Campus cuts costs, emissions

Ara Institute of Canterbury’s Timaru campus continues to clear the air after converting to wood pellets.

The campus converted its boiler system, its main form of heating, from coal seven years ago, successfully reducing carbon emissions, its facilities manager says.

According to an Ara spokesperson, fuel for the wood pellet boiler costs $30,000 a year in pellets, as opposed to $18,000 spent on coal, but this is offset by savings related to the cleaner ash and air, reduced labour requirements and increased efficiency to heat 6906 square metres of campus buildings.

The campus is mitigating 248.04 tonnes of carbon dioxide each year, a possible 6201 tonnes of carbon dioxide emissions saved over the 25-year life of the boiler, the spokesperson said.

‘‘[There are] indirect but significant benefits, including community health improvements and other indirect gains as a result of a cleaner Timaru.’’

Timaru campus facilities manager Roger Luscombe said the change in 2013 was done at no cost as the system was a solid state boiler that could run on coal, pellets and chips.

‘‘An efficiency gain of 7 per cent was achieved by running wood pellets opposed to coal,’’ Luscombe said.

‘‘Even though pellets are a little more expensive compared to coal there are benefits – less maintenance to the system and a cleaner burning stack. Unlike coal, wood leaves no toxic ash behind. Formerly, two to three 40-litre drums a day of coal ash containing toxic heavy metals such as mercury and cadmium had to be sent to the landfill.’’

The wood-pellet-fired boiler produces less smoke, and the smoke is not charged with toxic particles. Consequently the system no longer requires an air discharge consent.

‘‘It’s much cleaner for the guys. They are not breathing in sulphur gas, and now when you walk in there is a lovely fragrance of pine.’’

Luscombe said the smaller amount of ash produced by the wood pellets is so clean it can be used as garden fertiliser on the Timaru campus gardens.

‘‘It amounts to about 60 litres of ash a week. Wood pellets are a win for both the institute and the community when all aspects are accounted for.’’

BEJON HASWELL/ STUFF Ara Institute of Canterbury Timaru campus facilities manager Roger Luscombe with some of the pine wood chips used in the boiler. The converted boiler saves money in the long term and burns cleaner.