BY: Sangeeta Anand
When diesel prices threatened to touch the $2 a litre mark a couple of years ago, The New Zealand Wine Company (NZWC) got worried. The owner of Grove Mill winery, a participant in Landcare Research’s carboNZero programme, began to explore ways to lower its energy bill.
With the help of consultant Vine Gas, the winemaker built a $15,000 prototype that uses vine prunings to make gas to fuel the vineyard’s four tractors.
With the Marlborough vineyard producing about 200 tonnes of burnable wood a year, the trial showed the potential for the business to reduce diesel use by 75%, cutting carbon emissions in the process.
The project was ruled out as not immediately viable, but it sits within the winemaker’s mission of building a business using environmentally sustainable practices. NZWC exports mainly to the United Kingdom, the US and Australia.
“We implement an annual emission reduction plan,” says Craig Fowles, the winemaker’s sustainability and compliance co-ordinator.
Such projects will become more relevant from July when the emissions trading scheme will push up petrol prices by 3c a litre and power prices from Mercury and Contact Energy by about 3%. Petrol prices will go up by a further 7c from October when GST and fuel tax increase, according to the AA.
Stopping heat waste
The winemaker also captures waste heat in its cool cellar. “Waste heat from refrigeration is captured and used in the warm cellar for warming wine for bottling. The cool cellar is also passively cooled during the evening,” says Fowles.
In fact, heat waste is one of the main areas of improvement in making energy savings.
Energy savings opportunities vary from site to site and industry to industry, says Dave Taylor, energy engineer for Enercon. “But typically large savings can be found in utilising waste heat streams more effectively, utilising low-cost energy sources and reducing electricity load during peak times.
Specialist consultants like Enercon offer complete energy management services from energy audits to tariff reviews, sustainable design studies and greenhouse gas emission assessments. These services can reduce the price paid for energy and ensure efficient energy use, cutting energy bills.
The capital cost of energy saving measures may look daunting initially, but it pays off. “On average our audits have identified savings of 19% of annual energy costs with a payback of less than three years,” says Taylor.
Enercon saved $1.3 million at a large wood processing facility by installing variable speed electric motors, using waste heat, optimising air flow and fitting lighting controls.
“Increasing insulation and installing variable speed drives on a large fishing boat resulted in savings of $170,000 a year,” says Taylor. And optimising air-handling unit operation and fuel selection has saved $400,000 at a large Christchurch facility.
So far, Enercon has performed 89 energy audits throughout New Zealand in a wide range of industries resulting in savings totalling $11.6 million a year with a three-year investment payback. Its largest customer had an annual energy spend of $15 million, which Enercon pruned by $1.4 million.
On the face of it the consultants’ fees appear to be money well spent. Some go as far as putting their money where their mouth is.
“We are willing to guarantee that the savings from our projects [at paybacks under three years] will exceed our costs, or we refund the difference,” says Rob Bishop, technical director of Energy Solutions.
“We believe most businesses can save 20% to 30% of their present use, at paybacks under three years [over 30% return on investment]. Many of our clients have saved this much, with some getting over 50% savings.”
One of Bishop’s clients, the Reserve Bank, invited Energy Solutions to perform an energy audit, and hired the company to help implement a programme of heating, ventilation and air-conditioning (HVAC) optimisation —to “tweak” control settings — for energy savings.
“The result was another 22% saving and improved comfort. We verified those savings, and are projecting another 20% saving this year from three more projects, all estimated at under one-year payback.”
But how complicated is the process for first-time clients? It’s a three-step approach which requires strong commitment at every step.
“The first step is an energy audit, to analyse energy usage and identify cost-effective areas where savings can be made. Then we help implement the chosen savings projects.
“Finally, we monitor energy use after the projects are complete to verify that the expected savings have been made,” says Bishop.
And for those short on funds, assistance is available. The government’s Energy Efficiency and Conservation Authority provides, among other things, funding and financial assistance to help New Zealand businesses invest in more efficient products, or switch to renewable energy.
EECA helped the New Zealand pork industry, a major source of exports, to trim its energy spending. An EECA-funded project investigating the feasibility of using pig manure to make biogas has been nominated for a Green Ribbon Award.
New Zealand Pork’s chief executive, Sam McIvor, says the feasibility study shows that biogas technology can work in a range of New Zealand farming situations.