When Golden Bay High School issued a tender in March 2008 for a new 700kW diesel or LPG boiler to replace their end-of-life coal boiler, they had no idea that March 2009 would see the installation of a 350kW Binder wood-fired boiler by Living Energy. Serving the town of Takaka and its surrounds, Golden Bay High School may be in the sunniest part of New Zealand, but winter temperatures can still plunge towards the zero mark, making a robust and reliable heating system a must.
The innovative step-grate technology of the schools’ Binder boiler means that they’re able to burn a wide variety of woodfuels, with moisture contents of up to 55% - that’s a freshly felled tree. In an area like Takaka, where the woodfuel industry is in its infancy, the flexibility that a system such as this offers is critical to the long term success of the solution, and guarantees that there’ll always be fuel available throughout the year.
The school also uses the boiler to extend the swimming season of the school pool, which also serves the wider community, without the crippling costs that would come with a fossil fuel solution.
Boiler house before... ...and during alterations.
During the planning phase it became clear that the existing boiler house and fuel store at Golden Bay would not readily accommodate the replacement wood-fired boiler and rotary arm fuel recovery system. As a consequence, Living Energy redesigned the whole boiler house, retaining and making use of existing walls wherever possible, and utilising the innovative Mus Max chip blowing system. The chip blower, which can transport woodchip from the reception trough to the fuel store by means of a powerful fan, enables a lower cost above-ground fuel store to be constructed at the site. This maximises the available fuel storage volume, thereby reducing the frequency of deliveries and improving the overall environmental performance of the installation.
The school were pleased to learn of the automatic fuel-feed and de-ashing systems that their new wood-fired system came with as standard. The dirty and often dangerous jobs of redistributing fuel and de-ashing the boiler by hand had long been a concern of the property manager and senior managers at the school. Their state-of-the-art Binder wood chip boiler operates with little more than a 10 minute daily walk round first thing in the morning - a far cry from the coal system it replaced.