solutions
A collaboration of chemists, mathematicians and engineers at Michigan State University is driving to improve solar panel technology, backed by a $1.9 million grant from the National Science Foundation.
The 3-year grant comes from American Recovery and Reinvestment Act monies and will focus on developing methods for making a new class of solar cells from cheaper materials.
“For renewable energy to succeed, it has to get to a point where it is economically competitive with current technology,” says chemistry Professor James McCusker, the project leader. “This means we need totally transformational technologies.”
Today’s solar panels are based on science worked out when the Beatles’ “Good Day Sunshine” was new to the airwaves, McCusker says. Their primary light absorber is extremely pure – and costly — silicon. Electricity produced by solar panels today costs two or three times as much as energy produced by coal.
“With estimates showing global power consumption tripling by 2050, we need to have scalable approaches that balance cost efficiency with environmental stewardship,” McCusker argues. “Only solar can be scalable to the amounts required.”
Solar energy is plentiful, if underutilized: The amount that hits the Earth’s surface in one hour equals the energy humans consume in a year.
The group is developing a solar cell based on a design that combines a dye with an inexpensive semiconductor — titanium dioxide – instead of silicon. Titanium dioxide is an opaque white pigment commonly used in paint and other consumer products. Applying advanced materials and nanoparticle technology can make electron conduction more efficient, researchers say.
The efficiency of these devices is around 11 percent, McCusker says, but that requires using a liquid electrolyte. His project will use a more efficient and inexpensive solid-state material.
The complexity of developing new approaches for converting sunlight into energy requires interaction among a variety of specialists. Research team members include chemical engineer Lawrence Drzal; chemists McCusker and Greg Baker; and mathematicians Keith Promislow and Andrew Christlieb. The mathematicians will develop modeling to efficiently guide the chemists, who experiment with materials alongside chemical engineers.
“Math is the steroids of experimental science,” Promislow says. “Nanoscale networks are key ingredients in the formation of efficient energy conversion devices, as they’re the infrastructure that does the ‘just-in-time’ delivery of reactants to catalyst sites — much like the interconnected networks of railroads, highways and shipping lines deliver raw materials to a factory.
“Getting these networks to self-assemble in an optimal way is a fundamental challenge, as there are millions of ways to build the networks,” Promislow adds. “Mathematicians build, code and analyze models that guide the experimental efforts by identifying the approaches most likely to succeed.”
McCusker leads a research group at MSU that is deeply involved in many areas of solar energy research. Some of his other research, supported by the U.S. Department of Energy, focuses on using other abundant elements such as iron and copper.
“To properly address the future demands of energy, we need to first solve the science in order to develop the technology for tomorrow,” McCusker says. “It takes a long time and much collaboration, but our job as scientists is to conquer the fundamental hurdles and address the scientific problems, so companies can then build and develop the technologies needed based on the science.”
