Shortly after President Joe Biden offered tax credits to anyone buying solar panels, a Colorado homeowner named Stacie took out loans to install $30,000 worth of panels on her roof. Nearly six months later, however, those panels sat unused, generating no power. The problem seemed to have a simple fix: Stacie's energy provider merely needed to hook the panels up to its power grid—but there's no room. Increased demand driven by Biden's green subsidies, combined with inadequate power grid capacity, has left thousands of green energy projects like Stacie's without power, rendering them useless. "When you put out $30,000, you...