Hey guys, So I was running a 600w HPS flowering tent on 12/12... inside the tent was an oscilating fan using 30 watts, an inline fan using maybe 60 watts, and a dehumidifer using 240 watts on 24/7. I also have another tent with a fluorescent for veg, using 225 watts on 24/7. I just recently switched my flowering tent light from 600 to 750 watts, since it has an adjustable ballast and it's a 1000w bulb. My kWh/daily average went from 30 to 45.... I went to a watt to kWh calculator and put in 150 watts (the difference) running at 12 hours and it says it should only be 1.8.. Do bulbs completely waste power when they get older? Is there some reason to explain why my kWh daily usage should be up this high just from this increase? Are dimmable ballasts bad for this reason?
By time their efficiency decreases and they emit less lumen in general. Also keep that in mind a 1000w lamp does not consume 1000w from your line and it's usually a bit higher, depends on the brand and your setup.(same goes with your ballast and other electrical devices) IMHO have a room for 20% difference overall.
Even with a 20% overall difference in mind though, my kWh increasing by 20 just because I increased it by 150watts for 12h/daily seems insane.. according to the watt calculator I'm using it should only be an increase of 1.8 watts? Sent from my iPhone using Grasscity Forum
Hope I got it right and what I'm gonna say will help you understand and figuring out what's wrong in your calculations. Depends on your circuit and number of devices, you may have some hidden devices as well but that would not even be considered as "kilo"watt per hour and to me a kw/h sounds like a A/C unit or vacuum cleaners running for some reasonable amount of time. Regarding the "daily" usage, personally I haven't seen such thing on my bills. (not where I live, perhaps other countries have such thing.) Calculation of the kw/h and even daily usage is pretty easy and straightforward. Wattage of all devices summed together would give you the kw/h and for calculating your bill you can multiply that by number of your (growing)daily hours. Also keep that in mind they usually charge you by different rates during different periods.(for example 00:00 to 08:00, 08:00 to 16:00, 16:00 to 19:00, 19:00 to 23:59) p.s. That's not your kw/h which has increased by 20 because in that case you'd write your message from a federal prison (Think of kw/h as a 1000w HPS bulb running for an hour, so 'kWh increasing by 20' means you added twenty 1000w HPS to your "current" setup)
Ah, by kWh increasing by 20, I mean the kWh consumed daily. So it's gone from 30 -> 45 ish with only the wattage being upped from 600 to 750.
I'm really suck at math(even elementary one LOL) but assuming that you run a 750w(lets say 800) for 12 hours a day, you'd get: 800x12 = 9600 Which is 9.6kw/h per your (growing) day. Also by adding tolerance for ballast, you'd get somewhere around 9.8 or 10 the worst case. I feel like something is wrong, either in your bill or the counting system or the way they calculate it. If it was about $$$, that "different periods different rates" would apply but in case of kw/h, it's not the way that it should be. And by the ways, WTF 45kw per day? I means you are drawing ~1800w per *hour*. Here I I run ~400w constantly and bill shows ~200kwh per *month*.
So I just took the average of the last 3 days, of which I haven't run the dishwasher and haven't washed or dried clothes. My average was 40.3 kWh consumed daily. This is with me being gone most of all day too, so no lights or gaming or anything of the sort is being run, just the grow lights for the most part, probably 35 kWh of the 40.3 used from the grow alone... The only things I'm running are: Flowering Tent: 750w HPS (12/12) (Should be 9 kWh daily used) 240w dehumidifer (24/7) (Should be 5.76 kWh daily used) 6" (60 watts of 120) inline fan at 50% strength (24/7) (1.44 used daily) Oscilating Fan on Low (Probably 30 of 60 total watts used at 24/7) (Should be .72 kWh daily) Veg Tent: 450w Fluorescents running at 50% so 225 watts (24/7) (Should be 5.4 kWh daily) So 9+5.76+1.44+.72+5.4 = 22.32 kWh daily I have no idea what could be gathering this additional 18 kWh daily....
750w * 12h = 9000Wh = 9 kWh 240w * 24h = 5760Wh = 5.76 kWh 60w * 24h = 1440Wh = 1.44 kWh 30w * 24h = 720Wh = 0.72 kWh 225w * 24 = 5400Wh = 5.4 kWh ---------------------------------------- 22.32 kWh total - the problem here isn't your maths. If anything it's this: There is energy conversion efficiency (watts to lumens) and power draw efficiency (mains to a stable voltage/current distribution). Both of these are going to be factors.