By Maureen MCINTYRE January 14, 2015
Bob and Carmen Garver, co-owners of Wicked Joe Coffee Roasting Company, 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.
So it’s no surprise that their new roasting facility in Topsham, Maine, features cutting-edge solar and energy-efficiency features. The Garvers teamed up with local energy experts to transform the former commissary at Topsham’s Navy Annex into a model of sustainable design.
Michael Mayhew of Heliotropic Technologies in Boothbay Harbor worked with Conserval Engineering to modify the typically unglazed SolarWall® system design to create a glazed solar air heater that captures 40 percent more heat and meets the needs of the project and the local climate.
Based on initial assumptions and local weather conditions using the RETScreen model, he expected that the fully glazed SolarWall would operate about 30 percent of the time in September, 100 percent from October through May, and 50 percent in June. This scenario would have saved more than 4,240 therms of natural gas every year. Due to internal gains from the roasting equipment, however, the system wasn’t operational in heating mode until the end of October.
“If I had known how much heat the roaster throws off,” says Mayhew, “I would have modeled the heating season as November through April, and the SolarWall would contribute about 3,100 therms.”
Even with a shorter heating season, the SolarWall system’s energy savings result in less than a five-year payback, creating about a 25 percent return on investment. If natural gas rates increase during the next five years, the return on investment will be even better and the payback period shorter.
Energy advisors Fred Horch and Pat Coon of Spark Applied Efficiency in South Portland helped the Garvers select super-efficient LED lighting for many of the offices and enclosed areas. They also installed motion sensors on high bay fluorescent lights to ensure no energy is wasted on unnecessary lighting. Skylights provide daylighting, which allows sunlight to reduce the amount of artificial light required.
The new facility also features:
• A 3.57-kilowatt grid-connected photovoltaic system;
• An electric car charging station;
• Heat pump water heaters that harvest energy from indoor air to provide hot water and cool the air
around the water heaters; and
• Loring SmartRoast roasters that use 80 percent less energy than traditional roasters.
For more information, visit mainesolar.org.