On June 15th-16th 2022 The West Central Research and Outreach Center hosted the 2022 Midwest Farm Energy Conference. The two-day event drew speakers and attendees from around the region to discuss two broad trends in renewable farm energy; Green Ammonia, and Agrovoltaics and Farm Electrification.
The first day covered the use of Green Ammonia on farms. Green does not refer to the actual color of the product but rather the means in which the product was produced. In the case of green ammonia, it is produced using solar or wind energy. Speakers on the first day covered a range of uses for this green ammonia. The most direct use for the ammonia is its use as a fertilizer. Specifically, the nitrogen in the ammonia enriches the soil. In 2022 roughly 80% of all ammonia produced in the world is used for fertilization, the vast majority of which is produced using fossil fuels. Thus, green ammonia production offers a clear way to help decarbonize the fertilizer industry. Additionally, presenters emphasized the economic opportunity that exists for this kind of production; the state of Minnesota alone imports over 1.6 million tons of nitrogen based fertilizers each year. At a current price of $1200 per ton, the economic benefit of producing this resource locally using renewable energy is immense.
Speakers from the WCROC and the University of Minnesota’s Small Engine Lab also presented the use of green ammonia as an additive or replacement for farm fuel and diesel. To demonstrate this idea, the team converted an old John Deer tractor to partially run on green ammonia. The ammonia was mixed into the diesel before being combusted in the engine. The tractor experiment proved to be a successful demonstration of the feasibility of using anhydrous ammonia as a fuel source. Additionally, research from UMN’s Small Engine Lab showed that anhydrous ammonia can be combusted by itself if a portion of the ammonia is “cracked,” allowing the freed hydrogen atoms to kick start the combustion reaction.
Matt Palys, a post-doctoral chemical engineering researcher spoke on the Techno-Economic Profile of Renewable Ammonia for Sustainable Agriculture and Energy Production. The first issue that Palys tackled was that of energy production and storages specific to agriculture. Ammonia can be used as a cost effective and carbon free method of storing energy long term. Energy can be stored in the bonds of the anhydrous ammonia. Then, when the energy is needed, the ammonia can be burned in a turbine, similar to natural gas-based energy production. The main emissions from this reaction are water and dinitrogen gas. Additionally, the hydrogen can be cracked off of the ammonia and used as a separate fuel source. Palys argues that this form of energy storage and later released can be used to help “shave down” the extreme energy demand peaks that often times occur in agricultural regions. An example of this is grain drying in the fall. Although grain drying may only occur for one week out of the year, its electrical demand and load can be equal to that of a small city. This additional load makes it difficult for both farmers and electric utilities to decarbonize their energy mix as renewable energy can be intermittent and unreliable. One way to counteract and to help minimize these demand peaks would be to use stored renewable energy in the form of ammonia. The ammonia can be used by the electric utility to produce energy for the grid or by farmers as an alternative fuel source directly in their operations.
The second day commenced with presentations on Agrovoltaics and Farm Electrification. Agrovoltaics refers to the combination of Photo-Voltaic Solar Energy production with different agricultural cash crops and livestock production.
The easiest livestock to raise alongside standard height ground-mounted arrays are sheep, which graze the grasses and other plants. They also utilize the shade provided by the solar to keep cool during the hottest periods of the day. Speakers noted other animals that have been raised under solar panels. Goats, while initially a good idea, proved to be solar production’s worst enemy. Goats are curious by nature, and when they began mounting the solar arrays, walking on top of the arrays and chewing at exposed wiring, researchers realized they are not the best candidate to be raised alongside solar energy production.
Although it is not yet a common practice, speakers also covered raising cattle under solar arrays. The Farm at WCROC is one of the first locations to pilot this livestock production method. One of the main reasons that raising cattle under solar is not more common is that it requires a custom ground mount that lifts the leading edge of the panels to 10 ft off of the ground. This is to ensure that the cattle can’t directly reach the panels. Speakers also covered the benefits of incorporating pollinator habitat alongside solar installations. Pollinator habitat is now more important than ever before, and its importance to agriculture in general is immense. Presenters said that if pollinator habitat was expanded to every solar installation in the state of MN, over 800,000 acres of farmland will see benefits. These benefits include a fourfold increase in beneficial species and pollinator species. It was also noted that raising animals under solar or creating pollinator habitat alongside solar production helps to soften the image of grid scale solar production plants. One of the biggest barriers to the installation of grid scale solar production plants is that it forever limits the productivity of the land. By combining pollinator habitat and local honey production with these solar installations, it changes the public image of solar and changes, its perception from an industrial energy generation facility to an innovative and synergistic method of energy and food production.
Eric Buchannan, a farm energy researcher for WCROC, presented on different methods of electrifying farm production. He underscored the importance of decarbonizing agricultural operations. In 2018, the Intergovernmental Panel on Climate Change released a report that said we must reduce our CO2 emissions by half by 2030 if we are to avoid the direst effects of climate change. Buchannan says that this type of reduction will be impossible to accomplish without decarbonizing agricultural production, especially in the United States. He also notes that energy costs can makeup up to 16% of overall input costs for farmers. About 75% of the energy used on farms comes from the use of Diesel, Gasoline, Liquefied Natural Gas, Propane. Diesel and Gasoline are used to power tractors, farming implements, and farm vehicles. These fossil fueled processes can be offset through a several different methods, primarily the electrification of these assets. However, the current electrical farm vehicle market is still being developed. Another option is the use of Bio-Fuels in these vehicles, or use of other alternative fuels like the anhydrous ammonia powered tractor mentioned earlier. LNG and LP are mainly used for heating and other thermal load needs. Buchannan says that these sources of hydrocarbons can be replaced by using heat pumps, which is a device which can transfer thermal energy between two sinks. The most common types of heat pumps are air source and ground source heat pumps, where excess heat is removed from one area and dumped either into the atmosphere or into the ground to cool a given space. Conversely, heat can be pulled from outside air or from the ground and used to heat a given space. Buchannan has begun looking for other sources of heat that can be used to electrify thermal loads in agriculture. One example of this is the Dairy Parlor at the WCROC. In the parlor, a heat pump is used to pull heat from fresh milk. This process helps to cool the milk from over 100 degrees F to its 41 degrees F storage temperature. The heat is transferred into water and is stored in an highly insulated tank. This hot water can then be used to pre heat water used for cleaning the parlor. Buchannan has also researched using a heat pump to pull excess heat from mother sows and transferring it directly to the baby piglets.
The second half of the second day began with an electrical vehicle showcase. Ottertail Power Company showed off their 2021 Ford Mustang Mach-E, a fully electric cross-over SUV based off of Ford’s Mustang line, that gets around 250 miles of range on a single charge. The Agralite Electric Cooperative brought a 2021 Nissan Leaf to show off. The Leaf line of vehicles was one of the first mass produced and purchased EV’s in the US. Their 2021 model features 235 miles of range on a single charge. Finally, the main event at this showcase was the Runestone Electric Cooperative’s brand new 2022 Ford F-150 Lightning, a fully electric full-sized pickup truck. The new Lightning has been an elusive sight, as supply chain shortages and COVID related delays have bogged down the release. As one of the first full size electric pickup trucks, it has an EPA estimated range of over 250 miles with 1,000 pounds of cargo in the bed. It also boasts a generous starting price of just under $45k, which makes it even more appealing as a cost effective electric replacement for vehicles with IC engines. One of Morris’ electric school busses was also at the showcase and aided in moving conference guests.
After lunch, the conference was wrapped up with a short tour of the renewable energy projects on the farm at the WCROC. Conference guests loaded onto the electric school bus and we headed to our first point of interest. One of the other projects that is being explored at the WCROC is the use of autonomous ‘robots’ that can complete common farm tasks. One of these robots is an lawn mower that can be used to manage grazing land. The mower is a riding Toro flail mower with an electric motor conversion to run off of a battery. The top of the mower is equipped with two GPS monitors that can track the mower placement, direction, and speed within the mowing area. On the front of the mower, a LiDAR scanner uses infrared lights and sensors to make sure that the mowing path is clear of obstacles. Finally, the front and back of the mower are equipped with bumpers that are wired to power off the unit if anything comes into contact with them. In one case, the mower was able to be powered off by a particularly large thistle. The next stop on the tour was the 240 kW solar array by the Water Treatment Plant. This array is the one that has been raised 10 feet off of the ground to allow for the grazing of cattle underneath. The final stop on our tour was at the anhydrous ammonia production plant. The plant utilizes wind energy produced by the two 1.68 MW wind turbines on site. This energy is used to power an electrolyzer which runs an electric current through water to produce H2 and O2. The H2 is stored and the O2 is vented off into the atmosphere. N2 is collected from the atmosphere (on average our atmosphere is 78% nitrogen) using a pressure swing absorption method. Then the stored hydrogen and nitrogen are combined using the Haber Bosch process. The Haber Bosch Process is an industrial chemical reaction between nitrogen and hydrogen under high pressure and temperature to produce ammonia. It is often credited as one of the innovations that has helped global population growth by allowing us to grow more food on less land. Once the ammonia has been produced it is stored on site in a storage tank. When the idea to install an ammonia plant was first proposed, the WCROC operated as a standard farm. However, once the ammonia plant was finished the farm had begun the process of becoming an organic dairy operation. Organic agriculture in Minnesota doesn’t use anhydrous ammonia, so most of the ammonia produced is sold to Morris’ local Ag Co-Op and is then used to fertilize fields across the county.
Overall the conference was a resounding success. Attendees learned from presenters on several different topics including green ammonia production, renewable energy production and storage for agricultural applications, lessons learned from combining agriculture and solar PV energy production, and so much more.
Special Thanks to Mike Reece, Eric Buchannan, and Esther Jordan who made this conference possible.