Energy-Efficient Lighting for the Farm

The National Sustainable Agriculture Information Service, ATTRA (www.attra.ncat.org), was developed and is managed by the National Center for Appropriate Technology (NCAT). The project is funded through a cooperative agreement with the United States Department of Agriculture’s Rural Business-Cooperative Service. Visit the NCAT website (www.ncat.org/sarc_current.php) for more information on our other sustainable agriculture and energy projects.

Funding for the developmentof this publication was providedby the USDA Risk ManagementAgency.

1-800-346-9140 • www.attra.ncat.orgA project of the National Center for Appropriate Technology

By Leif Kindberg

NCAT Farm Energy

Specialist

© 2010 NCAT

Contents

Energy-Ef f icient Lighting for the Farm

Energy-effi cient lighting options present farmers with new opportunities to reduce electricity costs and

help manage farms sustainably. Cost-eff ective energy-effi cient lighting can be used to improve produc-

tivity and safety, and reduce operating costs. This publication provides an overview of energy-effi cient

lighting technology and explains how to select lighting options that are appropriate for the farm.

Introduction

Lighting is an essential part of most farms. Even so, most farms do not use it as an opportunity to reduce energy costs. Energy-effi cient lighting may off er inexpensive opportunities for farms to reduce energy costs and improve productivity.

Energy-effi cient lighting technologies are avail-able in many sizes and types, including linear fl uorescent lamps, compact fl uorescent lamps (CFL), induction lighting, pulse-start metal halide lamps, high- and low-pressure sodium vapor lamps, light-emitting diodes (LED), daylighting tubes, and skylights. Th ese long-life technologies can reduce costs in two ways: lower fi xed costs through fewer replacements and lower operating costs through lower energy consumption. Electronic ballasts, lighting controls, and proper refl ectors further improve the effi ciency, quantity, and quality of light used on the farm.

Th is publication will introduce you to energy-effi cient lighting technologies, and terms used by the lighting industry, and help you select options that meet your farm’s lighting requirements. Th e term lamp is interchanged with the term light bulb throughout this publication.

Light QuantityMeasuring the light level (also thought of as bright-ness or quantity of light) is helpful to determine the type of lamp you need. Light output is mea-sured in diff erent ways. It might be measured in the units of light leaving the lamp (lumens), or it might be measured by the amount of light falling on a surface (foot-candles). Foot-candles are the common method of measuring light quantity in agricultural operations.

Th e foot-candle (fc) is the light level at the work-ing surface and is defi ned as the amount of illu-mination from a candle falling on a surface at a distance of one foot. Outside on a bright

Ef f icient lighting can help reduce farm energy costs. Photo by Andy Pressman.

Introduction ......................1

Light Quantity ..................1

Light Quality .....................2

Focus on Effi ciency .........3

Fixtures ...............................4

Ballasts ................................4

Lamps ..................................4

Daylighting ........................7

Energy Conserving Controls...............................7

Lighting Greenhouses .....................7

Lighting for Alternative Poultry Production .........................8

Dairy Lighting ...................9

Lighting Disposal ............9

Summary ............................9

References .......................11

Resources .........................11

ATTRA Energy-Ef f icient Lighting for the Farm

Light quality is generally measured by color temperature and color rendering index (CRI).

Color temperature (also called correlated color temperature, CCT) is measured in degrees Kelvin (K). A higher color temperature num-ber indicates that a lamp will emit a more blue or cooler light, and a lower color temperature number indicates that a lamp will emit a more orange/red or warmer light. Th is is sometimes confusing, but just remember that a higher color temperature is more like sunlight. Most man-ufacturers provide a color description on the packaging such as “warm white” or “cool blue.” A cool, white light might have a color temper-ature of 3,500 degrees Kelvin or above, and a warm, yellow lamp might have a color tempera-ture of less than 3000 degrees Kelvin.

Color rendering index (CRI) is a measurement of how a light source will reproduce colors of vari-ous objects in comparison with sunlight. Some tasks on the farm, such as produce sorting, require light that makes colors appear as they would in sunlight. Be aware that CRI is mea-sured at any given lamp’s color temperature and is therefore more diffi cult to use as a comparison between lamps with diff erent color temperatures. CRI is measured on a scale of 0 to 100. Th e larger the CRI value, the closer the lamp renders a color the same as sunlight. A value of 0 means that col-ors all look the same under the lamp.

Although lamp output or quantity of light is important, light quality characteristics like color temperature and CRI also aff ect your per-ception of light quantity and comfort. Both of these characteristics should be considered when replacing a lamp.

sunny day in midsummer, the light level will be around 8,000 fc. Inside, a brightly lit desk-top surface will be about 100 fc. A dimly lit street at night may be at one fc or less. Th is is what light meters measure, and it is equivalent to one lumen per square foot.

Lumen fl ux is the quantity of light that leaves the lamp, and is measured in lumens (lm). All lamps are rated in lumens and may be rated in both initial and mean lumens. Th e mean lumens of a lamp provide the average rated output over the lamp’s rated life. Th e initial and mean lumens may be used to compare one lamp with another. Th e lumen output of a lamp is printed on the package of most lamps and will be discussed further.

Th e light loss factor (LLF) is the measure of a lamp’s lumen output near the end of its use-ful life in comparison to the lumen output pro-vided by the manufacturer. Lamps decrease in output because lamp and ballast components degrade over time due to normal operation and environmental factors such as dust buildup. LLF may be measured and presented in many ways. It is important to remember that lamps may need to be selected for a higher-than-needed light level or replaced before they burn out to take into account light loss as the lamp and its components age.

Average rated life, usually determined under lab-oratory conditions, is the point at which some percentage of the initially installed lamps have burned out. Th e operating conditions that aff ect the average rated life lamp include ambient tem-perature, humidity, dust, power surges, and switching the lamp on and off . Light output and light quality (discussed next) change over time for almost all lamps. Th erefore, considerations such as color shifting, lumen depreciation, and loss in luminous effi cacy (an industry term for effi ciency) may reduce average rated life and should be taken into account.

Light QualityUnderstanding light quality (also thought of as brightness or light color) is important for farms that are using light to manage the photo-period and activity of livestock. A balance among ani-mal health, comfort, and productivity should be considered. (ATTRA off ers a variety of publica-tions on sustainable livestock production. Visit www.attra.ncat.org for more information.)

Related ATTRA publications

Farm Energy

Calculators:

Tools for Saving

Money on the Farm

Effi cient Agricultural

Buildings:

An Overview

Solar Greenhouses

Comparing

Energy Use in

Conventional and

Organic Cropping

Systems

Poultry House

Management for

Alternative Production

Dairy Farm Energy

Effi ciency

Color temperature is a scale of color

(not brightness) rated in Kelvin.

12000K

7000K

4000K

3000K

2000K

6

5500K Midday

5000 - 6500K Natural or Daylight

4100K Moonlight

3500 - 4100K Cool White, Bright White

2700 - 3000K Warm White, Soft White

1850 - 2000K Candlelight

6500 - 7500K Overcast Sky

ATTRAwww.attra.ncat.org

or less in applications where the lights are oper-ated eight hours a day or more. (ASABE, 2005)

Determining lamp efficiency can be accom-plished in a several ways. To determine the luminous effi cacy (lumens per watt), look at the package and divide the number of lumens by the wattage. For example, a 23-watt (W) com-pact fl uorescent lamp produces about 70 lumens per watt (70 lm/W) for a total of about 1,600 lumens, where watts is the rate of electric power required to operate at peak output. For compari-son, a 100-watt incandescent light lamp might produce only 10 lumens per watt, making it sig-nifi cantly less effi cient in comparison to a com-pact fl uorescent lamp. Another quick way of choosing an effi cient lamp is to fi nd lamps with the light output (lumens) you need, and then choose the lamp that uses the fewest watts.

Focus on Ef f iciencyEnergy effi ciency in lighting is referred to as effi -cacy and is measured in lumens per watt (lm/w). Effi cacy is somewhat like measuring miles per gallon. Th e more lumens you can get from a watt of power, the more effi cient the lamp and the more you will likely save on your electricity bill. Effi cacy is the ratio of light output from a lamp to the electricity it uses.

There are two major cost-efficiency consid-erations: the cost of operating the lamp and the cost of replacing the lamp. In most cases, replacing an existing lamp with one which has a higher luminous effi cacy and longer average rated life will reduce operating costs and may also reduce replacement costs. Energy-effi cient lighting will typically pay for itself in two years

Compare the energy cost savings of diff erent lamps by determining the amount of energy the lighting system will consume. Con-

sider the example of operating 10 CFL vs. 10 incandescent lamps for 7 days/week, 14 hours/day, and for 40 weeks per year. To

determine the energy consumption of this or any lighting system, multiply input wattage (W) by time (hours of operation during

a year). To help choose which lamps to install, calculate the annual operating costs.

Adjust the operating hours or lamp wattage so this example matches your lighting needs.

Table 1: Energy cost comparison

Other lighting considerations not included in this example may be relevant to your application. Developed from manufacturer literature and pricing.

Type of Lamp CFL Type of Lamp Incandescent

Input Wattage 24 W Input Wattage 100 W

Lumen Output 1,380 lm Lumen Output 1,026 lm

Effi cacy 57.5 LPW 1,380 lm ÷ 24 W Effi cacy 10.26 LPW 1,026 lm ÷ 100 W

Operating Hours 3,920 h7 days/week x 14 hours/

day x 40 weeks/yearOperating Hours 3,920 h

7 days/week x 14 hours/day

x 40 weeks/year

Energy Use 94,080 Wh 24W x 3,920 hrs/year Energy Use 392,000 Wh 100W x 3,920 hrs/year

Energy Use 94.08 kWh

94,080 watt-hours

(Wh) ÷ 1,000 = 94.08

kilowatt-hours (kWh)

Energy Use 392 kWh

392,000 watt-hours

(Wh) ÷ 1,000 = 392

kilowatt-hours (kWh)

Utility Charge/

kWh$0.0928

Utility Charge/

kWh$0.0928

Energy Cost/Year $8.7394.08kWh x $0.0928/

kWhEnergy Cost/Year $36.38 392kWh x $0.0928/kWh

Lamp Cost $3.95 Lamp Cost $0.48

Annual Operating

Costs$87.30 # of lamps x $8.73

Annual Operating

Costs$363.80 # of lamps x $36.38


lamp, a rated wattage diff erent from that listed with the lamp should be considered. Th is new rated wattage will be published by the ballast manufacturer. In general, ballasts for fl uores-cent lamps are either magnetic or electronic. Electronic ballasts are more effi cient and now considered to be the industry standard.

LampsEnergy-effi cient lamps are available in many dif-ferent shapes and sizes, with a broad selection of light color temperatures, lumen outputs, and color rendering qualities. Lamp replacement is generally “do-it-yourself” on the farm, but bal-last and fi xture replacement requires experience with AC electrical.

IncandescentIncandescent lamps are the least expensive and most commonly available lamps. Incandes-cent lamps create light by resistance to the fl ow of electricity through fi nely coiled wires that become hot enough to glow. However, they are also the least effi cient. About 90 percent of the energy used by an incandescent lamp becomes heat, and only 10 percent becomes light. (Hiatt, 2008) Incandescent lamps generally have a very short average-rated life. Th eir short life and poor use of energy make them ineffi cient and some-times costly to operate.

Tungsten-halogenTungsten-halogen (or just halogen) lamps are a type of high-pressure incandescent lamp that is more energy-effi cient than a regular incandes-cent lamp. Halogen lamps operate at very high temperatures and use less energy by recycling heat to keep the fi lament hot with less elec-tricity. Halogen lamps can be used with many dimmers and do not take any time to warm up. (ASABE, 2005) Read the instructions carefully before handling halogen lamps.

Compact Fluorescent (CFL)CFLs last up to 10 times longer and may use 75 percent less energy than the common incandescent lamp. (U.S. Department of Energy, 2006) CFLs may have a single spiral tube, multiple tubes, or tubes covered to look similar to an incandescent light. Regular CFLs have a hot cathode (electrode) made of tungsten wire that is coated with barium carbonate. Th e cathode emits electrons that pass

FixturesFixtures generally consist of a frame, lamp sock-ets, and lamp(s) but may also include a ballast, refl ector, diff user, or other hardware. Lamp fi x-tures are very important to the quantity and quality of light provided as well as effi ciency and safety. Th e number and placement of fi xtures should be carefully matched to the application for the best effi ciency. Fewer fi xtures with higher wattage lamps will produce greater variation in light. More fi xtures with lower wattage lamps will provide greater uniformity in the light.

Refl ectors and refl ector geometry help trap less light in the fi xture and push more light out of the fi xture, improving light quantity. A lamp fixture with a ref lector, for example, directs more of the light to the area where it is required, and in some cases allows lower wattage lamps to be used. It is not uncommon in the typical yard light for 30 percent of light to be wasted due to ineffi cient fi xtures that may let light go up or out from the lamp. (Sanford, 2004a) Similarly, diff users can be used on many types of lamps to distribute light horizontally.

Agricultural fi xtures should be resistant to cor-rosion, moisture, and dust. For a lamp in a wet location, a sealed polycarbonate or other gas-keted and weatherproof enclosure should be installed. Th e enclosure should be approved for use with the lamp, especially CFL lamps, to pre-vent fi re hazards and premature lamp failure.

BallastsTh e purpose of a ballast is to provide the voltage necessary to initiate lighting in gas-discharge and some other lamps. Lamps that require a bal-last for start-up include high- and low-pressure sodium, fl uorescent, induction, mercury-vapor, and metal halide lamps.

Ballasts function by heating electrodes with low voltage or in some cases supplying very high voltage to start the lamp. Once the lamp is started, the ballast controls the voltage to the lamp to sustain the light discharge. Because ballasts increase or decrease the voltage to the

You may wish to use the Natural Resources

Conservation Service (NRCS) Energy Self

Assessment tool http://ruralenergy.wisc.edu/

conservation/default.aspx for lighting to help

you choose energy-effi cient lighting.


and ballast, the T-8 fl uorescent lamp provides about 15 percent more lumens per watt, and the ballasts are 40 percent more effi cient. (Sanford, 2004) Both T-8 and T-12 lamps can be used in sealed fi xtures needed in most farm applica-tions. Most magnetic ballasts used with T-12 lamps will no longer be manufactured after July 1, 2010. Th ey can be replaced with higher effi -ciency electronic ballasts or with more effi cient fi xtures and lamps like the T-8.

High-output versions of linear fl uorescent lamps will start in temperatures as low as -20 degrees Fahrenheit but are less effi cient than regular lin-ear fl uorescent lamps. Th ese lamps use a double recessed contact instead of the traditional bi-pin or single pin contact used with standard fi xtures. High-output lamps use a special ballast as well. Ambient temperatures aff ect fl uorescent lamps. Th e minimum starting temperature for standard fl uorescent lamps is 50 F. (ASABE, 2005) High output lamps are generally not required unless the lamp will experience recurring starting tem-peratures of 50 degrees Fahrenheit or below.

Although T-5 lamps are even more effi cient than T-12 and T-8 lamps, they also produce more heat than larger-diameter lamps and cannot be used in sealed fi xtures. Sealed and weatherproof fi xtures are necessary in many areas with live-stock, moisture, or dust. For these reasons, T-5 lamps are generally not recommended for agri-cultural applications.

Lamps and ballasts should be upgraded together. Fixtures that are the same length can be con-verted from a T-12 lamp to a more effi cient T-8 lamp with a new ballast and lamps. Th e sockets for T-12 and T-8 lamps are usually either a sin-gle pin or medium bi-pin and must be matched with the lamp. Th e double recessed contacts used by high-output lamps must be replaced when converting to more effi cient T-8 lamps.

through a mercury vapor and generate light. A tube with a larger surface area will generally emit more light. Most CFLs will not operate below 0 degrees Fahrenheit and require about a minute to reach full output. CFLs make a good replacement for many farm applications.

Another type of compact fl uorescent lamp, cold cathode fl uorescent light (CCFL), is widely used in the poultry industry. Cold cathode lamps oper-ate in the same way as regular CFLs but last two to three times longer, are compatible with many types of dimmers, start at lower temperatures than regular CFLs, and can be turned on and off without sig-nifi cantly shortening the lamp life. (Tabler, 2009)

Th e unheated cathode of a CCFL requires more energy to release the electrons. As a result, cold cathodes are slightly less energy-effi cient than a regular CFL. Th ey are also more expensive than most other CFLs. Th e long life of these lamps will potentially off set the higher initial cost, especially when replacing incandescent lamps. Cold cathode and regular CFL lamps are direct replacements for incandescent lamps with the same medium screw base.

Linear FluorescentLinear fl uorescent lighting is commonly used in shops, barns, and other covered spaces. Th e most common designations for linear fl uores-cent lighting include T-5, T-6, T-8, T-10, T-12 and T-17. Th e T indicates the shape of the lamp tube, and the corresponding number indicates the tube diameter in eighths of an inch. A T-8 lamp is tubular and 8/8” (1 inch) in diameter.

The T-8 lamps are the most energy-efficient option (usually 75 to 98 lm/W) commonly used in farm applications. Compared to a T-12 lamp

A T-8 linear fl uorescent lamp with medium bi-pin

contacts. Photo by Leif Kindberg.

Two T-12 linear fl uorescent lamps with a single pin

contact. Photo by Leif Kindberg.

The T-8

lamps are

the most

energy-effi cient

option (usually 75

to 98 lm/W)

commonly used in

farm applications.


High- and Low-Pressure Sodium Vapor (HPSV & LPSV)High-pressure sodium vapor lamps are more effi cient (usually 50 to 140 lm/W) than metal halide lamps. Th ey emit a yellow-orange light and have a low CRI, making them less desir-able for areas where color recognition is needed. HPSVs are often used for street and security lighting where color quality is less important. Th ey may also work well for side sheds, lighting pathways between buildings, and general out-door lighting needs. HPSVs perform well at cold temperatures (21 degrees Fahrenheit and below). (ASABE, 2005)

Low-pressure sodium lamps (LPSV) may be slightly more effi cient than HPSVs (usually 60 to 150 lm/W). Th eir color rendering qualities are lower than HPSVs. LPSVs may work where very dim lighting is required such as in secu-rity lighting, road lighting and other indoor/outdoor applications.

Mercury Vapor (MV)Mercury vapor lamps emit a greenish-bluish light similar to daylight and are commonly used as security lights. MV lamps have low color-ren-dering properties and the lowest effi ciency of any of the HID lamps (usually 25 to 60 lm/W). In addition, mercury vapor lamps create an environmental risk due to the mercury gas they contain. High-pressure sodium vapor lamps are more effi cient than mercury vapor lamps but require a diff erent ballast.

Light Emitting Diode (LED)LEDs are energy-efficient lamps commonly used in home electronics, road signs, accent

InductionInduction lighting is a type of fl uorescent light that does not have electrodes or fi laments like other types of lamps. Induction lighting works well in hot and cold environments with mini-mal loss of light output and is less sensitive to heat than other types of lighting. Induction lamps use a ballast, a coupling device to gener-ate a magnetic fi eld, and a special type of lamp globe. Th e mercury in the globe is excited by the magnetic fi eld and emits light.

Induction lamps are very effi cient (usually 50 to 90 lm/W) and may have a rated life of 100,000 hours or more. Th ey switch on almost instantly and do not need to cool down before re-strik-ing, unlike many other light systems. Induction lighting costs more than most other lighting sys-tems and may work well in areas where chang-ing burned-out lamps is diffi cult or expensive. (U.S. Department of Energy, 2006)

Metal HalideMetal halide, high-pressure sodium vapor, and mercury vapor lamps are all considered high intensity discharge (HID) lamps. Th ese lamps are not suited for applications where light is needed only for short durations due to their long warm-up time. Th ese lamps do not burn out the same way other lamps do. Most HID lamps should be replaced when they begin to fade (metal halide and mercury vapor) or when they continually shut off and re-strike while the power is still on.

Th e pulse-start metal halide (PSMH) is a high-effi ciency (usually 60 to 80 lm/W) metal halide lamp and fi xture. Metal halide lamps are avail-able in pulse-start and a standard version. Th e pulse-start system can extend lamp life by half over the standard metal halide lamp and provide about eight percent more lumens per watt than a standard HID. (Sanford, 2004) Pulse-start metal halide lamps use a diff erent type of bal-last and are not interchangeable with standard metal halide lamps. PSMHs start, warm up, and restart faster than other HIDs. Th ese lamps are not recommended for places where instant-on is needed because they may take one to three minutes to warm up and emit full light. When turned off , pulse-start metal halide lamps may take up to fi ve minutes to restart because they must fi rst cool down.

The typical 175-watt mercury vapor yard light uses about 200 watts when the ballast losses are included. This amounts to 876 kWh of electric-ity per year or $78 per year cost at $0.085/kWh.

If the MV lamp fi xture is replaced with a 70-watt high pressure sodium fi xture with a full cutoff refl ector, the operating cost would be reduced to $39 per year. The cost of the fi xture is estimated at $80–$100 for a 2.5- to 3.2-year payback.

Source: Sanford, Scott. Energy-Efficient Agricultural Lighting

W hen

turned

off ,

pulse-start metal

halide lamps may

take up to fi ve

minutes to restart

because they must

fi rst cool down.


Daylighting applications where these panels may work well include shops, garages, and outbuild-ings. Panels can be integrated into existing sheet metal roofi ng.

Energy Conserving ControlsTh ere is a variety of energy saving controls avail-able that can reduce lighting costs and increase productivity and safety. Th ese include motion sensors, timers, photo sensors, and half-night lighting photo controllers.

Motion sensors are designed to detect motion from just a few feet or up to 100 feet or more. Th ey can be used with regular incandescent, halogen, and some CFL lamps. Most motion detectors are not designed to work with other types of high effi ciency lamps. Motion sensors provide on-demand lighting for security and work areas and eliminate lighting of unoccupied areas. Check and adjust the motion sensor to avoid unintentional triggering by livestock.

Timers allow you to control the exact time lamps come on and shut off . Manual timers can be pur-chased very inexpensively and often installed in existing switch boxes. Timers are especially useful for areas occupied for short periods of time, such as feed rooms, entryways, and sheds. Electronic and digital timers are more expensive and pro-vide multiple on and off points throughout the day or week. Th ese timers are common in poul-try houses, greenhouses, and other applications where lighting is closely managed.

Photo sensors are commonly used with security lights in a yard. Many photo sensors turn on at dusk and off at dawn. Sometimes, security and other lighting are not needed from early morn-ing to before dawn. Half-night sensors measure the length of every night and switch the light off halfway. Using half-night photo sensors will reduce your security light electricity bill by half. Th ey can be purchased from most any local elec-trical supplier.

For more on energy conserving controls, visit University of Wisconsin’s Biological Systems Engineering Web site at www.uwex.edu/energy/lighting_OL.html.

Lighting GreenhousesGreenhouse lighting is usually designed to con-trol fl owering and fruiting (called photoperiod or day length) or increase photosynthesis in

lights, and spotlights. Th e popularity of LEDs is growing, and new lamps are available that are designed specifi cally for agriculture appli-cations. LEDs operate by transferring electrons between two diff erent materials inside the lamp. In the fi rst material, free electrons are released and move to the second material. As the elec-trons move to the second material, they give off photons. Th ese photons are refl ected using the optical components of the LED lamp.

Th e electronics in LEDs make them suscepti-ble to moisture, heat, and dirt, all of which can cause color-shifting and shortened life. LEDs should be carefully selected if used where they will be exposed to moisture or very dirty condi-tions. LEDs are still expensive but may work well in locations where electricity costs are high, where lamps operate for long periods of time, or where a specifi c type of task is matched with the LED optical components. LEDs are currently being fi eld tested in Arkansas for conventional poultry brood and feed lighting, with promising results.

DaylightingDaylighting uses windows, light tubes, or sky-lights to direct sunlight inside a building. Day-lighting is well suited for work areas such as open feedlots, sheds, and other areas where work is conducted during the day. For barns, shops, and rooms with activity only during the day, a well-designed and effi cient lighting system can rely on daylighting and use electric lamps as backup.

South-facing windows and skylights let more winter sunlight into a work area and can reduce heating costs. Properly shading south-facing windows will let in less sunlight during the sum-mer and also help reduce cooling costs. Day-lighting can be most effi ciently integrated dur-ing new construction.

Light tubes are becoming a common daylight-ing method in a range of applications such as windowless rooms. Light tubes are tubular sky-lights that operate by collecting light, usually in a clear dome on the roof, and refl ecting the collected sunlight through the tube to an inte-rior space. Light tubes work well in applications where windows and traditional skylights may not work well and where light is needed mostly during the day.

Clear or colored roofi ng panels made of PVC or polycarbonate can be used for daylighting.


that blue light wavelengths help calm birds; red wavelengths may be used to help reduce feather picking; blue-green wavelengths help maintain growth; and orange-red wavelength helps main-tain reproduction.

Th e light intensity for layers should be enough to read a newspaper by and will vary with the poultry breed. Generally, “warm” wavelength lamps of less than 3,000K in the red-orange spectrum are best for small fl ocks with outdoor access. Th e day length should never be extended past 16 hours or the longest day of the year.

Solar photovoltaic lighting provides a simple solu-tion to maintaining egg production during shorter days. Solar lighting systems basically consist of a solar module, a deep-cycle battery, a charge controller, a 12V programmable timer, and an effi cient DC lighting fi xture with lamp. Energy-effi cient LED lamps work very well with solar modules. All of the components to build a basic low-voltage solar lighting system can be purchased online for less than $300 or as a kit.

To conserve energy and keep poultry healthy, use timers to switch lights on and off . Program-mable timers must be 12V when used in con-junction with a 12V solar lighting system. Th ere are 12V timers available online as well as sche-matics to convert a household programmable thermostat to a 12V timer. Timers also ensure that birds receive a uniform number of light hours each day. Set timers to light in the morn-ing instead of the evening to give birds a natural dusk and allow them to roost. Check timers at least once a week, and clean lamps if dust builds up. Lamps should be free of obstructions that cause shadows on the fl oor.

plants. Photoperiod lighting is usually measured in hour or minute intervals and is adjusted for plant type. Lighting to increase photosynthetic activity is normally measured in photosynthet-ically active radiation (PAR) instead of foot-candles. PAR is defi ned as the number of micro-moles of photons that reach one square meter each second. Supplemental lighting to enhance photosynthesis activity is usually in the range of 40 to 80 PAR. (Fisher and Donnelly, 2001)

Lighting systems for greenhouses often use a combination of high-pressure sodium vapor (HPSV) and metal halide (MH) lamps. Th e MH contributes light in the blue-violet range and the HPS contributes light in the yellow-orange range of the light spectrum. (Sanford, 2004) Linear fl u-orescent lamps are also used in greenhouses when broad light distribution is required.

Improvement of natural light transmission helps plant growth and reduces lighting costs. Th e type of greenhouse cover, dust on the cover, and shaded areas created by ballasts, fi xtures, and other suspended objects all aff ect transmission of natural light. (Fisher and Donnelly, 2001)

Lighting systems in greenhouses are complex. Use a professional lighting contractor to map lighting uniformity, select the best fi xtures and determine fi xture placement for larger projects if possible. If designing a small system your-self, purchase a light meter, start with fewer fi x-tures, and add fi xtures until your needs are fully met. More information on greenhouses and greenhouse lighting is available in the ATTRA publication Solar Greenhouses.

Lighting for Alternative Poultry ProductionSupplemental lighting is normally used by alter-native egg producers to maintain productivity, and sometimes for alternative broiler production in northern climates. Small layer fl ocks housed during late spring through mid-summer with daily access to the outdoors do not require sup-plemental light. Supplemental lighting is neces-sary for pullets to maintain production during late fall and winter as days shorten.

Poultry are very sensitive to three aspects of light: intensity of light (measured in foot-candles), wavelength (measured in color temper-ature), and day length (duration of light period). Research by Michael Darre and others has found

Winter laying hens in a hoophouse. Photo courtesy of

Jericho Settlers’ Farm.

Supplemental

lighting is

necessary for

pullets to maintain

production during

late fall and winter

as days shorten.


and utility rooms. Th e second category includes lighting for holding areas, feeding areas, ani-mal sorting and observation and general cleanup. Th ese areas and tasks require high to moderate light quality and quantity. Finally, low to moder-ate light quality and quantity is adequate for gen-eral lighting for livestock resting areas, passageway lighting, general room lighting and indoor and outdoor security lighting. Lamps and fi xtures used in dairy lighting include fl uorescent, metal halide, and high-pressure sodium. More on dairy lighting is available in the ATTRA publication Dairy Farm Energy Effi ciency.

Baby chicks require additional light in their fi rst 72 hours to help them fi nd food and water. A low watt “warm” lamp is recommended for every 200 square feet of fl oor space. (Hawes) Th e high heat from incandescent lamps may double as a brood light and heat source, although it may be more energy-effi cient (and cost-eff ective) to use a separate heat source and a solar lighting system. More information on poultry lighting is available in the ATTRA publication Poultry House Management for Alternative Production.

Dairy LightingAppropriate lighting can improve productivity and safety on a dairy farm. On average, lighting represents 17 percent of total dairy farm electrical energy use. (Peterson, 2008) Optimal lighting con-ditions may increase milk productivity and con-serve energy. Factors that contribute to increased milk production include the type of light, the amount of light provided per watt, the tempera-ture of the work area, the height of the ceilings and the length of the lighting period.

Lighting requirements on a dairy farm can be divided into three categories. Th e fi rst category is visually intensive task lighting, which requires the highest light quality and quantity (Ludington et al., 2004). Areas that benefi t from this type of lighting include milking parlors; equipment wash-ing, equipment maintenance and repair areas; offi ces; maternity and veterinary treatment areas;

Lighting may be a signifi cant portion of dairy energy

costs. Photo by Andy Pressman.

The basic outline of a DC solar lighting system for

small alternative poultry production. Do-it-yourself

solar lighting systems can be installed in movable

poultry housing in the South for about $300 for a two

2-watt LED lamp system or $1,300 for fi ve 23-watt

lamps in larger, permanent houses in northern states

with fewer sun hours.

Lighting Disposal Most lamps should never be thrown in the trash or disposed of in burn barrels. Use recycling programs – especially for fl uorescent, mercury vapor, metal halide, and other HID lamps that may contain mercury and other hazards. Lamp recycling cen-ters can be found by zip code at www.earth911.org.

Summary Conserving energy with lighting may involve simple solutions like switching lights off , install-ing a timer, or replacing incandescent lamps with compact f luorescents, replacing T-12 fl ourescent lamps with more effi cient T-8 fl uo-rescent lamps, or upgrading to induction, LED, or daylighting. Effi cient lamps and controls can save money in many farm applications. Th e ini-tial investment should be compared to the cost savings, and lighting improvements should fully meet the farm’s lighting needs. Some farms will require consultation with a professional, but many other projects can be “do-it-yourself.” Use the tools in the Resources section to help you choose the correct lighting option for your farm.

10 - 300 Watts

Charge Controller

Battery Bank 25-3500

Watt Hrs.

Fuse

Two to Five 2 - 23 Watt Lamps

12 VoltTimer


Table 2: Lamp comparison. Adapted from ASABE, ASAE EP344.3; Sanford, 2004; Auburn University, University of Arkansas, U.S. Department of Energy and manufacturer literature.

Lamp TypeLumens/watt

Average Rated Life (hrs)*

Color CRI CCT (K)Instant On (min.)

BallastMinimum Start Temp. (oF)**

Application

Standard Incandescent

5 – 30 750 – 4,000

White98 – 100

2,700 – 2,850

Yes No Below 0 Indoor/outdoor

Tungsten Halogen

12 – 252,000 – 6,000

White98 – 100

2,750 – 3,200

Yes No Below 0 Indoor/outdoor

Compact Fluorescent

50 – 806,000 – 12,000

White65 – 95

2,700 – 6,500

Yes but warms up to full output

Yes 50

Indoor/outdoor, poultry houses, storage room and general lighting

Cold Cathode Compact Fluorescent

41 – 49 18,000 – 25,000

Bluish to White

82 – 84

2,200 – 4,500

Yes Internal -10Indoor/outdoor, poultry, and general lighting

T-12 Fluorescent

75 – 98 6,500 – 20,000

White52 – 95

3,000 – 6,500

Yes Yes 50

Indoor, milking parlor, milk room, storage rooms and bay areas

T-12 High Out-put Fluorescent

75 – 98 6,500 – 20,000

White70 – 95

4,100 – 6,500

Yes Yes -20


T-8 Fluorescent

75 – 98 7,500 – 20,000

White52 – 95

3,000 – 5,000

Yes Yes 0General area lighting of all kinds and low bay areas

T-8 High Output Fluorescent

75 – 98 6,500 – 20,000

White70 – 95

3,500 – 4,100

Yes Yes-20


Induction 50 – 90 60,000 – 100,000

White80 – 90

2,700 – 6,500

Yes Yes -40Where maintenance costs are high

Quartz Pulse-Start Metal Halide

60 – 805,000 – 20,000

Bluish65 – 75

2,900 – 4,200

No (1 – 3) Yes Below 0Indoor/outdoor including high bay and greenhouses

Ceramic Pulse-Start Metal Halide

60 – 80 20,000 Bluish85 – 94

2,900 – 4,200

No (1 – 3) Yes Below 0Indoor/outdoor including high bay and greenhouses

High-Pressure Sodium Vapor

50 – 14015,000 – 24,000

Yellow-Orange

20 – 80

1,900 – 2,200

No (3 – 5) Yes Below 0

Indoor/outdoor, poultry, livestock holding areas and greenhouses

Low Pressure Sodium

60 – 15012,000 – 18,000

Yellow -441,700 – 1,800

No (7 – 15)

YesBelow 0

Indoor/outdoor, general and security

Mercury Vapor 25 – 6016,000 – 24,000

Bluish 503,200 – 7,000

No (1 – 15)

Yes Outdoor

Light Emitting Diode

4 – 150 35,000 – 50,000

White80 – 90

2,700 – 10,000

Yes “Driver” NAIndoor/outdoor where color identifi -cation is important

All data and information are based upon a survey of literature and do not necessarily represent all available lamps.*Average rated life may vary depending on the lamp being switched on and off and the operating environment.** Minimum start temperatures may vary depending on the lamp and ballast combination.


References

American Society of Agricultural and Biological Engineers (ASABE). Lighting Systems for Agricultural Facilities. Standard EP344.3. January 2005.

Darre, Michael. Light and Lighting for Poultry. University of Connecticut. Last accessed February 2010. www.sp.uconn.edu/~mdarre/poultrypages/light_inset.html

Fisher, Paul and Caroline Donnelly. Evaluating Supplemen-tal Light for Your Greenhouse. Department of Horticulture, Clemson University. May 2001. Last accessed April 2010. http://extension.unh.edu/Agric/AGGHFL/OFAlight.pdf

Hawes, Robert. Lighting for Small-Scale Flocks. University of Main Cooperative Extension. Maine Poultry Facts. Bulletin #2227. Last accessed February 2010. www.umext.maine.edu/onlinepubs/htmpubs/2227.htm

Hiatt, Richard. 2008. Agricultural Lighting. Presentation at the Farm Energy Audit Training for Field Advisors workshop. Augusta, ME. January.

Lightsearch.com. Lighting Guides. Last accessed April 2010. www.lightsearch.com/resources/lightguides

Ludington, David, Eric Johnson, James Kowalski, Anne Magem and Richard Peterson. 2004. Dairy Farm Energy Effi ciency Guide. Ithaca, NY: DLTech, Inc.

Natural Resources Conservation Service. Energy Self Assessment. http://ruralenergy.wisc.edu/conservation/lighting/default_lighting.aspx

Peterson, Richard. 2008. Energy Management for Dairy Farms. Presentation at the Farm Energy Audit Training for Field Advisors workshop. Augusta, ME. January.

Sanford, Scott. 2004. Energy Conservation in Agriculture: Energy Effi ciency Agricultural Lighting. University of Wisconsin - Cooperative Extension Publication (A3784-14). Madison, Wisconsin: University of Wisconsin.

Tabler, Tom. 2009. Energy-Effi cient Lighting. Presentation at the Southeast Asian American Farmers Association meeting. Clarksville, Arkansas. October.

U.S. Energy Information Administration. Voluntary Reporting of Greenhouse Gases Program. Last accessed April 2010. www.eia.doe.gov/oiaf/1605/ee-factors.html

U.S. Department of Energy. Energy Savers. Last accessed April 2010. www.energysavers.gov/your_home/lighting_daylighting/index.cfm/mytopic=11980

U.S. Department of Energy. EnergySTAR. Lighting. 2006. Last access June 2010. www.energystar.gov/index.cfm?c=business.EPA_BUM_CH6_Lighting

Resources

Equipment SuppliersFarmTek1440 Field of Dreams WayDyersville, IA 52040Toll-free: 1-800-327-6835www.farmtek.com

www.growerssupply.com Sells many types of lamps and lighting equipment for poultry, greenhouses and the farm.

Real Goods Solar, Inc.833 W. South Boulder Rd.Louisville, CO 80027Toll-free: 1-800-919-2400www.realgoods.com Sells many types of solar lighting components and kits.

Backwoods Solar1589 Rapid Lightning Creek Rd.Sandpoint, ID 83864 Phone: 208-263-4290www.backwoodssolar.com Sells 12-volt DC timers and other solar lighting components for do-it-yourself solar poultry lighting.

Rooster Booster Poultry LightingSelmech Supplies Ltd19 Norton Enterprise ParkChurchfi eldsSalisburyWiltshireSP2 7YS Phone: 01722 413440 www.roosterbooster.co.uk Sells lighting equipment for poultry.

ACF Greenhouses380 Greenhouse Drive Buff alo Junction, VA 24529 Toll-free: 1-888-888-9050 www.littlegreenhouse.com Provides resources on greenhouse lighting design and sells

equipment for do-it-yourself projects.

EnviroCept Greenhouses & SupplyP.O. BOX 914Benton City, WA 99320Toll-free: 1-888-326-8634www.greenhouses-etc.net/lighting Sells greenhouse lighting equipment for large commercial and

do-it-yourself projects.

Visit ATTRA’s Directory of Energy Alternatives (www.attra.ncat.org/dea) for a state-by-state directory of alternative

ATTRA

Energy-Ef f icient Lighting for the Farm

By Leif Kindberg

NCAT Farm Energy Specialist

© 2010 NCAT

Holly Michels, Editor

Amy Smith, Production

This publication is available on the Web at:

www.attra.ncat.org/attra-pub/farmlighting.htmlor

www.attra.ncat.org/attra-pub/PDF/farmlighting.pdf

IP369

Slot 368

Version 083110

EnergySTARwww.energystar.gov/index.cfm?c=products.pr_fi nd_es_products Provides guidance on selecting energy-effi cient lamps

and fi xtures.

EnergySTAR Lightingwww.energystar.gov/index.cfm?c=business.EPA_BUM_CH6_Lighting Discusses lighting application considerations and

general lighting.

EnSavewww.ensave.com Th is commercial site off ers technical papers on effi cient

lighting and other farm energy topics.

Rural Electricity Resource Councilwww.rerc.org National clearinghouse and technical support provider on

energy effi ciency with an emphasis on rural applications.

Wisconsin’s Focus on Energywww.focusonenergy.com Wisconsin-based program providing information, resources

and fi nancial incentives to help implement energy-effi cient and renewable energy projects. Agricultural and Rural Business Programs provides information on energy effi ciency for agricultural producers.

Biological Systems Engineeringwww.uwex.edu/energy/AgEnergy.html A University of Wisconsin – Madison resource that provides

guidance on lighting and other farm energy topics.

energy installers and consultants, or call ATTRA at 1-800-346-9140.

Tools and Websites

Lighting Self Assessment Toolhttp://ruralenergy.wisc.edu/conservation/lighting/default_lighting.aspx Th e Lighting Energy Self Assessment Tool available from the

USDA Natural Resources Conservation Service is designed to estimate your current lighting energy use based on your inputs and to suggest more effi cient alternatives.

Energy Savers – Lighting and Daylightingwww.energysavers.gov/your_home/lighting_daylighting/index.cfm/mytopic=11970 Th e Department of Energy (DOE) Energy Savers

website provides information and resources on energy-effi cient lighting and daylighting.

Lightsearch.comwww.lightsearch.com/resources/lightguides Th is commercial site provides a large list of lighting design

formulas and other useful lighting tools.

Center for Ecological Technologywww.cetonline.org Organization provides publications and links on energy-

effi cient and renewable energy technologies.

Energy-Efficient Lighting for the Farm

Education

Transcript of Energy-Efficient Lighting for the Farm