Transferring panels from generator

[Mr. Sparkles]

Hello fellow sparky's,

I am trying to figure out gear needed for a large indoor cultivation project. This is an off grid grow that will be powered by generator. The lights are 240v 1000w and each room will have 48 lights. Each room will probably need a 400 amp panel just doing rough calculations because just lights alone without other equipment is 200 amps. There are 2 large flowering rooms that are on 12 hour cycles. The owners are trying to see if the rooms can be switch automatically at 12 hours so one will go from on to off and other vice versa. Is there a piece of equipment out there that can do this transfer automatically? Anyone out there done anything like this, I would appreciate feedback.

Thanks,
MS

 

[texie]

This is easy enough to do with an alternating relay and appropriately rated contactors.
But I'm curious what flavor of genset you are proposing for this. No matter diesel or LP it is going to be far more expensive power than POCO power. It will also have to be rated for this kind of duty as this is essentially a prime power application.

 

[hillbilly1]

This is easy enough to do with an alternating relay and appropriately rated contactors.
But I'm curious what flavor of genset you are proposing for this. No matter diesel or LP it is going to be far more expensive power than POCO power. It will also have to be rated for this kind of duty as this is essentially a prime power application.

A crop that is sold in Colorado and California. It sure ain’t tomatoes! LOL!

 

[electrofelon]

Hello fellow sparky's,

I am trying to figure out gear needed for a large indoor cultivation project. This is an off grid grow that will be powered by generator. The lights are 240v 1000w and each room will have 48 lights. Each room will probably need a 400 amp panel just doing rough calculations because just lights alone without other equipment is 200 amps. There are 2 large flowering rooms that are on 12 hour cycles. The owners are trying to see if the rooms can be switch automatically at 12 hours so one will go from on to off and other vice versa. Is there a piece of equipment out there that can do this transfer automatically? Anyone out there done anything like this, I would appreciate feedback.

Thanks,
MS

Doing this at 240 is pretty miserable. I would try to get them to go 277/480.

There are several options for control:

1. Set up a lighting contactor controlled by a time clock.
2. There are "flip flop" ballast that have two outputs that alternate. You only have to buy half the ballasts. Google "horticontrol" as an example.
3. Some lighting systems have contactors built into the ballasts and all the ballasts are interconnected with cat5 to a central controller that tells them all what to do. Dimlux are one example (and are available in 277V also).

 

[Mr. Sparkles]

I just met with them last week and still haven't hammered out details on generator. Still figuring out AC units and what other loads might be. They said they were thinking they were going to spend 20-30k a month on fuel but PGE drop is way to far away so this is only option. 3 phase would be my choice but they seem set on 240 volt Gavitas but just was looking into it and Gavita makes a 277. The problem I see with 3 phase is fans and other 120v loads can't be used without running another generator, unless you can transform off of the 3 phase gennie. Stupid question, but can you even have a XFMR off a diesel generator? Done a lot of this type of stuff grid tied but to be honest, the generator stuff is something I don't have a strong grasp of. Thinking of maybe reaching out to EE, but appreciate the support here

 

[hillbilly1]

I just met with them last week and still haven't hammered out details on generator. Still figuring out AC units and what other loads might be. They said they were thinking they were going to spend 20-30k a month on fuel but PGE drop is way to far away so this is only option. 3 phase would be my choice but they seem set on 240 volt Gavitas but just was looking into it and Gavita makes a 277. The problem I see with 3 phase is fans and other 120v loads can't be used without running another generator, unless you can transform off of the 3 phase gennie. Stupid question, but can you even have a XFMR off a diesel generator? Done a lot of this type of stuff grid tied but to be honest, the generator stuff is something I don't have a strong grasp of. Thinking of maybe reaching out to EE, but appreciate the support here

Transformers off a generator is done all the time, I think they will find it cheaper to buy a three phase generator of that size than a single phase.

 

[Todd0x1]

You can run the generator 277/480 and have a 480->120/208Y transformer for the 120v (and/or 208v) loads.

In california you are going to need permits from the air pollution police. Expect a lengthy and expensive permitting process for a stationary diesel generator supplying prime power. Also, (assuming legal permitted generator operation) you can't get away with buying an older used unit as they dont meet current emission regs -thats why they are so cheap. If I were doing this, and could get by with trailer mounted gensets at the site, I would purchase two, register them in the CARB portable equipment registration program, and swap them every 89 days.

Another thing to keep in mind, is the tier 4 final diesel generators can be temperamental however the high kw continuous load will help with that. A couple manufacturers have the whole DPF / SCR thing perfected where the unit will run continuously on no load without shutting down, other manufacturers not so much.

Expect to pay ~$140k ish for a good 240kva / 190kw portable unit.

How many kw of load do you think you have?

 

[Mr. Sparkles]

Thanks for the detailed info Todd. This whole grow is permitted and building being constructed now is permitted as ag building. Definitely need to ask them about the air quality management permit, didn't even cross my mind until you mentioned it. CARB portable equipment permit seems like a hassle just to obtain, and switching out generators every 3 months is a pain in butt for sure, but may be only way for this to work. PGE is about 800k to run a mile and they are probably 1-1.5 miles from transmission lines. Over long haul, might be cheaper to do utility service though, even with rising rates. This job would still be a long process with PGE but seems like it would be easier to figure out if it was just utility power and new switchgear.
So, back of the envelope math using the 240 gavitas in the flower rooms...

-120-125kw for flower rooms that switch every 12 hours to other 2 flower rooms. So constant 125kw in flower.
-(2) Mom and clone rooms that are same size as large grow room (48 lights). These rooms will be running 18, maybe 24 hours but could be using a little less lighting. Probably close to 100kw in these rooms as well for lights and everything.
= 250 kw more or less

In your experience Todd, which manufacturers are better with the DPF/SCR? Most folks use whisperwatts around here for this type of application, but trying to give customers most options and learn more myself in the process.

 

[Todd0x1]

The carb permit for portable registration is just a form and a month or so of waiting. Depending on your aqmd, stationary unit can be 6-12 months and all sorts of expensive engineering. If the install is in a rural AG area maybe its not as bad.

 

[cpickett]

Not sure what the life cycle/expectancy of this project is, but 26 months of $30k/month fuel bills and you're almost at $800k. Also, after 1 year of continuous duty you'll have 8,760 hours on the generator, so I'm guessing you'll be buying a new generator after 2-3 years? Plus maintenance costs will be non-zero, so need to be accounted for as well. Obviously $800k is a huge amount of money to spend at one time, and maybe the timeline is more important, as you mentioned. But if they want a true cost comparison they'll have to look at all the costs, and the breakeven may be sooner than you think.

 

[electrofelon]

Not sure what the life cycle/expectancy of this project is, but 26 months of $30k/month fuel bills and you're almost at $800k. Also, after 1 year of continuous duty you'll have 8,760 hours on the generator, so I'm guessing you'll be buying a new generator after 2-3 years? Plus maintenance costs will be non-zero, so need to be accounted for as well. Obviously $800k is a huge amount of money to spend at one time, and maybe the timeline is more important, as you mentioned. But if they want a true cost comparison they'll have to look at all the costs, and the breakeven may be sooner than you think.

I agree, I am having a hard time seeing how they can compete with other growers that dont have these expenses.

 

[Todd0x1]

Not sure what the life cycle/expectancy of this project is, but 26 months of $30k/month fuel bills and you're almost at $800k. Also, after 1 year of continuous duty you'll have 8,760 hours on the generator, so I'm guessing you'll be buying a new generator after 2-3 years? Plus maintenance costs will be non-zero, so need to be accounted for as well. Obviously $800k is a huge amount of money to spend at one time, and maybe the timeline is more important, as you mentioned. But if they want a true cost comparison they'll have to look at all the costs, and the breakeven may be sooner than you think.

Dont forget this is California and to factor in the cost of utility electricity.

PG&E's agricultural tariff for example ranges from $.252 winter - $.322 summer. I am going to just call it $0.25/kwh. At their 250kw load, this is $62.50/hr. A 300kw generator consumes 16.7gph fuel at full load. This is $50/hr in fuel. Add in maintenance for the generators and the hourly cost would probably still be close. Fuel might cost a little more if they're really far away from the fuel supplier.

Now weigh the 1.5 million dollars to install utility power against 300k in generators and some transcube fuel tanks. The generators should last 20,000-30,000 hours, however it would probably make more sense to replace them and auction off the old ones every year.

Last, the generator purchases can be written off taxes under section 179 (assuming they haven't hit the limit on 179), so $250k in generators is really $175k in money, then add back what is recovered when auctioning off the units and the cost is even lower.

Obviously this is just an example and they would have to run their own numbers.

 

[cpickett]

Dont forget this is California and to factor in the cost of utility electricity.

PG&E's agricultural tariff for example ranges from $.252 winter - $.322 summer. I am going to just call it $0.25/kwh. At their 250kw load, this is $62.50/hr. A 300kw generator consumes 16.7gph fuel at full load. This is $50/hr in fuel. Add in maintenance for the generators and the hourly cost would probably still be close. Fuel might cost a little more if they're really far away from the fuel supplier.

Now weigh the 1.5 million dollars to install utility power against 300k in generators and some transcube fuel tanks. The generators should last 20,000-30,000 hours, however it would probably make more sense to replace them and auction off the old ones every year.

Last, the generator purchases can be written off taxes under section 179 (assuming they haven't hit the limit on 179), so $250k in generators is really $175k in money, then add back what is recovered when auctioning off the units and the cost is even lower.

Obviously this is just an example and they would have to run their own numbers.

Of course I did forget to factor in electricity cost, was focused on the other numbers too much. Residential cost here is about $0.11/kwh, but it's still non-zero. It's amazing how many factors you need to add up to get a true cost analysis when looking at options. The tax write off is a good example, that could extend the breakeven point out quite a bit. This is an interesting project, just goes to show how it's easy to take utility power for granted, as much as you need is always there as long as the bill is paid each month.

Back to your original question, I imagine you'll need to build your own 'load control' panel using contactors and some control relays and timers, but since this is a substantial project and energy consumption may be more of a concern than usual you may consider PLC control for the entire system. The PLC can control the switching based on time, and possibly other aspects like ventilation/HVAC based on outside and inside temps? Are the rooms enclosed entirely or is there ambient lighting? The PLC could turn lights off when there is enough ambient light, saving electricity. Heck, you could program alarms for room temperatures, fuel tank levels, irrigation system status, you name it...

 

[PhenixFord]

Recently, I seen a load center that was using some type of Smart Breaker. I really don't know much about these breakers. And don't remember the manufacturer of the system that I seen. The load center "I saw" was a 277V lighting distribution panel. And the loads were being switched by the smart breakers. Here is an example. \/ \/ \/

Energy management circuit breaker

www.eaton.com

 

[hillbilly1]

Eaton’s breaker is called SOB’s, no,solenoid operated breaker! Square D has motorized ones, I think it was in the mid to late 80’s when I first installed some of those.

 

[Todd0x1]

Has the cost on the motorized breakers come down enough to make sense? I looked at SQD years ago and it was a few hundred per breaker for 1P20A, ended up using a ton of little contactors.

 

[hillbilly1]

Has the cost on the motorized breakers come down enough to make sense? I looked at SQD years ago and it was a few hundred per breaker for 1P20A, ended up using a ton of little contactors.

Walmart uses them, so you know they must be getting them cheap! LOL!