Wineries use energy- and water-intensive practices that can greatly benefit from conservation strategies. Uncorking these savings can help boost your bottom line and help your winery become more environmentally responsible.
Although electricity is the main source of energy at wineries, they also use natural gas, liquid petroleum gas, and diesel fuel, especially for water heaters, boilers, and engines. Consumption of gas fuels varies depending on the amount of hot water or steam required. Roughly half of the electricity consumed at wineries goes to refrigeration at various stages of the winemaking process, including fermentation cooling, cold stabilization, and cold storage (figure 1). After you make the facility’s refrigeration more efficient, focus on upgrades for pumps, fans, drives, and packaging and bottling equipment.
Average energy-use data
Your first step should be an audit of energy and water use. Examine the existing equipment and measure actual consumption to determine whether the systems are working as intended. Audits typically result in a list of straightforward and cost-effective measures that can conserve resources and improve system performance. They can also provide baseline data that will help you assess the effectiveness of larger or longer-term improvements. Contact your utility to learn more about audits; it may offer a low- or no-cost audit service.
Several systems in wineries have substantial energy-saving potential, including refrigeration and cooling, compressed air, lighting, and packaging. Look for savings opportunities in tasting rooms and gift shops too. Many efficiency strategies are easy to implement and are either free or inexpensive.
Turn things off or down
Turning off a power switch is simple but effective. For every 1,000 kilowatt-hours (kWh) you save by turning things off, you save $120 on your utility bill, assuming an average electricity cost of $0.12/kWh.
LightsTurn off lights when they aren’t in use. Occupancy sensors and timers can help, but changing your team’s behavior is even less expensive. Develop protocols for shutting off lights during closed hours—particularly in tasting rooms and gift shops—and train employees to follow them.
Electronic displaysMany stores or tour areas have electronic displays that are left on after the facility closes. Shut off the displays during closed hours, either manually or with timers.
HVAC temperature setbacksWhen the winery is closed, turn temperature settings down in warm seasons and up in cool seasons. Smart thermostats help automate this process. Make sure that HVAC settings in stockrooms, offices, and other peripheral rooms are at minimum settings.
Refrigeration and cooling
Temperature and pressure setpointsRefrigeration systems will run at higher efficiencies when operated at higher suction pressure setpoints. To increase the suction pressure, raise the glycol temperature. Each 1-degree increase in suction temperature can result in a savings of 2% to 3% of refrigeration compressor energy.
Outdoor airBring in low-temperature outside air during the night to provide cooling. This process can reduce electricity consumption and peak power use during the day. It’s particularly effective in spaces where outside-air circulation isn’t otherwise required, such as warehouses, offices, and cold-stabilization areas. Savings can easily add up to about 20% of overall cooling energy.
Door sealsBy checking and replacing faulty door seals and ensuring that doors between refrigerated and nonrefrigerated areas are properly closed whenever possible, you could save as much as 15% of total refrigeration energy consumption.
Packaging and bottling
Bottling and palletizing operations often use conveyors. In many facilities, they run even when they aren’t fully loaded. To reduce energy consumption while also conserving lubricants and water, only run conveyors when necessary. Automation controls make conveyor management easier, though it can be done manually as well.
In many wineries, lighting accounts for 8% to 20% of electricity consumption. Improving the efficiency of your lighting systems can be a straightforward and inexpensive way to save energy.
Areas that aren’t consistently occupied—such as storage rooms, restrooms, back offices, and walk-in refrigerators—are ideal places for occupancy sensors. Lighting these low-usage areas only when they’re in use can save between 30% and 75% of lighting energy in those areas. Occupancy sensor installations typically yield simple payback periods of one to three years.
Check the economizerMany air-conditioning systems use a dampered vent called an economizer that draws in cool outside air when it’s available to reduce the need for mechanically cooled air. If not regularly checked, the linkage on the damper can seize up or break. An economizer that’s stuck in the fully open position can add as much as 50% to a building’s annual energy bill by allowing hot air in during the air-conditioning season and cold air in during the heating season. Have a licensed technician check, clean, and lubricate your economizer about once a year, and repair it if necessary. Calibrate the controls at this time too.
Check air-conditioning temperaturesWith a thermometer, check the temperature of the return air going to your air conditioner and then check the temperature of the air coming out of the register that’s nearest the air-conditioning unit. If the temperature difference is less than 14°F or more than 22°F, have a licensed technician inspect your air-conditioning unit.
Change the filtersFilters should be changed every one to six months. Change filters more often when the economizer is in use because outdoor air is usually dirtier than indoor air.
Check the cabinet panelsOn a quarterly basis (or after filters are changed), make sure the panels to your packaged rooftop air-conditioning unit are fully attached, with all screws in place and all gaskets intact so that no air leaks out of the cabinet. Chilled air leaking out can cost $100 per rooftop unit per year in wasted energy.
Clean the condenser coilsCheck the condenser coils quarterly for debris that can collect in them. At the beginning and end of the cooling season, thoroughly wash the coils.
Check the airflowHold your hand up to the registers to ensure that there’s adequate airflow. If there’s little airflow or if the register contains dirt or dust, have a technician inspect your unit and ductwork.
Look for longer-term solutions to save even more energy. Although the conservation measures covered in this section are more involved and cost more, they’re good investments. Most won’t only save money but will also improve the winemaking environment and the comfort inside your buildings. Ask your local utility representative for more information about initiating such projects as well as available financial incentives.
Refrigeration and cooling
Upgrade chillersInstall high-efficiency chillers with variable-frequency drives (VFDs)—also called adjustable-speed drives—to reduce both electricity and maintenance costs by roughly 20%. The Danfoss Turbocor is one such chiller. It’s much more efficient at partial load than 300-ton or smaller screw, centrifugal, or reciprocating chillers; costs less to maintain; and is quieter.
If your equipment uses centrifugal compressors, install a VFD to make them more efficient. This upgrade can be an inexpensive alternative to complete replacement.
Insulate tanksMake sure that the storage tanks used for fermenting and aging wine are well insulated. Insulation types include spray-on (for large applications), foil-covered bubble wrap, and rigid foam. Insulated tanks reduce refrigeration energy use by about 25%, though exact savings will vary depending on the specific tank and insulation used.
Properly sequence compressorsCompressors operate most efficiently when running at full power. In a refrigeration system that uses multiple compressors, verify which compressors are needed to produce the necessary airflow when running at full power. Turn off other compressors or allow only one compressor to run at a reduced power level.
Implement floating head pressure on glycol chillersSet a glycol chiller’s head pressure to “float” or vary in response to changes in outdoor wet-bulb temperatures. Refrigeration compressors with floating head pressure consume 5% to 20% less power.
Install a desuperheater on the glycol chiller compressor’s exhaustA desuperheater is a secondary heat exchanger that’s installed between the evaporative condenser and the refrigeration compressor. It can simultaneously heat the boiler makeup water and reduce the amount of heat that’s wasted by the condensers. A heat exchanger saves 10% to 20% in natural gas costs.
Use flotation for white juice settlingInstead of using refrigeration to settle the solid byproducts of white wine to the bottom of the tank, use flotation. This technique uses compressed air or nitrogen gas to saturate the grape juice, known as must. The gas bubbles stick to the solid particles and float up to the top, forming a cap of foam that you can then remove.
Use electrodialysis instead of cold stabilizationTartrates are small crystals that form when tartaric acid mixes with potassium in the wine at low temperatures. They’re tasteless and odorless, but unsightly. They’re frequently removed using a process called cold stabilization, which requires wine to be chilled to between 25° and 36° Fahrenheit (F) and then reheated. This process is only necessary when the wine can’t easily be maintained at the optimal 59°F due to cold outdoor temperatures.
Electrodialysis is an efficient alternative to cold stabilization. It uses membranes and an electric current to remove tartrates from the wine. It can reduce energy consumption by nearly 90% because it eliminates the need for freezing and reheating. Membranes are expensive to replace, so check with manufacturers to ensure that this measure will be economical for your particular winery.
Install destratification fansDestratification ceiling fans help maintain a consistent air temperature throughout a cellar or warehouse, lowering cooling requirements for that space. Improving air circulation with high-volume, low-speed (HVLS) fans, such as those described on Washington State University’s High-Volume, Low-Speed Fans web page, can be an effective way to save energy. They provide better air circulation and greater energy efficiency compared with multiple smaller, high-velocity fans. In air-conditioned spaces, HVLS fans save energy by improving air flow, which allows you to raise the temperature in your facility by as much as 4.5°F (2.5°C) while still maintaining occupant comfort. If your facility is heated, warmer air will naturally stagnate near the ceiling. HVLS fans will circulate that warm air vertically.
Create cave storageStore wine barrels in caves rather than above-ground buildings. You’ll save energy, and temperature and humidity will remain at ideal levels. Payback periods for creating caves vary; to be most cost-effective dig new caves when increased production prompts the need for more storage.
Motors are widely used in fans and pumps and are a good target for efficiency improvements. Pumping systems often account for 10% to 25% of electricity consumption in wineries, and simple changes can lead to large energy savings.
Install VFDsVFDs match motor output torque to real-time load. They can save energy by as much as 45%, depending on the application and motor duty cycle. VFDs also improve power factor, which indicates how effectively your facility uses electricity. A better power factor (usually about 90%) can result in fewer utility surcharges. VFDs are especially suitable for screw compressors, condenser fans, glycol circulation pumps, and air-handling fans. In these applications, simple payback periods can range from one to six years.
Use multiple pumpsWhen handling varying loads, it’s more cost-effective and efficient to use multiple smaller pumps because they can be run closer to full capacity rather than at a less-efficient part load. This measure can save anywhere from 10% to 50% of the energy used for pumping.
Downsize motorsMotors are often more powerful than necessary, resulting in needlessly high energy consumption and peak power draw. If possible, replace oversized motors with smaller units to better match the needed load.
Upgrade to high-efficiency motorsWhen you need to either repair or replace aging motors, keep in mind that new, more-efficient units can save significant amounts of energy and usually produce short simple payback periods.
Compressed air is not a free resource, but many people view it that way. In fact, compressed air systems typically account for nearly 10% of overall electricity consumption in wineries. And they’re often poorly designed or maintained. Optimize your compressed air system to find significant savings.
Match the supply to the loadGenerate compressed air only at the pressure required. If you reduce the pressure by half, you can cut the energy needed in half. Also, sequence your machines so that when the demand is at partial capacity, some compressors are entirely shut off rather than having several operating inefficiently at part load.
Check for leaksAir leaks can cause enough energy loss to nearly double the cost of compressed air. Because leaks also result in lower pressure at the point of use, operators often set pressure levels higher than necessary. Leak detectors cost $1,000 to $15,000 to install, but they often pay for themselves the first time they’re used on a system that hasn’t been maintained (figure 2).
Figure 2: Savings from leak detectors
The US Department of Energy’s Advanced Manufacturing Office measured the energy savings, dollar savings, and simple payback periods of finding and repairing compressed air system leaks in four industrial facilities.
|Facility||Annual energy savings (kilowatt-hours)||Annual dollar savings ($)||Simple payback period (years)|
|© E Source; data from the US Department of Energy|
|Chrysler Transmission Plant||227,483||17,737||0.60|
|Southern Clay Products||170,745||11,952||0.80|
Packaging and bottling
Packaging comprises everything from bottle-filling to palletizing, and it consumes a lot of energy. One way to save packaging energy is to install a heat-recovery system. To help labels stick to bottles, the wine bottles are heated to about 50°F. Capture and use refrigerator waste heat for this process with a heat-recovery system. It will reduce the energy needed to warm bottles and cut water consumption and maintenance costs. Often, enough waste heat is also available to supply hot-water coils for space heating in cold weather.
Upgrade to LEDsLEDs are more efficient than conventional light sources. They also last longer and work well with controls. With these advantages and a downward trend in pricing, LEDs are a good solution for many applications, including exit signs, task lighting, recessed downlighting, and ambient lighting. Make these LED upgrades just about anywhere in the winery, such as in warehouses, processing and production areas, gift shops, and tasting rooms.
Fluorescent troffers—the rectangular fixtures that fit into a drop ceiling—are the most common type of lighting fixture found in US commercial facilities, accounting for 50% of existing fixtures. You can replace them with LED troffers to improve lighting efficiency. In the right applications, this change can boost energy savings and operational productivity while lowering maintenance needs. The best LED products outperform their fluorescent equivalents, but at a higher installed cost. You can install LED troffers or LED retrofit kits, or you can swap fluorescent tubes for tubular LEDs.
When buying LED products, ask for performance data from the manufacturer or distributor. Also, check that the reported performance metrics conform to standard test procedures and are verified by accredited third-party laboratories. As you compare LEDs to other options, account for cost savings in both energy and maintenance. And make sure that the LED solution will provide both the quantity and quality of light that you need to maintain safe, comfortable, and productive working environments. Refer to the DesignLights Consortium’s Qualified Products List to keep up with LED technologies.
Use daylightingUse dimming ballasts and daylighting controls to reduce the amount of electric light needed when daylight is present. Daylighting also improves ambience.
Replace fluorescent lampsIf your facility uses T12 fluorescent lamps, relamping with modern T8 lamps and electronic ballasts can reduce your lighting energy consumption by 35% or more. Adding specular reflectors and new lenses can increase these savings and yield short simple payback periods.
Humidification is required in barrel storage rooms to keep wooden barrels at their best. Energy-efficient ultrasonic or high-pressure humidifiers work well in these areas. These humidifiers are great for facilities that need simultaneous humidification and cooling. But they aren’t appropriate for simultaneous heating and humidifying.
Use high-efficiency boilersHigh-efficiency boilers can reduce natural gas use by up to 6%. They have simple payback periods of one to three years. Newer boilers feature a variety of efficiency improvements that justify the replacement of older boilers before failure. Improvements include condensing heat exchangers, sealed combustion, electric ignition, and fan-assisted combustion. Smaller boilers are more efficient than large ones. And grouping multiple smaller boilers allows staged operation of each unit at its highest efficiency. Grouping boilers also provides redundancy. If a larger boiler isn’t ready to be retired, you can add a smaller boiler to serve the base heating load, reserving the larger boiler for additional heating as needed.
Preheat boilers with recovered heatRecover waste heat from refrigeration equipment and use it to preheat boiler water. Heat recovery also helps cool the refrigerant and saves on both natural gas for the boiler and condenser fans for the refrigerant. You could see 6% to 20% natural gas savings, and simple payback periods range from three to six years.
Wastewater can pose environmental hazards and, depending on state pollution laws, may require quite a bit of energy to treat.
Automate dissolved-oxygen controlIn wastewater treatment, the aeration step adds dissolved oxygen to wastewater to fuel the microorganisms that help degrade contaminants. Many facilities use manual controls for this process. Instead, use automatic dissolved-oxygen controls that will monitor the oxygen level in wastewater and shut off once that level meets a given threshold. As described in the California Public Utilities Commission’s Wastewater Energy Program Case Study (PDF) of the LangeTwins Winery in Acampo, California, “automated dissolved oxygen control is able to reduce the aerator energy consumption by approximately 50% during the non-crush season.”
Recover biogasAfter fermentation and aging, lees (leftover yeast) and marc (grape remains) produce biogas. A biogas-recovery system can provide heating or generate on-site electricity. According to an article in the journal Waste and Biomass Valorization, Energy Recovery and Treatment of Winery Wastes by a Compact Anaerobic Digester, a 40-cubic-meter compact anaerobic digester is optimal for a winery that processes 1,000 tons of grapes per season. Simple payback periods for adding an anaerobic digester range from six to seven years.
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