# Energy Efficient School Lighting:

I live right down the road from both of my kid's schools. They are involved with in after school sports.  We end up carting them back and forth at various times of the day.  Last evening I picked them up and I was amazed to see all the lighting on throughout the buildings for the cleaning staff as late as 9 P.M.

One of the areas that I see a tremendous waste of energy is in school Gymnasiums.  I have put together an example showing what it costs to operate 400 watt Metal Halide fixtures.

## Energy Efficient Gymnasiums?

Do they exist?

We all know by now that Metal Halide lighting is highly inefficient (..if you missed our earlier blog posts on the cost of metal halides..check out Energy Efficient Lighting:400 Watt Metal Halide vs. T-5 High Bay OR How To Calculate Watts: 400 Metal Halide vs. T-5 High Bay Fluorescent) and costly to maintain, so why are we still using it?

I know for a fact that in my kids schools the gynasium lights start burning at 6:30 A.M. and don't turn off until 8:30 P.M.

I did a rough count between both gymnasiums thei e are (45) 400 WMH fixtures.

Of those 45, there are usually 4-5 burned out and the rest are well past their lamp life giving you shadows and sub-par lighting.

## Cost of Energy Efficient Solutions

For this example, we will compare the 45 400 Watt Metal Halide to 45 T5 fluorescent high bays and see what we can do.

You can safely use a 4 lamp T5 fixture and exceed the light levels of the 400 Watt Metal Halide fixtures and only use 190 watts compared to the existing 456 watts.

Old =  \$8,577.36 per year to run.

New = \$3,573.90 per year to run.

Your going to have to trust me on the math.

## Less Energy = Less \$\$\$

So lets see what we saved.

Old = \$8,577.36

New = \$3,573.90

Savings = \$5,003.46...which isn't bad, what else can we do?

## Gaining Energy Efficiency with Motion Sensors

If we add motion sensors we can conservatively say that the gymnasium lighting will be on only 70% of the day.

30% reduction in run time = \$1,072.00 in additional savings.

## New Fixtures = Less Maintenance

By switching to Fluorescent we easily double the lamp life over Metal Halide. A very low estimate of maintenance savings is \$500 per year.

There will still be maintenance associated with the new lighting but fluorescent T5 has a life of roughly 30,000 hours.

Metal Halide is roughly 15,000 hours. Realistically, with the motion sensors limiting the burn time the new fixtures could go 10 years with no maintenance. That's a conservative savings of \$5,000 dollars over that ten year period.

## So where does that leave us?

I originally calculated the cost of operating 45 metal halides at \$8,577 per year to run the lights.

By changing the lighting and implementing sensors it looks like this:

Annual savings = \$5,003

Sensor savings annually = \$1,072

Maintenance savings annually = \$500

Grand Total Annually = \$6,575.00

## How Much Does It Cost? vs. How Much Does It Cost Me Already?

The old adage that it takes money to make money is true. Their are up front costs involved with this process. However with the savings and also the readily available municipality incentives, the payback in many cases is around a year.

The mentality of "how much does it cost?" Needs to be replaced with "how much does it cost me already"

## YES, Energy Efficient Gymnasiums Do Exist...Check This One Out...

Take a look at a report we put together about upgraded lighting at the Northwood Hach Gymnasium.  We completed a lighting upgrade just like this example.  See the real savings of upgrading Metal Halide fixtures to T5.