It was just your basic annual address to the legislature — until New York Gov. George Pataki (R) surprised and thrilled environmentalists yesterday by announcing that he would require 25 percent of the state’s electricity to be generated from renewable resources within the next decade. New York already gets about 17 percent of its electricity from renewable sources (largely hydropower), but an 8 percent increase in that figure would represent a substantial step forward, given the size of the state. It would also help make New York a national leader in alternative energy: Of the 13 states that already have renewable energy goals, New York would boost one of the most ambitious plans. To date, alternative energy projects in the state have stalled because of concern that no one will buy the power they generate, but Pataki’s directive guarantees a market for such energy. The governor also noted in his speech that he wants New York to require reductions in carbon dioxide emissions from automobiles.