One of the potential options for lowering the cost of solar energy would be the development of more efficient plastic solar cells.  However, to increase the current low energy conversion efficiencies of plastics requires custom-made polymers.  Research at the University of Michigan now allows calculations that can predict energy levels of different plastic monomers, the building blocks of polymers.  By using this new technique to measure the energy absorption range the solar energy level of the resulting polymer can be estimated.  Now the challenge will be to figure out a way to use this tool to develop cheap and efficient plastic solar cells and bring them to market.