Nearly two years ago Alden Research Laboratory in Holden, Mass., hauled the scale model of a promising hydropower turbine out of its massive test flume and set it in a dim corner of the company's hydraulics laboratory building. As an innovation developed in the 1990s, the device proved quite promising in reducing one of hydropower's drawbacks: the turbines kill creatures that pass through them. The novel design enabled at least 98 percent of fish to survive. But orphaned by federal budget cuts, it has sat gathering dust. Now a new push has begun to retool the turbine for potential commercial use.