This project teamed Penn State Extension with farmer Will Brandau to create and distribute a thorough case study of on-farm grass pellet production, as experienced at Woodcrest Farm in Wapwallopen, PA. The project team gathered information on the experiences and lessons learned in the course of developing the switchgrass pellet operation and participating in the Grass Energy Cooperative. They also collected data on equipment performance, including labor requirements, energy use, and operating time. Results indicated that operating costs for the facility were $592 per hectare ($240 per acre), plus 37.9 hours of labor. Total fuel use of the pelleting operation (diesel fuel only) was 59.2 litres per tonne of final product (14.2 Gallons per ton). If we ignore labor, operating costs are approximately $97 per tonne of product ($88 per ton). The information in the case study has been compiled in a thorough report that is now available via print and internet. Also, a spreadsheet model of on-farm grass pellet production was created and is available for use by farmers. Results of this study continue to be used, both regionally and internationally.
Farmers in the Northeast are interested in the sustainable production of perennial grass based fuel pellets for use as a renewable heating fuel, as evidenced by attendance at recent grass energy short courses and open houses sponsored by Penn State Extension as well as by the Grass Energy Cooperative, a farmers’ organization in Northeast PA. Grass pellets are an opportunity for local, renewable production of energy either to meet on-farm needs or for production of a local, renewable energy fuel for sale in the community. In addition to this, there has been talk in the region about significant amounts of perennial grass Conservation Reserve Program (CRP) land coming out of the CRP program, with concern about the ecological impacts of this shift. Grass based pellet production may be a valuable incentive for farmers to keep land in ecologically beneficial perennial grass production rather than switching to a less ecologically sustainable crop.
While a few early adopters have made efforts to grow and produce grass pellets, there remains a lack of relevant, practical information to assist farmers in effectively producing grass pellets in the region. Many studies have investigated the impact of various process parameters on pellet quality, but there is very little practical guidance available for the aspiring on-farm pellet producer. Grass production, harvest, storage, pre-processing, pelletizing, and marketing are all challenging obstacles that farmers currently must face with minimal guidance or support, not to mention the economics and ecological considerations associated with the venture.
Practical guidance for farmers interested in grass pelleting would be very helpful for meeting these needs.
The objectives of this project were to
– investigate operating characteristics of a farm-scale sustainable grass pellet fuel operation, and
– develop a case study that can be used as a gude for farmers interested in pursuing this opportunity.
– disseminate this information to the farming community
Interviews of farm-based pellet producer Will Brandau were a key component of this project, allowing for capture of experiential learning and understanding that could not otherwise be collected. This included
– compilation of tips for successful growing, handling, and processing of perennial grass for pellet manufacture.
– Recounting problems that were encountered, as well as the approach used to find solutions,
– review of Facility records, providing information on methodologies, yields, and costs.
In addition, direct measurements were taken of equipment operation (pellet yield rate, electrical and/or fuel use, labor requirements, moisture content, resulting pellet density) for the pelletizing operation as well as for upstream pre-processing operations. Measurements of field operations were taken at the farm site during the April 2014 harvest, and measurements of pelleting were recorded during a pelleting session in June of 2013.
This information was compiled in a case study document, formatted and printed for public use. A spreadsheet-based model was also created of the pelleting operation, withh the ability to vary inputs to investigate the impact of farm changes on productivity, costs, labor, and energy use.
Information collected, as per the project proposal, included:
1. Farmer interview: information from the farmer interview was extremely valuable in establishing processes and inputs at the farm, as well as for identifying challenges and solutions to difficulties that were faced. This information was incorporated in the case study document.
2. Facility records: very little in the way of written records was found to be relevant for the project. Instead, the farmer’s detailed memory of costs and usage were relied on to characterize equipment costs and input usage. This information was incorporated in the case study document.
3. Direct measurement: Direct measurement of the pelleting operation yielded the following data:
– pellet production rate: 90 kg hr-1 (200 lbs hr-1)
– pelleting energy use: 59.2 litres diesel fuel per tonne of pellets (14.2 US gallons per ton)
– pelleting labor needed: 13.3 hours per tonne (12.1 hours per ton)
– pellet density: 1.126 kg l-1 (70.0 lbm ft-3)
– bulk density: 0.568 kg l-1 (35.4 lbm ft-1)
– moisture content: 12.6% (wet basis)
– durability: 97.0%
– energy content: 15,637 kj kg-1 (wet basis), 17,891 kj kg-1(dry basis)
note: energy use and labor needed includes grinding as well as pelleting operations.
In addition, data were collected as to the time and labor required for harvesting and baling operations at the farm, with results all incorporated into the case study document.
Total pellet production cost (including growing and harvesting the feedstock) was $97 per tonne ($88 per ton) if labor cost is zero. The majority of these non-labor costs are due to fuel and lube costs for the equipment ($69 per tonne / $63 per ton). If we add a $15 per hour labor cost, this increases the total cost to $307 per tonne ($279 per ton).
These findings not only provide a comprehensive view of on-farm pelleting of biomass, but also indicate some interesting points. Foremost of these is that, for on-farm pelleting to be a viable operation, it must be carried out in situations that are well suited for the enterprise (i.e. low- or no-cost land available, access to equipment, facilities, and labor). It is most likely to succeed if it is a”fit” for the farmer’s existing operation, rather than serving as a standalone enterprise. Second, significant reductions in cost and resource usage could have dramatic positive impacts on the viability of the operation. Chief opportunities in this respect are to improve pelletizer throughput, reduce labor requirements, and improve process energy efficiency. When these improvements are realized, on-farm pelletizing will become much more attractive as a sustianable energy option for farmers in the region.
Accomplishments of the project are as follows:
Several students (Colin Crawford, Vincent Vendetti, Nichole Heil, Kenny Lee, Samantha Goldberg, Rachel Miller) worked part time on the project, providing project assistance while simultaneously learning about sustainable grass energy.
The case study was completed, edited, and published as a Penn State Extension document titled “On-Farm Production of Biomass Grass Pellets” (available online at http://extension.psu.edu/publications/ee0130). This 24-page, full color document gives detailed information on equipment, procedures, and costs for producing grass pellets on the farm, starting with field preparation and moving through to pelleting and sales. The farmer’s collected experience and wisdom is sprinkled throughout, providing practical tips as well as technical data on farm pelleting.
Synergistic benefit was obtained by producing a summarized version of the case study for a complementary SARE Grant project titled Farm Energy IQ, and incorporated into that project’s “farm pelleting” educational module (visit http://www.extension.org/pages/72595/northeast-farm-energy-iq-curriculum#.VVX12flVhBc). Thus, project information was delivered at the Farm Energy IQ workshops in Vermont, Pennsylvania, and New Jersey. Will Brandau assisted with delivery of the New Jersey workshop.
A presentation was given on farm pelleting at the energy showcase of the Ag Progress Days agricultural show in August of 2014, a large education event held every August in Pennsylvania.
Project findings were also shared at the Pennsylvania Farm Show – the nation’s largest indoor agricultural show – in January 2015.
The case study is being used by Will Brandau in collaboration with a local RC&D district to carry out pelleting education in the area.
A pelleting video was developed, providing a demonstration of successful techniques for small scale pellet production.
The spreadsheet model has been adapted and utilized by Professor Michael Jacobson during his sabbatical in Kenya, where he is using it to analyze the potential for pellet production in conjunction with high efficiency cook stoves as well as for possible use in the tea industry.
A paper will be presented at the NABEC (Northeast Agricultural and Biological Engineers) conference in Newak Delaware in July 2015, withi possible submission to a scientific journal for publication.
Data collected from Wood Crest Farm provide significant insights into the process, resources, and costs associated with on-farm switchgrass production. The study showed that availability of labor, land, and equipment can have large effects on overall costs, and that improvements to the pelleting operation will significantly improve the cost effectiveness of the operation. Switchgrass pellet production promises to be cost effective in those situations where farms and farmers can take advantage of favorable scenarios, but establishment of a market remains the most challenging task.
Education & Outreach Activities and Participation Summary
Outputs from this project include:
Pelleting Project Web Page: http://extension.psu.edu/natural-resources/energy/field-crops/pelletizing-biomass – includes information on work done prior to this SARE Grant project, as well as the SARE Grant
“On-Farm Production of Biomass Grass Pellets” – complete case study of Wood Crest Farm (available online at http://extension.psu.edu/publications/ee0130
“Farm Pellet Analysis Spreadsheet” – calculation tool that helps farmers estimate operations and costs related to on-farm pellet production. https://extension.psu.edu/natural-resources/energy/field-crops/pelletizing-biomass/farm-pellet-analysis-spreadsheet/at_download/file
Abbreviated case study of On-Farm Pellet Production (available online at http://www.extension.org/pages/72595/northeast-farm-energy-iq-curriculum#.VVX12flVhBc)
Producing Switchgrass Pellets on the Farm – Presentation to Penn State Extension Energy Team. 09 July, 2014.
On Farm Biomass Pelleting – Presentation at Ag Progress Days Energy Showcase. 14 August, 2014.
Small Scale Biomass Pelletizer Video – Instructional video prepared by student interns. (note: adjustments to audio levels still underway – will be posted to youtube shortly)
Areas needing additional study
This project identified the areas of scientific need for improving the biomass pelleting process – namely understanding the pelleting process sufficiently to improve machine throughput and control labor inputs, thus making on-farm pellet production more effective and attractive for farmers in the region. Research addressing these needs would be very welcome and useful.