Turning vine prunings into Biofuel

A Marlborough wine producer has successfully converted a tractor to run on a completely free, renewable biofuel – its own vine prunings.

The New Zealand Wine Company, which produces the Grove Mill label, decided in early 2008 that the rising cost of diesel warranted a look at other options. It commissioned a prototype tractor to run through ‘gasification’ – a process where biomass is partly combusted to create a gas which can be used for fuel.
The tractor was successfully converted, proving that it’s both possible and practical to power vineyard tractors on the natural by-product of growing vines. Diesel use reduced by 75 per cent and CO2 emissions by just over 0.35 tonnes per hectare, per year – which would equate to 42 tonnes of CO2 per year over the vineyard’s 120 hectares.

Between the start and end of the trial the cost of diesel dropped, meaning it’s currently more economic to use diesel – but the vineyard has a proven ‘escape route’ from high fuel prices when they rise again in future.

NZWC has a company ethos of sustainability, and its Grove Mill winery was the first to achieve carboNZero certification. The winery worked with Vine Gas Ltd on the tractor prototype, a company set up to promote the use of gasification as a fuel for vineyards.

NZWC sustainability and compliance co-ordinator Craig Fowles said: “At the time we started this project, the cost of diesel was going through the roof. We can be pretty sure fuel prices will go up again, and we now have this fantastic alternative that fits perfectly with our environmental vision. We’ve proved gasification works, and it’s a great way of utilising a waste stream to reduce our diesel use and our carbon footprint.”

EECA business programme manager, Murray Bell, said, “Not every business has the potential to grow its own energy source and it’s great to see NZWC grasp the opportunity to turn a waste product into a money-saving fuel source. Kiwi companies exporting to global markets are always looking for a competitive edge – demonstrating good environmental practice is a winner. Grove Mill’s project has the potential to benefit the whole wine industry by showing that a viable biofuel source is right under their noses.”

The project was supported with funding from the Energy Efficiency and Conservation Authority (EECA). EECA promotes innovative energy-saving and renewable energy projects with funding, advice and support.
Source: EECA