Principles & Environmental Benefits:
Inda-Gro
Electromagnetic Induction Lamp
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Lighting and the Environment
Global Warming is a growing concern and there
is a heightened desire to reduce our environmental footprint. In many
cases, the technology to do so is readily available but often too
expensive to implement.
For example, pollution scrubbing technology used for factory smokestacks
while available, is costly, disruptive to install, and in some cases may
consume more energy (thereby actually adding to carbon output from energy
production) than the environmental remediation benefits it offers. On the
other hand electrode-less magnetic induction lamps are a cost effective
way to implement an environmentally friendly technology while also
reducing environmental impact in several areas.
As you’ll learn here; we’ll consider reducing electrical energy use in
lighting and its attendant reduction of C02 production from power
generation; secondary energy reduction through lower thermal loads in
buildings; reduction of material usage and manufacturing energy; and
reduction of mercury content and its impact on the environment by the use
of induction lighting products and controls.
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Electrical Conversion
Efficiency
Electrical conversion efficiency (sometimes stated as conversion
efficiency) is a measure of how well a lamp converts electrical energy
into light. The conversion efficiency is stated in Lumens per Watt (L/W)
and is usually in a range since there is some economy of scale where
higher wattage lamps tend to have better conversion efficiencies than
lower wattage lamps of the same type.
For example, the common incandescent lamps we are all used to, generally
have a conversion efficiency of between 12.5 and 19 lumens per watt.
Induction lamps have conversion efficiencies in the 70 to 84 Lumens/Watt
range. This means you get more light output for the same amount of energy
input, or, stated another way, the same amount of light (when comparing
lumen output) for less energy input.
We’ll go into more detailed design issues in the next section. But for the
purpose of the energy consumption when dealing with the side by side
comparisons of various lamp types the induction lamp will deliver the
perceived light levels at 50% less of its alternatives.
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Understanding Apparent
Brightness
There is wide agreement and scientific data that shows how the spectral
distribution of the light produced by a particular lamp affects human
vision and plant growth differently. Higher blue output, sometimes
referred to as High Scotopic Output lamps, appear brighter to the eye than
the same wattage of lamp, with the same conversion efficiency, but with
little or no blue output. Thus the lamps spectral output of light that is
useful to the human eye is also a factor in perceived light quality and
brightness or a phenomenon known as Apparent Brightness while plants
require narrower bands of ultraviolet and infrared that maximize
chlorophyll absorption specific for the plants stage of growth
development. This measurement is known as photosynthetic active radiation
or PAR for short.
There are two types of lumen output which the human eye can perceive. The
first being Photopic and the cones within our eyes see this light in
daylight values as measured in Lumen, Lux or Foot Candles. Utilizing
conventional lighting design we would factor the project’s Design Lumens,
in Photopic values only and measured with a standard light meter.
The second type of lumens are called Scotopic, which represents the
sensitivity of the eye under typical interior or night lighting conditions
and cannot be measured directly with a standard light meter. Scotopic
lumen output is registered by the rods of the human eye and also controls
pupil size directly effecting visual acuity for given task levels.
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Understanding
Visually Effective Lumens (VEL)
While there is currently no scientific or an industry wide consensus for a
terminology to describe the Apparent Brightness phenomenon, there is
growing use of the term Visually Effective Lumens (VEL) or Pupil Lumens as
a way to not only describe it but to accurately measure these levels as
well.
As we discussed earlier, the conventional lighting design recognizes the
Photopic lumen output values only. To gain the complete benefits of a
lamps VEL values it becomes necessary to adjust the Photopic values during
the design standard since the minimum lumens normally associated with a
given task (LUX = Lumens per sq/ft) or Foot Candles (FC) values.
Design levels, as you’ll see a bit later here, that only rely on a lamps
FC or LUX are much less energy efficient since they do not take into
consideration the additional light output and it’s Apparent Brightness
when factoring that lamps Scotopic lumen output and upwardly adjusting the
lumen output within the VEL values.
The VEL of a lamp can be determined by multiplying the output in lumens by
a conversion factor. The conversion factors are derived from the
Scotopic/Photopic Ratio (S/P ratio) of a lamp. The S/P ratio measure the
amount of light being output in the Photopic sensitivity region, and the
amount of light output in the Scotopic sensitivity region, of the human
eye, and then derives the ratio of the two.
When the ratio is used as a multiplier of the actual output lumens, the
amount of light useful to the human eye (VEL) can be determined. For
example, a 100 Watt incandescent lamp with a conversion efficiency of 30
L/W provides 3,000 Lumens of light – multiplied by it’s S/P ratio of 1.4,
it is producing 4,230 VEL – light useful to human vision. The S/P ratio
correction factor drastically changes the conversion efficiency of the
lamps.
The lamp type which has the highest conversion efficiency, Low Pressure
Sodium (SOX) at 100~180 L/W, is now one of the least efficient light
sources at 35~63 L/W when corrected for S/P ratio. This is because the SOX
lamps produce nearly monochromatic yellow light. While they score high on
the Photopic curve (where conversion efficiencies are measured), they
score low when corrected for VEL due to lack of blue output. SOX lamps are
an excellent example of why these conversions our useful for a more
accurate measurement relative human vision or plant spectra.
The induction lamps have the highest energy conversion efficiency once the
correction factor is applied (as they have a high S/P ratio of 1.96 or
2.25 depending on model). Induction lamps are therefore a better choice as
they produce more light useful to the plant while using less electrical
energy.
With this information in mind we can now compare light sources, based on
the actual amount of VEL which they produce.
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Chart I Measuring Energy
Efficiency: Shows how different
light sources Design Lumen readings compare when read by a standard light
meter and measured in Conventional Photopic Lumen values. For lighting
design that wishes to maximize energy efficiencies by specifying light
sources with both high Scotopic and Photopic Lumens, a Correction Factor
(S&P Ratio) must be applied to the Photopic Lumen per Watt readings. When
applying this correction factor you will notice drastically different
usable light outputs as measured in VEL. Higher VEL/W will significantly
reduce the amount of energy necessary to satisfy the plants lighting
requirements.
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Measuring Energy
Efficiency |
| Design
Lumens |
Conventional
Lumens per Watt |
Correction Factor
(S&P ratio) |
Pupil VEL per Watt |
|
Induction Lamp (5000K) |
85 |
1.96 |
166.6 |
| Metal Halide |
85 |
1.49 |
126 |
|
Warm White Fluorescent (2900K) |
65 |
0.98 |
64 |
| Low-Pressure
Sodium |
165 |
0.38 |
63 |
|
High-Pressure Sodium |
65 |
0.76 |
49 |
| LED (5000K) |
20 |
2 |
40 |
|
Tungsten Halogen |
22 |
1.32 |
29 |
| Standard
Incandescent |
15 |
1.26 |
19 |
|
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Chart 2 Apparent Brightness:
Shows actual Photopic and Scotopic Values with different lamp
types and how bright they appear to the eye. This perceived value is known
as Apparent Brightness and is not measured in the conventional Lumens, Lux
or Foot Candle readings. Apparent Brightness is then measured in Visually
Effective Lumens (VEL). Induction VEL values are much higher at lower
wattages than the HID lamps.
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Apparent Brightness |
|
Type |
Wattage |
Photopic Value |
Scotopic Value |
VEL |
|
Induction |
100 w |
9,625 |
19,250 |
16,527 |
|
200 w |
20,500
|
41,000
|
35,201 |
|
250 w |
27,200 |
54,400 |
46,706 |
|
400 w |
54,090 |
108,180 |
92,883 |
|
High Pressure Sodium |
150 w |
11,250 |
8,550 |
9,082 |
|
250 w |
22,100 |
16,796 |
17,841 |
|
400 w |
36,000 |
27,360 |
29,063 |
|
1000 w |
90,000 |
68,400 |
72,630 |
|
Metal Halide (Pulse Start) |
150 w |
8,000 |
11,920 |
10,919 |
|
250 w |
15,000
|
22,350 |
20,473 |
|
400 w |
28,000 |
41,720 |
38,216 |
|
1000 w |
93,000 |
138,570 |
126,940 |
|
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Secondary Design
and Energy Consumption Factors
Ballast Overhead: An additional factor which
must be taken into account when considering lighting fixture energy
consumption is ballast overhead. Almost all modern, high output lighting
systems, use some form of ballast to control the energy provided to the
lamp. The two most common types of ballast are the so-called core & coil
ballasts (magnetic) and electronic ballasts.
* The core and coil ballasts use coils of copper wire wound around an iron
core to form a special purpose transformer which controls the electrical
energy provided to the lamp. The ballast may have additional components
which perform other functions such as a starter circuit. The core and coil
ballasts typically consume between 10% and 15% of the energy fed to the
lighting fixture. This is wasted energy that usually just produces heat
and detracts from the efficiency of the lighting fixtures.
* Electronic ballasts perform the same function of controlling the energy
fed to the lamp and providing a start pulse if required, but they do this
using electronic components rather then a transformer type ballast. As a
result, they are very efficient since they can use active feedback control
and a microprocessor to keep the lamp within correct operating parameters.
In the case of the electronic ballasts used for induction lamps, only 2%
of the total system energy is lost on the ballast. When we take ballast
overhead into account, the induction lamps have significantly lower losses
than most conventional lighting.
Electricity Production and CO2
Emissions: Carbon Dioxide (CO2) is a greenhouse gas which traps solar
radiation (heat) in the Earth’s atmosphere increasing global warming and
climate change. In North America, average electrical power generation is
71% from fossil fuels [coal and gas] and 26% from fossil fuels in Canada.
Most of the CO2 emissions in the USA are from the generation of
electricity.
Burning fossil fuels to generate electricity emits C02 into the
atmosphere. Figures for the amount of CO2 emitted per Kilowatt hour of
electricity generated vary from .612 Kg/KWh (1.35 Lbs/KWh) in the USA.
These figures can vary widely depending on the mix of fossil fuel and
other types of generating plants in use. For the purpose of this paper, we
will use an average figure of 0.43 Kg/KWh (0.95 Lbs/KWh) in our
discussions although the reader should bear in mind that this figure will
be higher in the USA due to extensive use of coal. By reducing electrical
power consumption, we not only save money, but we also reduce the emission
of CO2 into the atmosphere from power generating stations.
Based on operating the lighting fixtures 24/7 for one year, replacing the
Metal Halide lamp fixture with an induction lamp fixture will reduce CO2
emissions from electrical power generation by 1,270 Lbs or about 55%.
Again, this is the figure for one fixture and typically there will be
dozens or even hundreds of fixtures in a facility¦ thousands when
considering a city or region. Replacing inefficient lighting technologies
with energy efficient Induction lamps, can contribute to significant
energy consumption savings and CO2 emissions reduction.
The primary mode of energy reduction from replacing conventional lighting
with energy efficient lighting fixtures is the energy savings on
electrical consumption. However there are also other ways that energy
efficient Induction lamps can reduce energy consumption and its attendant
environmental impact.
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Thermal Loads:
The Ballast overhead, which we discussed earlier, represents the loss of
electrical energy in the ballast. This lost energy manifests primarily as
heat, which is added to the heat output by the lamp itself. This heat
output is the thermal load contribution of the fixture or the amount of
heat it contributes to the space in which it is operating.
The 250W Metal Halide lamp we have been using as an example, will
contribute 25W or more of heat (for each fixture) to the space it is
operating in. In effect, each lighting fixture becomes a 25W [or more
depending on the heat output from the lamp] radiant heater.
In winter conditions, when the space must be heated, this is a welcome
contribution and represents energy that can be used. In spaces which are
air-conditioned, the thermal load of the lighting represents additional
heat that must be removed by the HVAC system with adds to energy
consumption. While this is, generally speaking, a small amount of heat, in
applications such as cold-storage facilities or commercial/industrial
freezers, the thermal load from lighting can represent a significant
fraction of cooling costs.
By installing Induction lamps with efficient electronic ballasts, where
both the ballasts and the lamps operate at lower temperatures than Metal
Halide or High Pressure Sodium fixtures, there are secondary energy
savings to be gained from the reduced heat load produced by the induction
lighting fixtures.
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On-Demand Usage
In some applications, for example an infrequently visited section of a
warehouse or storage facility, the management must keep Metal Halide and
High Pressure Sodium fixtures operating continuously. These types of
fixtures (and almost all other high-light-output fixtures) are not
designed for instant on or multiple on/off switching of the fixture. These
lamps require some time to warm up to full output. Therefore it is
impractical and inconvenient to turn them off in applications where the
usage is predicated on staff activity, since people entering the area will
have to wait 5 to 15 minutes for this type of lighting to reach full
output. >
On the other hand Induction lamps are considered instant-on since they
typically start operating at around 80% of maximum light output, and reach
100% of output in a very short time (90 to 240 seconds depending on the
model).
Indoor grow applications that may utilize solar tube or skylighting
systems for indoor lighting contribution may elect to switch off the
Inda-Gro fixtures when the outside light levels are measured high enough
for the task levels thereby further reducing thermal load as the lights
are only operated as needed. This can be a significant energy savings when
compared to MH or HPS fixtures operating continuously in a similar
application and require the cooling systems to overcome their thermal
contributions.
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Environmental
Resources Consumption Considerations
All lighting fixtures require resources of material and energy to
manufacture. Since it is almost impossible to find figures for the
resources and energy required to manufacture lamps and lighting fixtures,
let us consider only the resources entailed in manufacturing replacement
lamps.
When a lamp is first struck on it will be producing the most lumens it is
capable of. This lumen output is known as the lamps Initial Lumen Output.
From this point a lamps lumen output reduces as it ages. This reduction in
lumen output known as the lamps Lumen maintenance and is a measure of how
well a lamp type maintains its light output over time.
While Lumen Depreciation occurs in all lamps as they age, lumen
depreciation levels over the lamp life can vary between a 70% loss of
lumen output (HID lamps) to no more then 30% (induction) of their initial
lumen output.
The information for Lumen depreciation is usually published as Lumen
maintenance curves. The lumen depreciation of a lamp type will determine
how often it must be replaced. Experts recommend that lamps should be
replaced once they have depreciated to 70% of their initial output. While
a drop in light output from a lamp of up to 15% is almost imperceptible to
the human eye, a drop in light output of between 15% and 30% is quite
noticeable to the human eye. Once the light output from any lamp falls
below 70% of initial output, it is considered due replacement.
MH and HPS lamps will require far more frequent lamp replacement than the
Induction lamps. If, for the sake of simplifying the example, we presume
that the amount of energy and materials needed to manufacture one of each
kind of lamp is the same, then we can see that using MH lamps consumes 8.7
times the resources, and the HPS lamp consume 5.8 times the resources,
compared to the materials and manufacturing resources for an induction
lamp. Induction lamps therefore conserve resources and reduce waste due to
their long lifespan.
Those materials have to go somewhere once any lamp reaches end of life.
While expired lamps used in industrial/commercial applications typically
end up in the landfills, much of the materials in the lamps, such as the
glass and metals, can be recovered and recycled.
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Mercury Utilization:
Almost all modern high output light sources depend on using mercury inside
the lamps for operation. When considering the environmental impact of the
mercury in lighting, we must take three factors into consideration:
* The type of mercury (solid or liquid) which is present in the lamps,
* The amount of mercury present in a particular type of lamp, and
* The lifespan of the lamp which will determine the amount of mercury used
per hour of operation.
Liquid mercury, which is the most common form of mercury used in lighting,
represents the greatest hazard. If a lamp is broken, the liquid mercury
can find its way into cracks in concrete flooring, the fibers of carpets,
or into spaces in other floor coverings. Over time, the mercury will
evaporate into the atmosphere causing a local hot spot of low level
contamination. The more liquid mercury present in a lamp, the longer the
resulting contamination will last.
Mercury can be compounded with other metals, into a solid form called an
amalgam – this is the type of mercury used in induction lamps. It is
similar to the once widely used dental amalgam in tooth fillings. The
solid form of mercury poses much less of an environmental problem than
liquid mercury. The small slug of amalgam can easily be recovered (always
wear disposable gloves) in the case of induction lamp breakage and
therefore can be disposed of properly with little or no risk of creating a
locally contaminated area. The solid mercury amalgam is also simpler to
recover for recycling at end of lamp life.
A pellet of Mercury amalgam can be seen in the glass “fill tube” of a
typical round induction lamp. The silver object at the bottom left of the
picture is one of the external inductors. This is easily broken off and
recycled.
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Comparison of Mercury
Utilization for Typical Commercial Light Sources |
|
Lamp type Low Pressure |
Sodium (SOX) High |
Pressure Sodium (HPS) |
Metal Halide 48" |
Fluorescent tube |
Induction Lamps |
|
Average Mercury (Hg) Content (in mg[1] |
GE: 6-8-16
Phillips: 12
|
Osram: 13-20
Sylvania: 12-15 |
GE: 11-30|Phillips: 12-15 |
Sylvania: 40-43
Phillips low Hg: 10-12 |
Miser: 6.4 mg |
| Mercury use per
20,000 hours [2] |
12.4 mg Hg
|
14.3 mg Hg
|
37.8 mg Hg |
27.6 mg Hg
|
1.3 mg Hg |
1. Mercury content taken from
manufacturers data sheets then adjusted as if comparing 100W lamps.
2. The usage figure is calculated from average Mercury content and average
lifespan figures given above (rounded up or down to one decimal place). |
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Induction lamps use the least amount of mercury of any lamp technology,
when considered based on both initial quantity and amount used per 20,000
hours of lamp life. Induction lamps are therefore much more
environmentally friendly since they use very little mercury over their
lifespan. Further, the mercury is in solid amalgam form reducing
contamination in the case of accidental breakage and making recovery for
recycling simpler.
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Recycling Considerations:
As mentioned above, induction lamps require much less
resources, in terms of the raw materials for manufacturing, than other
lamp technologies considering the long lifespan of the lamps, and the
number of replacement lamps required by competing technologies. LED
circuit boards cannot be easily recycled and can also be expensive to
dispose of.
Further, induction lamps are simpler and cheaper to recycle. The solid
mercury amalgam is easily removed and can be recycled with little chance
of environmental contamination. The external or internal inductors can be
removed (for metal recovery) leaving a glass envelope free of metal parts
which takes less energy to recycle. Competing lamp technologies have a
significant amount of metal embedded in the lamp envelopes, thus higher
temperatures and more energy must be expended to recycle the components.
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Summary
Like you we at Inda-Gro firmly believe reducing our environmental impact
and carbon footprint are worthy goals which can make a difference in
limiting global warming and climate change. Lighting consumes a
significant fraction of energy production with its attendant CO2
emissions. By installing energy efficient lighting systems, you can not
only reduce energy costs and expenditures, but also reduce environmental
impact through reduced CO2 emissions from electrical generation, reduced
waste and improved recycling.
When comparing various lighting technologies used in industrial,
manufacturing. retail and grow applications, it becomes clear that
induction lamp based lighting fixtures offer the best environmental
characteristics when compared to the most commonly used lighting
technologies.
When compared to the two most commonly used lighting technologies (Metal
Halide and High Pressure Sodium lamps), Induction lamps offer the
following benefits:
* Significant reduction of electrical energy consumption;
* More light output when corrected for Visually Effective Lumens/Pupil
Lumens;
* Significant reduction in CO2 emissions from electrical power generation
due to reduced energy consumption;
* Secondary energy consumption reduction through reduced thermal loads
thereby saving HVAC costs and energy, and the ability to use on-demand
technologies such as occupancy sensors due to the instant on feature of
induction lamps;
* Extended lifespan which reduces the materials needed for replacement
lamps compared to MH, HPS and SOX lighting technology; 1.5-2 times the
lifespan of LED
* Low mercury consumption over the induction lamp lifespan compared to
competing lighting technologies;
* Induction lamps use a solid mercury amalgam which produces significantly
little environmental impact compared to other technologies, if
accidentally broken. The solid mercury amalgam is also easy to recover and
recycle at the end of lamp life; and
* End of life de-construction for recycling and materials recovery
requires less energy.
Magnetic Induction Lamps represent not only a breakthrough in cost
effective energy efficient lighting, but also a sound environmental
choice, when all aspects of the lamp technology are considered.
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