Tennis Lighting: The Life & Slow Death of Metal Halide (2014)

Part 1

(appeared in 2014 Sept/Oct edition of TennisIndustry magazine)

For over 50 years, most tennis courts around the world have been lit with Metal Halide (MH) fixtures, yet few who use them understand their unique qualities.  They SEEM to last endlessly, but that’s far from the truth.  More importantly, the long reign of MH may be coming to an end in favor of new, much more efficient, “green” technology.

For those new to the lighting industry, a little “Flood Lighting 101” is in order.  Metal Halide technology is one member of a family of High Intensity Discharge (HID) lighting systems, which includes street and shopping center lighting.

In HID lighting, electricity heats a metal for several minutes until it vaporizes inside a bulb to give off light, and plenty of heat, which is energy lost.  In this case around 8,000 degrees Fahrenheit, which is a lot of lost energy!  The next
standard for tennis/sports lighting, will prevent this waste.

As you know, MH bulbs are housed inside a fixture, or “Can”, which has reflectors that focus the light from the back and sides of the bulb downward and outward.  It is important to know that MOST current MH light is reflected light from the back and sides of the bulb and not direct light.  This makes a difference in its actual and perceived intensity compared to the direct LED lighting you see in office and home lamps.

For a shopping center or highway, the HID metal to be heated is sodium, which comes in two types, Low Pressure Sodium (LPS) or High Pressure Sodium (HPS).  Each gives off a “champagne”, yellowish color.  LPS and HPS are great for black and white security cameras but not very pleasant for the human eye as it washes out color.  This makes people a bit uncomfortable and they do not want to loiter too long in this light.  On the other hand, LPS/HPS is VERY efficient, very cheap, and long lasting so it is great for parking lots, alleys, and highways.

For sports, the metal of choice inside the bulb is mercury.  Older players might remember the name “Mercury Vapor”.  Since mercury gave off a “blue-ish” light, trace amounts of other metals (or halides) were added to help stimulate our eye’s sense of color, so “Metal Halide” was born.  MH is also MUCH better for a television camera so prime time sports went “cha-ching”!

The MH Downside

First, experts tell us that MH bulbs lose about 5-10% of their illumination PER YEAR!  This is according to Ricc Bieber (Bieber Lighting Consultants) and Greg Moreland (Moreland Lighting LLC).  Most lamps we know are either fully on performing near maximum, off, or burned out.  But MH is different in that it degrades quickly then levels off for years.  Also, most lamps familiar to the public do not require warm up.  That 6,000 degrees takes a while!

Why do the experts say ”5-10%”?  It’s because a hot MH bulb attracts dust and particulates like the warm computer at your desk

and some environments have more particulates in the air than others.  Either way, it’s a significant drop in performance.

(Above)  The lighting tech approaches a very cloudy lens.  Then he secures a clean bulb and lens.  Notice the reflections.

A recent experiment conducted by the author, Bieber Lighting Consultants, and Moreland Lighting LLC confirms this and more.  We compared the illumination of old 1000 Watt MH bulbs behind dirty lenses, clean lenses, and new 1000 Watt MH bulbs, all with two types of light meters.

Our results showed that just cleaning the lenses can result in up to 24% more light, and replacing the old bulbs created up to another 40% more light to the court.   Plus, it’s smart to do both at once.  My vendor charges $105 for the trip, $95 per lamp (for six or more per court), which includes labor.

At that time, all capacitors should be checked and changed if needed and noisy transformers replaced.  For an 8 light court, I plan to budget $900 to clean the lenses and replace the bulbs from my vendor.  More details on this in Part 2.

Now you know that MH performance drops quickly each year.  It flat lines at what lighting experts call “Mean Lumens” which, is around 40% of new bulb capacity.  This is despite the fact that it often still ignites and might “appear” to work for many years after that.   Here are our MH lighting tips to facility operators and tennis directors:

1) Clean lenses and properly operating MH bulbs SHOULD be uncomfortable to look at directly.
2) Bulbs and lenses can be cleaned but NEVER the reflectors.
3) Budget for MH bulb replacement and lens cleaning at the same time, between 3 to 5 years max.

What’s Next?

In Part 2, we will review the hard costs of running MH lights and compare them to their most likely successor.  For now, picture MH lighting like 8 hair dryers on full blast at their 1000 Watt setting, with diminishing performance every year, and significant repair costs.  There must be something better than that, right?

What if the next technology could save 70% or more of that power and produce better light?  What if it was guaranteed to go maintenance free for 7 years?  What if it used American raw materials, created American manufacturing jobs, and could have custom designs for your facility?   I would give that a big, patriotic, and green “WOW”!  Investment anyone?

Here’s a peak at a possible custom design:

Like the racket design?  Me too!  More peaks in Part 2.

Part 2

In Part I, we outlined some of the downsides to current Metal Halide (MH) lighting, but don’t get me wrong.  MH has served us well for a VERY long time.  Now its time for the details, why we need a change, and what the next technology has to offer.  Let’s start with the hard costs of MH.

MH Maintenance Costs

What does MH cost per court and what can be saved?  Well, we have to make some assumptions, but this analysis will give you an “apples to apples” point of comparison between an MH court and its most likely successor, LED technology.  A typical tennis court has 8 MH fixtures (called “Cans”) of 1,000 Watt bulbs or 8000 Watts total.  Assumptions:  a busy outdoor facility might run them an average of 4 hours a night (an indoor club obviously MUCH more) and 180 nights a year (some climates more, some less).  In my city an hour of electricity (a Kilowatt Hour or KWH) costs about 15 cents, times 8 fixtures or $1.20 per hour to light one court.  Multiply by 4 hours and you get $4.80 for the night, times 180 nights a year is $864 in electricity costs to light one court.  For 7 years, electricity costs $6048.  I’ll tell you why we need to use 7 years of power costs below.

My local lighting maintenance vendor charges $105 for the trip, and $95 per lamp or $865 for an 8 lamp court, not including needed transformers, capacitors, and tax, so lets round up to

$900 per court.  Individual bulbs may burn out sooner, but this is a reasonable average vendor cost for a budget to maintain appropriate light levels described in Part 1.  On an 8-fixture court, over a 7-year period (tell you why “7 years” soon!), you should replace all 8 bulbs twice near the beginning and end of this period, or  $1,800.  So we have $1,800 in maintenance plus $6048 of electricity over 7 years gives a total operating cost of $7,848.  

What Can We Expect Next?  Instead of a bulb that loses enormous amounts of energy to heat and sends light in all directions, the likely successor to MH is based on a Light-emitting Diode or LED.  You know them from the electronic screens in your TV, phone, and computer.  So, why hasn’t LED technology jumped into sports as quickly?  

First, even the major lighting companies like Phillips and Sylvania have struggled trying to push enough electricity into the light emitter for sports.  But unlike the heat in your computer, the heat for a sports light must be dissipated passively without a fan.  Right?  It’s been a tricky problem but there are also obvious and HUGE incentives to get it right.  Direct light is much more efficient because over 50% of MH light is reflected and tends to spill where it is not wanted.  LED light can be easily directed to where it’s needed most on the playing field.  In these new sports lamps, the light emitter is encased in 3 inches of shatterproof, solid glass without an air gap.  The manufacturer calls it “Explosion Proof” and it might be bullet proof too.  Since there is no air at the LED, there is no air pollution, dust, or condensation to block its light over time like MH.

In the pictures below, you can see the clear glass lens and the spokes that passively draw heat away.  The core design you see here is EXTREMELY sturdy.

Clearly, and thankfully, the days of the old square “Can” can now be history.  LED technology lends itself to an open architecture of customized mounting design choices (see a couple in Part 1).  Here are a few more:

This customization also favors native, medium sized companies that are able to quickly adapt to end user needs.  These companies would use American raw materials, American employees, and new American factories serving a very large new market.  That’s why we say, “Investments anyone?”

Unlike an MH “can”, an LED lamp stays room temperature saving on air-conditioning for indoor use.  It won’t break or explode, won’t attract dust or condensation, is instant on/off, does not degrade in performance, can be placed on a motion sensor or a dimmer for mood lighting a party, and can even be remotely controlled from a smart phone.  That deserve a high tech “Wow”!

Despite these creative designs, the best innovation is the savings.  LED technology is an impressive, environmental alternative to MH power consumption because there is very little wasted electricity.  We will know soon if the electricity/maintenance costs will be merely enormous, or spectacular.  As of now, it is not known if one or two LED fixtures will be equivalent to one MH 1000 Watt fixture.   One complication is that the two light sources cannot be compared with a standard light meter.  Yikes!

Operating Costs/Savings

To give you MORE than 1000 Watts of equivalent light with better distribution, you would need to change each can and pole arm to a fixture for your court that holds one OR two LED fixtures.  Let’s assume two for now. Two of the LED fixtures pictured above use ONLY 300 Watts!  Even if two are needed, 16 LED’s per court (2,400 Watts vs 8,000 Watts) is an enormous 70% savings or  $5494 in JUST electricity over 7 years.  That deserves a high tech, very green, WOW!   Plus, there’s more.

The service costs are also impressive.  Because the LED emitter is encased in shatter proof solid glass, mounted to a heavy gauge aluminum base, the parts/bulbs are unconditionally, 100% guaranteed for 5 years but the expected life is 10 years for the LED chip and the housing is guaranteed for 20 years.  ===>  That’s why the manufacturer advises a conservative, budgeting choice of 7 years maintenance free.   They will very likely go longer.

So, we have another $1,800 saved in maintenance, plus $5494 in electricity, for a total of $7,294 over 7 years.  Pretty impressive for one court huh? Again, unlike an MH bulb, this lamp stays room temperature so it doesn’t push air conditioning, does not attract dust or condensation, is instant on/off, does not degrade in performance YEARLY over time like MH, can be placed on a motion sensor, and can even be remotely controlled from a smart phone.  That deserves another WOW!

Installation Costs

These LED fixtures are designed so that any licensed electrician can do the job.  To remove the 8 old arms/cans and install the new LEDs on 8 poles, in parts and labor, is around $15K, so over 7 years about 50% of those costs are returned, at CURRENT electric rates.   Most general contractors will agree that‘s pretty impressive for any construction upgrade.

Will electricity costs stay the same?  What if just one LED fixture can replace a typical MH lamp?  What about LED’s for football, baseball, and basketball?  Here’s another option we would like to see get the “green” light:Yes, it’s possible sports lighting of the future might be powered by the sun!  The mind truly boggles at the prospects for LED’s in sports and new American workers to get the job done.