If you wanted to save some money by learning how to check your home for air leaks, poor insulation, and power-hungry lightbulbs, the Department of Energy’s website was ready to help. And if you needed an expert, the site guided you to another page for help lining up a professional energy assessment, a well-established first step to cut utility bills and curb pollution at the same time. That is, until this summer, when both of those resources va…