Anaerobic Digester Implementation on Small Dairy Farms in Michigan and Wisconsin: A Literature Review By: Ben Bailey Purpose • The purpose of this literature review is to identify factors that encourage and discourage small digester implementation in Michigan and Wisconsin. • Offer possible solutions to barriers that prevent building more small on-farm anaerobic digesters. Introduction Figure 1: Size distribution of US dairy herds in 2011 Image from http://thedairymom.blogspot.com Small Digester Implementation Image from www.epa.gov Figure 2: Number of anaerobic digesters (2012) by state. Results: Why install an anaerobic digester? Increased Income Figure 3: The anaerobic digestion process and its outputs Images from http://www.plugflowdigester.com/ Plant Available Nutrients / Odor Control Images from http://www.jipl.co.nz/anaerobicdigestion.html Figure 4: Digestate State Policy: Wisconsin and Michigan Figure 5: Portrayal of Wisconsin’s projected green energy output by 2025 Images from www.usuca.org Flexibility of Systems Figures 6 & 7: Examples of two very different digester systems that ultimately perform the same process Images from Wikipedia.com and http://brisbanelocalfood.ning.com/profiles/blogs/problem-pollution-solution-biogas Results: Barriers to anaerobic digestion implementation. Dairy industry consolidation trends Images from www.ers.usda.gov Figure 8: The decreasing number of dairy cows over a thirty year period Farmer views on small scale digestion “…digesters would not be a “real improvement” for farms that already utilize “good farming practices”.” “it burns carbon when methane is burned as fuel,” “One respondent indicated that he had “no ability to do it”… “Overall, 45% of farmers surveyed were disinclined and 21% were inclined to adopt anaerobic digester technology.” From Wilkerson, as cited in literature review State policies Figure 9 & 10: Michigan and Wisconsin Images from michfencing.net and wisconsinbroker.net Cost of digesters ($3,500,000) (4,000 head) $875/cow ($1,000,000) (600 head) $1,667/cow Figure 11: Comparison of Capital Cost of implementing a digester to number of head Image from www.epa.gov Natural gas market Image from Energytrendsinsider. com Climatic conditions Figure 13: A comparison between heat input requirement for digesters compared to daily temperature Image from http://www.sciencedirect.com/science/article/pii/S0961953410004757 Electricity and connecting to the grid Figure 14: Cost of electricity (cents/kWh) in leading countries Images from http://thinkprogress.org/ What’s Missing? • An economically viable way to install anaerobic digesters • Federal funding • High electrical reimbursement • Stable market economy for digesters to gain footing • State policies and permitting • High farmer opinions of digesters How to Fix it? Figure 15: Number of Anaerobic Digesters per Country • Model off Germany and other countries • Think outside the box • Identify synergies with other forms of renewable energy that generate profits for the farm. • Identify or develop less expensive materials that reduce the capital costs of the digester vessel. Images from http://www.iea-biogas.net How to fix it? • Research • Develop new digester systems. • Develop new uses of digestate to increase profits • Develop new strains of methanogens that work more efficiently at colder temperatures • Educate • Develop new training programs focused for farmers • Help policy makers understand the role of digesters • Help policy makers identify and react to overcome digester barriers Thank you for your time! • Questions will be held after the next presentation. • I now direct you to Charles Gould for the next segment of the webinar Small digester design and small digester case studies results M. Charles Gould Extension Educator-Agricultural Bioenergy and Energy Conservation Agriculture and Agribusiness Institute Michigan State University Small digester design Dairy Farms in the United States (2009) Herd Size Number of Farms Percent of (hd of cattle) Total Farms 1-29 20,400 31.4 30-49 11,500 17.7 50-99 17,300 26.6 100-199 8,600 13.2 200-499 3,850 5.9 500-999 1,700 2.6 1,000-1,999 910 1.4 2,000+ 740 1.1 Total 65,000 99.9 Adapted from: USDA, NASS Farms, Land in Farms and Livestock Operations 75.7% 88.9% 13.2% 94.8% 5.9% 61,650 farms <500 cows 94.8% of total farms Small digester design Average U.S. Digester Cost: $1.5 million (U.S. EPA, 2009) Source: AgStar. 2010. Anaerobic Digestion Capital Costs for Dairy Farms. Small Digester Case Studies Farm Joneslan Farm1 Number of cows Total Project Cost ($) $/cow with grants 230 823,000 278 3,578 Keewaydin Farm1 90 512,000 277 5,688 Bakerview EcoDairy1 44 600,000 ? 13,636 Cornell Case Studies2 1,078 1,782,558 What components cost the most? • Digester vessel and energy conversion • Small farms – approximately 50% • Large farms – approximately76% 1. 2. $/cow without grants Source http://ncrcrd.msu.edu/ncrcrd/webinars Source: http://www.manuremanagement.cornell.edu/Pages/Resources/Resources-Case_Studies.htm 1,653 Small digester design Jose Luis’ milking parlor. He ships his milk to Nestle. Humza standing on a Sistema Biobolsa BB20 digester. Installing a Sistema Biobolsa BB40 digester. Concrete ramp to manure receiving basin. Photos courtesy of Charles Gould. Sistema Biobolsa web site: http://sistemabiobolsa.com/home/ The Small Digester Concept H2S and moisture removal, piping, valves, electrical, and pumps Pictures courtesy of EPT (http://eptpac.com/index.html), Garb-el Company (http://www.garb-el.com/) and M. Charles Gould. Small digester design • Assumptions • 21 day HRT • Daily volatile solids loading rate – 0.33 lb/ft3 • • • • Three 40’ bladders would be needed for 100 cows. One 40’ bladder would be needed for 38 horses. Bladder dimensions are 40’x7.66’x3.92’. Estimated cost for equine digester system described in previous slide using a 40’ bladder and cargo container is $20,000. Small digester design • Increase digester efficiencies • Digester design • Scale up, not down • Reduce hydraulic retention time • Modular components • Cheaper digester vessels • Use materials other than concrete and steel • Focus on biogas as the end product • Improve digester performance • Feed digester high energy feedstocks such as fats, oils and grease, food waste, etc. • Manipulate methanogenesis? • Methanogens that are more efficient at producing methane? Sources: Lansing. S and Moss A.R. 2010. Small-Scale Anaerobic Digestion: Technology and Applications presentation. Siemens Industry Inc. 2010. Process analytics support higher yields in biogas plants The bioenergy industry with smaller-scale digesters US annual natural gas consumption (MMcf/yr) US natural gas consumption reduced by 25% (equivalent to 1 billion barrels of oil annually) MMt CH4 emissions from livestock manure/yr US methane emissions reduced by 5% per year (reduction of 34.5 million tons of CO2 equivalent) Source: Lansing. S and Moss A.R. 2010. Small-Scale Anaerobic Digestion: Technology and Applications presentation. Small Digester Case Studies • Bakerview EcoDairy - BC • 44 milk cows • Avatar digester • Joneslan Farm - VT • 230 milk cows • UEM Inc. digester • Keewaydin Farm - VT • 90 milk cows • Avatar digester • Two Wisconsin case studies will be posted shortly. Small Digester Case Studies • Joneslan Farm • Financial • Below are the projected estimated percent of revenue: – – – – Total revenue from Total revenue from Total revenue from Total revenue from tipping fees (0%) electrical generation (61.9%) “avoided cost” of purchasing fossil fuels for heating (4.6%) “Other” sources: » Fiber sales (11%) » Avoided cost - On-farm bedding use (22.5%) • It is difficult to arrive at a true value of the electricity produced because of generator issues, but at a minimum, the value of the electricity produced is approximately $50,000. • In terms of annual operating expenses, if the generator engine was functioning correctly the annual operating expenses would be approximately 5% more than what was predicted. Small Digester Case Studies • Keewaydin Farm • Financial • The digester has not been in operation long enough to arrive at a reasonable estimation of profit and loss. – From January through August 2013 the gross value of the electricity produced was $4,178. • Operating expenses are much higher than projected when the project was designed because of many costly repairs. Small Digester Case Studies • Bakerview EcoDairy • Financial • Ongoing operational challenges had made it difficult to assess long-term operational requirements, as the system has yet to operate as a stable system for any length of time (>6 months). • Net annual cash flow: $3,480, based on the period of June 1, 2011 to December 1, 2012 when electrical production was metered and fiber was used as bedding. Small Digester Case Studies • Reported problems/failures 1. 2. 3. 4. 5. Site planning and design Engineering Construction and equipment Biogas utilization and systems System control and operation monitoring and control Small Digester Case Studies • Lessons learned from farmers • • • • It is best to have a turnkey contract with performance guarantees. Choose a digester vendor with capital and experience behind them. Keep the system as simple as possible. Hiring local skilled labor and making digester components locally reduces the overall cost of the project. • Digester vendors should include farmers in the design of the digesters as farmers may have suggestions that can save a project time and money. • Digester vendors should talk among themselves and share information to avoid the same costly mistakes that seem to be repeated when on-farm digesters are built. • Be careful with assumptions. Project Summary • Less expensive digesters and favorable policies will support small digester growth in the U.S. • Need more basic and applied research. • Targeted farmer educational programs. Ben and Jerry’s Ice Cream store in Vermont. Photo credit: Charles Gould. This project was made possible by funding from The North Central Regional Center for Rural Development (NCRCRD). M. Charles Gould Extension Educator-Agricultural Bioenergy and Energy Conservation Agriculture and Agribusiness Institute Michigan State University 12220 Fillmore St, Suite 122 West Olive, MI 49460 Toll Free: (888) 678-3464, Ext. 68829 Direct line: (616) 994-4547 Email: [email protected] MSU is an affirmative-action, equal-opportunity employer, committed to achieving excellence through a diverse workforce and inclusive culture that encourages all people to reach their full potential. Michigan State University Extension programs and materials are open to all without regard to race, color, national origin, gender, gender identity, religion, age, height, weight, disability, political beliefs, sexual orientation, marital status, family status or veteran status. Issued in furtherance of MSU Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Thomas G. Coon, Director, MSU Extension, East Lansing, MI 48824. This information is for educational purposes only. Reference to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned.