Ok i'm a bit confused with something. Could someone please explain to me the difference between the power that a light consumes and the power a light emites. Now i know i'm going to sound like a total idiot but, iv'e been reading around forums and looking at people saying stuff like, if you use a hps thats 400w and then maybe another 40 for the fan, ect... When i add up the total of watts i got on, and then find out the total kwatts and then taking the total of hours i have my stuff on over the amount of days they are on and multiply the price per hour for the amount of kilowatts i'm using. IT DOESNT ADD UP. IT'S A HUGE BILL. IVE NEVER PAID FOR ANYTHING SO EXPENSIVE FOR IN MY LIFE. All together i have 415watts running, that's .415 kw right?
Yes, and you are charged in units of kwh, kilowatts used in one hour. Suppose it's 8 cents per kwh... .415 x .08 = 3.32 cents per hour 3.32 cents x 18 hours = ~60 cents a day, or $18.00 per month Seems pretty straightforward to me... you just need to know what your kwh rate is, and whether it varies between day hours and night hours***. Great info here...
I have a problem because i'm using LED lights and the thing is, i know they output a total of 345 watts, it's just that i don't know how much electricity they are using because i know there's a thing about incadecent lighting and i really don't have a clue how to find the right mesurement if that is the case. If it's outputting 345 incadencent, how much is it really consuming?
Bro - if you're using LEDs then they are NOT consuming enough power to raise your bill enough to gawk at. Unless you're house glowed. LEDs are extremely efficient. So it's something else. You're wiring, AC, appliance...something in that place is eating up the juice. For a test, and it's REALLY easy to do.... Walk out side and count how long it takes for your meter to spin 1 turn. If it's a digital meter then write down the reading and measure it until it updates (usually 10seconds). Now go in and ONLY shut off your LEDs. Now go back outside... see any difference? You shouldnt. And if you don't, then it's something else eating power. If you do - then you've got some seriously fucked LEDs my man....
Charges for KWH can change as your consumption raises,tiers 1-5 here. You need to first find the actual watts used,i use a simple battery back-up used for my LCD TV with several plug ins and an LED read out which tells me what the device or devices are using at that time. Costco and sams club both have them too.
You are asking two fundamental questions, one of which has been answered (how to determine the electrical cost of your grow op. But your other question reflects a gross misunderstanding -- your lights do not output wattage. Wattage is a measure of electricity as parsed out by the power company and as consumed by electrical devices. So if your LEDs are a total of 345 watts, that means they consume 345 watts for each hour they are on. That is how much electricity they are using. You cannot directly and easily translate watts consumed into light output because different kinds of lights have different efficiencies by which they convert that consumed electricity into light. Regular incandescent household bulbs are very inefficient, much of the energy consumed gets converted to heat rather than light. LEDs are very efficient. You will sometimes see CFLs (and possibly also LEDs though I don't know) marketed as having the equivalent light output of a xx watt bulb. This is just a shortcut way of referring to light output that we are all familiar with -- we all have a general sense of how "bright" a 75w regular bulb is, for example, even though the wattage is not a measure of the amount of light, so to try to sell CFLs as a replacement for these bulbs companies rate them as having an equivalent light output. What they are really saying is that this CFL is rated at about the same lumens as a 75w incandescent bulb. Lumens is a standardized way of comparing the amount of light a bulb gives off, specifically the amount of light at a distance of 1 foot. But that still isn't a measure of how much light you are delivering to your plants because you have to factor in the distance. Light intensity is the inverse square of the distance, meaning that if you move the light to half the original distance (say from 1 foot to 6 inches) then you have quadrupled the light intensity being delivered to the plant.
That is correct if your light is a point source (or approximately so). It doesn´t work if your light is a line source (or approximately so) - like a long fluorescent tube - where a simple linear inverse relationship applies - half the distance, twice the intensity.
Totally agree cantharsis. A tube fluoro will have a variety of distances that the light source is from the plant. To expand on the inverse-square-of-the-distance concept, this is why LST or scrog is so beneficial in particular for an indoor grow. If you are growing a 3-foot tall plant under a light that is 1 foot from the top of the plant, then a branch at about the 1-foot height level is getting only one-ninth the amount of light that the top is getting (top is 1 foot away from the light, bottom branch is 3 feet away, inverse square of 3 is 1/9). With LST and/or scrog, you keep much more of the plant at a close distance to the light source. You can still benefit greatly from LST or scrog using the sun as lighting by exposing more of the secondary growth to direct light, but the inverse square thing doesn't really apply -- the top of the plant is getting light from 93,000,000 miles and the bottom of the plant is getting light from 93,000,000.0004 miles, not a measurable difference.
And rates for power consumption can change depending on how much you use, time of day/night of usage, etc., depending on how your utility's rates are structured. But to get a general sense you should be able to find your rate printed on your bill, or else just divide the dollar amount of your bill by the amount of kwh you consumed, that is a straightforward way to get the average of the rate you pay.