The project marks a significant step towards McCain's global commitment to reduce its carbon emissions by 50 per cent by 2030, cease any reliance on coal by 2025 and have 100 per cent of its plants powered by renewables by 2030.
"During daytime hours we basically will be off-grid once the solar power is running, that's on a sunny day when it's at full efficiency," Mr Wolthers told The Australian Financial Review.
"To get to be totally clean energy, we will have to buy a residue of clean energy from the grid, from a clean energy supplier, because we won’t be able to generate 100 per cent, but this gets us a hell of a long way towards that goal which for us is very exciting."
The project, which will cut the site's carbon-dioxide emissions by more than 27,000 tonnes a year, involves 8.2 megawatts of capacity in total, including 1.2MW of biomass and the rest solar.
Most of the solar panels will be mounted on the ground, covering 10 hectares of land behind the manufacturing plants, and will have a single-axis system that allows them to track the sun during the day. About 500kW of panels will be mounted on a carpark structure and on a truck flyover at the site entrance.
McCain pays no upfront costs for the system, signing up for a 20-year power purchase agreement with industrial solar specialist Smart Commercial Solar. The circa $15 million cost of the solar panel and biogas plants is being funded by Solar Bay, a renewable energy fund backed by a consortium of family offices, which has a $350 million mandate to invest in solar projects across industrial and commercial real estate.
Smart Commercial Solar managing director Huon Hoogesteger said the decline in wholesale power prices would likely drive a slowdown in solar in the commercial space but that his company was one of the few able to offer deals under the cost of network tariffs.
The self-generation of 39 per cent of the Ballarat plant's energy consumption would avoid network tariffs on that part of its usage. Gas use would drop by 16 per cent a year.
Mr Hoogesteger said the ability of the biomass plant to run around the clock meant it could smooth the output of the solar plant, which only generates in the daytime. The biomass plant could be ramped down during the day, effectively saving power for the evening.
"It's almost like having a grid-scale battery, working together with solar," he said, adding that McCain's predictable operations and regular output of potato waste ensured the steady supply of waste that was critical to the success of biomass projects.
"Behind the meter" refers to systems installed on an energy user's side of its power meter, rather than on the grid side.