Optimizing Renewable Electric Energy Generation on Minnesota Dairy Farms
Agriculture uses immense amounts of fossil energy to support food, feed, fiber, and energy production in the United States. Agriculture’s dependence on fossil-based energy has both severe economic and environmental risks that can be addressed through energy conservation practices and renewable energy generation. This project seeks to increase renewable electric energy generation on Minnesota dairy farms by establishing a model “net-zero” energy dairy parlor.
The three-year project titled “Optimizing Renewable Electric Energy Generation on Minnesota Dairy Farms” builds off previous research in which energy efficiency improvements and clean energy systems have and are being installed within the WCROC dairy. Past research has been geared towards auditing energy consumption, installing and testing energy efficient milking systems, and developing thermal energy production and storage. (Read more on our past projects here.) This new project seeks to increase renewable electric energy generation on Minnesota dairy farms by establishing a model “net-zero” energy dairy parlor where the same amount of energy consumed is also produced on-site.
The WCROC dairy parlor project involves a detailed evaluation of how energy is used in the milking parlor and the redesign of those energy processes for optimum energy efficiency.
One principle used to optimize efficiency in the dairy systems is to make the best use of already available resources, namely heat in freshly harvested milk, the sun, and in the manure lagoon. Since heat is not always available when it is needed, a way to store thermal energy is also needed. Further efficiency can be gained by converting thermal appliances from models that burn fuel to electric models. Most electric appliances are at least 90% efficient while gas models are typically around 60% efficient. The conversion to electric appliances will improve energy efficiency, but may not improve economic efficiency depending on the relative price of electricity and the replaced fuel. However, another benefit of electrifying thermal loads is renewable electric energy systems can be added to provide enough energy to make the milking parlor “Net-Zero”.
Another principle guiding the design of the new dairy energy systems is to use heat pumps where possible. Heat pumps have a Coefficient of Performance (COP) of around 2.5 meaning that for every unit of electricity used 2.5 units of heat can be moved. This compares to a traditional heat generating appliance that can never exceed a COP of 1.0 because it can never create more heat than is in the fuel being burned. Heat pumps merely move heat from one place to another.
Finally, renewable electric generation systems can be used to provide electricity for newly optimized energy systems making the milking parlor “Net Zero” by producing as much energy on site as is used. Energy auditing and analysis determined that 20 kW of wind power and 54 kW of solar PV power would result in a net zero dairy parlor at the WCROC.
Project goals include increasing the market penetration of renewable electric energy resources on Minnesota dairy farms by developing an optimized and integrated on-site electrical generation system to model what a “Net Zero” dairy parlor looks like, and to support Minnesota companies through field testing and validation of their commercial renewable electric generation systems and components. Another goal is to reduce the carbon footprint and increase the long-term profitability of Minnesota dairy farms through on-site renewable electrical generation.
The project is scheduled to run through June 1, 2018.
Project funding provided by customers of Xcel Energy through a grant from the Renewable Development Fund.
- AKF (engineering design firm)
- Daikin Applied (equipment, controls, and installation)
- Wehking Electric
- Mohr Plumbing
- Diamond Energy Systems (pipe insulation)
- Custom Fabrication & Repair, Inc. (thermal storage tank)
- American Resource & Energy (small wind towers)
- Ventera (wind turbines)
- Cedar Creek Energy (solar contractor)
- Electronic Guidebook Optimizing Energy Systems for Midwest Dairy Production
- Decision spreadsheet tool (marco-enabled excel file)
- Net-Zero Dairy Milking Parlor: Making Milk Green with Renewable Energy
- Powering Minnesota Dairy Farms with Renewable Energy (presentation) and Energy Analysis (paper)
- Economic Analysis of Energy Efficiency (presentation) and (paper)
- Optimizing Energy Production and Use for a Net-Zero Energy Dairy
- WCROC Dairy Baseline Energy Audit
- Milestone 9-11 Report, July 2020
- Milestone 7 & 8 Report, May 2020
- Milestone 6 Report, January 2020
- Milestone 5 Report, August 2019
- Milestone 4 Report, December 2017
- Milestone 3 Report, March 2017
- Milestone 2 Report, October 2016
- Milestone 1 Report, April 2016
- Predicted Performance of Planned Renewable Energy Systems
- Project Accouncement from Michael Reese, Renewable Energy Director