Good lighting and ventilation improves human and livestock productivity, safety and building longevity. Lighting can account for 15 to 20% of energy used in diary operations. Many electric companies offer lighting and energy audits to identify cost-saving opportunities.
Lighting bulb and equipment upgrades often have a reasonable payback period through energy savings, especially when replacing old incandescent bulbs.
Lighting for increased milk production
Dairy cows are day-length sensitive. Offered 16 to 18 hours of steady lighting and 6 to 8 hours of darkness, cows will increase milk production by 5 to 16 percent. Artificial lights run with daylight sensors and timers can be very efficient. “Lighting Dairy Facilities” by Kevin Janni, Minnesota Extension Engineer describes barn lighting needs for freestall, feed bunk and other barn areas. Janni also described installation heights. (Learn more in Janni’s piece here.)
Milking parlors, equipment washing and maintenance areas, offices, maternity areas and utility rooms need strong task lighting. Animals holding, feeding sorting and observation areas need good lighting. Livestock resting areas, halls, general room lighting and security lighting can have lesser light levels.
Incandescent lamps (bulbs) are inefficient and most sizes will soon be phased out. Fluorescent tubes and compact fluorescent lights (CFLs) are significantly more efficient and available in a wide range of sizes and shapes. Fixture upgrades are often required along with fluorescent tube bulb changes (not CFLs) to reap maximum savings. Many utility companies subsidize these upgrades.
Farmers should use enclosed fixtures to protect against corrosion, dust, humidity and manure gases. This will also extend bulb life. CFLs often last ten times longer than incandescent bulbs. CFLs can be used outdoors. In cold temperatures, CFLs will not produce as much light at start up or last very long.
High intensity discharge (HID) lamps are a very bright and efficient but often require a warm-up period. HID lamps must be mounted high to spread light and minimize glare. Diffusers help distribute light. Mercury vapor lamps simulate daylight but they are the least efficient HID lamp. Their mercury gas means they need special disposal as hazardous waste. Metal halide HID lamps offer good color and are twice as efficient as a mercury vapor lamps. A new, pulse-start system extends lamp life 50%, offers more light and faster warm-up but requires a special fixture. HID bulbs last twice as long as CFLs.
High- and low-pressure sodium lamps are more efficient and offer an orange light. High-pressure sodium lamps work for outdoor and indoor lighting. Low-pressure sodium lamps are very efficient but offer poor light color. They are often used for outdoor security lighting.
Light-emitting diode (LED) lights work well in cold conditions, are very efficient and are available in a variety of light colors. Bluish lights are the most efficient. LEDs are the longest lasting of all light bulbs offering more than twice the hours of HIDs. LEDs are more expensive to purchase than most other bulbs but last significantly longer. Learn if LEDs could work for your farm here.
See a chart of lighting cost comparisons at here.
Timers, daylight sensors/photo controllers and motion detectors reduce lighting energy costs.
Good air circulation is important in dairy barns year-round for animal health, productivity and staff comfort. Animals make barns warm and humid. Ventilation systems bring in and circulate fresh cool air and exhausts dust, manure gases and odors.
Fresh air prevents heat stress, respiratory ailments, mastitis, reproductive problems and reduced milk production. Reducing mold spores and dust lowers milk contamination risks and protects farm staff health. Ventilation can extend building life by reducing moisture levels, minimizing rot, mildew and electrical problems.
Natural ventilation uses the least energy. Adjustable side and end walls on barns can be opened for natural breezes. Mechanically ventilated barns use air intake and exhaust fans on opposite sides of the building.
DIY Farm Energy Audits
Some farmers use do-it-yourself energy calculators like ATTRA’s “Farm Energy Calculators: Tools for Saving Money on the Farm” available free here.
Federal, state and nonprofit grants, loans and incentives are available implementing energy efficiency and renewable energy systems on dairy farms. Learn about state and federal incentives available to farms and small businesses, at the Database of State Incentives for Renewables and Efficiency (DSIRE). Learn about grant and loan guarantees for agriculture producers purchasing renewable energy technologies and energy efficiency improvements, see the U. S. Department of Agriculture’s Rural Development Business and Cooperative Programs website.
To learn more about dairy lighting for dairy operations, see ATTRA’s piece called “Energy Efficient Lighting for the Farm” here. To learn more about general energy efficiency in dairy operations, see ATTRA’s piece called “Dairy farm energy efficiency” here.
A similar story ran in the October 21, 2013 New England edition of "Country Folks."