May (No. 496)
Wineries of the future, cutting energy use
After grapes and people, energy is usually the biggest variable cost in wine production. Energy, usually in the form of electricity, is needed for heating, cooling, crushing and pumping. And the electricity supply to many small wineries is not too crash hot. They are often isolated, at the end of a line and the supply may be limited.
Therefore it comes as a surprise that few wineries have so far taken more than a passing interest in energy saving and alternative energy sources.
An exception is the Wolf Blass winery in Barossa, South Australia, which has signed up for the Federal Government’s “Wineries of the Future” program to achieve Energy Efficiency Best Practice.
Alan Edward, general manager production, said the winery used the waste heat from fridge compressors to heat its water, but there are many more ways to harness waste heat, reduce water usage, use off-peak energy more effectively and reduce the output of greenhouse gases.
“We will take a detailed look at what we are trying to achieve at each process step and investigate ways of achieving the same outcome using less energy,” said Edward. “We want to try to look outside the square, and take advantage of not only existing technology but also emerging technology.”
Leeuwin Estate, near Margaret River, has travelled down the same road. It has a peak load tariff, which limits the maximum load it can take at any one time.
“Our main problem is at vintage time when must cooling takes a lot of energy,” said chief winemaker, Bob Cartwright. “We installed an Andover computer control system that senses the amount of electricity we are drawing. If we are near our maximum it takes out items one at a time in our order of preference.”
Energy saving is also important.
“There are lots of little ways to save energy. When we read the Andover handbook – it’s that thick and we were using only the first two pages of its capabilities – we expanded the system to monitor our effluent and control the warehouse air-conditioning.
“We turn off the air-conditioning during the day and run it at night. During the day energy is wasted through the door. Next we used the Andover to control the must cooler. It operates the mixer valve to prevent it freezing.
“We have fitted infinitely variable speed motors wherever possible to control the compressors, so we only use as much power as we need to.”
Wineries of the Future has identified refrigeration as taking up to half the electricity demand of wineries, especially during vintage.
“We replaced older machines for cooling grapes. The motors on modern refrigeration plants are much smaller and use less power. Infinitely variable speed motors allows the pressure to ramp up and down to do what we want.”
Leeuwin’s first energy-saving step was to insulate everything including the tank cooling jackets. The buildings, mainly made of rammed earth, are designed with a high thermal mass so temperature fluctuations are small. The building remains cool in hot weather without electricity for 24 hours or more.
The Leeuwin Estate art gallery, restaurant and tasting room have 70-80 globes. They are controlled by an infrared sensor that switches lights off after an interval if there is no movement in the area.
“Saving energy is important, but at the end of the day winemaking is all about quality,” said Cartwright.
Leeuwin Estate takes the power off the highway at a high voltage and it has its own transformer on its own line. Other wineries are not so well placed. A few have installed generators to cope with maximum power demands during vintage.
Although there are many theoretical options for renewable energy, only solar water heating is universally accepted as competing economically with fossil fuel, except in very remote situations.
A survey of solar energy manufacturers in Australia produced only one winery actually using solar water heating. Others are showing an interest, but have not yet invested in the technology.
The one early adopter is Michael and Alison Kelly’s Fermoy Estate, near Margaret River. The Kelly’s installed three Solarhart units with gas boosting, producing 1000L/day of water at 88oC.
“It’s been absolutely fantastic. We’ve had the units for 15 years and they provide all the hot water we need for the winery,” Kelly said.
Chris Dodd, of Energy World WA, said the case for solar hot water in areas without piped natural gas is very strong.
“Water has a very high specific heat which means you have to put a lot of energy into it to increase its temperature.
“In the home the hot water system is by far the largest consumer of power at around 31% – compare this with lighting at 3%. In industry and agriculture it's a similar story.
“Most businesses don't know where their gas and electricity is being consumed and I think they would be surprised to know that a hard-working domestic water heater could be costing upwards of $2000 year in power.
“As an approximate guide, 60oC hot water costs around $6-$10 per 1000 litres in energy when heated by a conventional LPG gas or electric system. A solar hot water system will consume the same amount of energy but most of this will be free from the sun.
“Solar hot water costs $1-$2 per 1000 litres,” he said.
Solar hot water systems are generally backed up by a conventional gas or electric booster that kicks in on cloudy days or during periods of high water demand.
“A typical winery using an average of 5000 litres per day of hot water could save up to $16,000 per year in power bills by moving to a solar system.”
The high initial cost of solar has put off many buyers. Solar systems cost around three times as much as conventional heaters, but last three times as long, so over a 20-year period the capital costs of solar and conventional systems are about the same. However, the solar system will cut water costs by up to 80% every year.
In a desktop study of water use by Ferngrove Winery in the Frankland River region, Dodd calculated the winery needed 5000-10,000 litres of water day at 90oC. He suggested a series of modular 10kW systems consisting of eight solar collectors to preheat the water to 60oC. Each module costs about $4500 (+ GST) after discount for Renewable Energy Certificates.
“Compared with a LPG boiler operating at 70% efficiency, and a LPG price of 70c per litre each module will save nearly $1800 a year, paying for itself in less than three years.”
The annual saving in carbon dioxide emissions is 26 tonnes per 10kW module.
While Australian wineries are beginning to take carbon dioxide seriously, Champagne, that most conservative of French wine regions, has a head start. In 2003 the Comité Interprofessionel du Vin de Champagne (CIVC), decided to find out how far Champagne production contributes to global carbon dioxide emissions.
An analysis of its survey data showed the industry could reduce emissions by 20-30% over the next 10 years without serious technical disruption.
Arnaud Descôtes, CIVC environmental officer, told Decanter, that while it was clear they had a 'moral duty' to protect the environment, there were 'sound economic reasons' for what they were doing.
“First, there is Champagne's image: environmental considerations are increasingly important to consumers.
“Then there is the inevitability that energy costs will increase and the likelihood that carbon emissions will be taxed in future. Our aim is to anticipate stricter regulations, rather than having to react to them.”
In Australia the Wineries of the Future project has similar aims. Participating wineries are signing partnership agreements with the Energy Efficiency Best Practice Program. According to its website “Wineries of the Future” provides a framework for involving winemakers, cellar operations and engineers in an innovative process that will identify major efficiencies in time and energy.
The clean, green image of Australia is a bonus when exporting wine. Responsible energy use will add to that.
Moreover, State sustainable energy development offices will help fund research, development and implementation of new sustainable energy technologies.
It is up to wineries to take advantage of the goodies on offer.