Solar panels don’t make sense for all homes. Even houses on the same street can have dramatically different solar situations, depending on which way roofs face, whether trees are blocking the sun, and other factors. On just one street in Washington, D.C., one house could make $30,000 over the lifetime of the installation, another could return $11,000, and still another would find that solar saved its owner no money at all.
That analysis is according to David Levine of Geostellar, a company that’s created a sophisticated house-by-house tool for assessing solar costs and benefits. It takes up to 15 sources of data, including overhead color-infrared imagery showing trees, yearlong weather data, state incentives and local utility rates, and gives users an immediate read-out for any ZIP code.
Geostellar has been providing data to solar installers since 2010. But it’s only just released a site and mobile app for consumers and homeowners, called Solar Mojo. As well as assisting end-consumers, it wants to cut costs for solar companies by reducing the need for house visits, and by being a lead-generator. House owners can go to Geostellar, do their analysis, and sign up for a lease or loan, or buy a panel for self-installation, all in one place. Levine equates it to shopping at 7-Eleven for beer and diapers.
By building a 3-D virtual model for each house, Geostellar is effectively replacing the guy who currently comes to your door, and spends two hours wandering around the property with a clipboard. “It’s as if a very patient solar designer was standing at each spot by the house, and tracing the sun’s movement through the sky,” Levine says. “Over the course of a year, we know exactly how much sunlight reached that one square meter of rooftop.”
Next year, Geostellar plans to expand further by offering an API to outside parties, like real estate sites and state agencies. This could, for example, let home buyers factor in a house’s solar potential before deciding where to live.
Better market information should give a further boost to the solar industry, especially as Geostellar is also able to tell installers where to set their prices to remain competitive with traditional energy. For example, it can analyze the break-even point for 80% of homes in a particular county and state, allowing installers to lower their per-watt cost if necessary. “We basically make the market by showing what the fair market value of solar is in the area,” Levine says.
You can check out the rate of return for your state–based on the cost of the solar energy itself, utility rates, and incentives–at Geostellar Solar Index, which it publishes quarterly. Otherwise go to the site or app, and plug in your ZIP. Easy peasy.