Quartz vs HID Lighting

Which is Cheaper? A 500 watt Quartz Flood or a 150 watt High Pressure Sodium Flood?

Which gives more light? A 500 watt Quartz Flood or a 150 watt High Pressure Sodium Flood?

Which is Cheaper? A 500 watt Quartz Flood or a 150 watt High Pressure Sodium Flood?
It's a trick question, really.
The answer is-- Although a Quartz fixture costs far less to purchase initially, $16 compared to $77 for the High Pressure Sodium flood light, it is actually far more costly over a 10 year period, by over 900%!
Here's a 10 Year cost comparison between a Quartz fixture and an HPS fixture that produces equal light output

Fixture and Wattage

150 watt HPS

500 watt Quartz

Light output in lumens:

16,000 lumens

10,500 lumens

Lamp Life

24,000 hours

2,000 hours

Initial Fixture Cost

$77

$16

Annual Electricity Cost @ $ .07 kwh*

$30

$300

Electricity Cost over 10 year lifetime

$300

$3000

Lamp life @ 10 hours per night

6.8 years

7 months

Lamp replacement costs for 6 years

$24

$264**

Total Lifetime Cost

Which gives more light? A 500 watt Quartz Flood or a 150 watt High Pressure Sodium Flood?
Another trick question.
The answer is-- Although 500 is indeed more wattage than 150, the lights are very different in their ability to convert watts (power) into lumens (light).
In other words, the highly efficient 150 watt HPS fixture converts watts to lumens so efficiently that its lumen output (16,000 lumens) is about equal to the less efficient 500 watt quartz fixture (10,500 lumens).