Paul Krugman’s column today makes the case: “We really can invest in new energy sources, divest from old sources, and actually make the economy stronger. So let’s do it.” [New York Times]
For applications where weight is a crucial factor — such as in spacecraft, aviation or for use in remote areas of the developing world where transportation costs are significant — such lightweight cells could already have great potential, Bernardi says.
Lyndon Rive, chief executive of San Mateo, Calif.-based SolarCity Corp., said in an interview this week that his rooftop solar company plans to roll out a system that would allow customers to generate power by panels during daylight hours and store the energy in battery packs at night.
Today’s chalcopyrite thin film cells based on copper indium gallium selenide are already reaching efficiencies of more than 20 percent. For the fabrication of the extremely thin polycrystalline layers, the process of coevaporation has lead to the best results so far: During coevaporation, two separate elements are evaporated simultaneously, first indium (or gallium) and selenium, then copper and selenium, and, finally, indium (or gallium) and selenium again. This way, a thin film of crystals forms, which exhibit only a small number of defects. “Until recently, we did not fully understand what exactly happens during this coevaporation process,” says Dr. Roland Mainz of the HZB’s Institute of Technology. The team of physicists worked for three years using on-site and real-time measurements to find an answer to this question.
This slenderness is not only advantageous in shipping, but also in ease of mounting solar panels. About half the cost of today’s panels is in support structures, installation, wiring and control systems, expenses that could be reduced through the use of lighter structures.
If there really is a so-called “War on Coal,” then coal exports — which have doubled in the last 4 years — are certainly not losing many battles. [New York Times]