Energy-Efficient Lighting for the Farm

1. A project of the National Center for Appropriate Technology 1-800-346-9140 • www.attra.ncat.org
Energy-Efficient Lighting
for the Farm
By Leif Kindberg Energy-efficient lighting options present farmers with new opportunities to reduce electricity costs and
NCAT Farm Energy help manage farms sustainably. Cost-effective energy-efficient lighting can be used to improve produc-
Specialist tivity and safety, and reduce operating costs. This publication provides an overview of energy-efficient
© 2010 NCAT lighting technology and explains how to select lighting options that are appropriate for the farm.
Contents
Introduction ......................1
Light Quantity ..................1
Light Quality .....................2
Focus on Efficiency .........3
Fixtures ...............................4
Ballasts ................................4
Lamps ..................................4
Daylighting ........................7
Energy Conserving
Controls...............................7
Lighting
Greenhouses .....................7
Lighting for
Alternative Poultry
Production .........................8
Efficient lighting can help reduce farm energy costs. Photo by Andy Pressman.
Dairy Lighting ...................9
Lighting Disposal ............9
This publication will introduce you to energy-
Summary ............................9 Introduction efficient lighting technologies, and terms used by
References .......................11
Lighting is an essential part of most farms. Even the lighting industry, and help you select options
Resources .........................11
so, most farms do not use it as an opportunity that meet your farm’s lighting requirements. The
to reduce energy costs. Energy-efficient lighting term lamp is interchanged with the term light
Funding for the development
may offer inexpensive opportunities for farms to bulb throughout this publication.
of this publication was provided
by the USDA Risk Management reduce energy costs and improve productivity.
Agency.
Energy-efficient lighting technologies are avail- Light Quantity
able in many sizes and types, including linear Measuring the light level (also thought of as bright-
fluorescent lamps, compact fluorescent lamps ness or quantity of light) is helpful to determine
(CFL), induction lighting, pulse-start metal the type of lamp you need. Light output is mea-
The National Sustainable
Agriculture Information Service, halide lamps, high- and low-pressure sodium sured in different ways. It might be measured in
ATTRA (www.attra.ncat.org),
vapor lamps, light-emitting diodes (LED), the units of light leaving the lamp (lumens), or it
was developed and is managed
by the National Center for daylighting tubes, and skylights. These long- might be measured by the amount of light falling
Appropriate Technology (NCAT).
The project is funded through life technologies can reduce costs in two ways: on a surface (foot-candles). Foot-candles are the
a cooperative agreement with common method of measuring light quantity in
the United States Department lower fi xed costs through fewer replacements
agricultural operations.
of Agriculture’s Rural Business-
Cooperative Service. Visit the
and lower operating costs through lower energy
NCAT website (www.ncat.org/ consumption. Electronic ballasts, lighting The foot-candle (fc) is the light level at the work-
sarc_current.php) for
more information on controls, and proper reflectors further improve ing surface and is defined as the amount of illu-
our other sustainable
agriculture and
the efficiency, quantity, and quality of light mination from a candle falling on a surface
energy projects. used on the farm. at a distance of one foot. Outside on a bright

2. sunny day in midsummer, the light level will be
around 8,000 fc. Inside, a brightly lit desk-top 12000K 6
surface will be about 100 fc. A dimly lit street 7000K 6500 - 7500K Overcast Sky
at night may be at one fc or less. This is what 5500K Midday
light meters measure, and it is equivalent to one 4000K 5000 - 6500K Natural or Daylight
lumen per square foot.
4100K Moonlight
Lumen fl ux is the quantity of light that leaves 3000K
the lamp, and is measured in lumens (lm). All 3500 - 4100K Cool White, Bright White
lamps are rated in lumens and may be rated 2700 - 3000K Warm White, Soft White
in both initial and mean lumens. The mean
lumens of a lamp provide the average rated 1850 - 2000K Candlelight
2000K
output over the lamp’s rated life. The initial
and mean lumens may be used to compare Color temperature is a scale of color
one lamp with another. The lumen output of a (not brightness) rated in Kelvin.
lamp is printed on the package of most lamps
Related ATTRA
publications and will be discussed further.
Farm Energy The light loss factor (LLF) is the measure of a Light quality is generally measured by color
Calculators: lamp’s lumen output near the end of its use- temperature and color rendering index (CRI).
Tools for Saving ful life in comparison to the lumen output pro- Color temperature (also called correlated color
Money on the Farm vided by the manufacturer. Lamps decrease in temperature, CCT) is measured in degrees
output because lamp and ballast components Kelvin (K). A higher color temperature num-
Efficient Agricultural
degrade over time due to normal operation and ber indicates that a lamp will emit a more blue
Buildings:
An Overview environmental factors such as dust buildup. or cooler light, and a lower color temperature
LLF may be measured and presented in many number indicates that a lamp will emit a more
Solar Greenhouses ways. It is important to remember that lamps orange/red or warmer light. This is sometimes
Comparing may need to be selected for a higher-than- confusing, but just remember that a higher color
Energy Use in needed light level or replaced before they burn temperature is more like sunlight. Most man-
Conventional and out to take into account light loss as the lamp ufacturers provide a color description on the
Organic Cropping and its components age. packaging such as “warm white” or “cool blue.”
Systems A cool, white light might have a color temper-
Average rated life, usually determined under lab-
Poultry House oratory conditions, is the point at which some ature of 3,500 degrees Kelvin or above, and a
Management for percentage of the initially installed lamps have warm, yellow lamp might have a color tempera-
Alternative Production burned out. The operating conditions that affect ture of less than 3000 degrees Kelvin.
Dairy Farm Energy the average rated life lamp include ambient tem- Color rendering index (CRI) is a measurement of
Efficiency perature, humidity, dust, power surges, and how a light source will reproduce colors of vari-
switching the lamp on and off. Light output and ous objects in comparison with sunlight. Some
light quality (discussed next) change over time tasks on the farm, such as produce sorting,
for almost all lamps. Therefore, considerations require light that makes colors appear as they
such as color shifting, lumen depreciation, and would in sunlight. Be aware that CRI is mea-
loss in luminous efficacy (an industry term for sured at any given lamp’s color temperature and
efficiency) may reduce average rated life and is therefore more difficult to use as a comparison
should be taken into account. between lamps with different color temperatures.
CRI is measured on a scale of 0 to 100. The larger
Light Quality the CRI value, the closer the lamp renders a color
the same as sunlight. A value of 0 means that col-
Understanding light quality (also thought of as
ors all look the same under the lamp.
brightness or light color) is important for farms
that are using light to manage the photo-period Although lamp output or quantity of light is
and activity of livestock. A balance among ani- important, light quality characteristics like
mal health, comfort, and productivity should be color temperature and CRI also affect your per-
considered. (ATTRA offers a variety of publica- ception of light quantity and comfort. Both of
tions on sustainable livestock production. Visit these characteristics should be considered when
www.attra.ncat.org for more information.) replacing a lamp.
Page 2 ATTRA Energy-Ef f icient Lighting for the Farm

3. Focus on Ef f iciency or less in applications where the lights are oper-
ated eight hours a day or more. (ASABE, 2005)
Energy efficiency in lighting is referred to as effi-
cacy and is measured in lumens per watt (lm/w). Determining lamp efficiency can be accom-
Efficacy is somewhat like measuring miles per plished in a several ways. To determine the
gallon. The more lumens you can get from a luminous efficacy (lumens per watt), look at the
watt of power, the more efficient the lamp and package and divide the number of lumens by
the more you will likely save on your electricity the wattage. For example, a 23-watt (W) com-
bill. Efficacy is the ratio of light output from a pact fluorescent lamp produces about 70 lumens
lamp to the electricity it uses. per watt (70 lm/W) for a total of about 1,600
lumens, where watts is the rate of electric power
There are two major cost-efficiency consid- required to operate at peak output. For compari-
erations: the cost of operating the lamp and son, a 100-watt incandescent light lamp might
the cost of replacing the lamp. In most cases, produce only 10 lumens per watt, making it sig-
replacing an existing lamp with one which has nificantly less efficient in comparison to a com-
a higher luminous efficacy and longer average pact fluorescent lamp. Another quick way of
rated life will reduce operating costs and may choosing an efficient lamp is to find lamps with
also reduce replacement costs. Energy-efficient the light output (lumens) you need, and then
lighting will typically pay for itself in two years choose the lamp that uses the fewest watts.
Table 1: Energy cost comparison
Compare the energy cost savings of different 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.
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
Efficacy 57.5 LPW 1,380 lm ÷ 24 W Efficacy 10.26 LPW 1,026 lm ÷ 100 W
7 days/week x 14 hours/ 7 days/week x 14 hours/day
Operating Hours 3,920 h Operating Hours 3,920 h
day x 40 weeks/year 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
94,080 watt-hours 392,000 watt-hours
Energy Use 94.08 kWh (Wh) ÷ 1,000 = 94.08 Energy Use 392 kWh (Wh) ÷ 1,000 = 392
kilowatt-hours (kWh) kilowatt-hours (kWh)
Utility Charge/ Utility Charge/
$0.0928 $0.0928
kWh kWh
94.08kWh x $0.0928/
Energy Cost/Year $8.73 Energy Cost/Year $36.38 392kWh x $0.0928/kWh
kWh
Lamp Cost $3.95 Lamp Cost $0.48
Annual Operating Annual Operating
$87.30 # of lamps x $8.73 $363.80 # of lamps x $36.38
Costs Costs
Other lighting considerations not included in this example may be relevant to your application. Developed from manufacturer literature
and pricing.
www.attra.ncat.org ATTRA Page 3

4. lamp, a rated wattage different from that listed
You may wish to use the Natural Resources
Conservation Service (NRCS) Energy Self with the lamp should be considered. This new
Assessment tool http://ruralenergy.wisc.edu/ rated wattage will be published by the ballast
conservation/default.aspx for lighting to help manufacturer. In general, ballasts for fluores-
you choose energy-efficient lighting. cent lamps are either magnetic or electronic.
Electronic ballasts are more efficient and now
considered to be the industry standard.
Fixtures
Fixtures generally consist of a frame, lamp sock- Lamps
ets, and lamp(s) but may also include a ballast, Energy-efficient lamps are available in many dif-
reflector, diff user, or other hardware. Lamp fi x- ferent shapes and sizes, with a broad selection
tures are very important to the quantity and of light color temperatures, lumen outputs, and
quality of light provided as well as efficiency and color rendering qualities. Lamp replacement is
safety. The number and placement of fi xtures generally “do-it-yourself” on the farm, but bal-
should be carefully matched to the application last and fixture replacement requires experience
for the best efficiency. Fewer fixtures with higher with AC electrical.
wattage lamps will produce greater variation in
light. More fi xtures with lower wattage lamps Incandescent
will provide greater uniformity in the light.
Incandescent lamps are the least expensive and
Reflectors and reflector geometry help trap less most commonly available lamps. Incandes-
light in the fi xture and push more light out of cent lamps create light by resistance to the flow
the fi xture, improving light quantity. A lamp of electricity through fi nely coiled wires that
fixture with a reflector, for example, directs become hot enough to glow. However, they are
more of the light to the area where it is required, also the least efficient. About 90 percent of the
and in some cases allows lower wattage lamps to energy used by an incandescent lamp becomes
be used. It is not uncommon in the typical yard heat, and only 10 percent becomes light. (Hiatt,
light for 30 percent of light to be wasted due to 2008) Incandescent lamps generally have a very
inefficient fi xtures that may let light go up or short average-rated life. Their short life and poor
out from the lamp. (Sanford, 2004a) Similarly, use of energy make them inefficient and some-
diff users can be used on many types of lamps to times costly to operate.
distribute light horizontally.
Agricultural fi xtures should be resistant to cor- Tungsten-halogen
rosion, moisture, and dust. For a lamp in a wet Tungsten-halogen (or just halogen) lamps are a
location, a sealed polycarbonate or other gas- type of high-pressure incandescent lamp that is
keted and weatherproof enclosure should be more energy-efficient than a regular incandes-
installed. The enclosure should be approved for cent lamp. Halogen lamps operate at very high
use with the lamp, especially CFL lamps, to pre- temperatures and use less energy by recycling
vent fire hazards and premature lamp failure. heat to keep the fi lament hot with less elec-
tricity. Halogen lamps can be used with many
Ballasts dimmers and do not take any time to warm up.
The purpose of a ballast is to provide the voltage (ASABE, 2005) Read the instructions carefully
necessary to initiate lighting in gas-discharge before handling halogen lamps.
and some other lamps. Lamps that require a bal-
last for start-up include high- and low-pressure Compact Fluorescent (CFL)
sodium, fluorescent, induction, mercury-vapor,
CFLs last up to 10 times longer and may use 75
and metal halide lamps.
percent less energy than the common incandescent
Ballasts function by heating electrodes with lamp. (U.S. Department of Energy, 2006) CFLs
low voltage or in some cases supplying very may have a single spiral tube, multiple tubes, or
high voltage to start the lamp. Once the lamp tubes covered to look similar to an incandescent
is started, the ballast controls the voltage to the light. Regular CFLs have a hot cathode (electrode)
lamp to sustain the light discharge. Because made of tungsten wire that is coated with barium
ballasts increase or decrease the voltage to the carbonate. The cathode emits electrons that pass
Page 4 ATTRA Energy-Ef f icient Lighting for the Farm

5. 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 fluorescent lamp, cold
cathode fluorescent 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 Two T-12 linear fluorescent lamps with a single pin
three times longer, are compatible with many types contact. Photo by Leif Kindberg.
of dimmers, start at lower temperatures than regular
CFLs, and can be turned on and off without sig- and ballast, the T-8 fluorescent lamp provides
nificantly shortening the lamp life. (Tabler, 2009) about 15 percent more lumens per watt, and the
ballasts are 40 percent more efficient. (Sanford,
The unheated cathode of a CCFL requires more
2004) Both T-8 and T-12 lamps can be used
energy to release the electrons. As a result, cold
in sealed fi xtures needed in most farm applica-
cathodes are slightly less energy-efficient than a
T
tions. Most magnetic ballasts used with T-12 he T-8
regular CFL. They are also more expensive than
lamps will no longer be manufactured after July
most other CFLs. The long life of these lamps lamps are
1, 2010. They can be replaced with higher effi-
will potentially off set the higher initial cost, the most
ciency electronic ballasts or with more efficient
especially when replacing incandescent lamps.
fixtures and lamps like the T-8. energy-efficient
Cold cathode and regular CFL lamps are direct
replacements for incandescent lamps with the High-output versions of linear fluorescent lamps option (usually 75
same medium screw base. will start in temperatures as low as -20 degrees to 98 lm/W)
Fahrenheit but are less efficient than regular lin- commonly used in
Linear Fluorescent ear fluorescent lamps. These lamps use a double farm applications.
recessed contact instead of the traditional bi-pin
Linear fluorescent lighting is commonly used or single pin contact used with standard fixtures.
in shops, barns, and other covered spaces. The High-output lamps use a special ballast as well.
most common designations for linear fluores- Ambient temperatures affect fluorescent lamps.
cent lighting include T-5, T-6, T-8, T-10, T-12 The minimum starting temperature for standard
and T-17. The T indicates the shape of the lamp fluorescent lamps is 50 F. (ASABE, 2005) High
tube, and the corresponding number indicates output lamps are generally not required unless
the tube diameter in eighths of an inch. A T-8 the lamp will experience recurring starting tem-
lamp is tubular and 8/8” (1 inch) in diameter. peratures of 50 degrees Fahrenheit or below.
The T-8 lamps are the most energy-efficient Although T-5 lamps are even more efficient than
option (usually 75 to 98 lm/W) commonly used T-12 and T-8 lamps, they also produce more
in farm applications. Compared to a T-12 lamp heat than larger-diameter lamps and cannot be
used in sealed fixtures. 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 efficient T-8
lamp with a new ballast and lamps. The 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. The double recessed contacts
A T-8 linear fluorescent lamp with medium bi-pin used by high-output lamps must be replaced
contacts. Photo by Leif Kindberg. when converting to more efficient T-8 lamps.
www.attra.ncat.org ATTRA Page 5

6. Induction The typical 175-watt mercury vapor yard light
Induction lighting is a type of fluorescent light uses about 200 watts when the ballast losses are
that does not have electrodes or fi laments like included. This amounts to 876 kWh of electric-
other types of lamps. Induction lighting works ity per year or $78 per year cost at $0.085/kWh.
well in hot and cold environments with mini- If the MV lamp fixture is replaced with a
mal loss of light output and is less sensitive to 70-watt high pressure sodium fixture with a
heat than other types of lighting. Induction full cutoff reflector, the operating cost would
be reduced to $39 per year. The cost of the
lamps use a ballast, a coupling device to gener- fixture is estimated at $80–$100 for a 2.5- to
ate a magnetic field, and a special type of lamp 3.2-year payback.
globe. The mercury in the globe is excited by the
Source: Sanford, Scott. Energy-Efficient
magnetic field and emits light. Agricultural Lighting
Induction lamps are very efficient (usually 50 to
90 lm/W) and may have a rated life of 100,000
hours or more. They switch on almost instantly High- and Low-Pressure Sodium
and do not need to cool down before re-strik- Vapor (HPSV & LPSV)
ing, unlike many other light systems. Induction
High-pressure sodium vapor lamps are more
W
hen lighting costs more than most other lighting sys-
efficient (usually 50 to 140 lm/W) than metal
tems and may work well in areas where chang-
turned halide lamps. They emit a yellow-orange light
ing burned-out lamps is difficult or expensive.
off, and have a low CRI, making them less desir-
(U.S. Department of Energy, 2006)
able for areas where color recognition is needed.
pulse-start metal
HPSVs are often used for street and security
halide lamps may Metal Halide lighting where color quality is less important.
take up to five Metal halide, high-pressure sodium vapor, and They may also work well for side sheds, lighting
minutes to restart mercury vapor lamps are all considered high pathways between buildings, and general out-
because they must intensity discharge (HID) lamps. These lamps door lighting needs. HPSVs perform well at cold
are not suited for applications where light is temperatures (21 degrees Fahrenheit and below).
first cool down.
needed only for short durations due to their (ASABE, 2005)
long warm-up time. These lamps do not burn Low-pressure sodium lamps (LPSV) may be
out the same way other lamps do. Most HID slightly more efficient than HPSVs (usually 60
lamps should be replaced when they begin to to 150 lm/W). Their color rendering qualities
fade (metal halide and mercury vapor) or when are lower than HPSVs. LPSVs may work where
they continually shut off and re-strike while the very dim lighting is required such as in secu-
power is still on. rity lighting, road lighting and other indoor/
The pulse-start metal halide (PSMH) is a high- outdoor applications.
efficiency (usually 60 to 80 lm/W) metal halide
lamp and fi xture. Metal halide lamps are avail- Mercury Vapor (MV)
able in pulse-start and a standard version. The
Mercury vapor lamps emit a greenish-bluish
pulse-start system can extend lamp life by half
light similar to daylight and are commonly used
over the standard metal halide lamp and provide
as security lights. MV lamps have low color-ren-
about eight percent more lumens per watt than
dering properties and the lowest efficiency of
a standard HID. (Sanford, 2004) Pulse-start
any of the HID lamps (usually 25 to 60 lm/W).
metal halide lamps use a different type of bal-
In addition, mercury vapor lamps create an
last and are not interchangeable with standard
environmental risk due to the mercury gas they
metal halide lamps. PSMHs start, warm up, and
contain. High-pressure sodium vapor lamps are
restart faster than other HIDs. These lamps are
more efficient than mercury vapor lamps but
not recommended for places where instant-on
require a different ballast.
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 Light Emitting Diode (LED)
take up to five minutes to restart because they LEDs are energy-efficient lamps commonly
must first cool down. used in home electronics, road signs, accent
Page 6 ATTRA Energy-Ef f icient Lighting for the Farm

7. lights, and spotlights. The popularity of LEDs Daylighting applications where these panels may
is growing, and new lamps are available that work well include shops, garages, and outbuild-
are designed specifically for agriculture appli- ings. Panels can be integrated into existing sheet
cations. LEDs operate by transferring electrons metal roofing.
between two different materials inside the lamp.
In the first material, free electrons are released Energy Conserving Controls
and move to the second material. As the elec-
There is a variety of energy saving controls avail-
trons move to the second material, they give off
able that can reduce lighting costs and increase
photons. These photons are reflected using the
productivity and safety. These include motion
optical components of the LED lamp.
sensors, timers, photo sensors, and half-night
The electronics in LEDs make them suscepti- lighting photo controllers.
ble to moisture, heat, and dirt, all of which can
Motion sensors are designed to detect motion
cause color-shifting and shortened life. LEDs
from just a few feet or up to 100 feet or more.
should be carefully selected if used where they
They can be used with regular incandescent,
will be exposed to moisture or very dirty condi-
halogen, and some CFL lamps. Most motion
tions. LEDs are still expensive but may work well detectors are not designed to work with other
in locations where electricity costs are high, where types of high efficiency lamps. Motion sensors
lamps operate for long periods of time, or where provide on-demand lighting for security and
a specific type of task is matched with the LED work areas and eliminate lighting of unoccupied
optical components. LEDs are currently being areas. Check and adjust the motion sensor to
field tested in Arkansas for conventional poultry avoid unintentional triggering by livestock.
brood and feed lighting, with promising results.
Timers allow you to control the exact time lamps
come on and shut off. Manual timers can be pur-
Daylighting chased very inexpensively and often installed in
Daylighting uses windows, light tubes, or sky- existing switch boxes. Timers are especially useful
lights to direct sunlight inside a building. Day- for areas occupied for short periods of time, such
lighting is well suited for work areas such as open as feed rooms, entryways, and sheds. Electronic
feedlots, sheds, and other areas where work is and digital timers are more expensive and pro-
conducted during the day. For barns, shops, and vide multiple on and off points throughout the
rooms with activity only during the day, a well- day or week. These timers are common in poul-
designed and efficient lighting system can rely on try houses, greenhouses, and other applications
daylighting and use electric lamps as backup. where lighting is closely managed.
South-facing windows and skylights let more Photo sensors are commonly used with security
winter sunlight into a work area and can reduce lights in a yard. Many photo sensors turn on at
heating costs. Properly shading south-facing dusk and off at dawn. Sometimes, security and
windows will let in less sunlight during the sum- other lighting are not needed from early morn-
mer and also help reduce cooling costs. Day- ing to before dawn. Half-night sensors measure
lighting can be most efficiently integrated dur- the length of every night and switch the light
ing new construction. off halfway. Using half-night photo sensors will
reduce your security light electricity bill by half.
Light tubes are becoming a common daylight-
They can be purchased from most any local elec-
ing method in a range of applications such as
trical supplier.
windowless rooms. Light tubes are tubular sky-
lights that operate by collecting light, usually For more on energy conserving controls, visit
in a clear dome on the roof, and reflecting the University of Wisconsin’s Biological Systems
collected sunlight through the tube to an inte- Engineering Web site at www.uwex.edu/energy/
rior space. Light tubes work well in applications lighting_OL.html.
where windows and traditional skylights may
not work well and where light is needed mostly Lighting Greenhouses
during the day.
Greenhouse lighting is usually designed to con-
Clear or colored roofing panels made of PVC trol flowering and fruiting (called photoperiod
or polycarbonate can be used for daylighting. or day length) or increase photosynthesis in
www.attra.ncat.org ATTRA Page 7

8. 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 defined 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. The MH Winter laying hens in a hoophouse. Photo courtesy of
contributes light in the blue-violet range and the Jericho Settlers’ Farm.
HPS contributes light in the yellow-orange range
of the light spectrum. (Sanford, 2004) Linear flu- that blue light wavelengths help calm birds; red
orescent lamps are also used in greenhouses when wavelengths may be used to help reduce feather
broad light distribution is required. picking; blue-green wavelengths help maintain
S
upplemental
growth; and orange-red wavelength helps main-
lighting is Improvement of natural light transmission helps
tain reproduction.
plant growth and reduces lighting costs. The
necessary for
type of greenhouse cover, dust on the cover, and The light intensity for layers should be enough
pullets to maintain shaded areas created by ballasts, fi xtures, and to read a newspaper by and will vary with the
production during other suspended objects all affect transmission poultry breed. Generally, “warm” wavelength
late fall and winter of natural light. (Fisher and Donnelly, 2001) lamps of less than 3,000K in the red-orange
as days shorten. Lighting systems in greenhouses are complex. spectrum are best for small flocks with outdoor
Use a professional lighting contractor to map access. The day length should never be extended
lighting uniformity, select the best fi xtures and past 16 hours or the longest day of the year.
determine fi xture placement for larger projects Solar photovoltaic lighting provides a simple solu-
if possible. If designing a small system your- tion to maintaining egg production during shorter
self, purchase a light meter, start with fewer fix- days. Solar lighting systems basically consist of
tures, and add fixtures until your needs are fully a solar module, a deep-cycle battery, a charge
met. More information on greenhouses and
controller, a 12V programmable timer, and an
greenhouse lighting is available in the ATTRA
efficient DC lighting fixture with lamp. Energy-
publication Solar Greenhouses.
efficient LED lamps work very well with solar
modules. All of the components to build a
Lighting for Alternative basic low-voltage solar lighting system can be
Poultry Production purchased online for less than $300 or as a kit.
Supplemental lighting is normally used by alter- To conserve energy and keep poultry healthy,
native egg producers to maintain productivity, use timers to switch lights on and off. Program-
and sometimes for alternative broiler production mable timers must be 12V when used in con-
in northern climates. Small layer flocks housed junction with a 12V solar lighting system. There
during late spring through mid-summer with are 12V timers available online as well as sche-
daily access to the outdoors do not require sup- matics to convert a household programmable
plemental light. Supplemental lighting is neces- thermostat to a 12V timer. Timers also ensure
sary for pullets to maintain production during that birds receive a uniform number of light
late fall and winter as days shorten. hours each day. Set timers to light in the morn-
Poultry are very sensitive to three aspects of ing instead of the evening to give birds a natural
light: intensity of light (measured in foot- dusk and allow them to roost. Check timers at
candles), wavelength (measured in color temper- least once a week, and clean lamps if dust builds
ature), and day length (duration of light period). up. Lamps should be free of obstructions that
Research by Michael Darre and others has found cause shadows on the floor.
Page 8 ATTRA Energy-Ef f icient Lighting for the Farm

9. and utility rooms. The second category includes
10 - 300 lighting for holding areas, feeding areas, ani-
Watts mal sorting and observation and general cleanup.
12 These areas and tasks require high to moderate
Volt
Timer light quality and quantity. Finally, low to moder-
Fuse ate light quality and quantity is adequate for gen-
Charge eral lighting for livestock resting areas, passageway
Controller
lighting, general room lighting and indoor and
outdoor security lighting. Lamps and fixtures used
in dairy lighting include fluorescent, metal halide,
and high-pressure sodium. More on dairy lighting
Two to Five is available in the ATTRA publication Dairy Farm
Battery Bank 2 - 23 Watt
Lamps
Energy Efficiency.
25-3500
Watt Hrs.
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 five 23-watt
lamps in larger, permanent houses in northern states
with fewer sun hours.
Baby chicks require additional light in their
first 72 hours to help them find food and water.
A low watt “warm” lamp is recommended for
every 200 square feet of floor space. (Hawes) The
high heat from incandescent lamps may double Lighting may be a significant portion of dairy energy
as a brood light and heat source, although it may costs. Photo by Andy Pressman.
be more energy-efficient (and cost-effective) to
use a separate heat source and a solar lighting Lighting Disposal
system. More information on poultry lighting Most lamps should never be thrown in the trash or
is available in the ATTRA publication Poultry disposed of in burn barrels. Use recycling programs
House Management for Alternative Production. – especially for fluorescent, mercury vapor, metal
halide, and other HID lamps that may contain
Dairy Lighting mercury and other hazards. Lamp recycling cen-
Appropriate lighting can improve productivity ters can be found by zip code at www.earth911.org.
and safety on a dairy farm. On average, lighting
represents 17 percent of total dairy farm electrical Summary
energy use. (Peterson, 2008) Optimal lighting con- Conserving energy with lighting may involve
ditions may increase milk productivity and con- simple solutions like switching lights off, install-
serve energy. Factors that contribute to increased ing a timer, or replacing incandescent lamps
milk production include the type of light, the with compact f luorescents, replacing T-12
amount of light provided per watt, the tempera- flourescent lamps with more efficient T-8 fluo-
ture of the work area, the height of the ceilings and rescent lamps, or upgrading to induction, LED,
the length of the lighting period. or daylighting. Efficient lamps and controls can
Lighting requirements on a dairy farm can be save money in many farm applications. The ini-
divided into three categories. The first category tial investment should be compared to the cost
is visually intensive task lighting, which requires savings, and lighting improvements should fully
the highest light quality and quantity (Ludington meet the farm’s lighting needs. Some farms will
et al., 2004). Areas that benefit from this type of require consultation with a professional, but
lighting include milking parlors; equipment wash- many other projects can be “do-it-yourself.” Use
ing, equipment maintenance and repair areas; the tools in the Resources section to help you
offices; maternity and veterinary treatment areas; choose the correct lighting option for your farm.
www.attra.ncat.org ATTRA Page 9

10. 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.
Average Minimum
Lumens/ Instant On
Lamp Type Rated Color CRI CCT (K) Ballast Start Temp. Application
watt (min.)
Life (hrs)* (oF)**
Standard 750 – 98 – 2,700 –
5 – 30 White Yes No Below 0 Indoor/outdoor
Incandescent 4,000 100 2,850
Tungsten 2,000 – 98 – 2,750 –
12 – 25 White Yes No Below 0 Indoor/outdoor
Halogen 6,000 100 3,200
Yes but Indoor/outdoor,
Compact 6,000 – 65 – 2,700 – warms up poultry houses,
50 – 80 White Yes 50
Fluorescent 12,000 95 6,500 to full storage room and
output general lighting
Cold Cathode Indoor/outdoor,
18,000 – Bluish to 82 – 2,200 –
Compact 41 – 49 Yes Internal -10 poultry, and general
25,000 White 84 4,500
Fluorescent lighting
Indoor, milking
T-12 6,500 – 52 – 3,000 – parlor, milk room,
75 – 98 White Yes Yes 50
Fluorescent 20,000 95 6,500 storage rooms and
bay areas
Indoor, milking
T-12 High Out-
6,500 – 70 – 4,100 – parlor, milk room,
put 75 – 98 White Yes Yes -20
20,000 95 6,500 storage rooms and
Fluorescent
bay areas
General area lighting
T-8 7,500 – 52 – 3,000 –
75 – 98 White Yes Yes 0 of all kinds and low
Fluorescent 20,000 95 5,000
bay areas
Indoor, milking
T-8 High
6,500 – 70 – 3,500 – -20 parlor, milk room,
Output 75 – 98 White Yes Yes
20,000 95 4,100 storage rooms and
Fluorescent
bay areas
60,000 – 80 – 2,700 – Where maintenance
Induction 50 – 90 White Yes Yes -40
100,000 90 6,500 costs are high
Quartz Pulse- Indoor/outdoor
5,000 – 65 – 2,900 –
Start Metal 60 – 80 Bluish No (1 – 3) Yes Below 0 including high bay
20,000 75 4,200
Halide and greenhouses
Ceramic Pulse- Indoor/outdoor
85 – 2,900 –
Start Metal 60 – 80 20,000 Bluish No (1 – 3) Yes Below 0 including high bay
94 4,200
Halide and greenhouses
Indoor/outdoor,
High-
15,000 – Yellow- 20 – 1,900 – poultry, livestock
Pressure 50 – 140 No (3 – 5) Yes Below 0
24,000 Orange 80 2,200 holding areas and
Sodium Vapor
greenhouses
Low Pressure 12,000 – 1,700 – No Yes Indoor/outdoor,
60 – 150 Yellow -44 Below 0
Sodium 18,000 1,800 (7 – 15) general and security
16,000 – 3,200 – No
Mercury Vapor 25 – 60 Bluish 50 Yes Outdoor
24,000 7,000 (1 – 15)
Indoor/outdoor
Light Emitting 35,000 – 80 – 2,700 –
4 – 150 White Yes “Driver” NA where color identifi-
Diode 50,000 90 10,000
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.
Page 10 ATTRA Energy-Ef f icient Lighting for the Farm

11. References Resources
American Society of Agricultural and Biological Engineers Equipment Suppliers
(ASABE). Lighting Systems for Agricultural Facilities. FarmTek
Standard EP344.3. January 2005. 1440 Field of Dreams Way
Darre, Michael. Light and Lighting for Poultry. Dyersville, IA 52040
University of Connecticut. Last accessed February 2010. Toll-free: 1-800-327-6835
www.sp.uconn.edu/~mdarre/poultrypages/light_inset.html www.farmtek.com
Fisher, Paul and Caroline Donnelly. Evaluating Supplemen- www.growerssupply.com
tal Light for Your Greenhouse. Department of Horticulture, Sells many types of lamps and lighting equipment for poultry,
greenhouses and the farm.
Clemson University. May 2001. Last accessed April 2010.
http://extension.unh.edu/Agric/AGGHFL/OFAlight.pdf Real Goods Solar, Inc.
833 W. South Boulder Rd.
Hawes, Robert. Lighting for Small-Scale Flocks. University
Louisville, CO 80027
of Main Cooperative Extension. Maine Poultry Facts.
Toll-free: 1-800-919-2400
Bulletin #2227. Last accessed February 2010.
www.realgoods.com
www.umext.maine.edu/onlinepubs/htmpubs/2227.htm Sells many types of solar lighting components and kits.
Hiatt, Richard. 2008. Agricultural Lighting. Presentation Backwoods Solar
at the Farm Energy Audit Training for Field Advisors 1589 Rapid Lightning Creek Rd.
workshop. Augusta, ME. January. Sandpoint, ID 83864
Lightsearch.com. Lighting Guides. Last accessed April Phone: 208-263-4290
2010. www.lightsearch.com/resources/lightguides www.backwoodssolar.com
Sells 12-volt DC timers and other solar lighting
Ludington, David, Eric Johnson, James Kowalski, Anne components for do-it-yourself solar poultry lighting.
Magem and Richard Peterson. 2004. Dairy Farm Energy
Efficiency Guide. Ithaca, NY: DLTech, Inc. Rooster Booster Poultry Lighting
Selmech Supplies Ltd
Natural Resources Conservation Service. Energy Self 19 Norton Enterprise Park
Assessment. http://ruralenergy.wisc.edu/conservation/lighting/ Churchfields
default_lighting.aspx Salisbury
Wiltshire
Peterson, Richard. 2008. Energy Management for Dairy
SP2 7YS
Farms. Presentation at the Farm Energy Audit Training for
Phone: 01722 413440
Field Advisors workshop. Augusta, ME. January.
www.roosterbooster.co.uk
Sanford, Scott. 2004. Energy Conservation in Agriculture: Sells lighting equipment for poultry.
Energy Efficiency Agricultural Lighting. University of
ACF Greenhouses
Wisconsin - Cooperative Extension Publication (A3784-14). 380 Greenhouse Drive
Madison, Wisconsin: University of Wisconsin. Buffalo Junction, VA 24529
Tabler, Tom. 2009. Energy-Efficient Lighting. Presentation Toll-free: 1-888-888-9050
at the Southeast Asian American Farmers Association www.littlegreenhouse.com
meeting. Clarksville, Arkansas. October. Provides resources on greenhouse lighting design and sells
equipment for do-it-yourself projects.
U.S. Energy Information Administration. Voluntary
Reporting of Greenhouse Gases Program. Last accessed EnviroCept Greenhouses & Supply
April 2010. www.eia.doe.gov/oiaf/1605/ee-factors.html P.O. BOX 914
Benton City, WA 99320
U.S. Department of Energy. Energy Savers. Last accessed Toll-free: 1-888-326-8634
April 2010. www.energysavers.gov/your_home/lighting_ www.greenhouses-etc.net/lighting
daylighting/index.cfm/mytopic=11980 Sells greenhouse lighting equipment for large commercial and
do-it-yourself projects.
U.S. Department of Energy. EnergySTAR. Lighting.
2006. Last access June 2010. www.energystar.gov/index. Visit ATTRA’s Directory of Energy Alternatives (www.
cfm?c=business.EPA_BUM_CH6_Lighting attra.ncat.org/dea) for a state-by-state directory of alternative
www.attra.ncat.org ATTRA Page 11

12. energy installers and consultants, or call ATTRA EnergySTAR
at 1-800-346-9140. www.energystar.gov/index.cfm?c=products.pr_find_es_products
Provides guidance on selecting energy-efficient lamps
Tools and Websites and fixtures.
EnergySTAR Lighting
Lighting Self Assessment Tool www.energystar.gov/index.cfm?c=business.EPA_BUM_
http://ruralenergy.wisc.edu/conservation/lighting/default_ CH6_Lighting
lighting.aspx Discusses lighting application considerations and
The Lighting Energy Self Assessment Tool available from the general lighting.
USDA Natural Resources Conservation Service is designed to EnSave
estimate your current lighting energy use based on your inputs www.ensave.com
and to suggest more efficient alternatives. This commercial site off ers technical papers on efficient
lighting and other farm energy topics.
Energy Savers – Lighting and Daylighting
Rural Electricity Resource Council
www.energysavers.gov/your_home/lighting_daylighting/index.
www.rerc.org
cfm/mytopic=11970 National clearinghouse and technical support provider on
The Department of Energy (DOE) Energy Savers energy efficiency with an emphasis on rural applications.
website provides information and resources on energy-
efficient lighting and daylighting. Wisconsin’s Focus on Energy
www.focusonenergy.com
Lightsearch.com Wisconsin-based program providing information, resources
www.lightsearch.com/resources/lightguides and financial incentives to help implement energy-efficient
This commercial site provides a large list of lighting design and renewable energy projects. Agricultural and Rural
formulas and other useful lighting tools. Business Programs provides information on energy efficiency
for agricultural producers.
Center for Ecological Technology Biological Systems Engineering
www.cetonline.org www.uwex.edu/energy/AgEnergy.html
Organization provides publications and links on energy- A University of Wisconsin – Madison resource that provides
efficient and renewable energy technologies. guidance on lighting and other farm energy topics.
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.html
or
www.attra.ncat.org/attra-pub/PDF/farmlighting.pdf
IP369
Slot 368
Version 083110
Page 12 ATTRA