The city of Lancaster, California recently adopted an ordinance requiring builders of most new homes to install functional solar power generation systems on these homes prior to their sale to the public. The law is believed to be the first in the nation to actually mandate the installation of solar systems. Californians may recall that the California Environmental Protection Agency, in 2004, advocated the adoption of a home solar power mandate that would have required home builders to include solar power in at least 5% of new homes by 2010 (a figure that was proposed to increase to 50% by 2020). That proposal, which comprised a portion of the agency's "Million Solar Homes" initiative, never came to fruition.

The Lancaster law, built into the zoning code, is effective with respect to all new home construction permits issued after January 1, 2014. To obtain a building permit, 1 kilowatt of installed solar generation capacity per home within a proposed subdivision is generally required. There is some flexibility built into the law in that it does not necessarily require solar systems to be installed on each and every home within a particular subdivision. For example, for a subdivision consisting of 10 homes, the requirement can be met by having 2 homes that each have 5 kilowatts of solar installed, or 4 homes that each have 2.5 kilowatts installed. Builders are also required to include solar energy systems on model homes that are reflective of the solar energy systems that will be offered to home buyers.

For those of us in the solar industry in California, it should come as no surprise that Lancaster is the first city to adapt such a law. Lancaster's Mayor, Republican R. Rex Parris, is known as a champion of solar, and Lancaster is miles ahead of almost all cities in the country with respect to its support of solar power and its efforts to increase commercial and residential installation of solar power systems. In 2009, Lancaster worked with eSolar to streamline the permitting and construction process for the company's Sierra SunTower project, a 5MW solar thermal project that was completed in just 14 months. In 2010, the city launched the Solar Lancaster program, a public-private partnership with SolarCity designed to provide affordable solar system financing for residential, commercial and nonprofit customers. That program resulted in the installation of solar systems on 19 different Lancaster School District sites, a Toyota dealership, a church, a minor league baseball stadium, and numerous other municipal buildings. Residential installations have also been proliferating, with one research group calculating that the city has tripled the number of residential installations in the past 18 months. Mayor Parris and the city have managed to cast an impressive global reach when it comes to sharing their vision of a solar powered world – Lancaster in 2012 won first prize in the "Fire" category of the Wolfgang Neumann Energy Globe World Awards in Vienna, Austria, and the Mayor was one of the keynote speakers at the 2012 World Future Energy Summit in Abu Dhabi, United Arab Emirates.

I have had a few people ask me whether any legal challenges to the mandate are expected. Some home builders have expressed opposition to the law, which is not surprising given that it would seem likely to increase their costs (and hence, the cost they must charge to the public in selling the homes, thereby decreasing competitiveness with homes in the resale market that are not required to comply with the mandate). While a legal challenge is always a possibility, in my view such a challenge would face an uphill battle, as cities generally have wide discretion in establishing zoning rules and regulations. Opponents of the law may be waiting to see if more, larger cities (the Lancaster population is 158,000) adopt similar laws – if so, we might expect to hear more discussion regarding homebuilder industry opposition and possible legal challenges to such mandates.

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