Tag: Climate Variability and Change

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Existing Data on Long Term Manure Storages, Opportunities to Assist Decision Makers

Long-term manure storages on dairy farms are temporary containment structures for byproducts of milk production. Manure, milkhouse wash, bedding, leachate, and runoff are stored until they can be utilized as fertilizer, bedding, irrigation, or energy. The practice of long-term storage creates stakeholders who collect data in their interactions with storages. This presents an opportunity to support data driven  decision making on best use and operation of storages.

What Did We Do?

Prevalent stakeholders who collected data on storages were identified and the information they collected was examined. Data that could assist in depicting storage infrastructure was retained. Data not collected but of value to decision makers was noted. From this a combined data set was proposed that could depict the size, state, and impact of storage infrastructure. The feasibility of such a combined data set and opportunities from it were considered.

What Have We Learned?

General volume, general configuration, and year installed are most often collected by stakeholders while detailed configuration and detailed waste type are rarely collected. Cost is not collected. (Table 1) Stakeholders do not collect data on operations of all sizes. Most data is collected on large and medium operations while data is rarely collected on small operations. Stakeholders use their own definitions and classification structures.

Table 1 Combined data to be collected to assist decision makers
Data Specificity Currently collected by
Location County State, NRCS, CNMP
City STATE, CNMP
Address STATE, CNMP
Lat, Long NONE
Storage Volume Total STATE, NRCS, CNMP
Operational STATE, CNMP
Geometric Dimensions STATE, CNMP
Above/Below Ground STATE, NRCS, CNMP
Year Built Year Built STATE, NRCS, CNMP
Year Inspected STATE, CNMP
Year Recertified STATE, CNMP
Year Upgraded STATE, CNMP
Configuration Liner (Dug,Clay,Plastic,Concrete,Steel) STATE, NRCS, CNMP
Certification(313,PE,ACI318,ACI350) STATE, NRCS, CNMP
Cover(none, rain, gas) STATE, NRCS, CNMP
Waste Volume Produced STATE, CNMP
Type(manure,washwater,leachate,runoff) STATE, CNMP
Manure Type(liquid, stack, pack, liquid sand, liquid recycled) CNMP
Advanced Treatment CNMP
Costs Total NONE
Per Component NONE
Operational NONE
*STATE-State of Michigan

*NRCS-United States Department of Agriculture Natural Resources Conservation Service
Table 2 First level characterization
Parameter
Number
Location
Age
Total Stored Capacity
Precipitation Stored Capacity
Waste Stored Capacity
Produced Waste Volume
Produced Waste Type
Produced Manure Volume
Produced Manure Type
Liner Type
Cover Type
Certification Type

A first level characterization of storage infrastructure is proposed from Table 1, Table 2. Items in the first level characterization depict the location and condition of the storage infrastructure. Each of these items may be represented over a specific geographic area, such as state, watershed, or county. In a yearly inventory each of these items may be represented over time.  

Table 3 Second level characterization
Parameter
Length of Storage Estimate
Proximity to Sensitive Area Estimate
Storage Density
Seepage Estimate
Emissions Estimate

Using Table 2 a second level characterization is proposed, Table 3. Items in the second level characterization estimate the capacity and impact of the state’s storage infrastructure. Supplementary information to estimate certain parameters is required.  Each of these items may be represented over time and specific geographic area. Cost to implement and operate storage infrastructure are the third characterization, Table 4. Each of these items may be represented over time and specific geographic area.

Table 4 Cost characterization
Parameter
Cost Estimate
Implement, Per Volume
Per Configuration
Operate, Per Volume
Per Configuration

Combining and characterizing data from different stakeholders can provide a data-driven representation of storage infrastructure. Condition, capability, and impact of the storage infrastructure can be represented over time and geographic area. Monitoring, evaluating actions, forecasting issues, and targeting priority areas1 is made feasible.  Example opportunities are as follows.

Long-term storage is desirable to enable storage of manure during winter months. Combined data can provide feedback on average days of storage in the state or watershed. The cost to achieve target days of storage may be estimated and the days of storage may be tracked over time as a result of funding efforts.

New York State released $50 million for water quality funding, which assisted in the implementation of new storages. In the implementation of these storages opportunity exits to collect cost data to inform future funding levels, quantify the increase in long-term storage provided as a result of the funding, and forecast when these storages are projected to reach the end of their lifecycle2.   

As interest in cover and flare storages increase to offset livestock emissions combined data sets can assist in evaluating feasibility of such a proposal3 4 5. Potential emissions to be captured and cost to implement can be estimated.  

Obstacles to collecting and combining data are cost, insufficiency, and misuse. As specificity in the data to be collected increases so does the cost to collect, combine, and maintain. Additionally, stakeholders have existing data collection infrastructure that must be modified at cost to allow combination. If the combined data set is not sufficiently populated by stakeholders is will depict an inaccurate representation of storage infrastructure. Finally, the risk of misuse and conflict amongst decision makers is present. Stakeholders may purposely or inadvertently use the inventory to reach erroneous conclusions.  

Future Plans

Obstacles to implementation are not insignificant. Detailed analysis is required to determine the exact data to be collected, definitions to be agreed upon, and extent of coverage such that maximum benefit will be derived for decision makers.

Full benefit of storage data is increased by additional data sets such as state-wide livestock numbers, precipitation and temperature distributions, surface water locations, ground water levels, populations center locations, well locations, shallow bedrock locations, karst locations, complaint locations, and operator violations locations. The feasibility of obtaining these data sets should be determined.

The implementation and use of storages has additional stakeholders outside of those identified here. Additional stakeholders should be identified that can enhance or derive value from a combined data set on long term storages, such as manure applicators, handling and advanced treatment industry, extension services, zoning officials, professional engineers, environmental groups, and contractors.

Authors

Corresponding author

Michael Krcmarik, P.E., Area Engineer, United States Department of Agriculture Natural Resources Conservation Service, Flint, Michigan

Michael.Krcmarik@usda.gov

Other authors

Sue Reamer, Environmental Engineer, United States Department of Agriculture Natural Resources   Conservation Service, East Lansing, Michigan

Additional Information

    1. “Conservation Effects Assessment Project (CEAP).” Ceap-Nrcs.opendata.arcgis.com, ceap-nrcs.opendata.arcgis.com/.
    2. $50 Million in Water Quality Funding Available for NY Livestock Farms.” Manure Manager, 27 Sept. 2017, www.manuremanager.com/state/$50-million-in-water-quality-funding-available-for-ny-livestock-farms-30286.
    3. Wright, Peter, and Curt Gooch. “ASABE Annual International Meeting.” Estimating the Economic Value of the Greenhouse Gas Reductions Associated with Dairy Manure Anaerobic Digestions Systems Located in New York State Treating Dairy Manure, July 16-19 2017.
    4. Wightman, J. L., and P. B. Woodbury. 2016. New York Dairy Manure Management Greenhouse Gas Emissions and Mitigation Costs (1992–2022). J. Environ. Qual. 45:266-275. doi:10.2134/jeq2014.06.0269
    5. Barnes, Greg. “Smithfield Announces Plans to Cover Hog Lagoons, Produce Renewable Energy.” North Carolina Health News, 28 Oct. 2018, www.northcarolinahealthnews.org/2018/10/29/smithfield-announces-plans-to-cover-hog-lagoons-produce-renewable-energy/.
    6. Michigan Agriculture Environmental Assurance Program. MAEAP Guidance Document For Comprehensive Nutrient Management Plans. 2015,www.maeap.org/uploads/files/Livestock/MAEAP_CNMP_Guidance_document_April_20_2015.pdf.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2019. Title of presentation. Waste to Worth. Minneapolis, MN. April 22-26, 2019. URL of this page. Accessed on: today’s date.

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The Use of USDA-NRCS Conservation Innovation Grants to Advance Air Quality Improvements

USDA-NRCS has nearly fifteen years of Conservation Innovation Grant project experience, and several of these projects have provided a means to learn more about various techniques for addressing air emissions from animal agriculture.  The overall goal of the Conservation Innovation Grant program is to provide an avenue for the on-farm demonstration of tools and technologies that have shown promise in a research setting and to further determine the parameters that may enable these promising tools and technologies to be implemented on-farm through USDA-NRCS conservation programs.

What Did We Do?

Several queries for both National Competition and State Competition projects in the USDA-NRCS Conservation Innovation Grant Project Search Tool (https://www.nrcs.usda.gov/wps/portal/nrcs/ciglanding/national/programs/financial/cig/cigsearch/) were conducted using the General Text Search feature for keywords such as “air”, “ammonia”, “animal”, “beef”, “carbon”, “dairy”, “digester”, “digestion”, “livestock”, “manure”, “poultry”, and “swine” in order to try and capture all of the animal air quality-related Conservation Innovation Grant projects.  This approach obviously identified many projects that might be related to one or more of the search words, but were not directly related to animal air quality. Further manual review of the identified projects was conducted to identify those that specifically had some association with animal air quality.

What Have We Learned?

Out of nearly 1,300 total Conservation Innovation Grant projects, just under 50 were identified as having a direct relevance to animal air quality in some way.  These projects represent a USDA-NRCS investment of just under $20 million. Because each project required at least a 50% match by the grantee, the USDA-NRCS Conservation Innovation Grant program has represented a total investment of approximately $40 million over the past 15 years in demonstrating tools and technologies for addressing air emissions from animal agriculture.

The technologies that have been attempted to be demonstrated in the animal air quality-related Conservation Innovation Grant projects have included various feed management strategies, approaches for reducing emissions from animal pens and housing, and an approach to mortality management.  However, the vast majority of animal air quality-related Conservation Innovation Grant projects have focused on air emissions from manure management – primarily looking at anaerobic digestion technologies – and land application of manure. Two projects also developed and enhanced an online tool for assessing livestock and poultry operations for opportunities to address various air emissions.

Future Plans

The 2018 Farm Bill re-authorized the Conservation Innovation Grant Program through 2023 at $25 million per year and allows for on-farm conservation innovation trials.  It is anticipated that additional air quality projects will be funded under the current Farm Bill authorization.

Authors

Greg Zwicke, Air Quality Engineer, USDA-NRCS National Air Quality and Atmospheric Change Technology Development Team

greg.zwicke@ftc.usda.gov

Additional Information

More information about the USDA-NRCS Conservation Innovation Grants program is available on the Conservation Innovation Grants website (https://www.nrcs.usda.gov/wps/portal/nrcs/main/national/programs/financial/cig/), including application information and materials, resources for grantees, success stories, and a project search tool.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2019. Title of presentation. Waste to Worth. Minneapolis, MN. April 22-26, 2019. URL of this page. Accessed on: today’s date.

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Innovative Use of Solar Energy to Mitigate Heat Stress in Sows

Food retailers and consumers worldwide are pressuring producers to reduce the use of fossil fuels and the carbon footprint of swine production systems. The primary objective of this study was to evaluate a solar-powered system designed to cool sows that might reduce the use of fossil fuels in farrowing rooms and improve performance of lactating sows.

What did we do?

Two mirror-image, farrowing rooms equipped with 16 farrowing stalls each were used for this study.  Each farrowing stall in the COOL room was equipped with a cooled flooring insert (Cool Sow, Nooyen Manufacturing) under the sow and a single nipple drinker delivering chilled drinking water.  Circulating water cooled by a water-source heat pump powered by a 20 kW photovoltaic solar array cooled the floor inserts (60 to 65 °F) and chilled the drinking water (55 to 60 °F). Warm water (110 to 119 °F) was circulated through pads in the piglet creep area.  The CONTROL room was nearly identical to the COOL room except there was no cooling of floor inserts or drinking water and supplemental heat for piglets was provided by one heat lamp (125 W) per farrowing stall (Group 1) or an electric heating pad (Hog Hearth, Innovative Heating Technologies; Group 2).  Groups (n = 28 CONTROL sows and 28 COOL sows) were studied during summer months and room heaters were operated to keep rooms above 75 °F to ensure sows were heat stressed. Electric consumption for all systems (ventilation, piglet heating, lights, and cooling system) was measured and performance of sows and piglets were recorded over lactation.

What have we learned?

The COOL room consistently used more electricity than the CONTROL room (Figures 1 and 2).  For Group 1, the COOL room used 93.0 kWh/day while the CONTROL room used 35.3 kWh/day. Similarly in Group 2, the COOL and CONTROL rooms required 71.5 and 19.7 kWh/day, respectively.  Production of electricity from the solar panels totaled 95.3 and 86.7 kWh/day, respectively. Sows housed in the COOL room were more comfortable as indicated by a lower respiration rate (64.4 vs 96.8 breaths/min; P < 0.01), higher feed intake (11.39 vs 9.25 lb/d; P < 0.01) and reduced lactation body weight loss (35.1 vs. 54.2 lbs; P < 0.06) compared with sows housed in the CONTROL room.  Litter size at birth and weaning as well as piglet weaning weights were not different across rooms.

The cooling systems (cooled floor and cooled drinking water) and piglet heating systems studied effectively mitigated heat stress of lactating sows but did not enhance pig performance.  Furthermore, these systems required over 2.5 times more total electrical energy than a traditional lactation housing system without sow cooling.

Future Plans:

Effects of cooled floors and cooled drinking water were confounded in this study.  Cooled floors are expensive and difficult to install in existing facilities. The effects of cooled drinking water will be assessed independent of cooled floors in future studies.  Cooled drinking water will be easier to install in existing barns. Future analyses will consider the economic feasibility of various components of the sow cooling and piglet heating systems.  

Corresponding authors, titles, and affiliations:

B. M. Lozinski1, M. Reese1, E. Buchanan1, A. M. Hilbrands1, K. A. Janni2, E. Cortus2, B. Hetchler2, J. Tallaksen1, Y. Li1, and L. J. Johnston1

1West Central Research and Outreach Center, University of Minnesota, Morris, and

2Department of Biosystems and Biological Engineering, University of Minnesota, St. Paul

Acknowledgements:

The authors would like to express gratitude to the Minnesota Environment and Natural Resources Trust Fund for their financial support of this project.

 

Figure 1. Total energy use by room (kWh) and total solar energy produced (kWh) per day for Group 1.
Figure 1. Total energy use by room (kWh) and total solar energy produced (kWh) per day for Group 1.

 

Figure 2. Total energy use by room (kWh) and total solar energy produced (kWh) per day for Group 2.
Figure 2. Total energy use by room (kWh) and total solar energy produced (kWh) per day for Group 2.

 

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2019. Title of presentation. Waste to Worth. Minneapolis, MN. April 22-26, 2019. URL of this page. Accessed on: today’s date.

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Pasture-based Dairy Impact on Nitrogen and Phosphorus Cycling in Response to Grazing Grass-Legume Mixtures over Monocultures

There are over 3.5 million milk cows in the Western United States, making dairy one of the dominant sectors of western agriculture. Organic milk production is the fastest growing segment of U.S. organic agriculture and as a result there has been an increase in pasture-based milk production. To meet this increasing demand, improved grass-legume pastures that require fewer inputs, have high forage production and nutritive value, improve ruminant utilization of nitrogen, and have high dry matter intake are critical to the economic viability of pasture-based organic dairies. While grazing has many benefits, it may accelerate nutrient cycling and potentially increase nitrate leaching along with being a significant contributor of ammonia (NH3) and greenhouse gases (GHG). Dietary changes can impact emissions.  This study examines the effect of condensed tannins (CT) on nutrient cycling in the grass-legume versus grass monoculture grazing systems.  The nitrogen content in urine and feces of cattle grazing forages with, and without CT, was also examined and compared to a traditional TMR diet.  

What did we do?

Four grasses, with and without the addition of a tannin-containing legume, birdsfoot trefoil (Lotus corniculatus), are examined in this study.  The treatments include tall fescue (Lolium arundinaceum); meadow bromegrass (Bromus biebersteinii); orchardgrass (Dactylis glomerata); perennial ryegrass (Lolium perenne) planted as monocultures; and each of the four grasses planted with birdsfoot trefoil for a total of eight treatments.  Treatments were grazed by Jersey heifers using a rotational grazing system(1 week intervals). All treatments were fertilized with Chilean nitrate in April of 2017 and 2018.  Grass monocultures were fertilized with feather meal in June 2017 and March 2018, and Chilean nitrate in July 2017 and 2018.

Grab fecal and urine samples were collected at the beginning of the grazing season and additionally every five weeks at the end of grazing rotations.  Fecal samples were analyzed for total nitrogen by combustion method. Leachate was collected weekly by means of suction cup lysimeters and bi-weekly by means of zero-tension lysimeters and analyzed for nitrate-nitrogen using method 10-107-04-1-R on a Lachat FIA analyzer.

What we have learned?

Urea in urine, and fecal nitrogen were highest in the feedlot system (TMR diet).  Urea and fecal nitrogen in the grazing systems were higher in the grass-legume mixtures than the grass monocultures even though tannins have been shown to shift nitrogen from the urine to the feces.  This is most likely due to the higher protein (nitrogen) content of the grass-legume mixtures compared to the grass monocultures (data not shown). Despite the higher protein content of the grass-legume mixtures, the treatments containing birdsfoot trefoil exhibited less nitrogen loss due to leaching than the grass monocultures. Grass-legume mixtures have the potential to greatly improve the economic viability of a grazing operation while reducing the environmental impacts.  

Figure 1. Average total nitrogen (%) in feces.
Figure 1. Average total nitrogen (%) in feces.
Figure 2. Average urea in urine (mg/L)
Figure 2. Average urea in urine (mg/L)
Figure 3. Average leachate nitrate-N/lysimiter (mg)
Figure 3. Average leachate nitrate-N/lysimiter (mg)

Future plans

This study will be repeated for another year using Holstein heifers instead of Jersey heifers to see if there is a difference in nitrogen utilization between breeds. Treatments that are not being grazed will be harvested and fed in a feedlot setting to see if the benefits of birdsfoot trefoil remain when it is fed as silage.

Authors

Jennifer Long, Agricultural Systems Technology and Education Dept.; Utah State University

Jennifer.Long@aggiemail.usu.edu

 

Rhonda Miller, Ph.D.; Agricultural Systems Technology and Education Dept.; Utah State University

Blair Waldron, Ph.D.; USDA-ARS Forage and Ranger Research Lab

Clay Isom, Ph.D.; Animal, Dairy and Veterinary Sciences Dept.; Utah State University

Kara Thornton, Ph.D.; Animal, Dairy and Veterinary Sciences Dept.; Utah State University

Kerry Rood, Ph.D.; Animal, Dairy and Veterinary Sciences Dept.; Utah State University

Michael Peel, Ph.D.; USDA-ARS Forage and Range Research Lab

Earl Creech, Ph.D; Plants, Soils, and Climate Dept.; Utah State University

Jacob Hadfield; Animal, Dairy and Veterinary Sciences Dept.; Utah State University

Marcus Rose; Plant, Soils, and Climate Dept.; Utah State University

 

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2019. Title of presentation. Waste to Worth. Minneapolis, MN. April 22-26, 2019. URL of this page. Accessed on: today’s date.

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Thermal and Electrical Energy and Water Consumption in a Midwest Dairy Parlor

The typical dairy farm uses a large amount of energy during milking activities. This is due to the frequency of milking and the energy intensive nature of harvesting milk, keeping it cool, and cleaning the equipment with hot water. Renewable energy systems generally become more economically efficient as the amount of energy used increases, making dairy farms a great place to incorporate renewable energy.

Dairy farms have not typically been set up with energy efficiency in mind and often use relatively expensive fuel sources like heating oil or propane to heat water. One of the difficulties encountered with renewable energy systems is the intermittent generation of wind and solar energy, whereas the energy load on a dairy farm is very consistent since cows are typically milked twice or three times every day (very large dairies may milk continuously). An efficient way to store energy has long been sought to tie energy production and consumption together. A dairy farm’s need for both electricity and heat provides an ideal situation to generate electrical energy on-site to meet current electrical load requirements, displace conventional thermal fuels with electrical energy, and evaluate thermal storage as a solution to the time shifting of wind and solar electrical generation.

What did we do?

The dairy operation at the University of Minnesota West Central Research and Outreach Center in Morris milks between 200 and 275 cows twice daily and is representative of a mid-size Minnesota dairy farm. The cows are split almost evenly between a conventional and a certified organic grazing herd, and all cows spend the winter outside in lots near the milking parlor. The existing dairy equipment is typical for similarly sized dairy farms and includes none of the commonly recommended energy efficiency enhancements such as a plate cooler, refrigeration heat recovery, or variable frequency drives for pump motors. The WCROC dairy provides an ideal testing opportunity to evaluate and demonstrate the effect of on-site renewable energy generation and energy efficient upgrades on fossil fuel consumption and greenhouse gas emissions (Figure 1).

Heat pumps, electric water heaters, and thermal storage at the University of Minnesota Morris
Figure 1. Renewable energy upgrades that include new heat pumps, electric water heaters, and thermal storage tank at the University of Minnesota WCROC Dairy in Morris, MN.

A data logger was installed in the utility room of the milking parlor in August 2013 to monitor 18 individual electric loads, 12 water flow rates, 13 water temperatures, and two air temperatures. Average values were recorded every 10 minutes for the last 4 years. The milking parlor has gas and electric meters that measure the total consumption of natural gas and electricity within the parlor. The data helped us evaluate energy and water usage of various milking appliances. Some small energy loads were not measured in unused parts of the barn, or for equipment not directly related to the milking operation. These small and miscellaneous loads were estimated by subtracting monitored energy use from the total energy use.

Baseline measurements were collected at the WCROC dairy and overall, the milking parlor currently consumes about 250 to 400 kWh in electricity and uses between 1,300 and 1,500 gallons of water per day (Figures 2 and 3). The parlor currently uses about 110,000 kWh per year (440 kWh per cow per day) in electricity and 4,500 therms per year in natural gas. A majority of the electricity (26 percent) is used for cooling milk , with ventilation, fans and heaters  utilizing 16 percent. The dairy uses about 600 gallons of hot water per day, with a majority used for cleaning and sanitizing milking equipment (57%), followed closely by cleaning the milking parlor (27%). Energy and water usage fluctuates throughout the year; the dairy calves 40 percent of the cows from September to December and 60 percent from March to May. Therefore, water and energy use escalates dramatically during April.

The first energy efficiency upgrade was the installation of a variable frequency drive for the vacuum pump in September 2013. Prior to the upgrade, the vacuum pump used 55 to 65 kWh per day. Following installation, electrical consumption by the vacuum pump decreased by 75% to just 12 kWh per day. This data provides a vivid example of the significant energy savings that can be achieved with relatively simple upgrades.

Because the dairy operates both  organic and conventional systems, two bulk tank compressors are used: one scroll and one reciprocating. The scroll compressor is the newest and uses 15 kWh per day versus 40 kWh per day for the reciprocating compressor. Based on milk production, the scroll compressor costs $0.73 per kWh per cwt. versus $1.08 per kWh per cwt. for the reciprocating compressor, indicating that the scroll compressor is more efficient. In terms of fossil fuel consumption, milk harvesting consumed more energy than feeding and maintenance.  

Pie Chart: Electrical usage by equipment component for 2016.
Figure 2. Electrical usage by equipment component for 2016.
Pie chart: Hot water usage by activity during 2016
Figure 3. Hot water usage by activity during 2016

During the fall of 2016, a TenKSolar Reflect XTG 50 kW DC array was installed. The annual production from this solar PV system was projected to be 70,000 kWh. At a total cost of $138,000 ($2.77/W) for the solar system,  a 19.7-year simple payback without incentives was predicted. Adding the “Made in Minnesota” incentives would reduce the payback period to 8.6 years.

In 2017, two 10-kW VT10 wind turbines from Ventera were installed. These turbines are a three blade, downwind turbine model, each with an annual predicted generation of 22,400 kWh. The wind system cost was $156,800 ($78,400 per tower) with a 35-year simple payback without incentives. With the 30% federal credit, each turbine would have a 24.5-year payback.

What we have learned?

Our study suggests that fossil energy use per unit of milk could be greatly reduced by replacing older equipment with new, more efficient technology or substituting renewable sources of energy into the milk harvesting process. To improve energy efficiency, begin with an audit to gather data and identify energy-saving opportunities. Some energy efficiency options that may be installed on dairy farms include refrigeration heat recovery, variable frequency drives, plate coolers, and more efficient lighting and fans. A majority of these upgrades have immediate to two- to five-year paybacks. Make all electrical loads as efficient as possible, yet practical. Consider converting all thermal loads to electricity by the use of heat pumps that allow for cooling of milk. In the future, we have plans to harvest energy from our manure lagoon and store electricity as heat by use of heat pumps. Renewable energy options also can improve energy efficiency.

Solar panels
Figure 4. 50 kW solar array at the University of Minnesota WCROC Dairy, Morris, MN

Future Plans

We will continue to monitor the WCROC dairy and make renewable energy upgrades. We have begun monitoring the two 10-kW wind turbines, and installed a new 30-kW solar array in the WCROC pastures for renewable energy production. Additionally, we will evaluate the cow cooling potential of solar systems in the grazing dairy system at the WCROC. This study is the first step toward converting fossil fuel-based vehicles used in dairy farms to clean and locally produced energy. The knowledge and information generated will be disseminated to agricultural producers, energy professionals, students, and other stakeholders.

Authors

Brad Heins, Associate Professor, Dairy Management, hein0106@umn.edu

Mike Reese, Director of Renewable Energy

Eric Buchanan, Renewable Energy Scientist

Mickey Cotter, Renewable Energy Junior Scientist

Kirsten Sharpe, Research Assistant, Dairy Management

Additional information

We have developed a Dairy Energy Efficiency Decision Tool to help provide producers a quick way to estimate possible energy and costs savings from equipment efficiency upgrades. The tool can be used to quickly see what areas of a dairy operation may provide the best return on investment. Furthermore, we have developed a U of MN Guidebook for Optimizing Energy Systems for Midwest Dairy Production. This guidebook provides additional information about the topics that were discussed in this article, as well as the decision tool. More information may be found at https://wcroc.cfans.umn.edu/energy-dairy

Acknowledgements

To complete our goals, we have secured grants from the University of Minnesota Initiative for Renewable Energy and the Environment (IREE), the Minnesota Rapid Agricultural Response Fund, and the Xcel Energy RDF Fund.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2019. Title of presentation. Waste to Worth. Minneapolis, MN. April 22-26, 2019. URL of this page. Accessed on: today’s date.

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