A hydroponic seedling company in Neerabup near Perth is saving $250,000 a year by burning waste wood chips instead of LPG to heat its 1-hectare, climate-controlled greenhouse. Capital costs will be paid off in 2 years.
Trandos Hydroponics Growers grows grafted vegetable seedlings in a 1-hectare, climate-controlled greenhouse. The seedlings need to be kept at 20°C all year.
By using wood chips to heat the greenhouse, Trandos are:
- reducing their energy costs
- reducing their carbon footprint
- maintaining a high-quality product
- staying competitive
- seen by their customers as having an environmental advantage.
- Maintaining a constant 20°C requires 10,000 gigajoules of energy a year.
- The company buys the wood chips at $50/tonne, delivered to the greenhouse. Per year they spend $30,000 on wood chips.
- Using LPG, annual heating costs would be $280,000, or $140,000 for natural gas.
- Installing the wood chip heating system cost $150,000 more than an LPG-powered system would have, but it will be paid off in savings in 2 years.
- Over 10 years, the company expects to save close to $1,000,000.
How the system works
- Trandos buys clean and dry waste wood chips from Wesbeam, a manufacturer of laminated veneer lumber, located just down the road.
- The wood chips are waste from the factory, which makes the veneer timber from local plantation pine timber.
- At the greenhouse, the wood chips are put into a furnace and burnt to heat water.
- The water is pumped through heating pipes hanging near the seedlings.
- The system adjusts how much fuel it burns to keep the temperature constant in the greenhouse.
- The 4000 kilowatt (4 megawatt) system, at maximum capacity, is enough for the business to expand.