Commercial cannabis cultivation load calculations.

[kwired]

In a commercial hydroponic system the plants will generally survive for up to 12 hours without having freshly oxygenated water flowing around the roots. But if the garden is aquaponics which means fish waste is all that the plants are getting for nutrition then the pumps can't go down for more than an hour or fish will start dying. These commercial aquaponic gardens are becoming very popular as the investors can harvest tilapia, blue gill, perch, bass, cray fish, etc. These can be large indoor projects that exceed 200K sq ft. Like your livestock operations, back up power generation for the critical pump circuits is considered crucial.



I had never heard that. Without any type of inspection being required I can just imagine some of the things you encounter as far as accidents and equipment failures go. Hopefully the utilities will remain an ally by requiring these installations be inspected, especially when it comes to meter sets where an AHJ inspection has not occurred.





It is off topic to some extent but worth considering the situation as a whole. In Arizona, Prop 215 passed allowing a limited number of licenses for commercial propagation, cultivation and distribution of medical cannabis. Prop 215 makes it illegal to compete with any of the licensed centers by growing cannabis for personal use within a 25 mile radius of the licensed operation. If caught doing so the law deals with these people more severely then prepassage of 215. If other states adopt this approach there is likely to be more scab wiring as a means of avoiding detection. That's the only reason I see it as relative to what we may encounter (safety first) in the field in states where cannabis laws have been passed.

If there are any utility engineers on this forum I would be very interested in any research that you can provide which shows grid impact projections in those states where commercial cultivation has been granted. Has there been any coordination between lawmakers and the utilities as to how many of these licenses may be granted based on the 200 watts/sq ft metric that these facilities consume? I'm concerned that in the states rush to legalize and generate taxable revenues they may have not fully considered the impact the number of licenses relative to the total sq footage that these operations are going to have on overall utility service capabilities.

You have to remember the driving economic force in this state is agriculture, and the laws that exclude inspection of agricultural installations are 40+ years old with little or no changes since they were first introduced. Times have changed though, and we have stricter zoning and use laws then we used to, but electrical inspections is one thing that has not changed yet, though there have been more recent talk of some changes though not necessarily a complete turn around and permit requirements for all installations.

We kind of have had exactly the opposite of what you mentioned to some extent, where it was the small operators of livestock operations that were crying out when larger operations wanted to open facilities, which has led to the stricter zoning and use laws, and same people that complained in the past now complain when they have to jump through hoops they never used to, be careful what you wish for, you just may get it:roll:

I would like to see that 25 mile rule even for personal use come to play around here, just for amusement purposes. The before mentioned tomato facility likely has more tomatoes growing within a 25 mile radius for personal and maybe road side/farmers market sales than the commercial facility produces in the typical outdoor growing season, and they are better quality tomatoes for certain. Such laws that are primarily intended to eliminate competition IMO should not be allowed, and maybe are even unconstitutional.

 

[mgookin]

Florida has agricultural exemptions as well as other exemptions like highways & things accessory to highways (traffic signals, street lighting, draw bridges, toll booths, etc.) but POCO often wants an inspection, so we sell them a permit, do an inspection, and put an OK sticker on the meter can if safe. But the ag exemption is the pole barns "on a farm for the use of the farmer" which would not include an indoor grow operation IMO but I'm sure someone will challenge it one day.

 

[kwired]

Florida has agricultural exemptions as well as other exemptions like highways & things accessory to highways (traffic signals, street lighting, draw bridges, toll booths, etc.) but POCO often wants an inspection, so we sell them a permit, do an inspection, and put an OK sticker on the meter can if safe. But the ag exemption is the pole barns "on a farm for the use of the farmer" which would not include an indoor grow operation IMO but I'm sure someone will challenge it one day.

What if the indoor grow operation is inside a pole barn on a farm and is used by the farmer?

Your state maybe don't have a very clear definition of what is agriculture and what is not agriculture activity? Or at least the building/zoning/land use department(s) do not.

 

[cadpoint]

JMO

Many places in the book tell us to address the many "Service" or "Circuit" requirements.

I don't really see what the problem is electrically Articles 215, 220 tell us what to do.

The OP while presenting various points for social conversation they did not state any Code articles lacking in any respects
to addressing the needs of or appling modern electrical service requirements. Even Article 212.12 tell us that this is a
not less than specified Code an informational is used to clear up any misunderstanding that in fact this is the minimum.

Other loads Article 220.14, one could go pick out may other Articles that require use to address the electrical requirements. But I think I'm repeating myself!

 

[mgookin]

What if the indoor grow operation is inside a pole barn on a farm and is used by the farmer?

Your state maybe don't have a very clear definition of what is agriculture and what is not agriculture activity? Or at least the building/zoning/land use department(s) do not.

A grow operation in a tenant space in a strip mall is not "a pole barn on the farm for the use of the farmer". I think we can all agree on that.

Florida has a tremendous agricultural industry. We provide more of the country's tomatoes than anyone else during the winter and of course we have lots of citrus and other crops, corn, beef, etc. Both state and local laws are very clear on what is agriculture.

 

[K8MHZ]

Looking at the NEC, the only agriculture that is addressed relates to animals, not plants.

There is nothing about horticulture in the NEC. That may change in the future.

I just did a random search on Yahoo to see what an indoor garden may look like. Here are a few, some from 'how to' books, that tells me an electrical inspector has never been in them.

 

[K8MHZ]

A search done under 'setup' yielded these pictures.

 

[kwired]

A grow operation in a tenant space in a strip mall is not "a pole barn on the farm for the use of the farmer". I think we can all agree on that.

Florida has a tremendous agricultural industry. We provide more of the country's tomatoes than anyone else during the winter and of course we have lots of citrus and other crops, corn, beef, etc. Both state and local laws are very clear on what is agriculture.

Understand, maybe better than some residents of Florida that live in the cities. I also think we can agree that there is probably a better space to grow pretty much anything than the likely premium priced space in a strip mall or any commercial/retail zoned space.

Beef from Florida maybe surprises some. I found it interesting when I went to Hawaii many years ago that they had one of the largest beef operations of the US at that time there. Nobody thinks of beef when talking Hawaii. But they also need something to do with leftover pineapple material and a lot of it goes to the beef industry I was told.

Looking at the NEC, the only agriculture that is addressed relates to animals, not plants.

There is nothing about horticulture in the NEC. That may change in the future.

The livestock industries bring their own somewhat unique environments and needs that many other places just don't have the same combinations is part of why art 547 exists.

Horticulture environments are not that much different than some other environments. It may be wet or damp, but likely not very corrosive, with exception of fertilizer storage and handling, but I don't see that being the same kind of storage and handling for a smaller indoor facility as it is for the farmers that are handling fertilizer for hundreds of acres of outdoor farm land either.

 

[chazbolin]

Here are the significant common denominators in what you'll see as an electrical professional dealing with cannabis operations;

The prevailing wisdom requires metal halides for the UV-B spectrums at propagation thru vegetative stages. These will be 400-1000 watts each running between 18-24 hours for 3-6 weeks depending upon what method the grower is using. Typical area coverage per light will be a 4' x 4' area of coverage.

When the grower 'flips' the crop into flower they will reduce the lights on operations to 12 on 12 off. They will quit using MH and utilize 600-1000 watt HPS lamps for the Red-Far Red spectrums that the flowers depend upon. What many growers use our really expensive 'flip' boxes where they mfg boxes and mount relays on DIN rail so that the same ballast can service one room where the lights are on and one room where the lights are off. You can not believe the hosing these growers are taking from the local hydro shops for this equipment. Furthermore the lamps are HID and the 'recommended' replacement times due to 'depreciation' is at 25% of rated lamp life. Couple that with an HID 'grow' lamp ahem that costs 50% or more than an HID lamp you can buy at the local wholesale house and you can see why the 'hydroponic wholesale/retail industry' is determined to protect this portion of their business.

What that means to the electrical professional is that the end users will not give up the mentality that higher watts = higher yields. They have been conditioned for over 40 years to grow using HID. Simply put it has been a cash cow that generates recurring revenues on lamp replacements, ventilation, ducting and cooling systems as well. The problem with legalized commercial grows is that this same mentality will permeate these larger operations and the 200 watts/sq ft load calcs will be some of the largest loads these utilities will have to service.

Plant lighting is not like area lighting where there is a task measured in lux or foot candles. Plants react to spectrums outside visual spectrums. The same can be said for lactating cattle and even chickens. If you provide an artificial light source that meets the plants net action spectra regions you can have very successful crop production values for closer to 40 watts/sq ft. Same with cattle and chicken. Match their circadian rhythms like the sun does in long summer days and you will produce more milk, eggs and plumper chickens. The problem with the majority of cannabis growers is they are only driven by profits. They will not concern themselves with how much energy they consume or how safe the electrical installation is. Couple that with governments who are so deeply in the red they will launch into licensing programs that will generate revenues but require that the utilities, EE's and EC's find a way to 'make it work'.

I find a historical parallel in the 'dirty thirties' whereby the rush to tear up switchgrass and plant wheat meant the government had no problem homesteading these parcels and city folk rushed out to make their fortunes. Look at where that got us. Today's switchgrass is the grid and we would be wise to consider all options when advising energy and water savings strategies so history does not have a chance to repeat itself. Thus the electrical professional will be the source for this consultation. Not the hydroponic wholesale/retail monopoly that has encouraged unsustainable practices in high wattage/heat technologies and the woeful lack of proper recycling of these lamps that has contributed rising levels of Hg into our landfills and aquifers for better than 4 decades without giving it a second thought.

 

[chazbolin]

It seems the hydroponic retailers are already in front of these high wattage/heat issues by having found a way to reduce all these loads by up to 30%. Simply add one of these and you're all set.

http://www.hygrowdenver.com/powerConditioner/HG-power.html

 

[K8MHZ]

It seems the hydroponic retailers are already in front of these high wattage/heat issues by having found a way to reduce all these loads by up to 30%. Simply add one of these and you're all set.

http://www.hygrowdenver.com/powerConditioner/HG-power.html

Snake Oil.

 

[chazbolin]

Considering who would be reading this forum it is unlikely but on the off chance my sarcasm was not noted I have the following;

http://www.nlcpr.com/Deceptions1.php

If anyone were going to get behind one of these systems to save electricity it would be Energy Star. Here is what they have to say:

http://energystar.supportportal.com/link/portal/23002/23018/Article/14738/Can-Power-Factor-Correction-Devices-sometimes-called-Amp-Reduction-Units-or-kVAR-earn-the-ENERGY-STAR-label-Do-they-really-save-as-much-money-as-they-claim

Brandeis University actually tested one of these and this was their not so glowing review:

http://alignment.hep.brandeis.edu/Lab/KVAR/

Yet these companies continue to push these products as a ground breaking way to save on your power bill. They even go so far as to reference the Brandeis report suggesting it supports their claims.

This is a closeup image of one such box. Notice the fasteners do not allow you to easily open the cover. The labeling and instructions tell the installer that it's extremely dangerous to open the box and doing so will void all warranties. I really like the little LED light that tells you it's working. Nice touch.



I'll buy lunch to anyone who can point me to a major electrical wholesaler that sells one of these.

 

[kwired]

Considering who would be reading this forum it is unlikely but on the off chance my sarcasm was not noted I have the following;

http://www.nlcpr.com/Deceptions1.php

If anyone were going to get behind one of these systems to save electricity it would be Energy Star. Here is what they have to say:

http://energystar.supportportal.com/link/portal/23002/23018/Article/14738/Can-Power-Factor-Correction-Devices-sometimes-called-Amp-Reduction-Units-or-kVAR-earn-the-ENERGY-STAR-label-Do-they-really-save-as-much-money-as-they-claim

Brandeis University actually tested one of these and this was their not so glowing review:

http://alignment.hep.brandeis.edu/Lab/KVAR/

Yet these companies continue to push these products as a ground breaking way to save on your power bill. They even go so far as to reference the Brandeis report suggesting it supports their claims.

This is a closeup image of one such box. Notice the fasteners do not allow you to easily open the cover. The labeling and instructions tell the installer that it's extremely dangerous to open the box and doing so will void all warranties. I really like the little LED light that tells you it's working. Nice touch.

View attachment 9842

I'll buy lunch to anyone who can point me to a major electrical wholesaler that sells one of these.

Does it count if what my wholesaler sells is marketed as a "Power factor correction capacitor"?

I have about 30 on order that I need to install before irrigation season starts this summer, basically the same thing with a different label, but they are carefully selected to match the load they supplement though. They haven't figured a cost effective way to do the hydroponic thing with corn or soybeans for 160 acre fields yet

What time do you want to have lunch?

 

[chazbolin]

I'm good for 12:00 today. I know of an amazing Mexican restaurant near the shop. Will that work for you?

But you make a good point. Any chance you have a cut sheet of what you're buying for pumps that you can post up here? Also how much is your supplier selling them for?
A capacitor in a 3R box with a spiffy little LED light all mounted at the incoming service does not warrant a $465 price tag especially considering it does not do what it claims to do.

 

[K8MHZ]

One post mentioned a viable garden using 40 watts per square foot.

From Wiki

Direct sunlight has a luminous efficacy of about 93 lumens per watt of radiant flux, higher than most artificial lighting, including fluorescent. Multiplying the figure of 1050 watts per square metre by 93 lumens per watt indicates that bright sunlight provides an illuminance of approximately 98 000 lux (lumens per square meter) on a perpendicular surface at sea level.

Now, with no fancy ciphering, the 1050 watts per square meter comes out to about 100 watts per square foot.

Using the lumens as a guide, a 1000 watt HPS is advertised to put out 145,000 lumens. So one would be able to put out the amount of light the sun does for roughly 15 square feet. So a 150 square foot area would need 10,000 watts of HPS to equal the sun.

 

[K8MHZ]

I'm good for 12:00 today. I know of an amazing Mexican restaurant near the shop. Will that work for you?

But you make a good point. Any chance you have a cut sheet of what you're buying for pumps that you can post up here? Also how much is your supplier selling them for?
A capacitor in a 3R box with a spiffy little LED light all mounted at the incoming service does not warrant a $465 price tag especially considering it does not do what it claims to do.

You have to understand they are guaranteed to work. Now, it's been shown that if every product is defective, only about 85 percent will get returned. So, the unit has to be priced to make a profit at an 85 percent return rate. IOW, the 15 percent that didn't get returned has to be marked up high enough to show a profit on all of the devices made and sold.

It's a marketing scheme the 'guaranteed weight loss' product pushers have been using for decades. That was preceded by tonics that did nothing and were 100 percent guaranteed. The most famous was 'rattlesnake oil'.

Hence my short post referring to snake oil earlier.

 

[kwired]

I'm good for 12:00 today. I know of an amazing Mexican restaurant near the shop. Will that work for you?

But you make a good point. Any chance you have a cut sheet of what you're buying for pumps that you can post up here? Also how much is your supplier selling them for?
A capacitor in a 3R box with a spiffy little LED light all mounted at the incoming service does not warrant a $465 price tag especially considering it does not do what it claims to do.

I am buying capacitors, carefully selected to correct power factor for the motor they are connected to. I am not just buying some random sized capacitor and throwing it on the line in hopes it will happen to be sized just right to make any significant difference. Thing is if you have a lot of HID lighting it very well may make some difference, but you didn't optimize it to the load so you are not going to get optimal effects.

Those kind of devices can have some good, but you need to determine what your power factor is, and select them carefully. Then on top of that you really need a POCO charging you penalties for bad power factor or else they generally will not save enough to be worth the investment. That is what I am up against. POCO has required protection in recent years for all new installs, but this year is going to start charging penalties for older existing installs that don't have correction. Most of them are 60,75 or 100 hp motors, and range in the $200 -$300 range for the needed capacitor. I do need one for a 200 hp motor and it is closer to $500. The price of the capacitor will pay for the penalties alone in the first season, correction of power factor will reduce line losses which add up when you figure most of these motors are around 13-1400 feet from the source.

 

[chazbolin]

One post mentioned a viable garden using 40 watts per square foot.

With plants you can't use lumens, lux or footcandles as a guide for intensities as these are photopically corrected (human vision) values that are not of primary importance to plant chlorophyll absorption processes. The fact that many of the grow lamp manufactures list their lamps in lumen output is a deception that is slowly being revealed as the market for these products gets educated. To EE's and EC's this is important because your design should not be based on lux or Fc values per sq ft or sq meter in the first place. The design has to include the technologies with the greatest influence on plant response and spectral stability for repeatable crop production. Once decided the watts/sq ft (m) side of the equation can be determined.

There are two major influences in artificial plant lighting and that is the spectrums being emitted and the intensities.

Plant light intensities are measured by meter called PAR or quantum meters. These meters are not photopically corrected for human vision but pick up intensities on the sensor that are measured in micromoles or uMoles. This type of reading is of greater relevance to plants in that it encompasses the entire spectrum between 400-700 nanometers. Different plant species will have different saturation points when they have absorbed enough light and they do not need anymore for that photoperiod. It is knowing these values that allow the EE and EC to develop strategies to tailor the plants lighting needs to it's optimum saturation levels. Think of it as optimum task levels but for plants.



Next the plants need the proper spectrums that they would see in nature to optimize growth. This is not complicated either. In nature the plants see a very wide spectrum but only absorb the spectrums that are important to a particular cycle during it's growth. Hence the reason that for the last 40 years growers have went with Metal Halides for the propagation and vegetative stages and HPS for the flowering stages.

What we are seeing as commercial growers is the ever increasing need to conserve energy and water. So this has led to our reliance on experts, to date these have been mostly lighting manufacturers, to offer us lights that do not waste energy in spectral regions that our not important to plant development i.e. human vision 500-600nm regions, and can be output controlled so that we can maximize whatever sunlight is available should it be a greenhouse application.

I am buying capacitors, carefully selected to correct power factor for the motor they are connected to. I am not just buying some random sized capacitor and throwing it on the line in hopes it will happen to be sized just right to make any significant difference. Thing is if you have a lot of HID lighting it very well may make some difference, but you didn't optimize it to the load so you are not going to get optimal effects.

Those kind of devices can have some good, but you need to determine what your power factor is, and select them carefully. Then on top of that you really need a POCO charging you penalties for bad power factor or else they generally will not save enough to be worth the investment. That is what I am up against. POCO has required protection in recent years for all new installs, but this year is going to start charging penalties for older existing installs that don't have correction. Most of them are 60,75 or 100 hp motors, and range in the $200 -$300 range for the needed capacitor. I do need one for a 200 hp motor and it is closer to $500. The price of the capacitor will pay for the penalties alone in the first season, correction of power factor will reduce line losses which add up when you figure most of these motors are around 13-1400 feet from the source.

Well said. This is precisely why these PFC need to be tailored for the load. As to the HID systems where PFC could be of some benefit I agree that with magnetic ballasts this could hold some advantages if properly designed. But many of today's HID grow lamps are being driven by digital ballasts with a ~.99 pf making these all in one 'solutions' even less significant.

 

[kwired]

With plants you can't use lumens, lux or footcandles as a guide for intensities as these are photopically corrected (human vision) values that are not of primary importance to plant chlorophyll absorption processes. The fact that many of the grow lamp manufactures list their lamps in lumen output is a deception that is slowly being revealed as the market for these products gets educated. To EE's and EC's this is important because your design should not be based on lux or Fc values per sq ft or sq meter in the first place. The design has to include the technologies with the greatest influence on plant response and spectral stability for repeatable crop production. Once decided the watts/sq ft (m) side of the equation can be determined.

There are two major influences in artificial plant lighting and that is the spectrums being emitted and the intensities.

Plant light intensities are measured by meter called PAR or quantum meters. These meters are not photopically corrected for human vision but pick up intensities on the sensor that are measured in micromoles or uMoles. This type of reading is of greater relevance to plants in that it encompasses the entire spectrum between 400-700 nanometers. Different plant species will have different saturation points when they have absorbed enough light and they do not need anymore for that photoperiod. It is knowing these values that allow the EE and EC to develop strategies to tailor the plants lighting needs to it's optimum saturation levels. Think of it as optimum task levels but for plants.

View attachment 9843

Next the plants need the proper spectrums that they would see in nature to optimize growth. This is not complicated either. In nature the plants see a very wide spectrum but only absorb the spectrums that are important to a particular cycle during it's growth. Hence the reason that for the last 40 years growers have went with Metal Halides for the propagation and vegetative stages and HPS for the flowering stages.

What we are seeing as commercial growers is the ever increasing need to conserve energy and water. So this has led to our reliance on experts, to date these have been mostly lighting manufacturers, to offer us lights that do not waste energy in spectral regions that our not important to plant development i.e. human vision 500-600nm regions, and can be output controlled so that we can maximize whatever sunlight is available should it be a greenhouse application.



Well said. This is precisely why these PFC need to be tailored for the load. As to the HID systems where PFC could be of some benefit I agree that with magnetic ballasts this could hold some advantages if properly designed. But many of today's HID grow lamps are being driven by digital ballasts with a ~.99 pf making these all in one 'solutions' even less significant.

Most of the better quality magnetic ballast HID's - especially metal halides usually were high power factor anyway. The mercury vapors and HPS with simple reactor ballasts were the ones with low power factor. They are disappearing from the general indoor lighting applications though and being replaced by T8, T5, or LED technologies. Not sure what those technologies have to offer for horticulture markets though. Lighting market in general is driven toward human optimization and is massed produced for this market, so I can understand some of the difficulties. Any specialties, though similar design, to other lighting are not produced in the same quantities therefore you can expect them to come with a higher price tag.

 

[chazbolin]

You have to understand they are guaranteed to work. Now, it's been shown that if every product is defective, only about 85 percent will get returned. So, the unit has to be priced to make a profit at an 85 percent return rate. IOW, the 15 percent that didn't get returned has to be marked up high enough to show a profit on all of the devices made and sold.

It's a marketing scheme the 'guaranteed weight loss' product pushers have been using for decades. That was preceded by tonics that did nothing and were 100 percent guaranteed. The most famous was 'rattlesnake oil'.

Hence my short post referring to snake oil earlier.

I think you're being a little hard on snake oil. At least snake oil had alcohol in it. With these magical boxes they are offering a product that should not even be in existence, required a professional electrician to install it and when pressed for a return they are extremely reluctant to take them back. At least snake oil had some redeeming value.