Fonterra has taken a huge step forward in its commitment to renewable energy, going coal free at Te Awamutu for the new season.

Until now the site has used a combination of fuels to process milk - including coal.

The latest move is a switch to powering the boiler with wood pellets, following a successful trial last season.

And helping the dairy giant achieve its goal is engineering firm Stewart & Cavalier.

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Each baghouse was trucked across to the Fonterra site.
Each baghouse was trucked across to the Fonterra site.

The company had staff working on the project during Covid level 4 lockdown as it was deemed an essential service.

Stewart & Cavalier had to remove the roof from the coal fed system before installing a new one for the pellet fed system.

Fonterra's sustainable energy and utilities manager Linda Thompson says it's an exciting step for the co-operative and, in particular, the Te Awamutu team.

"It really demonstrates that sustainability, doing what's right for the long term good, is very much at the heart of how we're working and thinking about our future."

Last year, Fonterra announced a series of environmental targets relating to its coal use, manufacturing emissions and water efficiency, packaging and farm environment plans.

"The move to wood pellets at Te Awamutu will save the co-operative about 84,000 tonnes of carbon emissions every year, that's the equivalent of taking around 32,000 cars off the road and will reduce Fonterra's national coal consumption by approximately 10 per cent.

"It's a positive step forward as we look to reduce emissions and work towards net zero carbon emissions by 2050," she says.

The first baghouse is craned into position.
The first baghouse is craned into position.

Essential for the project were two massive steel baghouses to feed wood pellets from a conveyor belt into a furnace. This powers the boiler at the busy milk processing plant.

Stewart & Cavalier director and contracts manager Brent Mexted says the engineering company was delighted to play a key part in this project.

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He says it was a big job for the firm, with between 5-11 skilled staff on the project at any time.

"Operations manager Braydan Kete spent many hours planning the build around the position of the finished baghouses," says Brent.

"The two complete units are so large that manoeuvring them was beyond the reach of our gantry cranes and outside of our in-house lifting capacity, so the end-to-end process had to be meticulously thought through.

Two cranes are used to stand the second bag house up before it is lifted into its cradle.
Two cranes are used to stand the second bag house up before it is lifted into its cradle.

The baghouses were built to the design specifications Windsor Engineering. They are part of the total project which was carried out in different workshops.

Brent says it proved to be vital work for the company during lock-down, and allowed Fonterra to achieve its goal on schedule.

But it did require Stewart & Cavalier to remodel the workshop to make room for the project and allow other work to continue.

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"First, we moved all our equipment out, including workbenches and toolboxes," says Brent.

"We then spent lots of time programming incoming work and scheduling it for completion before we ran out of space."

Each of the two baghouses is 20 metres tall and 4.5m square - weighing in at over 20 tonnes.

They were built in manageable sized segments, starting with the bottom cones, which were completed and stored outside, then the main body in two U-shaped halves built back-to-back before being mounted to complete the shape.

Working during level 4 tested the team's social distancing technique, but fortunately when the major work of final assembly was undertaken the country had moved to level 2.

Work started in February and the baghouses were shipped over the road by truck and installed on time at the end of last month, despite the challenges of lockdown.

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The work was carried out over two nights due to size of the baghouses and transportation regulations.

A feature of the installation was the ease with which the components went together.

Bag houses in position at Fonterra Te Awamutu.
Bag houses in position at Fonterra Te Awamutu.

Brent says Stewart & Cavalier was one of four engineering firms making components, and on the days of installation everything lined up without a hitch.

The Te Awamutu site is one of three North Island Fonterra sites that are currently using coal.

Linda says the co-operative knows it's got a big challenge ahead of it to get out of coal but it's one that it's up for.

"There is no one single solution for us to transition out of coal," she says.

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"We know we can't do it alone, that's why working with others like wood pellet supplier Nature's Flame and the Energy Efficiency and Conservation Authority (EECA) are so important."

Taupō based Nature's Flame supplies pellets made from sustainable wood fibre residues from the surrounding areas.

Nature's Flame's operations manager John Goodwin says they're excited to be partnering with Fonterra.

"We're encouraged about the growth of the bioenergy (wood pellets) industry and we're proud to be part of something that's good for the environment and our local communities."

EECA's chief executive Andrew Caseley says, "This project fully aligns with EECA's purpose to help decarbonise the New Zealand economy.

"This is the largest boiler conversion project to biofuels to date, and this is why it has received $200,000 in funding from EECA's technology demonstration programme," says Andrew.

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"It also has the added benefit of establishing a more viable and large scale wood pellet supply chain."