Bob and Carmen Garver, co-owners of Wicked Joe, LLC, a coffee roasting company in Topsham, Maine, are clearly committed to doing things right. Their organically grown Fair Trade coffee is a tasty and sustainable option for their consumers and ensures a living wage for the farmers who sell to them. 

Taking their sustainability goals a step further, the couple wanted to incorporate solar energy into their new facility. Given Maine's northerly location and typically snowy winters, however, they worried that an investment in solar energy might cost more than it returned. 

Is it sunny enough for solar energy?

To decide if they should make a long-term investment in solar energy, the Garvers would need several years of data showing how much sunlight they could expect at their location during every month of the year. But monitoring the sunlight is something that the busy Garver's simply didn't have time to do.

It turns out that the information that businesses and homeowners need to help them make decisions about solar energy has already been collected. NASA's Applied Sciences Program, through its Prediction Of Worldwide Energy Resources (POWER) project, has processed and archived solar radiation data from satellite missions since 1983. Natural Resources Canada—our northerly neighbors' equivalent of the U.S. Department of Energy—offers POWER's solar radiation data through a user-friendly tool called RETScreen, short for Renewable Energy Technologies Screening Tool. RETScreen's primary purpose is to enable people around the world to screen out potential clean-energy projects that would not be cost-effective.

Choosing a solar wall

Based on initial assumptions and local weather conditions from the RETScreen model, the Garver's local consultant estimated that the solar installation they chose for heating would operate about 30 percent of the time in September, 100 percent of the time from October through May, and 50 percent of the time during June. This scenario could help them save up to 4,240 therms of natural gas every year.

The Garvers worked with a team of local professionals to build a solar wall for the coffee roastery: one large panel heats the space in the winter and a smaller solar photovoltaic array generates electricity. The installation also includes a fueling station for electric cars. Once the solar wall was installed, they discovered that interior heating from the roasting equipment in the facility let them put off additional heating until the end of October. Even with a shorter heating season, the solar wall system could pay for itself within five years if costs for natural gas remained steady.

People who make decisions in the fields of green energy, building design, and agriculture can use RETScreen or other tools that tap into data from the POWER project. Anyone who needs to know how much sunlight reaches the ground through the year—combined with information about wind, temperature, precipitation, and other factors—can access this information. 

Solar energy's potential

Small business owners across the nation are always looking for strategies that can help buffer them against slow-downs in business. Threats such as summer road construction, local economic impacts, and temporary closures due to weather-related damages all drive businesses to continually build their resilience. Investing in solar energy is one way businesses may be able to reduce costs and protect themselves from increases in energy prices.