Grams per kilowatt hour?

[magiccannabus]

Wouldn't it be more accurate and reasonable to compare the kilowatt per hour draw of a grow when calculating it's output weight's efficiency?

For example: Grow 1 takes 55 days of 12/12 to finish under a light. Under the same light, Grow 2 takes 70 days of 12/12 to finish. If both grows yield the same amount, it SEEMS like the GPW is the same, but in reality, the 70 day flowering took more power. Why do we not measure our grows this way?

Also, if we do measure like this, is it fair to include the draw of fans and other devices that are necessary to make the grow succeed?

 

[thesloppy]

I've tossed this thought around a few times, and I agree with you that GPW isn't very accurate, when comparing strains of widely different flowering times, but I think folks just default to that standard, and the magic 1.0 ratio, because the math is easy and quick.

If you were to go a more comprehensive GPKWH, wouldn't you also want to include veg time/wattage as well, since that is also going to drastically effect yield, and can be a big difference in time/power, depending on technique?

Something like: (DRY_YIELD) / ((VEG_DAYS* VEG_WATTS) + (BLOOM_DAYS * BLOOM_WATTS))

Again, not as quick or easy as GPW, and the result isn't going to come out to a nice easy to understand 1.0 ratio either (maybe something that could be adjusted by adding some constants to the formula), but it would definitely be more accurate than GPW. I might begin using that formula in my own logs, if nothing else.

 

[magiccannabus]

Yeah, calculating total kilowatt hours for all stages of growth would be ideal. I am going to be starting a perpetual run here soon and that definitely complicates the math. I would probably have to calculate how much surface area my plant has, then how many watts per square foot, and how much veg time that plant takes, plus how much flower time. This is definitely less complicated than a veg-flower-harvest-in-one-chamber type of grow.

 

[bilbobonger]

If you were to go a more comprehensive GPKWH, wouldn't you also want to include veg time/wattage as well, since that is also going to drastically effect yield, and can be a big difference in time/power, depending on technique?

Something like: (DRY_YIELD) / ((VEG_DAYS* VEG_WATTS) + (BLOOM_DAYS * BLOOM_WATTS))

Do you really get a better yield when vegging longer? Thought a bunch of little ones in a SOG setup's where it's at. It'd make it simpler just to dump the veg outa the equation, and use 60 as the constant to cancel out the usual bloom time. Then we still end up with the numbers we're all used to, i.e., .5 for the average yield, and 1 for that magic number we're all shooting for. Equation would read: (grams x 60)/(watts x days) We gotta come up with a new unit to use tho. Any ideas?

 

[ChrisGGG]

I don't think you can use a constant for bloom time would give an "unfair" advantage to longer flowering sativas. I personally think it should be:

Dry Yield/(Total KWH to room for the grow)

This would capture cooling/fans/etc and get a better idea when comparing led/hid/cfl/T5. This would also account for differing flower days like a 6:12 or 8:12.

 

[bilbobonger]

I don't think you can use a constant for bloom time would give an "unfair" advantage to longer flowering sativas. I personally think it should be:

Dry Yield/(Total KWH to room for the grow)

This would capture cooling/fans/etc and get a better idea when comparing led/hid/cfl/T5. This would also account for differing flower days like a 6:12 or 8:12.

Not sure I follow. The constant only makes the numbers easier to deal with. And what's 6:12 or 8:12? I don't understand, but your right about the fans and so forth, A/C most importantly.

 

[ChrisGGG]

Some people use 6 on 12 off or 8 on 12 off light schedules for an accelerated "day". Using total KWH for the grow may make those methods more attractive. Whats confusing to me is that some people do use G/KWH but report it as G/W. I guess what's most important is full disclosure of all power use and people can calculate what they really want to know. For my next grow I'm doing total power usage, maybe people will jump on the train.

 

[thesloppy]

Dry Yield/(Total KWH to room for the grow)

This would capture cooling/fans/etc and get a better idea when comparing led/hid/cfl/T5. This would also account for differing flower days like a 6:12 or 8:12.

I do think that is ultimately more accurate, but also would require a kill-a-watt for every outlet used in the room, right?

 

[bilbobonger]

I think the problem with measuring by kWh is it would make our numbers fluctuate dramatically from season to season, which would make it nearly impossible to figure out which strains are yielding better than others. Plus, for example, it would give my buddy over on the coast a hell of an advantage over me considering he only has to run his A/C a few months outa the year.

I think the idea is to calculate the yield under ideal room conditions (temp/humidity). This way we can compare different strains, lighting, nutrients and grow techniques.

 

[St3ve]

You guys are over thinking it all. Most people aren't talking about GPW because they are truly concerned with the actual electricity usage. (I mean yea we all care about saving $$, but that's not the top priority... we want primo bud).

We just need a frame of reference. It could be any arbitrary number really. Obviously a 80 day strain is going to use more electricity than a 58 day. The point is just to get to a common, easy to figure out benchmark to help set goals.

 

[VerdantGreen]

to be truly useful these things have to be easy to calculate so that comparisons can be made between as many people as possible.

beyond GPW i would say grams per watt per month takes into account flowering time and is easier to work out than grams per KWH.

VG

 

[bilbobonger]

(grams x 60)/(watts x days) Can't think of a simpler way to do this. Directly proportional to dry weight, and inversely proportional to the lights and bloom time. If nothing else, I'm gonna start using this formula for my own notes.

 

[Anti]

(grams x 60)/(watts x days) Can't think of a simpler way to do this. Directly proportional to dry weight, and inversely proportional to the lights and bloom time. If nothing else, I'm gonna start using this formula for my own notes.

I'm assuming that the 60 in the above equation should be replaced with "days" as in:

(grams x days)/(watts x days)

Otherwise, I have no idea where the 60 comes from. If I'm wrong, please let me know.

 

[bilbobonger]

I'm assuming that the 60 in the above equation should be replaced with "days" as in:

(grams x days)/(watts x days)

Otherwise, I have no idea where the 60 comes from. If I'm wrong, please let me know.

No. 60 would be a constant just to make the numbers come out pretty, e.g., .5 for average yield and 1 for the magic number. I went with 60, because that's the usual bloom time as far as the strains that I've been working with. If it were days on the top and the bottom they'd cancel each other out, and we'd be left with grams per watt.

 

[Anti]

Got it.

I usually take my plants at 65-67 days so that right there would count against me in your system.

Are we taking things like mom time/watts, clone time/watts, veg time/watts into account as well?

Like someone who cloned plants right before they flowered and then flowered those clones immediately after the harvest, perpetually would rate better than someone with a dedicated mom room or veg room that ran 365 days a year. (Someone who bought rooted clones from a dispensary straight into a SOG would rate better than either of them.)

 

[bilbobonger]

Got it.

I usually take my plants at 65-67 days so that right there would count against me in your system.

Are we taking things like mom time/watts, clone time/watts, veg time/watts into account as well?

Like someone who cloned plants right before they flowered and then flowered those clones immediately after the harvest, perpetually would rate better than someone with a dedicated mom room or veg room that ran 365 days a year. (Someone who bought rooted clones from a dispensary straight into a SOG would rate better than either of them.)

That's what thesloppy suggested a few days back with including veg and all, but I think it brings up a lotta problems like the ones you mentioned. Thinkin we're better off just sticking to bloom time/watts. My veg room's going 24/7, well... 18/7, with moms and all. No big deal taking cuttings a few weeks early and flippin on a t5 or two if need be. I'm more interested in comparing different strains, different nutes and different lights in bloom only. I'm growing basic SOG on 4x8 tables. Would dig seeing how they hold up against verts and so forth. Thinkin the colosseum type setups are probably where it's at.

 

[~Shhh~]

Where's Krusty and So Quick When u need em

If you don't include your veg time into the equation it's meaningless tbh, also need to include every last drop of power being used to make it truly accurate i.e: your 600w mag ballast is drawing 660w, your fans pumps etc... so if you hit 600g using SOG (no veg time) then you are still 150 g's out cause you probably used 750w+ to produce it.

If you veg for a month+ then you will never rival the gpw of a SOG grower over the period of a year. It's not possible, if you use a pre veg room then you must use good amount of watts to grow big plants, have extraction and dedicate a rather large space (big enough to flower off more plants under those watts being used SOG stylee )

A Sogger will use minimal watts to produce many many clones under 100w's of floro's in some cases, as soon as the clone is rooted it's flipped. Bonsai style moms can fit in with the clones with no real need for extraction....

Many factors to consider

 

[bilbobonger]

Where's Krusty and So Quick When u need em

If you don't include your veg time into the equation it's meaningless tbh, also need to include every last drop of power being used to make it truly accurate i.e: your 600w mag ballast is drawing 660w, your fans pumps etc... so if you hit 600g using SOG (no veg time) then you are still 150 g's out cause you probably used 750w+ to produce it.

If you veg for a month+ then you will never rival the gpw of a SOG grower over the period of a year. It's not possible, if you use a pre veg room then you must use good amount of watts to grow big plants, have extraction and dedicate a rather large space (big enough to flower off more plants under those watts being used SOG stylee )

A Sogger will use minimal watts to produce many many clones under 100w's of floro's in some cases, as soon as the clone is rooted it's flipped. Bonsai style moms can fit in with the clones with no real need for extraction....

Many factors to consider

I disagree. The point here is not to be truly accurate, but to have a standard reference point that varies accordingly. If someone's hitting high numbers, the questions to ask would be, for example, what type of lighting is being used, how long were the plants in veg, strain of course, nutrients, medium, Co2, grow technique etc. But none of this needs to be included in the equation.