# Blog

## Geek Challenge Results: Football Stadium Stumper

##### Geek Challenge

Last month’s Geek Challenge asked which football related activity used more energy:

A. NFL Stadium Lighting for 3 hours
B. Cooking 20,000 hotdogs
C. Field heating to keep a football field unfrozen at an ambient temperature of 20 deg. F.

We have concluded that the highest energy consumption, and correct answer is Stadium Lighting, A.  Here is a look at all three individually:

A. Stadium Lighting:  Some web searching found the stats for the new NFL stadium in Phoenix, AZ.  Lighting the field are 640 lights at 1,500 Watts each.  That’s 960kW and for the 3 hour game is 2,880 kWh, or 10,370 MJ.

B. Field Heating:  Since I write these questions before we figure out the answers, I must say that this was my odds-on favorite.  Some research found that at Lambeau Field in Green Bay, the field heating system uses 5 boilers delivering a total of 7.2 MBtuh, or 2.1 MW to heat the field.   That is 2.2 times the power of the stadium lights.

However, an analysis by DMC’s newest engineer, Ashley Enderlin, concludes that maintaining the 12 deg. temperature difference in the question scenario, would only require 3 Watts per square foot.  Over the 160 X 360 ft. playing surface, that comes to 170 kW, or 510 kJ for the 3 hour game.  That is only 18% of the energy consumed by the stadium lighting.  This conclusion is consistent with an article in Heating, Piping, and Air Conditioning which states that the capabilities of the Green Bay system are to keep the field heated to 70 deg. F so the grass can continue to grow.

C. Hot Dogs:  There are many normal ways to cook a hot dog including boiling, grilling and microwaving.  With the microwave it is easy to gauge the energy required.  If a 900 W microwave can cook a hot dog in 45 seconds, it that comes out to 40.5 kJ.  Perhaps the most energy efficient way to cook a hot dog is to electrocute it.  This is a classic school science experiment that most people have learned not to do because it is crazy dangerous.  However, a post on EvilMadScientist.com describing this method concludes it takes at most 14.4 kJ per hot dog.  A stadium dog is likely cooked by boiling which is less efficient.  If we conservatively estimate the power consumption to be 100 kJ per hot dog, that still comes out to 2,000 MJ total, which is 20% of the total for stadium lighting.

So if you guessed A, you were right.  Those lights consume about 5 times more energy than the other two items.

There were no correct answers submitted to this month’s Geek challenge.  However, previous Geek Challenge participants will be receiving *exciting* *new* DMC Geek Challenge Pocket Protectors as will future winners!

# kunal
Dear Sir,
Which type of 1500 Watts light?
1.Halogen
2.Mercury vapour lamp
3.LED
4.Metal halide lamps
?