Solar Energy Guide for Homebuilders

Adding solar panels to newly constructed homes can increase the sale price, attract new customers, and distinguish a homebuilder and their homes among competitors. A SETO-funded study found that homeowners across the country have been willing to pay a premium for homes with an average-size solar array.

A home with solar panels has lower electricity bills than an equivalent home without solar panels. Over the life of the solar system, the savings exceed the higher up-front price of the home. Homebuilders can share information with consumers about financing options and incentives described in the Homeowner’s Guide to Solar.

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 Solar. Additionally, homebuilders could educate potential owners on 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. Be sure to address schedule in addition to cost. Some installers have a stockpile of solar panels on-hand that allows them to reliably match your construction schedule. 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 crew complete the installation process, it’s important to ensure they have the proper training and certification—for the safety of both your crew and your customers. Training requirements vary from state to state, so be sure to check local laws. A dedicated, in-house solar installation team that is properly trained may help reduce the time and cost of installing solar panels on your projects.

Typically, solar panels perform best on unshaded, south-facing roofs with a slope between 15 and 40 degrees. Any orientation between southeast and southwest can work well, with orientation being less important for shallow slopes than steep slopes. Builders should ensure the roof can support solar panels and a racking structure. While trees are normally not a concern with new construction, overhangs, chimneys, or adjacent roof peaks can cast shadows that impact the power generation 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 solar energy system. The National Association of Home Builders has more information on design considerations and wiring considerations in its Builder’s Toolkit for Solar.

The PVWatts tool developed by the National Renewable Energy Laboratory estimates the energy production of grid-connected PV and battery energy systems, enabling users to estimate the performance of potential PV installations.

Commercially available solar panels for residential use are made with crystalline silicon solar cells. Silicon solar cells combine high efficiency, low cost, and long lifetime. Modules are expected to last for 25 years or more, while still producing more than 80% of their original power. Learn how solar works, including photovoltaics technology. Additionally, you can consider using building-integrated PV (BIPV) systems, in which solar panels also serve as functional components of a house, such as roofing, siding, skylights, awnings, or carports. BIPV systems offer different aesthetic options than traditional PV systems, though typically at a higher cost and reduced power generation for the same area.

Power produced by a solar power system is wired into the home’s main electric panel. There are special requirements for labeling, sizing of the panel, and even the placement of breakers within the panel. Builders need an interconnection agreement with the local utility in order to activate this connection to the grid. The nature of these agreements varies greatly depending on the utility company 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 permission to operate. If you engage a solar installer, they will do this for you.

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 installing solar for homeowners, so this option can command a sales price premium.

Battery storage for solar energy is a beneficial asset for homeowners because in the event of a power outage the rooftop solar system can still generate electricity for the home. Furthermore, the stored power can be used at night. This is clearly beneficial in the case of a power outage, but it also saves people from paying the high prices that most utilities charge for electricity in the evening hours. If you plan to offer solar energy storage batteries to potential homeowners, it’s important to involve the utility early in the process. Depending on your location, utilities configure electricity metering differently and may offer incentives for adding battery storage. 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 additional 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. For rapid EV charging, 240-volt outlets rated at 30 to 50 amperes are required, similar to those needed for an electric clothes dryer. Learn more about developing the infrastructure required for charging.