DB's Waitemata Brewery is part of New Zealand's brewing heritage, and is
home to such iconic Kiwi beers as DB Draught, Tui and Export Gold, as
well as leading international brands including Heineken, Amstel and
Erdinger. At the heart of DB's operations is an ongoing commitment to
reducing the energy requirements of each of their breweries, with
Waitemata the heavyweight user at around 76,000GJ per annum.
Living Energy were commissioned to look at the complex energy profile of the brewing operations at Waitemata, which has significant demands for both steam and hot water, which are currently met by gas, and for chilling, which is provided by electricity. As a large industrial user in Manukau City, DB benefit from some of the lowest cost gas in New Zealand, yet wood was still considered to offer DB the opportunity to cut both its operating costs and its substantial carbon dioxide emissions.
The study involved modelling the predicted energy use of the brewery once planned investment in a new brewhouse has taken place, and determining the size and configuration of the 'best fit' wood fired boiler for the site. Three steam boiler options were considered, ranging in size from 1.2MW up to 5MW. Absorption chilling and steam accumulation technologies were also explored in the comprehensive study of future energy options.
The study, which is available on the
Bioenergy Knowledge Centre website, showed that with investment levels of between $2m and $7m, DB would make savings of between $63,000 and $217,000 per year by making the switch to wood. While the currently available paybacks are slow, thanks to the low gas price paid by DB, the study showed that paybacks of between 9 and 13 years were possible, and that carbon dioxide emission reductions of between 11 and 40% could be achieved at the site, depending on the option pursued. Clearly, the likely upward price path of gas and an increase in the price of carbon could have a significant positive effect on the overall economics of the project.
Download the report (4.8MB)
here.