The Froling Energy crew stands by the new 42 ton wood chip silo which is 19 feet in diameter and 30 feet high.
School Administrative Unit (SAU) 48 in Plymouth, New Hampshire has just completed a $2 million energy retrofit project at Plymouth Regional High School. The project was designed by Energy Efficient Investments of Merrimack to have maximum energy savings as part of an energy performance contract with SAU 48.
One of the largest components of the project was upgrading the heating system to eliminate the aging oil-fueled heating system. Froling Energy completed this part of the project by installing a propane boiler in one boiler room and a biomass boiler in the other. The existing boiler rooms are far apart and are joined with well-insulated piping inconspicuously placed above hall and classroom ceilings. This allows either boiler to be used to heat the school.
The main heating source is a new Viessmann biomass boiler that was installed at the south end of the building near the service center’s garages. This location had the advantage of having open space outdoors, adjacent to the boiler room where a large dry chip silo could be installed. The silo is 19 feet in diameter and over 24 feet high.
The peaking and back up boilers are a pair of Viessmann high efficiency condensing propane boilers that replaced the less efficient, aging boilers that had served the school for a few decades.
Other aspects of the school’s efficiency project include:
- Retrofitting all existing fluorescent light fixtures to Philips LED.
- New AAON energy recovery ventilators for the science wing.
- Installation of two Daiken mini splits A/C for the principal’s office.
- Installation of six energy-efficient Powersmith transformers.
- New walk-in cooler controls for existing coolers and freezers.
- Weatherization includes air-sealing and insulating by Energy Efficient Investments.
- HVAC control updates.
The new Viessmann Vitoflex 300 wood chip boiler with a maximum heat output of 2.4 million BTUs/hr. Photos courtesy Froling Energy.
It is too early to know the exact savings for heating the school. However, in a short time, the lighting retrofit has resulted in a kWh savings of 45%! Jon Francis, Facilities Director at PRHS stated, “The school’s electric savings for the first two months post construction are on pace to be more than $60,000 per year. This is far in excess of what was projected.” The operating cost savings will be substantial.
The project benefited from a $325,000 grant from the NHPUC which supported the installation of the biomass boiler system. Additional incentive funding was obtained through the New Hampshire Electrical Co-op’s New Equipment and Construction Program. The remaining costs were then covered by a fifteen- year bond taken out by SAU 48.
With all the money spent, it may be surprising to report that local school taxes will not rise as a result of this project. This is because the annual debt payments for the project are less than the estimated annual energy savings. Therefore, the entire project is tax-neutral—or better.
SAU 48 plans to implement similar energy efficient measures at other district schools in the next few years.
Eric Sandberg from EEI, Jim Van Valkenburgh from Froling, and Michelle Harrison of Green Energy Times contributed to this article.
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