In May 2008 Cashmere High School switched from coal to renewable wood energy to heat its site.
The new boilers produce around five times less particulate emissions than a typical school coal boiler. Carbon emissions have reduced by 216 tonnes per year. The wood-fired system is also 14% more efficient.
"There used to be soot and ash in the gutters. Now we just have clean, clean emissions," says Cashmere High support services manager Roger O'Regan.