Boilers

A 50kW wood pellet-fired boiler is proving considerably cheaper than electricity for heating the Bay of Plenty‘s 30 bed Titoki Healing Centre.

Fully automated and fed by a 3-tonne hopper topped up by the truckload, the system operates virtually hands-free.

Installation cost around $80,000. That compared more than favourably to the other main option, heat pumps, at around $90,000. Running costs are even more competitive at about $4,400 annually, almost a third of the costs estimated for running heat pumps.

Christchurch specialty meats producer Verkerks is paying for a lot less energy after taking a fresh look at how it generates heat and processes waste.

By converting the boiler to burn tallow, a meat processing byproduct, Verkerks will likely cut their energy costs by $150,000 a year.

The boiler at the company's processing plant produces steam for heating the smoke houses and fermenting rooms, and water heating.

Until recently the boiler operated only on diesel, consuming around 7,000 litres - and thousands of dollars - every week.

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.

Waste was one of the first considerations for Southern Pine Products when it started manufacturing MDF (medium density fibreboard) products.

The company opted to install a briquette press, which turns MDF dust into combustible briquettes for boiler fuel.

Moffatts Flower Company, a greenhouse complex only 5 km from Southern Pine, now buys all the briquettes the company produces.

The saving in Southern Pine's waste disposal costs is projected to be $180,000 a year and annual revenue from briquettes is projected to be around $25,000.