A Growing Advantage

Commercial greenhouses are proving that biomass heating systems can provide an operational boost in an increasingly global, competitive flower and plant marketplace.
By Tim Portz | November 06, 2017

Len Busch Roses in Plymouth, Minnesota, and Schaefer’s Gardens in Triangle, New York, are both family-owned, commercial greenhouses that have been growing plants and flowers for the better part of a century. While Len Busch is a much larger facility, nearly 15 acres compared to an acre and a half, the two facilities face many of the same challenges, albeit a different scale. Greenhouse operations are labor and energy intensive, and for U.S. operators, those issues are exacerbated by the fact that low-cost, foreign competitors pay far less for each. With few options available to drive down labor costs, both Len Busch Roses and Schaefer’s Gardens turned their focuses to reducing heating costs, each using a biomass solution to do so.

Len Busch’s Saving Grace
Patrick Busch, owner of Len Busch Roses, speaks over the noise of a Rotochopper B66, while a fountain of recently chipped wood arcs onto a growing pile. “We used to have a smaller, electric chopper that couldn’t really handle logs,” Busch says. “We went to the diesel-powered B66 because it was at least three times larger than the older chopper, and it can easily handle logs. We did this because we wanted the flexibility to grind wood daily. We can now process chips, logs and brush in one pass, and have it ready for combustion.”

This flexibility is vital, as 100 percent of the biomass utilized by Len Busch Roses is urban wood waste, the vast majority of it coming from within 15 miles of the greenhouse, which is tucked in the northwest corner of the Minneapolis metropolitan area. As Busch discusses the operation, two city trucks approach the Rotochopper, a tangle of limbs and branches visible above the walls of their trucks. Over the course of the year, Busch tells Biomass Magazine, his operation will burn nearly 70,000 yards, or 700 tractor trailer loads of wood waste, for heat.

One of Busch’s biggest challenges is managing a biomass supply chain that has an inverse relationship with his demand. “The inbound volume of biomass in January and February is the slowest while the heating demand at that time is the greenhouse’s very highest,” he says. To keep both of the facilities boilers in biomass Busch has built as much storage space as his site will allow. The operation has constructed simple, but effective, covered storage barns that in total can keep nearly 25,000 yards of biomass out of the elements.

This accumulated biomass is eventually fed into one of two boilers on the premises. The first, a 350-horsepower Kewanee boiler, with a fire feeder system that Busch says has been “significantly modified” has been in operation since the 1970s. The other, installed in the late-2000s as a result of ongoing expansion is a Hurst boiler system. “We were growing and our expansions had us back to burning about half gas,” Busch says.

Together, the two boilers satisfy all of the operation’s thermal needs, and Busch estimates that at today’s natural gas prices, Len Busch saves over $500,000 annually. “We’ve got a couple million dollars invested in equipment, and while that makes this a multiyear payback, we think it’s still pretty decent,” he adds.

The biomass heating solution at Len Busch Roses is relatively straightforward, but its impact on the viability of the business is difficult to overstate. By way of explanation, Busch points to a dramatic shift in the cut flower business that began in the late 1980s. Cut flowers such as roses, tulips and lilies are sold already cut, and then bunched by supermarkets and flower shops. Prior to the ‘80s, the cut flower business was dominated by producers in California and Colorado. In the late ‘80s, foreign players, predominantly Columbia and Ecuador, began building a distribution pipeline that connected growers in those countries to importers in Miami. This supply chain is now so well-established that a cut flower can move from a greenhouse in Columbia to a florist in Minnesota in less than a week.

 Busch says that the cost of producing a cut flower in these countries is a fraction of the cost to produce the same flower in the U.S., even when considering the air freight involved in getting the flowers from Bogota to Miami. “Their greenhouses are so much cheaper to build down there, because the natural environment in those countries is so similar to the optimal environment for the flowers anyway,” he says. “Add to that the far lower labor cost those growers have, and it’s nearly impossible to compete with them.”

Two-thirds of Len Busch Rose’s production are cut flowers, business that Busch says he can only remain in because of his biomass heating operation. “For potted, blooming plants, we’re competing with other local producers with similar expenses to ours, but in the cut flower business, we’re competing with these foreign producers with a whole different cost structure,” Busch remarks. “Without our biomass system, heating costs would push us over the line to where it would just make more sense to buy them and resell them, rather than grow them ourselves.”

A Heating Cost Hedge
Compared to Len Busch Roses, Schaefer’s Gardens is a relative newcomer to biomass heating, and while the greenhouse doesn’t enjoy the access to a stream of free urban wood waste that Len Busch Roses enjoys, the operation installed a biomass solution to guarantee more predictable heating costs.
For years, Schaefer’s Gardens heated its 1.5-acre greenhouse with a heating oil. In 2010, the price of heating oil began to climb, and by the heating season of 2012-‘13, Schaefer’s was paying $3.50 a gallon for heating oil. “It was killing us,” says George Schaefer, owner of Schaefer’s Gardens. “We spent over a hundred thousand dollars a year for fuel. We burned about 30,000 to 32,000 gallons each heating season, and we only have an acre and a half greenhouse.” The rapid rise in operational costs were taking a significant bite out of the operation’s profits.

Schaefer and his daughter began investigating biomass alternatives, including wood chips, grass pellets and wood pellets. Eventually, a conversation with Gus Freeman from Bowman Stoves LLC offered Schaefer’s the most comfort. Bowman Stoves LLC is an authorized dealer of WoodMaster furnaces and boilers. Bowman Stoves and WoodMaster went to work designing a solution that would satisfy Schaefer’s heating needs, eventually landing on a CS500 commercial pellet boiler. The boiler is capable of producing 1.7 million Btu per hour, and is connected to an overhead radiant heating system. “We used to have our heating run through the concrete floor because we had our plants set directly on the floor,” Schaefer says. “Now, we’ve got all of our plants growing on tables, so the heat is above everything. It’s a better system, and I don’t miss trying to fix a leak buried in a concrete slab.”

Work began to install the system at the end of 2013, and in October of 2014, the system came online and went operational. Greenhouses benefit greatly from solar energy, and as a result, heat demand varies greatly during the day. The CS500 boiler can consume just over 20 tons of wood pellets per week when run at full throttle, but during the day, it is more common for the boiler to run at just under 50 percent capacity. The unit runs at nearly 90 percent capacity throughout the night, and the cycle continues the next day.  “Even if it’s zero out, if the sun is out, we don’t need any heat in the greenhouse, but by 3:00 or 3:30 p.m., we need a boatload of heat,” Schaefer says.

Operationally, Schaefer’s is impressed with the unit’s ease of use. “I love the pellet furnace,” he says. “It's very simple. It's not quite as easy as oil because you have to clean the ashes out, but when we use it at full steam, I would say it only fills up every 10 days.  And we can dump it in the field as there are no heavy metals or other impurities—it’s just ash, and easy to get rid of.”

During its first year of operation, Schaefer’s Gardens consumed nearly 250 tons of wood pellets, saving themselves nearly $37,000 in heating oil expenditures. While impressive and welcome, the rate of savings Schaefer’s Gardens will experience is directly tied to the price of heating oil. Not long after the system was installed at the greenhouse, the price of heating oil plummeted. Anticipating this potential, Schaefer chose to retain his heating oil assets, and during the heating season of 2015-’16, the price of heating oil made its use more economical than wood pellets. The system came online again for the heating season of 2016-’17, and Schaefer anticipates that this winter, he’ll be burning pellets as well. Still, Schaefer takes comfort in knowing that now, he has a choice. “Many of our competitors utilize natural gas, and there have been times when natural gas has been one-third the price of heating oil,” he says.

While installing a pellet boiler didn’t eliminate Schaefer’s heating costs, it has resulted in a protection against the roller coaster ride that heating oil dependency created for the operation. Now, Schaefer’s Gardens is able to capitalize on whichever fuel is most economical at the time.

The scope and scale of the biomass heating solutions at Len Busch Roses and Schaefer’s Gardens are vastly different. As a result, the savings offered by the respective systems are also very different. The solution at Len Busch Roses is enviable for any greenhouse operator, a virtually cost-free heating fuel, where the savings at Schaefer’s are more modest, even more so in an era of historically low fuel oil prices. Still, biomass heating offers each a way out from under a heating expense that poses a very real threat to the overall viability of their respective operations.

Author: Tim Portz
Executive Editor, Biomass Magazine
[email protected]