Winemaking involves several processes of fermentation to convert natural sugars from grapes into alcohol. These processes are supplemented by uses of refrigeration, pumps, and air compressors. The winemaking process includes harvesting, primary fermentation, secondary fermentation, filtering, and packaging. 

Fermentation requires a large cooling load. Therefore, the largest energy consumer in wineries is refrigeration. Compressor use can also be high due to high air needs during harvest. Compressed air is used for pneumatic punch down tools that mix the reds and bladders that are filled to press the grapes.

Common Opportunities

Listed below are common energy saving opportunities for breweries. For other potential energy savings measures such as lighting, see the attached industrial walkthrough checklist at the bottom of the page.

Improve Refrigeration System

Wineries use jacketed tanks to cool down the wine during the fermentation process to a specific temperature in order to maintain enzymatic activity of the yeast cells and increase alcohol conversion efficiency. Typically, packaged chiller units are used to achieve this. The most common medium that is cooled for jacketed tanks is glycol. 

To see a list of refrigeration savings opportunities in industrial systems, view the industrial walkthrough checklist PFD at the bottom of this page. Refrigeration systems are not exclusive to wineries, which typically use chiller units. These chillers can have modifications made to them that increase the efficiency of these units and how they operate. 

Opportunity: Insulate wine storage tanks. Secondary fermentation of wines can last up to 5 years. These vessels are stored at cold room temperatures that are typically controlled using refrigeration. There may be opportunities to insulate these units so that heat adsorbed from the surroundings is reduced, resulting in direct refrigeration savings. 

Identify: How are wines currently stored before bottling? Are they in tanks or barrels? Is there any insulation opportunities? Consult with facility personnel.

Savings: Reduction in the amount of heat adsorbed by stored wines results in electrical energy savings from refrigeration.

 

Opportunity: Add control schemes.

Identify: How are the condensing fans and compressors controlled? This may be indicated by cut-in and cut-out controls located on the compressors. If there is a fan control, it will be located on the compressors or another place in the unit. If the fans are not controlled separately from the compressors, there may be opportunities to install a separate control unit. 

Savings: Electrical energy savings will be obtained by only operating fans when cooling load is demanded. This will also have positive impacts on savings from reducing compressor lift. 

 

Opportunity: Adjust current set-points.

Identify: Based off the control schemes, what are the current compressor suction and discharge set-points? What are real time pressures of the compressor suction and discharge? If the suction is unnecessarily low or the discharge is above the minimum condensing temperature for that day there may be opportunities to reset these.

Savings: Electrical energy savings arise from reducing lift across compressors.

 

Opportunity: Pre-cool wort before fermentation.

Identify: Does the facility cool down the previously boiled wort prior to being added to the fermentation tank? There may be opportunities to add an intermediate cooling step using water or a recycled cool medium. 

Savings: Because the refrigeration system wouldn't be the only thing cooling down wort in this instance, electrical energy savings would arise directly from refrigeration system savings.

See: http://eeref.engr.oregonstate.edu/Opportunity_Templates/Refrigeration_Discharge_Pressure

See: http://eeref.engr.oregonstate.edu/Opportunity_Templates/Refrigeration_Suction_Pressure

 

Improve Compressor System

As stated above, compressors can be a high demand use of any winery. However, these are typically seasonal demands due to harvest. Making sure that compressor controls are appropriate is key and that the facility is maintaining good practices. 

 

Improve Current Pump System

Pumps can be a big energy user of any winery facility. Typically, breweries operate in a batch process. Most wineries utilize mobile pumps that they can use when they are needed.

Opportunity: Replace throttle control on pump with on-off control.

Identify: Are the pumps being throttled in order to control the flow rate when used? This can be identified by asking facility personnel. 

Savings: Restricting a pumps flow is a commonly used inefficient control method. Work required to deliver the reduced flow is greater than would otherwise be required. Replacing with on-off control will allow the pump to be turned on and ran at its optimum efficiency until the tank that it is servicing is filled then turned off. Electrical savings come from the increased mechanical efficiency of the pump.

 

Opportunity: Replace current control method with VFD control.

Identify: Do pumps currently have VFD's installed? Obtain operating parameters and pump curves from facility personnel to establish whether on-off controls or VFD controls are better suited to operation

Savings:  VFD allow pumps to operate at the best efficiency for the given operating needs of the facility instead of having to set one operating set-point.

See: http://eeref.engr.oregonstate.edu/Opportunity_Templates/Efficient_Pumping

See: http://eeref.engr.oregonstate.edu/Opportunity_Templates/Pump_Efficiency_Analysis_Tool_(PEAT)

 

Nitrogen Generation

Opportunity: Install a nitrogen generation system

Identify: Nitrogen is commonly used in wineries for bottling and sometimes in vessels. Does the facility currently use nitrogen gas for sparging of bottles and/or vessels? Does the facility buy or rent cylinders of nitrogen? A nitrogen generation system can be installed to make high purity nitrogen for uses in the facility.

Savings: Using a nitrogen generation system will allow the facility to eliminate all nitrogen purchasing costs. 

 

References

http://www.energy.wsu.edu/Documents/WSUEEP-WineryEfficienies-Feb2011.pdf