THE next time you buy glasshouse-grown hydroponic Flavorite-branded truss tomatoes, they might be from Yarragon, in Gippsland, Victoria.
That in itself is not so special.
What makes tomatoes grown at Yarragon so special is the renewable energy used to create the warmth to grow them in.
Andrew and Ange Bayley are dairyfarmers who wanted to do something else with their land.
Truss grown tomatoes were their choice in 2003.
They now produce 450,000 kilograms, eight months of the year.
What’s more, they have tripled production since 2014.
To do that, they are using the heat created from burning 84 tonnes of mixed species hardwood waste and 24t of sawdust per week, in a purpose-built boiler.
“We were using briquettes and we wanted to look at other options,” Andrew Bayley said.
“We travelled the world looking at boilers and glasshouses.
“What we bought enabled us to triple the size of our glasshouse-growing space, from 5000 to 15,000 square metres.
“When we built the new 10,000 m² glasshouse, we were changing from plastic twinskin to glass.”
It enabled them to grow 450,000kg of truss tomatoes, tripling their production and extending their growing season.
“We plant in June, pick 10 weeks later and through to mid-May,” Mr Bayley said.
“Then we pull the plants out and go into maintenance – cleaning for biosecurity purposes and repairs.
“We expanded because we had to get the new heating system.”
It was a choice driven by economics and sustainability.
The wood waste, a byproduct of forestry, is sourced from local timber yards, in sawdust and chip form.
The chips, up to 600mm long, make up at least 15 per cent of the mix, for moisture.
“It’s a clean product we’re burning, so we end up with very little waste ourselves,” Mr Bayle said.
“1100t of wood waste produces one bin of residue, which is emptied every four to five months.
“It’s also halved our heating costs.
“The cost recovery time was substantially very feasible.”
The wood mass is moved hydraulically through a fully automatic, self-cleaning system, driven by a computer.
This is integrated to Mr Bayley’s smartphone so he can remotely access the system and be alerted at any time to changes.
A camera in the incinerator also feeds information to the off-site technicians (in Austria) and to Mr Bayley through his smartphone.
A winter night-time temperature of 16° Celcius is maintained. During the daytime it is 20°-24°.
Vents open in the glasshouse to maintain that temperature.
Innovation did not stop with the heating system.
A 400kVA generator provides backup electricity in a region where the mainstream system regularly breaks down.
“When you’ve got watering at 10-minute intervals in 40° weather in summer, you’ve got to have backup,” Mr Bayley said.
Water is harvested from the many rooves – including the greenhouse, glasshouse and the shed that houses the boiler – and used to irrigate the dairy country next door. The next stage is to recycle the water used in the hydroponic watering system. They currently collect and have capacity to store 20 megalitres of rainwater from the glasshouse.
The bottom line: “I’ll install more glasshouses before I’ll buy more land to milk cows,” Mr Bayley said.