When building a new home, builders present potential buyers with several exterior options—and solar energy can be one of them. Integrating solar photovoltaics (PV) into new construction is a relatively new concept in the United States. In California, though, rooftop solar became a requirement as of January 1, 2020, with a California building code that requires all new construction homes to have PV as an electricity source. Other areas of the country have incentives to encourage builders to include PV as an option for their customers.
In addition to this guide for homebuilders, the Solar Energy Technologies Office (SETO) offers a guide for homeowners who are looking to add solar to their homes or buy a home with existing solar panels. If you’re new to solar and want to understand how it works, learn how solar works here.
Benefits of Solar to Homebuilders
There are various ways that adding solar panels on newly constructed homes can benefit a homebuilder. A study from the Lawrence Berkeley National Laboratory found that homeowners across the country have been willing to pay a premium for a home with an average-size hosted solar array. If homebuilders market their homes as being built with solar panels or with solar-ready roofs, they could draw the attention of sustainability-conscious consumers. Offering solar panels could also create a competitive advantage among new construction homes.
Yes, some states offer financial incentives for builders who use renewable energy. You can find financial incentive programs in your area by searching the Database of State Incentives for Renewables & Efficiency® website for your zip code or by searching for “builders” in their programs listing.
While consumers will likely pay more for a new home with solar panels than a home without, they can save money in the long run with lower utility bills. Consumers can learn more about financing options in the Homeowner’s Guide to Going Solar. Further, according to a recent study from New York University’s Center for Sustainable Business, demand for products marketed as sustainable grew more than five times faster than those that weren’t. If the solar system is tied to battery storage, the power generated from the panels could help homeowners maintain power during outages.
Homebuilders can inform consumers of the long-term savings on monthly utility bills that ultimately pay for the solar energy system. That information, along with much more about how solar energy will impact a home’s value, can be found in the Homeowner’s Guide to Going Solar. Additionally, homebuilders could educate potential owners on the federal investment tax credit and any other available state or local tax abatements on the value of the system. Those can be found through the Database of State Incentives for Renewables & Efficiency®.
Start by using a search engine to see which solar installation companies are in your local area. If there are multiple installers, you can ask for quotes to help narrow down the options. Additionally, you can visit the website of SETO awardee EnergySage, which has developed several tools that make the process of finding and selecting installers easier.
Construction professionals who are not certified to install solar panels should not perform any portion of the installation process. The North American Board of Certified Energy Practitioners offers educational programs and certification to ensure the safe installation, operation, and maintenance of solar panels. If you prefer your own construction crews complete the installation process, it’s important to ensure they have the proper training and certification—both for the safety of the homes and the employees. Training required might vary from state to state, so be sure to check local laws.
Typically, solar panels perform best on south-facing roofs with a slope between 15 and 40 degrees. Southwest- or west-facing roofs can work, too. Builders should ensure the roofing materials can support solar panels and a racking structure. While trees are normally not a concern with new construction, large trees near homes can create excessive shade on roofs, as can chimneys or other roof protrusions, which limit the functionality of solar panels. There are also considerations for the inside of the home, including an electrical panel that can handle the load and wiring to connect it to the panels. Electric space and water heating and appliances may decrease the time it takes to “pay back” the cost of a solar system through electricity savings and can eliminate the need for gas hookups. The National Association of Home Builders has more information on design considerations and wiring considerations in its Builder’s Toolkit for Solar.
A solar-ready home includes features that make solar installation easy. It has the same components and design considerations for the construction process as a home with solar panels does—the only difference is that the panels can be added later. Be sure to refer to the previous question to review considerations during the building process. Solar-ready homes can be appealing to homeowners who might want solar panels in the future but are not ready to make the initial investment. Solar-ready homes will also lower the cost of installation for homeowners, so this option can carry a premium.
The National Renewable Energy Laboratory’s System Advisor Model (SAM) is a free, open-source, techno-economic software model that facilitates decision-making for people in the renewable energy industry. SAM can model all types of renewable energy systems, including rooftop arrays with or without battery storage. In addition, the PVWatts and BeOpt tools developed by National Labs estimate the energy production and cost of energy of grid-connected PV and battery energy systems, enabling users to easily estimate the performance of potential PV installations.
Most commercially available solar panels are made with crystalline silicon. Silicon solar cells provide a combination of high efficiency, low cost, and long lifetime. Modules are expected to last for 25 years or more, still producing more than 80% of their original power. Monocrystalline panels are more efficient than polycrystalline panels, but are also more expensive. Check out the How Does Solar Work? webpage to learn more, especially the photovoltaics technology basics.
Builders need an interconnection agreement with the local utility in order to connect the solar energy systems to the grid. The nature of these agreements varies greatly depending on the utility and the local authority having jurisdiction. Utilities generally want to know the technical specifications of the solar energy system, and in some cases, they may want to inspect it along with the local authority having jurisdiction. Before you start building, it’s a good idea to reach out to the utility to gather all the information you need. After the interconnection agreement and potential inspection, the utility will grant the builder permission to operate.
Storage and Electric Vehicle Considerations
Battery storage for solar energy is a beneficial asset for homeowners because in the event of a power outage, the energy created by a rooftop solar system can still generate electricity for the home. The stored power can even be used at night when the sun isn’t shining. If you plan to offer solar energy storage batteries to potential homeowners, it’s important to involve the utility very early in the process. Depending on your location, utilities configure electricity metering differently. You should also review building codes in your area to ensure you are following protocol, as there may be specific fire code requirements for battery storage, and there will likely be electrical requirements.
In addition to providing electricity for a home, rooftop solar arrays can also provide power for EVs. The number of solar panels needed to power an EV is dependent on how much the EV is driven and the types of solar panels being used. Specific types of outlets are required for vehicle charging, much like the one needed to handle the load of a washer or dryer. Learn more about the requirements for charging a vehicle at home and developing the infrastructure required for charging.
- National Association of Homebuilders: A Builders Toolkit for Solar
- Lawrence Berkeley National Laboratory: Appraising into the Sun: Six-State Solar Home Paired-Sales Analysis
- Lawrence Berkeley National Laboratory: Selling Into the Sun: Price Premium Analysis of a Multi-State Dataset of Solar Homes
- National Renewable Energy Laboratory: System Advisor Model (SAM)
- National Renewable Energy Laboratory: PVWatts Calculator
- Database of State Incentives for Renewables & Efficiency
- North American Board of Certified Energy Practitioners
- Institute for Market Transformation: What is Green Worth? Unveiling High-Performance Home Premiums in Washington, D.C.