Industry groups, state and local governments, and nonprofits around the country are working hard to try to figure out new ways to get more solar on more roofs. But what if we take that goal to the next level – and try to get solar on every roof? The City Council of Lancaster, California, took a big step in that direction by approving a revision to its Residential Zoning Ordinance last month, making it the first U.S. city to require the installation of photovoltaic (PV) systems on all new residential construction. Incorporating solar into the design, construction and financing of a new home can provide substantial cost savings compared to a system installed on an existing home. For instance, a 2012 report from the National Renewable Energy Laboratory found that making a home “solar ready” at the time of construction could, in some circumstances, save homeowners more than $2,500 compared to retrofitting an existing home, and designing new homes with solar in mind also has the potential to enhance energy production by ensuring optimal roof orientation, and avoiding obstruction or shading issues. Moreover, going beyond solar readiness to actual solar installation may facilitate lower cost financing by allowing the cost of the system to be rolled directly into the home mortgage. Hoping to tap into these savings, a handful of city and state governments have adopted rules in recent years that attempt to encourage the inclusion of solar in new home construction, but none have gone as far as Lancaster.
Tucson, for example, adopted an ordinance in 2008 that requires all new single-family homes and duplexes to be built solar-ready. To comply with the PV requirements in the ordinance, a site plan must indicate the best roof space for locating the PV panels, and provide a roof structure designed for the additional collector weight. The site plan must also illustrate the best space available for accommodating PV equipment (meter, inverter, disconnect), which should be adjacent to the electrical service panel or on a wall near the proposed location of the panels.
California, New Jersey, and Colorado have laws that require homebuilders to offer solar as a standard option. Colorado, for example, requires homebuilders to give the buyer the option to have either a photovoltaic (PV) system or a solar water heating system installed on the home, or to have all the necessary wiring and/or plumbing installed so that they can easily add a solar system at a later date. The builder must also provide the buyer with a list, maintained by the Colorado Energy Office, of every solar installer in the area.
Lancaster puts itself on the leading edge of innovative policy by taking these requirements a significant step further. Effective January 1, 2014, all new residential buildings in the city must have a PV system installed. The minimum size requirement for the system varies from 0.5 kilowatts (kW) to 1.5 kW, depending on the type of dwelling, the zone, and the lot size. Single-family houses on lots of 15,000 square feet or larger must install a 1.5 kW PV system. Single-family houses on smaller lots and rural zones, and multifamily structures are subject to smaller installation requirements. The ordinance also provides some much needed flexibility for homes within a production subdivision. As long as the builder meets the aggregate energy generation requirement, they can consolidate the systems onto fewer roofs. For instance, a builder developing a subdivision of 10 homes, which are individually required to have 1.0 kW systems installed, could comply with the ordinance by installing 5.0 kW systems on only two houses. Homebuilders also have the option of purchasing an equivalent amount of solar renewable energy credits from another solar installation in the city. These alternative options allow for economies of scale that reduce overall costs for an equivalent amount of solar generation, and avoid mandating that systems be installed on unsuitable sites.
The newly adopted requirement is part of the Lancaster mayor’s larger goal of producing more electricity from solar than the amount of electricity the city uses, and in fact builds upon prior adoptions of specific regulations for large-scale solar farms and consumer roof or ground-mounted installations. With 39 megawatts of solar already installed and 50 MW under construction, Lancaster is more than half way to meeting that goal. The adoption process of the ordinance itself was not without a certain amount of disagreement among stakeholders and members of the Lancaster Planning Commission. During public proceedings, several homebuilders expressed concerns that the measure would increase building costs and stated a preference that solar remain an option rather than a requirement, or be offset by government incentives. One builder, KB Homes, indicated that it did not consider the requirement particularly difficult to meet, though KB Homes is unique in that it already offers solar as a standard feature in new homes. Concerns of this type probably make it unlikely that many other cities will follow Lancaster’s residential solar requirement example in the near term, but other portions of Lancaster’s zoning code are perhaps more replicable and solar-friendly zoning codes are only one of a number of ways that a local government can encourage solar development. Towards this end, Solar Outreach Partnership has a Resources Database filled with information on the variety of options available, and can provide Technical Assistance to help local governments build a strong policy framework and advance solar markets in their communities.