Raising a chilled glass to lower energy use

Refrigeration is the biggest energy use for most food and beverage industry businesses - from abattoirs to bakeries, cold stores, dairy processors and food, beverage and pet food manufacturers. Tamburlaine Winery in the Hunter Valley has slashed its power use by half. Find out how you can reduce your refrigeration power bills.

The reality for wineries, and hundreds of other food and beverage businesses, is that escalating power costs and the threat of the carbon tax are having significant implications on industrial refrigeration energy costs.

In NSW, the Office of Environment & Heritage Department of Premier and Cabinet has compiled the ‘Industrial refrigeration and chilled glycol and water applications technology report’ which details 15 technologies available to help the broader food and beverage industry save power and costs. The report is available for free download at http://www.savepower.nsw.gov.au/Portals/0/docs/business/110302ESRefrigRprtLowRes.pdf.

The report demonstrates, using data from the experience of companies like Tamburlaine, what technologies are available, how much they will cost and how much will be saved. A reduction in industrial refrigeration costs of a staggering 40% or more is claimed.

Tamburlaine’s managing director Mark Davidson said an energy audit conducted through Sustainability Advantage Energy Saver last year showed refrigeration accounted for 75% of the winery’s energy use and identified total efficiency savings of $114,000 a year.

The upgrades to refrigeration that Tamburlaine has since undertaken will alone save $54,000 a year and pay for themselves in less than 12 months.

“I thought I must have misheard my environment manager when he told me how much money we could save,” Mr Davidson said.

“The energy audit identified the problem and helped us break some old and wasteful energy habits.

“By doing some really simple things such as running time and thermostat controls, upgrading heat exchangers and making pipework modifications, we have reduced our overall electricity use by 48% and our refrigeration energy use by 54%.”

“This is resulting in significant benefits to the business. Not only in cost savings, but also because it aligns the way we operate with our business philosophy of minimising our impact on the environment.”

15 energy-saving technologies

There are 15 energy-saving technologies identified in the report, and while many require capital outlays, a series of verified case studies indicate that the payback period is often less than three years.

Industrial refrigeration specific technologies

1. Variable plant pressure control
2. Automated compressor staging and capacity control
3. Remote control optimisation of refrigeration plant
4. Heat recovery from discharge gas and oil cooling
5. Defrost management
6. Variable cold store temperatures
7. Variable evaporator fan speeds
8. Condensate sub-cooling
9. Refrigeration plant design review
10. Plant condition maintenance - removal of air and water

Chilled glycol and water specific technologies

1. Chiller efficiency - full and part load
2. Chilled water/glycol circuit design and control
3. Heat recovery from chillers and chiller/heat pump units
4. Variable chilled fluid temperatures
5. Variable cooling water temperatures

Several other site-specific energy-saving projects, such as installing high stage heat pumps to generate large amounts of hot water at between 60 and 65°C, which is not possible with the heat recovery techniques described in this report and insulation upgrades, are possible but not examined in the report.

The Office of Environment & Heritage has established Energy Saver Industrial Refrigeration, which aims to promote the widespread adoption of cost-effective, commercially proven and energy-efficient technologies throughout key industries, such as abattoirs, bakeries, cold stores, dairy processors, food and beverage manufacturers, meat packers and processors, pet food manufacturers and wineries.

For more information, visit www.savepower.nsw.gov.au.