Gas Technology: Craft brewers watch energy dollars
Smaller microbreweries, especially startups, are often located in facilities that were originally designed for other purposes. These might include warehouses, factories, or store buildings. Space is often at a premium, and compromises in energy systems may be unavoidable.
Few industries have seen as much growth and evolution in the past 30 years as craft breweries. This growing sector of the brewing industry has changed the purchasing and drinking habits of many beer lovers. Even the large international brewers are watching and making changes to their product offerings because of the growing craft brewing industry. Energy management has become a major priority for these brewery operators.
Explosion of interest
In 1979, there were 89 breweries in the United States. Today, the number is closer to 2,500, despite the fact that the volume increase in beer consumption has been relatively modest. With the growth of international travel, especially on the part of younger people, questions were asked, “Why can’t we have more variety in our beer, and why can’t it be more of a handmade product rather than a huge industrial output?” In the 1980s, small breweries began to pop up, many of them “nanobreweries”, such as brewpubs where the small production is largely consumed on the brewery premises.
Somewhat larger enterprises are classified as “microbreweries.” These produce up to 15,000 barrels per year and usually rely on local distribution of bottle and keg beers, as well as on-premises retail sales. A still-larger category is “regional craft breweries” that produce 15,000 to 6 million barrels of beer annually and usually sell to a larger but generally regional market. Taken together, these comprise the craft brewing industry that today produces about 8% of U.S. beer sales. Some brewers feel that the craft beer market could represent 20% of sales by 2020.
Attitudes toward quality and sustainability
However the growing production volume is only one accomplishment of the craft brewers. Their innovations in beer styles and flavors have enhanced the image of brewed malt beverages and have made them attractive to new customers. They have successfully promoted the concept of quality being more important than volume, in both production and consumption. As they’ve grown from hobbyist scale to commercial significance, craft brewers have taken a growing interest in sustainability, particularly in terms of energy use. As production has increased in scale, energy efficiency has also become a more important financial consideration.
Most microbreweries need significant amounts of both electricity and natural gas in their operations. Electricity is used for pumps, fans, lighting, packaging, refrigeration and compressed air systems. Owners are selecting adjustable frequency drives (AFDs) for pumps and fans to reduce electric usage. Lighting can be a significant expense, and where possible, owners are changing to higher efficiency choices such as T-8 fluorescents and LED system. Electric usage can also be reduced by monitoring filters on air handlers, reducing lighting in areas not in active use, and by purchasing higher efficiency motors and controls when replacement is required.
Stream energy for brewing
In the typical microbrewery, natural gas is used for boilers to produce steam for heating brew kettles and to make hot water. The brew process involves cooking large vats of water with malted grain and other ingredients to begin to break down starches, then chilling the liquid to a preset brewing temperature for the long period of fermentation. Normally the brew kettle is heated with a steam coil and held at temperature before being cooled using a refrigeration system. Significant energy can be recovered from the hot liquid using plate-to-plate heat exchangers, which transfers most of the heat to water incoming for the next brew batch. Thus the amount of steam, and the required amount of natural gas, is reduced. For this type system to be effective, production needs to be scheduled to take advantage of the availability of pre-heated water.
Another potential application for natural gas is to fuel a combined heat and power (CHP) plant to supply the plant with both electric power and to generate hot water or steam from the byproduct heat of electric generation. Again, to take advantage of such a system, it is necessary to evaluate times of usage of both electricity and the thermal input to assure they are a match.
Efficiency a priority
According to a guide produced by the American Brewing Association, the energy input per barrel of beer from a craft brewer ranges from $3.34 to $4.26 per barrel. Naturally this varies between regions and types of brewing process. It is believed that energy cost per barrel is higher for craft brewers than for larger industrial type breweries. For this reason, it is especially important for all the process energy to be used as efficiently as possible.
American Sky Brewery in Hudson, Wisconsin is a good example of this new age of brewing. Greg and Molly Harris took an interest is brewing years ago, learning about the range of styles of beer from home-brewers in their family. They started brewing beer for personal use, then a three-year stay in Europe stimulated a lasting interest in the microbrewery business. Both Greg and Molly have full-time jobs, but committed themselves to opening a microbrewery in Hudson, alongside the bluffs of the St. Croix River in Western Wisconsin. Hudson is part of the Minneapolis-St. Paul Statistical Area, and has a rapidly-growing population of 15,000 – many of them young families with professional jobs. This is a good location for a craft brewery.
Combining brewery operation with retail area
The American Sky Brewery is in its third year of commercial production, and according to the Greg Harris, the demand for the product is growing at about 20% per year. The brewery and its associated pub occupy about 40,000 square feet of space in a modern building featuring an aviation and military-theme décor. The brewery operation is open to the pub area, so customers can observe where the beer is being produced, and can interact with the owners and brewery employees.
Greg Harris notes that energy is the second largest operating expense for the brewery (after labor), and that as owners, they realize the need to use energy efficiently. They receive both electric and natural gas service from Xcel Energy. “They are the people we go to when we have questions or concerns about energy use. They’ve given us some good ideas on how to conserve energy.”
On the electric side, he indicates that lighting is a major energy use. Harris says, “We currently have incandescent lighting, but want to replace it with something better. That’s something we’re looking at right now.” He notes that for small breweries, payback is a major issue. “We look for improvements that can pay back the cost in energy savings in a year or so. We aren’t there with our lighting improvement project, but we really want to do it.”
Watching refrigeration expense
Another major electric energy expense is refrigeration. Molly Harris indicates, “We have a large walk-in cooler for finished keg beer, as well as for bottled product. We have lines direct from the cooler to the pub. That minimizes the number of times the door has to be opened. It also makes product quality management easier.” Other electric usages are fans, pumps, and the bottlers, which are old equipment but very reliable.
On the natural gas side, American Sky uses a low-pressure steam boiler to supply heat for the brew kettles. Greg says, “A lot of brewers are going away from direct-fired kettles in favor of steam, because of its better efficiency. Also, we have better control of the cooking temperatures, which is very important.” He indicates that the gas boiler is attractive because of its low-pressure characteristic. “We don’t need to have a boiler attendant on duty, and it can come up to provide steam very quickly.”
With brewery steam systems, it is important to prevent steam traps from leaking, and to use no more steam than necessary to reach set temperature for the mash. The Harrises indicate that water treatment and usage are critical to quality beers. “We study where we’re using water, and heat it only when necessary.” They indicate that scheduling operations is an important step in minimizing energy usage as well.
Efficiency limitations for startups
Smaller microbreweries, especially startups, are often located in facilities that were originally designed for other purposes. These might include warehouses, factories, or store buildings. Space is often at a premium, and compromises in energy systems may be unavoidable. One small Midwestern brewer wants to add a storage tank for hot water reclaimed from the brew kettle, but simply can’t find the floor space. Often these projects have to wait until the brewery is sufficiently established to build its own facility.
Toward the other end of the scale from the microbrewery in Hudson is Sierra Nevada Brewing Company, with large facilities located in Chico, California and a recently-opened brewery in Mills River, North Carolina. Sierra Nevada was a pioneer in the craft brewing movement, starting business in 1980 in Chico. Today, Sierra Nevada produces over 800,000 barrels of beer annually, with production numbers again rising with the new North Carolina facility.
Larger breweries mean more opportunities for conserving
Cheri Chastain is Sustainability Manager for Sierra Nevada. She notes, “We have worked for decades to make sure we are using our electrical and thermal energy as efficiently as possible not only out of economic necessity, but because we try to use all resources as efficiently as possible.” She notes that energy conserving steps at Chico include lighting control systems and heat recovery from the boilers and brew kettles. The electric system has been upgraded and onsite electric generation has been added. Onsite generation includes a 2 MW solar installation and a 1 MW fuel cell. These provide 70% of site energy needs.
Chastain explains that the Chico facility has been growing since the first brewhouse was built in early 1982. “This has resulted in a lot of disconnected and puzzle-like infrastructure. In Mills River, we had the opportunity to build a brand-new brewery in a much more streamlined design.” At that location they installed 600 kW of solar and 400 kW of biogas-fueled microturbines. She notes, “At that site we are not yet in normal operating conditions so we don’t know how much electricity we will be able to generate onsite.”
All breweries see the challenge
The craft brewing industry continues to look for opportunities for improving energy efficiency. Chastain explains, “Brewing and all the activities that accompany brewing (cleaning/sanitizing, packaging, warehousing) requires not only a tremendous amount of electric energy, but a great deal of thermal energy. Brewers large and small are not only embracing onsite electric generation systems, but are looking for ways to reduce electrical needs through efficiency, and to recover heat for thermal needs.”
At the Mills River facility, not only is heat being recovered from the brew kettles, but also from air compressors and chillers, and a water storage tank has been installed to allow use of the heated water as needed. In warehousing operations, the company is investigating replacing the use of electricity with hydrogen fuels. At the present time this does not appear practical, but investigation into alternatives continues. At both plants, treatment of spent yeast and plant wastewater generates biogas, which can be used as a primary brewing fuel. Also at both plants, spent grain is sold to area farmers as a cattle feed.
Eye on the energy dollar
The craft brewing industry is thriving, and one key to their success is keeping their eyes on energy usage and watching for ways to recover energy wherever possible. As with many industries, prudent use of energy is a high management priority. Important sources for guidance in conserving both electric and gas energy is the local utility. These have teams who can suggest methods for reducing energy usage. Another important source is the Brewers Association, which is focused on the needs of craft brewers. The association offers handbooks and training sessions on many brewing concerns, with a special emphasis on energy efficiency.
American Sky Brewery
Energy Star Guide for Breweries
Sierra Nevada Brewing Company
This article originally appeared on Gas Technology Spring 2015 issue.