Farm Industry News
Native grasses hold promise for renewable energy on farms but the process may take some experimentation to make it work Therersquos an increase in the number of farms using renewable energy

Native grasses hold promise for renewable energy on farms, but the process may take some experimentation to make it work. There’s an increase in the number of farms using renewable energy.

Producing renewable energy for the farm and for sale

On-farm renewable energy production has doubled. A range of materials can be used to heat and power farms. Matching the right material to the right use is one challenge.

Pork and Plants. It’s an interesting name for a company. In fact, Pork and Plants is interesting in a lot of ways — from selling half and whole hogs to be­ing a connoisseur of Red Wattle pork to raising poinsettias to burning biomass pellets for heating its 50,000 square feet of greenhouse space. Pork and Plants is among a small, but growing number of farms producing renewable energy.

According to the 2012 Census of Ag­riculture, the number of farms produc­ing on-farm renewable energy more than doubled from the last census in 2007.

Burning biomass pellets is less ex­pensive than buying propane to heat the greenhouses, says Eric Kreidermacher, who, with his family, owns and oper­ates Pork and Plants in Altura, Minn. But it took a few years of trial and error. Kreidermacher began burning shelled corn to heat the greenhouses in 2003 when corn was “dirt cheap.” But the first boiler was “a disaster,” and corn prices were rising, he says. With help from Minnesota’s Agri­cultural Utilization Research Institute (AURI), Kreidermacher learned about pellet mill dies that could create pellets from grasses and wood waste. AURI cre­ated a guide on technical feasibility, per­mits, cost estimates, ag feedstocks and other topics in 2007. Kreidermacher de­termined he could make biomass pellets work on a small scale.

That same year, Kreidermacher be­gan growing native grasses. But little information existed then on producing biomass. “Even seed companies were mainly selling native grasses for wildlife habitat,” he recalls. He made pellets from corn stover and soybean straw, but he believed a perennial grass and forb mix would make more sense on his hilly farm in Minnesota’s Driftless Region.

Kreidermacher’s attempts with the seed mix were unsuccessful. “I planted my ‘prairie’ on really productive land. Unfortunately, native prairie for biofuel production really only makes sense on more marginal land,” he says. “I tried to see if it could compete against corn and soybeans on good productive land, to no avail. We didn’t have any marginal land.”

For Pork and Plant, pelletizing material for use in boilers helps cover most of the farm’s energy needs. The system can pelletize a wide range of feedstocks, from native grasses to chaff, and turn it into a useful energy source.

Fast-forward to today. Kreidermacher is using two Pelco boilers, which burn pellets made from a variety of feedstocks. These boilers can produce 1.5 million Btu. Kreidermacher is now buying native grass straw and the chaff left over from a seed conditioning facility about 50 miles away. The straw is baled in round bales, which Kreidermacher hauls with a flatbed semi. Seed cleanings are trans­ported with a walking floor trailer.

“Eric started by purchasing bales from our na­tive grass production fields and then discovered that the byproduct from our seed-cleaning plant worked well, too,” says Mark Udstuen, Shooting Star Native Seeds.

Icing on the cake

The seed company had traditionally burned the chaff. “Pork and Plants now takes our trash and turns it into an energy source,” says Udstuen. “Na­tive plants have many other benefits as well, like offering cover and food for wildlife and providing long-term environmental stability. The byproduct from native plants as an energy source is just icing on the cake.”

The pellets meet about 85% of Pork and Plants’ heating needs; the rest is heated with LP gas. The greenhouse containing the operation’s poinsettias must be heated as early as September. The green­houses containing flowering annuals and perennials are typically heated until May.

It costs about $75,000 to heat the greenhouses with biomass pellets, compared to $130,000 with LP gas, Kreidermacher says. “The first 75% of your heat load is where you are going to realize your greatest return on investment.”

An advantage of the Kreidermacher model is that the price to burn the seed chaff and native grass straw remains relatively stable, unlike LP gas. The Kreidermachers use the boilers to heat their home and shop.

While Kreidermacher does not sell energy to a local utility, he does sell pellets to a nearby hog pro­ducer who uses the pellets to heat water for the heat mats for his baby pigs. He also provides pelletizing services to a neighbor who brings him native grass biomass and uses the pellets to heat his home.

Energy efficiency

The growing number of farmers producing renewable energy is at­tributed to a mix of actors, largely driven by economic sustainabil­ity, according to Fritz Ebinger, program manager of Clean Energy Resource Teams (CERTs) in St. Paul, Minn.

“As time has passed, the installed costs of farm-scale renewable energy technologies have become more reasonable. Technology performance and durability have improved, and farmers are real­izing these are intelligent investments for offsetting production costs,” Ebinger says. Investment tax credits have also played a role. As farm income has increased over the last few years, tax liability also has increased so many farmers have chosen to offset taxes by investing in renewable infrastructure, he says.

CERTs is focused on energy efficiency. “Every dollar spent on energy efficiency will save a person $3 to $5 on renewable energy,” Ebinger says. “We help farmers reduce production costs through conservation and aim to enhance production with more efficient technology and design. We encourage all farmers to have a farm energy audit completed through the [Natural Resources Conserva­tion Service’s Environmental Quality Incentives Program] or their local utility for a baseline understanding of their electrical and thermal energy consumption,” he says. Farmers can use this audit to plan equipment upgrades or address production costs. The au­dit includes payback times in terms of energy savings and explains how different technologies may be used.

CERTs provides information on the limitations and benefits of renewable energy technologies, such as farm-scale wind and solar siting, thermal (hot water and air), ground source heat pumps, and waste heat recovery. Ebinger has seen major growth in solar electric or photovoltaic energy in recent years, mainly due to the declining costs of installation and tax incentives. He says last year the Minnesota Legislature passed a Made-in-Minnesota produc­tion-based incentive for solar PV panels. The state’s Value-of-Solar Tariff for ratepayers of investor-owned utilities also compensates producers for the value of the solar energy they produce.

Rural electric co-ops, which service most farmers, were exempt­ed from these solar provisions because they have a fundamentally different business model: The community owns the electric dis­tribution cooperative and its infrastructure, not shareholders. Net metering is unchanged for rural electric co-ops and municipalities.

BIOMASS

Biomass as an alternative to liquid propane is another growth area. Ebinger notes the Minnesota departments of Agriculture and Natu­ral Resources have established grant programs to examine ways farmers can avoid volatile LP prices. “There has been greater in­terest in wood boilers, ground-source heat pumps, waste heat re­covery and solar transpired-air to address the LP challenges many livestock and greenhouse producers face,” he adds.

“The biggest challenge for farmers we work with is the up-front cost of technology,” he says. “Farm-scale renewable energy is simi­lar to purchasing a large farm implement. Farmers should focus on payback, including an examination of investment tax credits, potential grants and offsetting energy consumption.”

Learn more at cleanenergyresourceteams.org.

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