The alternative energy movement, says the FAA, at the behest of the Department of Defense and Department of Homeland Security, is threatening development of wind turbine projects, tagged by President Bush to become a power-producing mainstay in the U.S. The DOD is currently studying whether wind turbines interfere with defense and homeland security radar systems and that means the FAA is no longer routinely signing off on windmill farm applications as posing no threat to air navigation. The study was to have been finished by the end of April but wind-power proponents fear it could drag on for months, effectively stalling windmill farms that have already been approved by every other agency. The de facto moratorium on windmill farms could end up costing those developing them millions of dollars in federal tax credits that expire at the end of 2007. Perhaps more important, the DOD/DHS opposition to the farms has disrupted momentum in a shift from development of gas and coal-fired plants to wind power, which is regarded as the cheapest form of alternative energy. Wisconsin has at least 10 projects stalled by the study and it has proponents worried. "This is the worst possible time to place roadblocks in the way of wind development, when Wisconsin is making critical decisions about building new generation," Katie Nekola, program director for Clean Wisconsin, told BusinessNorth.com. "Wind energy is by far the best choice we have, and has to be an available option."