The Sierra Club threw a fake “retirement party” for the Ray Nixon power plant in Colorado Springs a few weeks back. The media stunt came complete with balloons, signs, retirement cards and speeches. But maybe it’s the Sierra-Clubbers who should retire, given how hopelessly disconnected they are from energy realities not just in Colorado Springs but in Colorado at large — where reliable old coal power is still far from dead and the “green energy revolution” they’ve been touting for 20 years is being exposed as a costly and risky blunder.    Clubbers descended on the Springs claiming a popular mandate to close a coal plant that still has a lot of life in it, and still dependably generates at least 20% of the city’s energy needs. But the climate crusaders had only 1,000 names on the petition, although the plant reliably produces power for roughly  half a million  El Paso County residents.…