Power struggle: Green energy versus a grid that's not ready

In a sprawling complex of laboratories and futuristic gadgets in Golden, Colo., a supercomputer named Peregrine does a quadrillion calculations per second to help scientists figure out how to keep the lights on. Peregrine was turned on this year by the U.S. Energy Department. It has the world's largest "petascale" computing capability. It is the size of a Mack truck. Its job is to figure out how to cope with a risk from something the public generally thinks of as benign — renewable energy. Energy officials worry a lot these days about the stability of the massive patchwork of wires, substations and algorithms that keeps electricity flowing. They rattle off several scenarios that could lead to a collapse of the power grid — a well-executed cyberattack, a freak storm, sabotage. But as states, led by California, race to bring more wind, solar and geothermal power online, those and other forms of alternative energy have become a new source of anxiety. The problem is that renewable energy adds unprecedented levels of stress to a grid designed for the previous century. Green energy is the least predictable kind. Nobody can say for certain when the wind will blow or the sun will shine. A field of solar panels might be cranking out huge amounts of energy one minute and a tiny amount the next if a thick cloud arrives. In many cases, renewable resources exist where transmission lines don't. "The grid was not built for renewables," said Trieu Mai, senior analyst at the National Renewable Energy Laboratory. The frailty imperils lofty goals for greenhouse gas reductions. Concerned state and federal officials are spending billions of dollars in ratepayer and taxpayer money in an effort to hasten the technological breakthroughs needed for the grid to keep up with the demands of clean energy...more