Keep Your Light Bill Down! Ohm's Law

What is Ohm's Law? Does Ohm's Law hold true for ballast operated lighting? Uh huh. So, I have three 150w hps systems spread over a 2ft. x 5ft. area. Each ballast uses 3.2 amps of current to operate. Total of 9.6 amps of current. Now, Ohm's law states that I multiply Voltage x Current and that tells me how much wattage is being billed by my Electric company.
9.6amps x 120volts is 1152 watts. Thats right, three little 150w hps light that put out 45000 lumens total combined now cost as much to run as one 1000w hps.

So lets recap, You can have: Two 400w hps systems, four 5000k 100w (23 actual) cfl's all combined totalling over 100,000 lumens and a 100 cfm exhaust fan for the same monthly cost as 3 LITTLE 150w hps lamps.

Wow that is crazy

yep, i switched to a 150 hps from 460actual watts of cfl's.... now they are growing much faster and the bill is alot lower...... i found the other day a led light that will replace the 150 watt hps and uses 15 watts. been doing research and from what i understand led's are excellent for the veg phase. as soon as i get the money i'm switching... at least in my veg room. we'll see downthe road for the flower room as led's dont work as well in flower...

by the way, actual wattage for your 150 hps is 165 watts.

heres the figure for finding your monthly electric usage.
hours run (times) watts (divided by) 1000 (times) what you pay per kwh (times) 30 days

for instance: 18hrs. (times) 165watts (divided by) 1000 (times) in my case .30cents (times) 30days. = $26.73 per month on 18/6 light cycle..... this is only the light, not the fans and other equipment running.

happy growing with low energy costs......

I made the classic newbie mistake and went to Home Depot to buy my lights. After taking the lights apart and making my ballast setup for all 3 ballast, is when I realized that each ballast is pulling 3.2 amps. at 120 volts. That 150 watt light uses 3.2 amps multiplied by 120 volts which equals 384 watts.. Please feel free to check a few sites and see the ratings on each ballast set up. THE WATTAGE OF THE BULB MEANS NOTHING..
THE AMPS USED BY THE BALLAST ARE ALL THAT MATTER. Also, please remember that increasing voltage does not reduce your light bill.. NO MATTER WHO TELLS YOU DIFFERENT. A ballast with 4 amps at 120 volts can also be configured to run on 240 volt at 2 amps. Your current is cut in half BUT You dont get billed by current draw you get billed by wattage. Look at the specs. on any ballast and you will see that if it has the capabilty to run at different voltages you will notice Amperage is cut exactly in half. That being said. 120 volts x 4 amps is the same as 240 volts x 2 amps which is the same as 480 x 1 amp.