Ask An Ag Consultant
(Farm News - September 2009)
Q: During today's challenging economic times, what proactive measures can I consider to help manage energy costs on my farm?
A: Energy use on dairy farms has grown gradually in the past 20 years due to increases in farm size, use of automated equipment and around-the-clock operation. Dairy farms typically consume between 800 and 1,200 kilowatt-hours (kWh) of electricity per cow annually. With energy use growing, it's wise to implement conservation measures whenever possible. Whether you have a small farm or a large commercial operation, there are steps you can take to conserve energy, lower bills and grow your bottom line.
No - And Low-Cost Solutions
If you're not using it, turn it off. Lighting and equipment that runs unnecessarily costs you money. Every 1,000 kWh of electricity you save by turning things off translates to $100 in energy savings (assuming an average electric cost of $0.10/kWh). If you don't want to think about turning equipment on and off, consider installing timers or motion sensors to do the work for you.
Turning down equipment also can save energy.
- Keep refrigeration units set at appropriate temperatures but not cooler than needed.
- Reduce the pressure on your compressors to a level that meets your needs. If you can drop the set point 20 pounds per square inch, you can cut compressor energy costs by 10%.
- Keep your water heater set at the required level for the work you need to do but not any higher. Turning it down by 10 degrees can lower water-heating costs up to 5%.
Larger farms charged for electric consumption and demand can yield significant savings by managing energy use during peak times. The demand component is the peak power, in kilowatts (kW), drawn by the farm during each month or during the previous 11 months. Demand charges can account for a major portion of an electric bill, so it's a good idea to reduce peak demand whenever possible. During peak time periods, especially during milking times, be aware of what equipment is running. If you have large motors that do not need to run at the same time, turn them off.
Well-maintained equipment operates more efficiently and often lasts longer. Consider these ideas:
- Clean heat exchanger coils quarterly to cut milk-cooling costs up to 5%.
- Clean fans as needed. Dirty fans and shutters can decrease ventilation efficiency up to 40%.
- Keep lights free of dirt and debris. Wipe off fixtures and bulbs so they perform as they should and provide acceptable light.
- Check pumps regularly. They should be cleaned and maintained periodically to keep them operating optimally.
Longer-Term Tips
Consider more extensive efforts to significantly improve energy efficiency at your farm without impeding speed or reliability.
Refrigeration
- Use scroll compressors to cut your energy costs up to 20% compared to traditional reciprocating compressors. Scroll compressors also are quieter.
- Use well water heat exchangers to pre-cool milk before it enters your refrigerated milk tank. This can save up to 60% in energy costs.
Ventilation
Ventilation is critical in barns because cows can get heat stress, which interferes with milk production, when temperatures reach 74 degrees with a 75% humidity level.
- Install controls and programmable thermostats to keep your barn at the proper temperature and turn fans down or off when they are not needed.
Lighting
- Replace incandescent bulbs with compact fluorescent lamps (CFLs). CFLs can cut energy use up to 75% with savings up to $20 per lamp annually.
- Convert from T12 to T8 fluorescent lamps to cut energy usage by 20%.
- Replace probe-start metal halide lamps with pulse-start metal halide lamps to reduce energy use by at least 10%.
Water Heating
- Purchase a heat-recovery system that takes heat energy from your refrigeration condenser and uses it to heat water. You can meet up to 50% of your water heating requirements with this type of system.
Pumping
- Purchase vacuum pumps that are sized appropriately for your needs. Oversized pumps increase energy consumption and your bills.
- Consider variable speed drives to operate your pumps at the lowest possible speed needed to perform a required task.
Engine Block Heaters
Some farmers keep engine block heaters plugged in overnight or 24/7. This is not necessary — and it wastes energy. Generally, a tractor only needs to be plugged in 2 to 3 hours prior to start up. At $0.10/kWh, plugging in that 1,500-watt block heater for 3 hours per day costs about $13.60 in monthly electric costs compared to $45 if that heater is plugged in for 10 hours per day. This same heater plugged in 24/7 would cost $108 per month to operate. Purchasing a timer for your engine block heater is a worthwhile investment which can be paid back with energy savings in just one month.
For More Information
To better understand which measures offer the greatest potential for energy savings on your farm, consider a free energy audit from Focus on Energy. Call 800-762-7077 or visit www.focusonenergy.com.
If you have additional questions about saving energy on your dairy farm, contact your WPS agricultural consultant or the Business Solutions Center at 877-444-0888.