Like Minneapolis, many state and municipal governments have renewable energy initiatives on the books. California, for instance, has passed legislation requiring utilities that serve the state to get 33% of their power from renewable sources by 2020, despite concerns about higher costs for consumers and businesses. The city of San Francisco has an even more ambitious goal of using 100% renewable power by 2020. And Austin, Texas, has already achieved its goal of running the city government entirely with renewable energy.
Driven by initiatives like these, solar will inevitably grow in importance as a power source for U.S. cities, with a mix of rooftop solar panels that feed energy directly to homes and businesses and utility-generated solar power that augments power from existing sources, according to Gartner's Velosa. Several small plants, such as the 32-megawatt Long Island Solar Farm in Upton, N.Y., and the 30-megawatt Cimarron Solar Facility in Colfax County, N.M., are already up and running.
"Depending on how you cut the data, we have hundreds of plants in the utility-centered photovoltaic market, ranging from 0.2-to-0.5-gigawatt behemoths to 5-megawatt projects," says Velosa. "Many still lack financing, but [the sector] is extremely active and dynamic."
For the foreseeable future, however, solar is unlikely to be the sole or even primary source of power for most U.S. cities, according to Velosa. The obvious problem, he says, is storage -- energy generated during the day has to be stored at night, which is why it's important to watch the solar storage technology market, not just advances in solar generation. "Storage is critical for solar, since utilities are measured on consistent power," he says.
Still, Velosa is bullish on solar's future in the U.S. "Given the experience in Germany" -- a world leader in solar power generation -- "over the past decade, if the financials make sense, we can expect very high adoption rates for solar as prices continue to decrease," he says.
Into the future