Solar power is on pace for the first time this year to contribute more new electricity to the grid than will any other form of energy – a feat driven more by economics than green mandates. The cost of electricity from large-scale solar installations now is comparable to and sometimes cheaper than natural gas-fired power, even without incentives aimed at promoting environmentally friendly power, according to industry players and outside cost studies. Buoyed by appeals to self reliance and environmental stewardship, as well as government subsidies, the early solar industry was dominated by rooftop panels that powered individual homes and businesses. But such small-scale installations are expensive, requiring hefty incentives to make them attractive to homeowners. Today, large systems that sell directly to utilities dominate. […]