According to University of Wisconsin-Extension, Wisconsin dairy farms typically spend an average of $57 to $91 per cow per year on energy, which includes electricity, natural gas, LP gas and heating oil. It's estimated that electricity accounts for about 2 percent of a dairy farm's cost of production. This translates to annual electricity use of 700-900 kilowatt-hours (kWh) per cow or 3.5 to 4.5 kWh per hundredweight of milk produced.
On most dairy farms, 70 percent of the electricity is used for milk harvesting, with bulk tanks, vacuum pumps and water heaters using the lion's share. However, you can save 20 to 50 percent by using reliable energy-efficient technology for milking, milk cooling and water heating, as well as lighting and ventilation.
A variable speed drive (VSD) adjusts the vacuum pump so that it creates no more suction pressure than is needed, and can cut your vacuum pump energy costs in half. Traditional single speed pumps operate at a constant 7 to 10 cubic feet per meter (CFM) per milking unit. But a VSD on the vacuum system can reduce this to 2 CFM per milking unit whenever possible. For more information visit our Vacuum Pump Technology section.
This technology saves money by reducing the number of hours your compressor operates, helps cool milk faster, and reduces milk agitation. Plate coolers (also known as plate heat exchangers) use well water to cool milk as it moves from the milking system to the bulk tank. On average, milk comes from a cow at 101° Fahrenheit and generally cools down to 95° F by the time it enters the bulk tank. A plate cooler speeds the cooling process so that milk reaches the tank at 55° F to 70° F, at least 25 degrees lower. Because the milk has been pre-cooled, the tank's compressors use less energy to chill the milk to the desired temperature.
Newer scroll compressor systems typically save 15 to 25 percent on electrical costs over traditional reciprocating compressors. Better still, they are quieter and more reliable than traditional reciprocating compressors. With only one moving part and no metal-to-metal contact, there are no seals to tear and no lubrication needed. Designed to wear in, not out, they improve with time and last longer. Additionally, they operate in cool Wisconsin weather, without the need of a crankcase heater. Visit our Scroll Compressors section for more information.
By installing a heat recovery system, you can use the heat from your compressor to pre-heat water. This can cut your water heating costs in half.
For 36 or 48 inch fans, look for an efficiency rating of at least 20 CFM per watt. And consider HVLS (high volume, low speed) fans for free stall facilities – they are an efficient way to move large amounts of air and make less noise than standard fans.
Use the Ventilation Systems Calculator to show how much you could save on energy costs by using energy-efficient ventilation systems.
Install T8 fluorescent lamps in a stanchion barn or pulse start metal halide lights in a free stall. Replace older incandescent light bulbs with energy-efficient compact fluorescent lamps (CFLs) and you'll instantly save up to 75 percent on lighting costs.
Photoperiod control, commonly known as long-day lighting, can increase milk production by between 5 percent and 16 percent, as long as cows receive a minimum of 15 foot-candles of light. When you have the lights on for 16 or 18 hours per day, make sure your equipment is as energy-efficient as possible.
An energy-efficient automatic livestock waterer can slash monthly electrical costs 20 percent to 80 percent. Energy-free waterers use no electricity – they rely on super insulation, self-sealing drink floats and large volumes of water to prevent freeze-up.
Energy-efficient replacements for failed equipment. When equipment fails, specify replacement motors, scroll compressors, etc., that provide you the highest energy saving benefits. For example, the initial cost of a motor is a mere fraction of what it will cost to operate that motor over its life. Don't buy inefficient equipment that you may use for the next 20 years.
As you expand your farm, you can find more energy efficiency information online by visiting wisconsinpublicservice.com. Just click the For Farms link and go to the Energy-Saving Tools & Ideas section.