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Can we refine GPW to be a little more accurate?

Y

yamaha_1fan

I was wondering if there was any way we could create a simple formula that would show the effectiveness of a grow. I think we all agree GPW is just too vague with different veg times, wattages etc.

I was thinking grams/total KW used= GPW.

This would allow you to factor in the wattage used in veg and flower, and the days in each.

For example:
A veg room running 80 watts (1 fluro) over clones, for 18 hours a day, for 2 weeks,

That is 18*14*80=20,160

A flower room running 9000 watts, for 12 hours a day for 60 days

That is 12*60*9000= 6,480,000

So to take your girl from a little baby to a full blown old lady that you chop down, it takes 6,500,160 Watts of lighting or 6500.16KW

Based on our old average of 1 GPW standard, this room should produce 9000 grams.


So 9000/6500.16=1.38 GPKW

I think this is a much more accurate measurement of yield versus lighting and allows comparisons to be more on the same level.

So anybody onboard or have a tweak to add to it?

Or do we just use the old GPW that really has no real meaning?
 
E

eLiguL

I agree with this GPW measurement. Time should really be a factor in this measurement.
 
This is a more accurate determination of the efficiency of a grow as it relates to the power consumed, I like it, a lot.

Would it be worth it to be even more accurate and include fans, pumps, A/C and so on?

I guess that would really depend on whether or not you want a grow room efficiency benchmark or a strain yield benchmark though wouldn't it?...

Nice Thinking
GG
 

coolx

Active member
i don't know anyone who seriously uses gpw - the only thing that makes sense is gpwpm - ie grams per watt per month ... I think this is what many people refer to when they say gpw then others forget that it's actually grams per watt per month.
 

chosen

Active member
Veteran
I like the idea kind of but not really. GPW is really aimed at people buying lights in order for them to have a clue. The rest is too room dependent. Usage is a different matter, because some people flower 12/12, 10/14, 11/13, and even 5hr 40 min per 12hr off. most just want to know how to light their garden. I would factor usage though when I get my power bill. Do I need a humidifier, dehumidifier, a/c, exhaust, exhaust and intake, co2, what do my nutes cost, what medium? I do look at cost to yield. And when I started it made me mad to say the least sometimes....
 
Y

yamaha_1fan

To calculate a formula that would include all the variables would probably require that guy from the TV show "Numbers"

Alot of people say GPW and we all agree that is just too vague. At least this takes into account the number of days the plants was vegging and flowering.

This isnt meant to break down the cost or show profit margins. Its more to compare results from grower to grower on a more level playing field. Obviously strains, environment, nutes etc will make a difference. But at least the lights will be pretty acurately measured
 
Did the calculation for 1200 watts and got the same , 1.38 gpw. Damn I wish could do that , but I have yet to maximize my 4x4 hut, hopefully soon with dsd pheno this year.
 
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