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
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.
Turning things down
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.
Boilers and steam
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.