Winery waste problem a zero-carbon opportunity

Steve Brennan of The Green Circle shows how marc left over from winemaking will be made into biochar. PENNY WARDLE / MARLBOROUGH EXPRESS

Penny Wardle, Stuff | March 01, 2024

Steve Brennan of The Green Circle shows how marc left over from winemaking will be made into biochar.PENNY WARDLE / MARLBOROUGH EXPRESS
Steve Brennan of The Green Circle shows how marc left over from winemaking will be made into biochar.
PENNY WARDLE / MARLBOROUGH EXPRESS

The Green Circle, a Blenheim startup company, and Yealands Wine are piloting a method to convert grape waste into 80% pure carbon.

The resulting product, biochar, held up to four times its weight in moisture, provided a home for soil microbes, boosted the value of compost and fertiliser, and could be added to animal feed.

As part of last week’s Climate Action Week Marlborough programme, a demonstration at the Yealands plant near Seddon showed forestry wood-waste and grapevine stumps being fed into one end of a machine and biochar being spat out the other.

The biochar, a charcoal-like substance, was slightly damp from moisture added to reduce its temperature from as high as 1000C.

Brennan encourages people to see, touch and interact with the biochar product.PENNY WARDLE / MARLBOROUGH EXPRESS
Brennan encourages people to see, touch and interact with the biochar product.
PENNY WARDLE / MARLBOROUGH EXPRESS

The Green Circle founder and director Steve Brennan and chief executive David Savidan said the machine being used for the pilot would dry marc at Yealands this vintage.

Marc is the seeds, skins and stalks left behind when wine is made.

“As much as possible” would be converted to biochar using pyrolysis, which is the burning of organic material at super-hot temperatures with no oxygen.

The biggest challenge would be scaling up to use available waste, improve efficiency and make biochar affordable, Brennan said.

Depending on the size and moisture content of material being fed in, an average of 20 tonnes could be processed per day, Savidan later told the Marlborough Express.

This time next year, the company planned to have several machines with capacity to process 15,000 to 20,000 tonnes. These would be based at a site central to vineyards, ideally in Renwick or Riverlands.

Last year, about 393,865 tonnes of grapes were harvested in Marlborough, according to Marcus Pickens of Wine Marlborough.

About 20%, or almost 80,000 tonnes, of that volume was marc.

Brennan said the 6 million or so vine trunks that were removed from Marlborough vineyards each year and 40,000 to 50,000 tonnes of prunings could also undergo pyrolysis.

Wine companies could dig biochar back into vineyards to sequester carbon for a zero footprint, he suggested.

However, there was not yet New Zealand demand for high-carbon biochar, Savidan said. The Green Circle’s business plan included researching local benefits that would later be shared.

Yealands sustainability manager Andrée Piddington, right, talks about biochar benefits with, from left, Heather Turnbull, John Baldridge and Tracy Taylor.PENNY WARDLE / MARLBOROUGH EXPRESS
Yealands sustainability manager Andrée Piddington, right, talks about biochar benefits with, from left, Heather Turnbull, John Baldridge and Tracy Taylor.
PENNY WARDLE / MARLBOROUGH EXPRESS

Yealands sustainability manager Andrée Piddington said the winemaker was keen for solutions because composting marc could cause leachate runoff.

Even if The Green Circle did nothing but dry marc, she would be happy, Piddington said. It could be stored with no risk of runoff and then sold as livestock feed.

Yealands was planning a trial in which biochar would be added to compost and then applied to soil.

Digging biochar into the ground to lock in carbon was appealing but not practical among the posts and wires of established vineyards, Piddington said. This could be possible as new areas were developed or old areas replaced.

Savidan said The Green Circle would charge clients to process their grape marc, at the cost of disposal. They could buy biochar at discounted rates.

Checking a handful of biochar are, from left, Nick Gerritsen, Gavin Beattie from Port Marlborough, and David Savidan of The Green Circle.PENNY WARDLE / MARLBOROUGH EXPRESS
Checking a handful of biochar are, from left, Nick Gerritsen, Gavin Beattie from Port Marlborough, and David Savidan of The Green Circle.
PENNY WARDLE / MARLBOROUGH EXPRESS

The company was the sole New Zealand distributor of its pyrolysis machine, bought from an Australian manufacturer that planned to take the technology global, Savidan said. The Green Circle designed and owned the New Zealand-made drier.

The company was also talking with Marlborough forest and aquaculture companies, Savidan said. OneFortyOne was looking into transforming wood waste, while New Zealand King Salmon was considering turning dead fish into soil stimulants.

In June 2020, the Marlborough District Council, Massey University and the Ministry for the Environment analysed five options for repurposing grape marc.

In their report, biochar was said to deliver “far and away the best environmental outcome. Going down the biochar route means the industry potentially has the opportunity to offset the emissions from all other parts of the production and supply chain.”

– Marlborough Express

Wine that’s truly chill: Yealands on path to climate ‘positivity’

Olivia Wannan, Stuff | Dec 07 2022

Blenheim-based Yealands wants to eventually absorb more greenhouse gas than it emits, making it climate positive. That’ll require the winemaker to cut its footprint by 5% every year, sustainability head Michael Wentworth tells Olivia Wannan.

When did Yealands’ sustainability journey begin?

In 2008, when we launched, it was Peter Yealands’ vision to lead the world in sustainable wine production. We have a philosophy: think boldly, tread lightly.

We were the first winery in the world to be certified as carbon-zero, from day one.

In sustainability, there’s never a finishing post. There are always improvements.

What are the major contributors to a winegrower’s footprint?

Michael Wentworth, Yealands sustainability general manager, is excited by the vineyard’s green plans.

Our operations here – the vineyard and winery – make up about 35% of our footprint. Of that, diesel and electricity are key.

That leaves 65% – the primary emissions are packaging and freight. This is challenging, because you have to work with multiple parties and countries. The big gains are beyond our vineyard boundary.

How do you get that to net-zero?

Diesel powered our irrigation pumps, though we’ve electrified those. We’re using smaller tractors, better suited to lighter work. Before, we had large agricultural tractors.

We reduced diesel emissions by planting wildflowers and legumes down the vineyard rows, so you don’t have to mow as regularly. The beauty of that is it naturally increases biodiversity within the vineyard and carbon and water in the soil.

We’ve got a significant composting operation.

Winemaking can be electricity-intensive. Right throughout the process, you’re regularly either warming wines or cooling it, depending on where your wine is at. That requires energy.

At the moment, we produce 20% of our energy requirements on site. We’ve got a solar system on our winery roof – and it was the largest array at the time, when it was installed. Within the next two years, we’ll be installing something that’s 10 times larger, on land opposite the winery. We’ll get to about 60% self-sufficient.

But what’s unique to us is that we bale a portion of vine prunings, dry them and use those as a heating source in the winery – rather than using LPG.

Increasingly, we are bottling in the market. When you’re shipping long distances, you want to be as efficient as possible. Sending packaged wine overseas means your container is full of air, or the air gaps between bottles – plus you’re shipping a heck of a lot of packaging.

By shipping more wine in less packaging, we reduce our freight footprint by 30%. In the foreign markets, you get more choice. For example, in Sweden a lot of their premium wine comes as cask wine – which is one of the lowest-emissions forms of packaging.

We calculate all our emissions and for all unavoidable ones, we purchase registered carbon credits. We’ve done that from day one. But we want to be carbon-positive by 2050 – we’ll achieve that without offsetting.

By 2050, we’ll have to sequester carbon: whether that’s planting native trees or using biochar, which locks carbon away in the soil.

2050 sounds like a long way away. To get there we need to reduce our carbon footprint by at least 5% every year. And by 2030, we want to reduce our emissions by at least 50%.

From 2013 to now, we’ve reduced our footprint by about 25%. There’s still a lot of work to be done.

What happened with Yealands’ eco bottle?

Yealands already has solar panels on its facility roof – but will expand its generation at a nearby site.

It was a PET plastic product, which had emissions advantages. A lighter bottle uses less resources, and when you’re moving that bottle, you produce fewer emissions transporting it.

It was always a starting point, in our quest to find a biodegradable product that stopped the wine being oxidised.

The public wasn’t really ready. We found people were buying it more for convenience, than the environmental aspect. It was easier to use outdoors, and doesn’t break.

Shoppers’ acceptance is key. There was a push against plastic. Ultimately, we didn’t progress.

How will a warming climate affect wine production?

Over the last six months in Marlborough, we’ve had three significant weather events that have impacted our ability to get to the winery and our ability to export our wine via Nelson.

Our industry is very reliant on the weather. A small change in temperature or the environment has a noticeable impact on the flavour profile of your wine. Marlborough sauvignon blanc is so distinctive on the international stage, so a small change in climate has the potential to affect the wines we produce. It is scary.

People are looking at ways to adapt – but the argument should be: what can we do to prevent it?

We believe that a more biodiverse vineyard is a more resilient one. The more we plant native trees and wildflowers, the less inputs we need to make and the better our vines will be.

Tasting – Everything Pinot – Feb 2022

The evening with Everything Pinot was a tippling success, with 37 people turning up for the Club’s own members to present to, plus a special guest for the evening’s last pinot – John Dawson with a whisky distilled in pinot barrels from Central Otago’s Lammermoor, ‘a farm to bottle distillery’: Lammermoor Distillery.

We tasted our way through the Club’s cellar after our opening pinot Waipara Hills Pinot Noir Rose’. Followed up with three 2017 Pinot Gris, from Peregrine Saddleback, Giesen Marlborough and Church Road McDonald series. The comparisons were quite distinct, and the discussion was good.

This was then followed by three 2016 Pinot Noirs, from Peregrine Saddleback Central Otago, Yealands Reserve Marlborough, and Russian Jack Martinborough.