Heard on the radio that there are so many greenhouses popping up across Oklahoma for the purpose of growing marijuana that it is straining utilities for electricity and water. The radio report said there are 8000 licensed marijuana growers in Oklahoma.
8000? Izzat possible?
Don't know.
However, if a mere 8000 extra greenhouses (what they are growing wouldn't matter) are straining your electric and water utilities, you have bigger problems.
The electricity consumption of growhouses is staggering when compared to business and residential use. In 2015, the average electricity consumption of a 5,000-square-foot indoor facility in Boulder County was 41,808 kilowatt-hours per month, while an average household in the county used about 630 kilowatthours. A 2012 report on the carbon footprint of indoor production found that cannabis production makes up 1 percent of national electricity use, and in California, the top-producing state, that number rises to 3 percent.
-- https://www.ncsl.org/research/energy/electricity-use-in-marijuana-production.aspx
Oklahoma simply has a list of licensed growers. California breaks theirs down by medium indoor, medium outdoor, etc., so they actually have 15 different categories, as well as a thriving non-licensed growth industry.
Oh, and they have 8,322 total growers on the list, as well as 1,222 manufacturers - the folks that make the edibles!
I've been under the impression for years that one reason for using a greenhouse is to save energy. Something to do with gathering energy directly from the sun instead of using electricity from the grid. Sounds like that premise may be in error. If it is in error, why use a greenhouse at all. Why not just grow your marijuana in a basement?
I've been under the impression for years that one reason for using a greenhouse is to save energy.
The higher the temperature and the brighter the light, the faster the crop matures. Since it's a highly profitable crop there's no need for good insulation etc.
AJ
the brighter the light, the faster the crop matures.
Not necessarily true. Brighter isn't better, lights of targeted wavelengths are better for growing. As for a green house, the double pane versions are better. Inserting a greenhouse gas between the two layers works even more so. The best gas to use when it's not freezing is water vapor.
True, but I was using a generalisation to make the point that growers don't need to care too much about saving energy.
But when it's a low margin crop like cabbages under glass during winter, energy efficiency is far more important. Luckily they're a cool weather crop and the temperature doesn't need to be kept much above freezing.
ETA the expense of heating a crop grown under glass increases exponentially for each extra degree of temperature.
AJ
Inserting a greenhouse gas between the two layers works even more so. The best gas to use when it's not freezing is water vapor.
99% of the heat retention in a real greenhouse comes not from recapturing reflected solar radiation, but from blocking heat loss by convection. A single layer of clear plastic film does just fine.
The primary reason to prefer glass windows is that some can be opened to increase convection heat loss where/when there might be a risk of the interior of the greenhouse getting too hot.
If you really want to maximize yield add CO2 to the greenhouse, not between double pane windows, but in the space where the plants are growing. As much as 2000 PPM.
Have you ever actually built or worked a greenhouse or is this just something you read some place?
Have you ever actually built or worked a greenhouse or is this just something you read some place?
I've been in greenhouses that are just flexible clear plastic wrapped over a wire frame.
They had no trouble keeping a temperature well above outside air temp without any kind of heat source other than sunlight.
I've been in greenhouses that are just flexible clear plastic wrapped over a wire frame.
Depends where you live and what you're growing.
There are very few areas in the UK where that would be adequate for growing frost-tender plants.
AJ
There are very few areas in the UK where that would be adequate for growing frost-tender plants.
I've seen people using that sort of greenhouse in Alaska, Of course those were raised off the ground on a wood deck (likely to prevent/reduce conductive heat loss to the ground).
If you really want to maximize yield add CO2 to the greenhouse, not between double pane windows, but in the space where the plants are growing. As much as 2000 PPM.
I can confirm this; the measurement gear (for the control of burners to raise the CO2) was a small but significant part of the product line of a place I used to work. However, I thought the set point could be up to 0.4% (4000 ppm) - probably varies by crop.
probably varies by crop.
Yes, some crops respond well to extra CO2, some show no response at all.
AJ
However, I thought the set point could be up to 0.4% (4000 ppm) - probably varies by crop.
Could be. I've read that most commercial greenhouses try to maintain 2000PPM C02.
Also from what I've read, based on the experience of the US Navy submarine program it doesn't get directly dangerous to people until you go over 8000PPM.
https://extension.okstate.edu/fact-sheets/greenhouse-carbon-dioxide-supplementation.html
https://extension.okstate.edu/fact-sheets/greenhouse-carbon-dioxide-supplementation.html
Reading this let me question all we do to reduce CO2 worldwide and to slow down global warming.
Earth is really a giant greenhouse and we should treat it so. But all measures the environmentalists force on us will hamper the growth of plants on our planet.
HM.
If they want to directly impact CO2 levels, they would stop clear cutting the Amazon forest and start cleaning up the oceans. Until such time, all the 'global warming' hysteria is just so much bullshit hypocrisy.
The higher the temperature and the brighter the light, the faster the crop matures.
Different crops react differently to temperature, having a certain temperature range where they do best. Their growth is hindered both by low temperatures and high ones - especially if there is a lack of water in the later case.
The intensity of light might affect some plants, although given a certain intensity of light, the number of hours a plant enjoys that intensity might affect it more (with the growth cycle depending on a certain number of hours of 'sunlight' a day and fruit start being produced once the light goes down to a certain number of hours per day.
You're right. I made an over simplification.
The crop in question is temperate but grows faster when heated. I don't know the optimum temperature but too hot would be as bad as too cold.
My understanding is that the crop needs a period of darkness, but rather less than provided by natural daylight.
AJ
Not too many crops can survive without the cycle of dark and light. Targeted wavelengths can dramatically shorten the needed amount of rest.
More than that. There are a total of 8,974 licensed growers as of Oct 6, 2021.
There are also 1,587 licensed processors, 111 licensed transporters, 26 licensed laboratories, and 2,436 licensed dispensaries.
https://oklahoma.gov/omma/businesses/list-of-businesses.html
Keep in mind that Oklahoma has just over 68,500 square MILES of land, and just under 4 million people. When 3/4 of the population of the whole state lives in either the OKC or Tulsa metro areas, there's a lot of empty land out there.
For those of you on the east coast of the US, that's the States of New York, Massachusetts, and Vermont - combined. On the eastern edge of the pond, Portugal and Slovakia - combined.
If there are so few people and so many square miles, why do they need greenhouses? Will marijuana not grow in fields? Or are all the fields covered with oil derricks?
If there are so few people and so many square miles, why do they need greenhouses?
Lots of off grid homesteaders use greenhouses to grow vegetables and other food crops, not because they can't grow those crops outdoors, but because it extends their growing season to year round.
but because it extends their growing season to year round.
That is why we use them. We also use hydroponics in conjunction with them.
The land we are on is very rocky and not conducive to large scale farming. However we produce more than enough by doing it that way.
Order up a load of grow lights and get a visit from the DEA. Use too much electricity, the same.
Since strawberries have been mentioned elsewhere on this board:
http://www.ledgrowlightshq.co.uk/strawberry-plants-like-the-blues/
In the study, scientists grew strawberry plants in a growth chamber under either fluorescent neon lights, blue (436nm) LED lights, or red (666nm) LED lighting. They grew 25 plants under each of the lighting conditions set to a constant photosynthetic photon flux density (PPFD) of 100µM / m2 / sec for 78 days with the fruit harvesting period from day 37 to day 59.
Light wavelength has been proven to have a dramatic effect on yield.
People considering growing plants indoors should do their research on that.
https://www.plantgrower.org/uploads/6/5/5/4/65545169/strawberry_paper_3.pdf
The study mentioned.
