Managing Energy Costs in Microbreweries

Many systems offer substantial energy-saving potential in breweries, including boilers, refrigeration and cooling systems, compressed-air systems, motors, and packaging systems. As a result, breweries can benefit greatly from a variety of strategies that are easy to implement at little or no cost—such as turning things off, turning things down, and keeping up with cleaning and maintenance.

Turning things off seems simple, but remember that 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.

Lights. Train staff to turn off lights in unoccupied rooms. Posting “Please turn the lights off when not needed” stickers above light switches will remind both staff and visitors to do so. Another option is delamping where illumination is excessive.

Install occupancy sensors. Areas that aren’t consistently occupied—such as storage rooms, restrooms, back offices, and walk-in refrigerators—are ideal for occupancy sensors. These sensors can save 30 to 75 percent in lighting energy consumption, and they typically have simple payback periods of one to three years.

Some equipment cannot be turned off entirely, but turning it down to minimum levels where possible can save energy.

HVAC temperature setbacks. During closed hours, turn temperature settings down in warming seasons and up in cooling seasons. Smart thermostats can help automate this process.

Peripheral and back rooms. Make sure that HVAC settings in stockrooms, offices, and other peripheral rooms are at minimum settings.

Boiling wort is the most energy-intensive step in brewing, and fuels for boilers alone can account for 25 to 35 percent of a brewery’s overall energy bill. There are several ways to cut energy use in the boiling process.

Identify leaks. Steam and condensate leaks directly waste energy, but they are generally straightforward to detect and seal.

Insulate effectively. Steam and condensate return lines and components are often poorly insulated. Ensure that a sufficient level of insulation is in place to minimize heat loss and save energy.

Properly sequence boilers. Many boilers are not fully efficient when firing at full load, and can be “sequenced” to be more efficient. Instead of having one or two boilers at full load, an intelligent boiler sequencing system can decide to operate several boilers at 33 percent load— potentially increasing overall boiler system efficiency by 5 percent.

Adjust steam pressure. Unnecessarily high pressures can cause leakage and steam loss, whereas pressures that are too low can cause significant heat loss during distribution and end use. Check steam pressure regularly to ensure that it’s just high enough to meet maximum equipment requirements.

Refrigeration plants commonly consume at least 20 percent more energy than needed. Because refrigeration represents around 35 percent of a brewery’s electricity bill, optimizing these systems presents a significant opportunity for energy savings.

Manage auxiliary loads. Poor control of auxiliary loads—including inadequate insulation of cold-storage areas, air infiltration, and open doors—can increase energy costs by more than 20 percent. The initial audit should identify major cooling loads and suggest ways to reduce them.

Properly sequence refrigeration compressors. Unlike boilers, compressors operate most efficiently at full load. In a system with multiple compressors, the most efficient operation occurs when you sequence compressors based on their loads and respective efficiencies, and when you ensure that only one compressor operates at part load.

Clean evaporator and condenser coils. Check condenser and evaporator coils quarterly for any debris or objects that may block airflow.

Set defrost timers properly. Defrosters prevent frost from building up on condensers and impairing their efficiency, but they require energy of their own. The trick is to find out how short a time you can have the defrosters on while still keeping the condensers defrosted. Experiment with this by slowly shortening the timer settings over the course of a week to find the minimum; it’s best to then add a little time back, just to be safe.

Increase suction pressure. Suction pressure is the intake pressure generated by the system compressor while operating; refrigeration systems run at higher efficiencies when operated at higher suction-pressure setpoints. Raising the glycol temperature will raise the associated suction pressure; you can save 2 to 3 percent of refrigeration compressor energy for each degree Fahrenheit (F) increase in suction temperature.

Optimize setpoints. A change in temperature of just 1°F—whether an increase in evaporating temperature or a decrease in condensing temperature—can reduce energy consumption by 1 to 2 percent. Evaporation temperatures, in particular, are often set lower than necessary. Each installation is different, so experiment by changing these temperatures until you find the right level for your situation. It is possible to fulfill the temperature needs of the product while also optimizing the refrigeration system to consume less energy.

Although compressed air is often viewed as an essentially free resource, it accounts for nearly 10 percent of overall electricity consumption. Compressed air systems are also often poorly designed and badly maintained.

Properly sequence air compressors. As with refrigeration compressors, air compressors operate most efficiently at full load. In a system with multiple compressors, the most efficient operation occurs when you sequence compressors based on their loads and respective efficiencies and when you ensure that only one compressor operates at part load.

Match your supply to your load. Generate compressed air at the pressure needed—in some instances, you can cut pressure by half without affecting operations and produce energy savings of more than 50 percent. In addition, sequence your machines to ensure that, when the demand is at less than full capacity, one or more compressors are entirely shut off instead of having several operating inefficiently at part load.

Check for leaks. Leaks are a major source of energy loss and can effectively double the cost of compressed air. Because leaks also result in lower pressure at the end point, they can cause operators to set pressure levels higher than would otherwise be necessary. A leak detector can provide long-lasting benefits and can pay for itself in less than six months.

Switch off compressors. Turn compressors off when production is down, and consider making piping changes to enable shutting off supply to production areas when there’s no need for compressed air.

Review operations. Look for areas where an alternative technology or modified operations could replace compressed-air use. If you use compressed air for clean-up, drying, or process cooling, consider switching to alternatives such as low-pressure blowers or electric fans. At a minimum, make sure hoses are equipped with nozzles.

Packaging comprises everything from bottle filling to palletizing, and it’s often the second largest energy consumer, after refrigeration. This means making packaging more efficient can be a great way to cut costs.

Optimize production line efficiency. In addition to reducing the number of shifts required, you can increase the efficiency of the entire production line by improving specific bottlenecks. Small changes can have a big impact on energy use by helping to eliminate losses when the line is idle. The bigger your facility, the better it is to hire a third party that specializes in analyzing and improving production line equipment, such as conveyors and depalletizers.

Run conveyors only when necessary. This simple step can save money by reducing energy consumption and demand while also conserving lubricants and water. Although this measure can be handled manually, automation controls can make this easier.

Although many brewers may be leery about changing their process or recipes, there are a few easy adjustments that can save energy without affecting your products.

Brew batches back-to-back. A large amount of energy goes into just preparing brew equipment, like boilers, for use. Brewing multiple batches back-to-back instead of spreading the process out over several days can reduce energy waste while also reducing peak-load consumption.

Use high-gravity brewing. Because most of the brewing process uses essentially the same amount of energy regardless of beer strength, one effective strategy is to produce, ferment, and process more-concentrated wort, and then dilute the beer to normal strength just before bottling. This approach can greatly reduce per-barrel energy consumption while increasing the output capacity of the brewery and improving consistency. Although some macrobreweries dilute their products by as much as 40 to 60 percent, diluting by as little as 3 to 5 percent will still yield benefits without a noticeable impact on flavor.

Move processes off peak. Even without reducing energy consumption, you may be able to immediately lower your electric bill by changing the times when energy-intensive processes, such as wort boiling, take place. Breweries are typically charged higher electricity rates during times of utility peak demand. It’s possible to reduce bills by as much as 20 percent through shifting major electric loads outside of peak times, running processes in blocks to avoid load during peak times, and looking for places where equipment can be shut off entirely. Contact your utility to learn more about your energy rate and find out how to reduce peak demand surcharges.

In any building, HVAC represents a consistent source of energy consumption and offers a suite of opportunities for energy savings.

Maintain your system. Making sure that your HVAC system is regularly cleaned and serviced can lower your heating and cooling costs. If your system uses an economizer, have a licensed technician check, clean, calibrate, and lubricate it about once a year because economizers are prone to failure. A broken economizer can increase heating and cooling costs by up to 50 percent. Also, be sure to maintain evaporative cooling or other nonrefrigerative cooling systems.

Pay attention to room temperature. During closed hours, turn temperature settings down in heating seasons and up in cooling seasons. You can automate these settings with programmable thermostats. In addition, make sure that HVAC settings in stockrooms, offices, and other peripheral spaces are at minimum levels.

Improving the efficiency of your lighting systems can be straightforward and inexpensive, offering simple and easy ways to save energy.

Upgrade your fluorescent lamps. If your facility uses T12 fluorescent lamps, relamping with modern T8 lamps and electronic ballasts can reduce your lighting energy consumption by 35 percent or more. Adding specular reflectors and new lenses can increase these savings and have short simple payback periods. Additionally, LEDs are becoming more affordable and even come in T12-shaped tubes.

If your microbrewery operates as part of a brew pub, you can find even more opportunities to cut your energy costs. For information on energy-saving measures for restaurants, such as efficient cooking equipment, vent hoods, and refrigeration, see Managing Energy Costs in Restaurants.

After you take advantage of the quick and easy methods to reduce energy consumption, consider some larger projects to cut costs even further. Although the actions covered in this section require more-extensive effort, they can significantly increase the efficiency of your brewery without compromising speed or reliability. Ask your utility representative for more information about initiating such projects.

Heat recovery is a great way to reduce energy waste, and it can be accomplished at several points in the brewing process—although the need for additional piping and heat exchangers may result in high initial costs.

One of the most effective applications for this technology is to recover heat from the steam released from the brew kettle (where wort is boiled) using spray condensers or heat exchangers. These systems can recover as much as 60 percent of the energy required for wort boiling, and the recovered heat can be used in a variety of applications, such as preheating new incoming wort or producing hot water for cleaning. New Belgium uses heat recovery to generate and store hot water in a large tank, which is then used to heat wort from 76° to 90° Celsius before it’s boiled.

Another approach is to capture waste heat from the mash or hot-water tanks, which can help reduce the amount of energy consumed in the mashing process. Heat can also be recovered from the wort-cooling step—this may be particularly cost-effective because the warm water essentially just needs to be rerouted.

Finally, adding heat recovery to a keg-washer system can reduce cleaning energy by 40 percent and provide 85 percent of the heat required to warm incoming water.

Install a high-efficiency chiller. In breweries, chillers provide cool water that’s used for cooling hot wort from boiling to yeast-pitching temperature. Replacing existing chillers with high-efficiency models can sometimes have fairly short payback periods of only 2 to 3 years.

Install floating head pressure controls on glycol chillers. Glycol is the standard refrigerant for industrial facilities because it absorbs heat efficiently. Allowing glycol chiller head pressure to “float” based on outdoor wet-bulb temperatures can reduce power consumption of the refrigeration compressors by 5 to 20 percent.

Improve ammonia compressor efficiency. If you use an ammonia refrigeration system, explore efficient options such as defrost float drainers and thermosiphon oil cooling which help ease the load on the compressor. For more information, reach out to your utility.

Install controllers on walk-in coolers. Walk-in cooler controllers can reduce the amount of heat generated by evaporator fan motors because full airflow is only required about half the time.

Apply insulation. Insulating refrigerant suction lines is an easy and effective way to reduce energy consumption of the entire refrigeration loop.

Install rooftop unit retrofit controls. Most US commercial floor space is cooled by self-contained, packaged air-conditioning and heat pump units, most of which sit on rooftops. These rooftop units can benefit from newer retrofit control devices that add variable-speed functionality and can deliver 25 to 70 percent energy savings for a relatively small investment.

Use demand-controlled ventilation. Microbreweries often have tasting rooms and common areas for drinking that handle waves of customers during tours and happy hours. Demand-controlled ventilation can be a great option for controlling energy use when many people occupy space. It works by using carbon dioxide sensors to estimate occupancy and eliminate unnecessary ventilation.

Motors, which are widely used in fan and pumping applications, are another good target for efficiency improvement. Additionally, fans and pumps themselves can be specifically selected or modified to further reduce energy used by the motors.

Use variable-frequency drives (VFDs). VFDs—also called adjustable-speed drives—match motor output to real-time load, and they can produce savings as high as 45 percent depending on the application. Applications include boilers, glycol and chilled-water pumps, air compressors, refrigeration fans and compressors, cooling tower fans, and HVAC systems. VFDs can also improve power factor, potentially reducing utility surcharges.

Downsize your motors. Motors are often more powerful than the application warrants, and the extra power can produce needlessly high energy consumption and peak power draw. Consider replacing oversized motors with smaller units.

Upgrade to high-efficiency motors. When considering whether to repair or replace aging motors, keep in mind that new, more-efficient units can save significant amounts of energy and yield short simple payback periods.

Install destratification ceiling fans. In brewery cellars, destratification fans can help maintain a consistent air temperature, which lowers cooling requirements. When the temperature in a room is inconsistent, it may trigger air conditioning, when just mixing the cooler air from the floor will suffice at keeping the whole room cool enough.

Match pumps to system requirements. Pumps are often conservatively designed to be larger than needed for industrial processes. The impeller within these pumps can be trimmed to reduce its diameter, which will require less energy. Trimming should be limited to about 75 percent of a pump’s maximum impeller diameter because excessive trimming can cause the pump to be less effective. This should be done by an experienced pump technician.