Monitoring Farm Energy Use
Over the last 7 years, the West Central Research and Outreach Center (WCROC) has been increasing energy monitoring activities on our research farm and partnering with local farms to examine energy use in commercial dairy and swine facilities. To do this, we began adding electrical monitoring equipment, documenting fuel use, and reviewing natural gas and electricity billing. Our goal is to determine where the most energy is used on farms and where energy savings could be found. We also wanted to understand how energy produced on-site from our solar and wind production systems matches up with our energy usage.
As part of this process, we gained a lot of experience with the equipment and options for monitoring energy use on farms. This information is becoming more valuable as farmers consider how to can squeeze more energy savings from their operations. As an example, we discovered that a single electric milk house heater in our dairy parlor utility room was costing over $100 dollars per month in electricity during the winter. The graph below shows the energy use data from the dairy parlor at the WCROC. The graph shows averaged 15 minute power use from July 2019. The two peaks (around 1:00 pm and around 11:00 pm) tell us that milk cooling and equipment cleaning after the morning and evening milking is responsible for the highest energy use.
For farmers interested in examining energy use, there are several options that might suit their needs. These can range from simply looking over energy bills to installing very accurate, instantaneous, internet-enabled, monitoring equipment on all farm machinery, including tractors. In addition, there are specialists who conduct farm energy audits to identify areas where savings can be found.
Although reviewing energy bills gives only a rough overview of energy use on the farm, it can still provide valuable information on the overall patterns of energy use. This simple approach can also help when deciding whether or not to purchase new, energy-efficient equipment that may save energy but has a high up-front cost. A new tool that some electrical utilities and cooperatives provide is a web page for each customer’s account that typically shows 15 minute, 1 hour, or 1 day energy use data. This is becoming more common as electrical providers upgrade residential and commercial meters to ‘smart’ meters that can send data to the utility wirelessly or over the powerline.
There are also several readily available electrical monitoring products that can be attached around electricity lines at the main power panel which provide capabilities similar to the utilities’ websites, but display power use in real time. This technology often has a dedicated in-home energy display screen or pairs with a smartphone to show energy use. A simple system that will log and display total electricity usage or up to four individual circuits can be purchased for less than $200. Real-time, whole farm monitoring is good for identifying electricity loads that only operate at certain times of the day or year, such as milking equipment or a grain drier, but this approach may not be able to identify which pieces of machinery are using the most electricity.
At the WCROC, we wanted to measure many different electrical circuits or pieces of equipment individually. We initially used specialized research-grade equipment that was complex and required training to use. Now, accurate, easy-to-use equipment is available to consumers that can track up to thirty different electrical loads. This equipment consists of an internet connected data logger mounted next to an electrical panel and individual electric current sensors that snap around electrical wires. Although no wires need to be disconnected to install the monitoring gear, an electrician should be consulted because the circuit panel cover needs to be removed. A monitoring set up like this typically costs between $600 and $1600 depending on how many circuits are monitored. This monitoring gear has allowed us to measure where our farm is using the most electricity and which activities or farming equipment we should consider changing to reduce energy use.
Using similar equipment on commercial farms, we have been able to detect electrical equipment problems that were unnecessarily costing farmers money. In a couple of cases, temperature regulated block heaters for backup generators began to continually run and increased energy use. At one farm, this cost roughly $450 per month during the summer. Another farm had feed augers that were jamming and causing random spikes in energy use. Once identified, these issues were easily fixed.
Tractor fuel use is another important consideration in many farming operations. Tractor fuel use for the same operation can vary depending on gear selection, engine rpm, and tractor size. A number of extension publications are available that describe how to optimize fuel use. However, it is important to know how much fuel is being used to gauge your potential fuel savings. Although newer tractors are beginning to include equipment to track fuel use as part of their in-cab display, this feature is not yet widespread. A simple option that we used was filling the tractor before and after each field work operation at a recently calibrated fuel pump and recording the fuel used. Using this information with the number of acres the tractor covered, we were able to calculate fuel use for many of our common field activities.
A final area of energy use is propane or natural gas. Unfortunately, tracking heating fuel consumption can be difficult depending on the use and type of fuel. In our case, we had a handful of natural gas meters that monitored different buildings of our dairy, swine, and cropping operations. Utility bills for these meters gave us a reasonably accurate indication of energy use, but some estimates had to be made where natural gas heated both water and the air in our buildings. Propane use can be tricky to monitor if a tank is filled only a few times per year and it supplies heating energy to different buildings or parts of a farm. One area where propane use can be more easily measured is for drying grain. Energy use for grain drying is very high and generally spans a very short period, but knowing the amount of fuel used is important to compare the costs of on-farm drying versus other options.
The cost of purchasing energy is currently the major reason why farmers are interested in their energy use. However, energy consumption data can help farmers as they begin to think about producing their own energy. With decreasing costs of solar energy production equipment and continued advancements in anaerobic digestion of manures, farmers are in a good place to consider how renewable energy could become part of their energy and cost saving strategies. Improving energy efficiency is also important as consumers increase demand for sustainably produced foods. The key to meeting these goals is understanding energy use in farming operations, and the key to understanding energy use is enhanced by monitoring. If you would like more information, contact the renewable energy staff at the WCROC by calling (320) 589-1711 or by visiting us online.