Solar Thermal Case Study #2
Solar thermal systems have a very high user satisfaction rating. There is no end to the number of successful solar thermal systems we might have chose to profile here. The following portrait of a solar thermal system in use comes from the Canadian Renewable Energy site from Natural Resources Canada. It profiles the use of solar thermal at a small inn in Nova Scotia.
Chanterelle Inn is a large country inn located in North River, Nova Scotia, approximately 50 kilometres north of Baddeck on the Cabot Trail. Although the inn operates year-round, most of the inn's guests, who come from around the world, visit during the spring, summer and fall.
The two-storey inn, shown in the photo with the Cape Breton Highlands in the background, was constructed in 2000. The wood-frame building measures 15 metres by 15 metres and has a full basement. It features eight suites on the upper floor, as well as a kitchen, a dining room, a lounge and another large suite on the main floor.
The building consumes no fossil fuels on site and depends upon solar energy with electricity backup for space and water heating. An in-floor radiant heating system also provides space heating for the inn.
The Solar Decision
Earlene Busch, owner of the inn, had three key environmental objectives in mind when she decided to construct the inn in 2000:
- The inn would provide a healthy environment for her guests, with no fossil fuels consumed on site.
- The inn would fit in with environmental concerns about the depletion of fossil fuels.
- The owner would consider power self-generation at the site in the future.
According to Busch, "Solar hot water seemed a natural fit with my three environmental objectives." One factor that helped her choose solar is Natural Resources Canada's Renewable Energy Deployment Initiative (REDI), which contributed 25 percent of the purchase and installation costs of the solar hot water system.
Thermo Dynamics Ltd. of Dartmouth, Nova Scotia, designed and supplied the solar hot water system. SunRoss Energy Systems Ltd. of Port Hawkesbury, Nova Scotia, installed it.
The system includes 16 flat-plate and two 12-volt solar electric (photovoltaic) collectors. They are located on the south roof and are mounted at a 35 slope with an azimuth of 10 west of south. The two photovoltaic collectors supply power to the system's water pump. The panels are mounted on Unistrut channels lagged to the roof and sealed with silicone to prevent leaks. Extra trusses were installed to ensure that the roof could support the additional load of the solar panels. The glycol piping runs down to the basement through the roof and walls. A rubber boot was installed around the piping on the roof to prevent water leaks. The mechanical equipment is located in the basement next to the in-floor radiant heating equipment.
The total project cost was $36,700. With REDI's 25-percent contribution, the cost was reduced by approximately $9,100 for a net total of $27,600.
Operating and Maintenance Experience
The system is in its first year of operation. Busch has encountered no maintenance problems to date.
The solar collectors were partially covered with snow in January 2001, which is unusual for an average Nova Scotia winter. The snow cover made the collectors less effective, but this had few implications since the inn operates at minimal capacity during the winter, and only one of the four electric backup water heaters was being used.
The reduced solar capacity during the winter should not affect the overall performance during the prime season (April to October). Should more guests arrive in the winter, then Busch may have to investigate increasing the collectors' angle to 45 to reduce the snow cover. Usually, flat-plate solar collectors can clear themselves of snow once a small part of the glass is exposed to sunlight. Still, the 35 angle for the collectors is close to ideal for summer operations, so changing the angle is fundamentally an operating decision. Since Busch is concerned about the snow cover during much of the winter, she is examining the best way to keep the panels clear.
Busch is very satisfied with the installation and operation of her solar system. "The sound of the solar pumps operating, even on grey days, is lovely," she says.
Integrating a solar hot water system into the design of the facility during construction was a problem. However, SunRoss Energy Systems Ltd., the installer, made an extra effort to ensure that all trades understood the specifications of a building with this type of equipment.
Busch, when asked about planned maintenance, indicated that she "hadn't really thought about it." Most solar heating systems should have an annual scheduled maintenance, as it will affect the long-term performance and benefit of the system.