How Two Thumb cuts costs with clean energy

Brewing with the sun! Two Thumb Brewing shows how solar power, local sourcing and smart water use can cut costs while making great beer in Ōtautahi Christchurch.

Sustainability

Why clean energy makes financial sense for Two Thumb

On a bright afternoon in central Christchurch, the most important piece of equipment at Two Thumb Brewing isn’t inside the brewhouse. It’s on the roof.

Up there, around 80 solar panels quietly power the brewery, the bar and even the garden – sometimes exporting electricity back to the grid. It’s not something most drinkers at the Colombo Street venue notice. But for Two Thumb, that understated approach is deliberate.

“Sustainability is just part of how we behave and what we value,” says chief executive Chris Mulholland. “We want to make the freshest, highest-quality beer we can, and being sustainable genuinely helps us do that.”

Brewing is a resource-heavy business, reliant on large volumes of electricity and water, with plenty of organic waste along the way. Two Thumb’s response has been a steady accumulation of practical decisions.

“When we started, we didn’t know much about the brewing industry,” says brewer Dave Dixon. “But we did know we wanted to create an environment that felt good for us and for our customers.”

In doing so, Two Thumb is part of a broader shift in Ōtautahi Christchurch toward growth that’s good for business, people and the planet – a core tenet of the city’s Economic Ambition.

Why sustainability started with supporting local suppliers

From the outset, that meant supporting Ōtautahi Christchurch and Canterbury suppliers wherever possible.

“Our thinking was: if we support local, local will support us,” Dixon says. “Buying local means less transport, less environmental impact, and it helps other local businesses thrive.”

That local-first mindset became Two Thumb’s first step toward lowering its footprint. All ingredients and packaging were sourced close to home – often just across the street – reducing transport emissions while building strong supplier relationships.

“It makes a huge difference,” says brewer Alex Grimshaw. “Our malt is grown and processed about two hours away, and most of our hops come from Okuora Farms in North Canterbury. It builds strong relationships with our suppliers, and the quality is second to none.”

How sunlight lowers Two Thumb's energy bills

The real turning point came when the brewery – which has four other sites in the South Island – expanded into its Colombo Street site, a building already designed with solar power, rainwater harvesting and low-waste systems.

“It was obvious we could get both a commercial benefit and a sustainability benefit at the same time,” Mulholland says. “Using what’s already around us – the sun, the water – helps us make great beer.”

“It was obvious we could get both a commercial benefit and a sustainability benefit at the same time,”

Chris Mulholland – Two Thumb Chief Executive

The brewery now runs two solar arrays, combining photovoltaic panels that generate electricity with solar systems that heat water. Together, they feed into a large inverter that powers the brewery, bar and outdoor areas.

“Using Mother Nature means we’re less dependent on the grid,” says Mulholland.

How Two Thumb cut electricity costs by a third

The energy savings are tangible. Two Thumb has cut roughly a third of its electricity costs – a significant buffer in an industry facing rising overheads.

Hot water is one of the brewery’s biggest energy demands, and solar has made a major dent. A 6,000-litre tank is heated by the sun to around 58–60°C, with only minimal additional heating required on brew day.

“That’s a massive energy saving,” Dixon says. “We also recapture heat from the brewing process itself, so we’re recovering heat in two different ways.”

Water use is tackled just as deliberately. Rainwater captured from the roof feeds the edible garden outside the brewery – produce that ends up in the bar and kitchen. Wastewater, meanwhile, is treated on site through a council-approved trade waste system.

“Breweries produce a lot of organic waste,” Grimshaw says. “Instead of that just going straight down the drain, we capture all of it.”

Organic material is separated and composted, while treated water is safely discharged back into the council system. Meanwhile, spent grain is sent to local farmers to feed livestock.

Why showcasing Canterbury based ingredients helps sustainability

Two Thumb’s sustainability philosophy also shows up in the glass. Its recent SMASH beer series – single malt, single hop – showcases Canterbury-grown ingredients with minimal intervention.

“It’s a simple recipe, but it really showcases the character of each malt and hop,” Dixon says.

Customers, it turns out, are paying attention.

“Our guests care about sustainability, and we share their values,” Mulholland says. “I think that’s why they support Two Thumb.”

Looking ahead, the team is exploring tools to better quantify its carbon footprint, alongside future investments such as CO₂ recapture during fermentation and expanded solar generation.

What other businesses can learn from Two Thumb

For Dixon, the advice to other businesses is simple.

“Support local,” he says. “It’s easy to buy cheap, but that’s not often the best thing for the business or the environment.”

At Two Thumb, those small, steady choices are adding up.

Key takeaways

Sustainability sits at the heart of Two Thumb’s values.
By prioritising locally sourced ingredients and packaging, the business has meaningfully reduced its environmental footprint.
Investing in solar power has paid off, cutting electricity use by roughly one‑third and creating a valuable buffer in an industry where overheads continue to rise.
Customers are increasingly recognising these sustainable choices, strengthening Two Thumb’s reputation as a brewery committed to doing things the right way.