20kw Sustainable Farm System - Input needed
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hdFarmer
Registered Users Posts: 10 ✭
We have a sustainable farm and we are submitting an FSA loan package that includes a backup system for our freezers and cooler.
We need your expertise and experience.
This is a diagram of what we are looking to build
Attachment not found.
We will be posting about each part of the system looking for feedback
We have a total proposed budget of $41,000. We know we can get the system down lower but we had to put in the prices we knew we could get for the loan - as a result we will end up with a good budget. We want to save as much money but at the same time create a very stable and complete system.
One key - we must have a backup generator as part of the system. We also want to have a wind system as we get good consistent wind of the river near where our farm is located.
Here is a breakdown on possible parts of the system
We need your expertise and experience.
This is a diagram of what we are looking to build
Attachment not found.
We will be posting about each part of the system looking for feedback
We have a total proposed budget of $41,000. We know we can get the system down lower but we had to put in the prices we knew we could get for the loan - as a result we will end up with a good budget. We want to save as much money but at the same time create a very stable and complete system.
One key - we must have a backup generator as part of the system. We also want to have a wind system as we get good consistent wind of the river near where our farm is located.
Here is a breakdown on possible parts of the system
Comments
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Re: 20kw Sustainable Farm System - Input needed
So the first question we asked was grid-tied vs off grid. That was an easy answer as we get $6750 from SRP in rebates for helping them be green.
We know we want to use this great Arizona sun for most of the production - 14kw or the 20
We also know that wind is not consistent and that 6kw is really 2 or 3 and we need an estimate 17.5 kw system in total.
One question is how large a battery bank do we need to have 6 hours of backup and we are having a hard time finding a good controller for this system. -
Re: 20kw Sustainable Farm System - Input needed
Grid-Tie inverters usually don't work when the grid is not present, therefore you cannot use them for backup purposes. XW6048 can do backups, but it will connect to the system in a totally different way.
The Chint-power unit you selected looks like an MPPT unit and is probably designed to be connected to solar array, not to the battery. XW6048 is designed to be connected to the battery.
I don't think the diversion controller you selected will be able to manage all these deverse sources at once. It's better to have a separate controllers for solar and wind. For the system of your size you may need several solar controllers (preferably MPPT).
DC generator is unusual. Most people use AC generators. Why do you want to go with the DC generator? -
Re: 20kw Sustainable Farm System - Input needed
We have grid power right now and we want to stay connected but have a system that will give us 99% of our power needs.
I was expecting that we would need more than one controller... Do you have one that you would recommend?
As for the generator I just found a sister unit to the one we found that is AC and almost a grand cheaper - thanks.
So what is the solution for an inverter that still works when the power goes down? -
Re: 20kw Sustainable Farm System - Input needed
In an area that regularly gets 5 hours of sun even in winter, it's a hard sell to have a wind generator, with it's sometimes available power. While it's nice when it's blowing, you have to have a backup for your backup...
This statement "...we need an estimate 17.5 kw system in total..." is ambiguous do you need to be able to draw 17.5Kw's at one time? if so in what form 240V 480V. Is this your daily needs for a peek usage? ...or Kw hours used? What are your peak at any single point needs? What are your daily usage?
Midnite solar produces a Classic (and Classic lite) which can handle roughly 80 amps at 48 volt nominal. and they can be strung together so they work as a unit. I think they said they have had 32 units working together.
Typically you would have a generator that output AC and an inverter that would also be able to charge your battery bank.
If you want to know "...how large a battery bank do we need to have 6 hours of backup? we need to know what size your load will be during that 6 hours or your peak 6 hours. are we talking 17.5 Kw per hour?
Lets get a handle on your loads and we can go from there.Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites, Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
- Assorted other systems, pieces and to many panels in the closet to not do more projects. -
Re: 20kw Sustainable Farm System - Input neededWe have grid power right now and we want to stay connected but have a system that will give us 99% of our power needs.
I was expecting that we would need more than one controller... Do you have one that you would recommend?
As for the generator I just found a sister unit to the one we found that is AC and almost a grand cheaper - thanks.
So what is the solution for an inverter that still works when the power goes down?
You need so called Hybrid Inverter, which can work from batteries, It also would have a grid connection and a generator connection. This will also let you charge your batteries from the grid. Two leading brands are Outback and Xantrex. One that is listed on your spreadsheets is XW6048.
You need to figure out what would be your loads are and how long do you want to support them during outage. The best way to ballpark your loads is to look at the electric bill and see how much energy in kWh you consume every month. You may choose to backup all the loads, or only critical ones (to save money on the size of the system). Once you know the loads, you can figure how much batteries you need.
You also need to figure out how your system is going to work. If your sole purpose is a backup, you probably want to maintain your batteries fully charged all the time and sell everything you produce to the grid. But if you get much less for a kWh that you sell to the grid than for a kWh that you buy from the grid, you may want to cycle batteries to decrease consumption. -
Re: 20kw Sustainable Farm System - Input needed
Instead of the battery back up, which comes at a considerable added cost, (and decrease in efficiency) why not just use the genny for back up for the occasional outage? Much cheaper, short and long term, as well as more reliable, since you are going to have a genny anyway.
Icarus -
Re: 20kw Sustainable Farm System - Input neededIn an area that regularly gets 5 hours of sun even in winter, it's a hard sell to have a wind generator, with it's sometimes available power. While it's nice when it's blowing, you have to have a backup for your backup...
This statement "...we need an estimate 17.5 kw system in total..." is ambiguous do you need to be able to draw 17.5Kw's at one time? if so in what form 240V 480V. Is this your daily needs for a peek usage? ...or Kw hours used? What are your peak at any single point needs? What are your daily usage?
Midnite solar produces a Classic (and Classic lite) which can handle roughly 80 amps at 48 volt nominal. and they can be strung together so they work as a unit. I think they said they have had 32 units working together.
Typically you would have a generator that output AC and an inverter that would also be able to charge your battery bank.
If you want to know "...how large a battery bank do we need to have 6 hours of backup? we need to know what size your load will be during that 6 hours or your peak 6 hours. are we talking 17.5 Kw per hour?
Lets get a handle on your loads and we can go from there.
I am not positive but I think I have a pretty good outline of our loads now on that same spread sheet - take a look, I may have missed something so let me know if I made a mistake.
How do I know if I need 240v or 480v? We do not have anything that is over 240v, our walk-in freezer and our cooler units are 230v.
As for wind we want to use this system as a testing model. We have farms that we are going to be working with in Utah, Colorado, Wyoming, Idaho, Oregon, California, New Mexico and Texas so far. Our farm is the template. This is why we want a battery bank that can last 6 hours. We also get winds up to 20-30 mph quite a bit and it hits 12-15 every day in the afternoon. -
Re: 20kw Sustainable Farm System - Input needed
We do want to run off the system and feed the grid only when we have extra. They cap the amount of load we can send back to the grid or at least that is what it says on the SRP site.
I have updated the spread sheet with a quick estimation of our loads - some are straight off the units and some are ball park. Take a look and let me know if I seem way off base or not, this is the first time I've done this.
As I've said we want about 6 hours of battery backup- how do I take what I have found in the load tab of my sheet and turn that into info that I can use to figure out my battery bank? -
Re: 20kw Sustainable Farm System - Input neededInstead of the battery back up, which comes at a considerable added cost, (and decrease in efficiency) why not just use the genny for back up for the occasional outage? Much cheaper, short and long term, as well as more reliable, since you are going to have a genny anyway.
Icarus
This is a great idea, and that is why we have the unit - just in case we need it. As I have said in another response we are trying to use our farm as a testing ground for a complete farm system that we can then help other farmers reproduce so we do want a more sustainable system. Batteries are not very sustainable but they last longer than the propane does...
I would like to get a diesel unit so I can use bio diesel - we have a farm up in Utah that we are going to grow about 10-15 acres of sunflowers for pressing into oil and making into bio diesel - so that would be more sustainable. -
Re: 20kw Sustainable Farm System - Input needed
I just have to say that wiring diagram is pretty inaccurate.
You're looking at a grid-tie system with both battery and generator back-up. The AC will center on the hybrid GTI unit (such as a Xantrex XW or Outback Radian). That will have input for grid and generator and will have the transfer switch to seamlessly controller the AC source for the output.
It will also have the connection for batteries. Those batteries will be kept charged by solar through the charge controller or grid/gen from the inverter. If there is "surplus" power available from the solar array the GTI will take care of selling it back to the grid.
I have never heard of a "Grid-tied rectifier and dump controller". The terminology doesn't even make sense.
Having a wind turbine complicates matters. Usually it is a lot of money spent for little performance. In the best case it would run through a MidNite Classic & Clipper set-up to regulate its output and maximize efficiency. -
Re: 20kw Sustainable Farm System - Input neededI would like to get a diesel unit so I can use bio diesel - we have a farm up in Utah that we are going to grow about 10-15 acres of sunflowers for pressing into oil and making into bio diesel - so that would be more sustainable.
Depending on how picky your diesel is, you could run it on straight vegetable oil if you make some modifications to the gen. Also, sunflower oil is a high quality food oil, using it as fuel is not that sustainable - would be more sustainable if you could sell it as food oil and then buy back waste oil for use in the generator. -
Re: 20kw Sustainable Farm System - Input needed
Regarding your loads, I think the estimates for some of the coolers might be off: 2500W for 18 hours/day. Do they really draw 2500W constantly for 18 hours?
Anyway, to work out how big the batteries should be for a 6 hour backup, roughly:
277kWh/day (!) 6 hours = 0.25 days so that's 69kWh. Usually recommended to draw a battery down to 50% SoC, so you'd need a 138kWh battery, at 48V that's 2875Ah.
EDIT: and since you'll draw them down in 6 hours that's 2875Ah at the C6 rate, they'll be considerably bigger at the more commonly used C20 rate. -
Re: 20kw Sustainable Farm System - Input neededWe have a sustainable farm and we are submitting an FSA loan package that includes a backup system for our freezers and cooler.
How large is your farm? Frankly, I can't believe FSA continues to waste tax payer dollars on this stuff - especially battery backup systems for farms. It just don't work. Back in the day (before they called it the Farm Service Agency and it used to be the ASCS) you could get USDA REAP (Rural Energy for America Program) grants and/or loans to put in wind turbines. But they had to be minimum 39 kW for the first program they had, then they went to minimum 10 kW installed capacity. There were thousands of Jacobs turbines installed on farms and ranches with those programs - successful installs - and many of the 10, 17.5 and 20 kW Jacobs turbines are still running today. But these are all grid-tied systems with no batteries.
When you start talking batteries and DC power and inverters for farms, you're talking stuff that don't work because the loads are too high. We also have an off-grid farm here, but our house system is totally separate from the farm. We have a 12,000 sq ft large equipment shop and it is powered and heated by a Cummins 4BT 45 kVA 277/480V co-generation set. And we have a Cummins N14 277/480V 250 kVA set to run our grain handling system in the fall. There is no way you could even hope to power those kinds of loads on batteries and be able to afford it. We cannot get residential utility service here, much less three-phase. So a diesel generator is the only way to go. When we came back home and took over the farm from my parents we looked at all this. We didn't want to live next to my parents so we built our house off-grid on an 80 a 1/2 mile away. And the old farmstead was not suitably set up for semis so we built all new with wide driveways and turnarounds.
We could run our cogen set on biodiesel, but we don't bother - we burn #2 off-road in it. There's no way we could run the big set on bio - it burns 20 gal/hr. By the time we start messing around pressing beans or canola, and heating oil, and making batches of bio, the labor time involved with it doesn't pay. Especially when a single semi load of soybeans is worth $15,000 these days, and then we would have to try to sell the soymeal to somebody with cattle and end up with handling costs in that.
I would suggest hiring a professional consultant that worked, or is working, with the USDA REAP programs to come and evaluate your setup. Otherwise, I see what you are proposing here as something that is more based on home-sized off-grid systems, and not for farms. Unless it's a really small farm and even then I question the validity of using batteries at all. There's practical sustainable farming. And then there's many systems that have had taxpayer money thrown away on them over the years with ASCS/FSA loan and grant programs.
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Chris -
Re: 20kw Sustainable Farm System - Input neededI am not positive but I think I have a pretty good outline of our loads now on that same spread sheet - take a look, I may have missed something so let me know if I made a mistake.
How do I know if I need 240v or 480v? We do not have anything that is over 240v, our walk-in freezer and our cooler units are 230v.
As for wind we want to use this system as a testing model. We have farms that we are going to be working with in Utah, Colorado, Wyoming, Idaho, Oregon, California, New Mexico and Texas so far. Our farm is the template. This is why we want a battery bank that can last 6 hours. We also get winds up to 20-30 mph quite a bit and it hits 12-15 every day in the afternoon.
I can't find any load information on the spread sheet, just links to advertisements, what does your electric bill say you use every month?
Some large motors use 480V, the electrician who checked out my system works for quarries and large farms around here, said he gets a lot of his work since he's done a lot of work on 480V systems.Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites, Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
- Assorted other systems, pieces and to many panels in the closet to not do more projects. -
Re: 20kw Sustainable Farm System - Input neededI can't find any load information on the spread sheet, just links to advertisements, what does your electric bill say you use every month?
There's tabs on that spreadsheet that show approximations. Basically:
Air conditioning at 3.6 kVA and 10,400 kWh/year
walk-in coolers @ 5.8 kVA and 38,000 kWh/year
On the "controller" tab I see 440 amp 10,000 watt (something or another) off ebay. I think I know what that is and (OMG).
I sure hope taxpayer dollars don't get wasted subsidizing a loan on this.
Really - please, hdFarmer - hire a certified consultant that has actually done farm renewable energy or backup power systems. What you have proposed is not even practical, much less the fact that it won't work.
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Chris -
Re: 20kw Sustainable Farm System - Input needed
I'm just opening it in Google docs and all I see is Green energy break down and links in first 12 lines or so, below is some general cost estimates...Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites, Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
- Assorted other systems, pieces and to many panels in the closet to not do more projects. -
Re: 20kw Sustainable Farm System - Input needed
'whit - if you look at the bottom of the spreadsheet there's "tabs" there like Excel spreadsheets have and they are labeled with the various items. You should be able to click on those and open the other parts of the spreadsheet.
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Chris -
Re: 20kw Sustainable Farm System - Input neededCariboocoot wrote: »I just have to say that wiring diagram is pretty inaccurate.
Wow - I am a visual person and I was hoping for input on the entire thing, for it to be torn apart and put back together from a more experienced POV - I actually think I made that clear. It seems my 'new guy' tab doesn't afford me any breaks - I'll make a note of that and spend more time getting it right before I post here, so I can just show off my knowledge rather than look for help...
I made that Diagram off of a few I found online that looked like they were clear and simple. By all means help me fix it... Here is one of the diagrams I worked off of - http://www.allwindturbine.com/products_info/H3-1-1kw-grid-tied-wind-generator-system-202444.htmlHow large is your farm? Frankly, I can't believe FSA continues to waste tax payer dollars on this stuff
Waste? Do you know that the average age of a farmer is almost 60 yrs old in the US? We are a group in our mid thirties and the owner of the farm just had to declare bankruptcy after his wife died and left medical bills up the ying yang - I would be careful how you judge. I was not aware we were going to be so off topic here on this forum. If you want to preach about governemnt waste go talk to someone else - we have $220,000 in equity in the farm but because of the bankruptcy he cant refinance for 2 years. This loan is the only way he could subsit. We manage the farm and this loan will be paid back over 7 years. We will pay it back, even if he has to get a heloc 2 years from now. This is not solindra, this is a farm that sells out of all its all natural and high quality products and we are using this loan to expand.
We sell our eggs for $6/doz, our beef for $6.50-24.50 lb, our Turkey for $7.50-9.99 lb, our Chicken for $6-8.50 lb - We have restaurant contracts, more than 15 gyms that we have freezers and fridges at where we drop off as if we have 15 different locations with out the overhead of having 15 locations. There is more demand than we can fill... We need to be able to process more beef and birds and store them along with more produce that we buy from local farmers for longer periods of time - this expansion costs money and I actually like a 1.25% loan from a stable source so sorry you seem to be so against the FSA program but feel free not to take part in it.
Now back to the plain and simple point of my post-
As for the system - I don't care what we build but here are our goals:
1. Get 99% of our power needs from renewable sources
2. Have a 100% backup system for our freezers and Cooler as we will at times have up to $40,000 of inventory stored there.
3. From a marketing perspective for our farm - if we have 25% of our power come from wind energy we get a nice little badge - http://www.windmade.org/about.aspx
We market to the top 5% of the food chain, our customers pay $150-$200 for membership to the gyms we supply (CrossFit) vs $30-50 for LA Fitness/Gold Gym etc. They want to see us go sustainable as much as we do and it helps us stand apart. We also have periods of up to 6 hours where the power goes out on us because we are not in a densely populated area, we aren't on the 'get these people back up first' list for the power company.
We are building a framed in walk-in cooler that will enclose the walk-in freezer but both will be on a carport slab so it is outside and willl run more often than if it were to be completely built into a more protective structure - here is an example of what we are building - https://docs.google.com/document/d/163S2UlSn1to71oVNHh7e3_6fch-dJ50CquYMC_PSmXk/edit?usp=sharing
We plan on enclosing this carport more and making it a store but we don't want to use tax payer $ to do that - hope that makes you feel better Chris... We can pay for this from profits. Here is a better breakdown of why we are dong this for those who are interested - https://docs.google.com/document/d/1keySWiUqpiwsQN-2vNIzmDeZkL7-FjQidxAesi_m3V4/edit?usp=sharing -
Re: 20kw Sustainable Farm System - Input needed
Don't worry, folks here are very helpful, but sometimes they get a little, shall we say testy either for reason or not. Don't hesitate to show your newbieness and ask away! That is what we are here for. As for the political overtones, I would advise everyone to keep it simple.
Welcome,
Tony -
Re: 20kw Sustainable Farm System - Input needed
As for getting a certified consultant - anyone have a recommendation?
We would love to pay room and board for any here who feels they could help us out once we get going - in October. Come visit us here on the farm, we have a 2 bedroom guest house and we could use the more experienced hands/minds.
The way we farm is different, we get $2000-$3500 per acre per month production and this expansion is helping us go from 5 acres of productive land to 55 acres. We are hiring our first 2 employees and we are growing fast. We already have 8 farms interested in replicating what we are doing so we want a system that we can pass along.
We really just want to create a great system, do it right from the start and then be able to build on it, expand it, cleanly and easily.
- Thanks icarus -
Re: 20kw Sustainable Farm System - Input neededWow - I am a visual person and I was hoping for input on the entire thing, for it to be torn apart and put back together from a more experienced POV - I actually think I made that clear. It seems my 'new guy' tab doesn't afford me any breaks - I'll make a note of that and spend more time getting it right before I post here, so I can just show off my knowledge rather than look for help...
I made that Diagram off of a few I found online that looked like they were clear and simple.
Whoa. Not criticism; comment.
It does not surprise me at all that you made that based on info found on-line, because there's lot of it out there that is bad/wrong/dangerous. What we do here is try to keep people such as yourself from being ripped by such misinformation.
Not going to comment on the whole loan situation as I'm not in the US and/or familiar with all their programs. Nor would I render an opinion of them if I were, as that strays into the political realm and I've already been spending a lot of time chopping that stuff out of posts of late. And if it starts brewing up here it's going to get chopped.
I think Chris's main concern is that you don't get led astray by misinformation. Evaluate your power needs first and foremost; the off-grid back-up plan may simply be financially impractical. It is a very expensive way to get power.
You probably didn't expect to read that on a solar forum. Usually they're too full of "everybody go green!" We try to stay practical here, because if it's impractical everybody suffers from it. -
Re: 20kw Sustainable Farm System - Input needed
Something doesn't add up, may be a typo, but looking at your page in the last link it states you need 20KWH per day, but you are buying a 20K generator?
I use roughly 30 KWHs per day and a 6K solar system over produces this time of year.
My advice, for what it's worth, is to size your system correctly, drop the wind, and simply go with a hybrid grid tie system with battery back up. -
Re: 20kw Sustainable Farm System - Input needed1. Get 99% of our power needs from renewable sources
If you're going to power all the loads that you listed practically off-grid, you're looking at a really massive sytem, somewhere in order of 70kW of solar panels and 10,000AH battery bank @48V.
Wind will be much more expensive and less reliable than solar. -
Re: 20kw Sustainable Farm System - Input needed
Wind is going to be a loser in Tolleson, AZ which is a suburb of Phoenix. The valley has about the worst wind characteristics around.
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Re: 20kw Sustainable Farm System - Input needed
We are not in Tolleson proper, we are about as south as it gets. We are not planning on putting the system together until October so I will get a weather tracker on the property so we can get some wind readings. If it gives me data that shows it would be a waste to do wind then I guess we throw it out...
We are about 300 yards off the Gila and we get better wind than this map would lead someone to believe.
I am really interested in getting a complete system - I am still not sure I have the loads right so if I could get some help there - check out the spread sheet and take a look at the load tab.
Once we know we have the load right we can then move on to the best system to build. -
Re: 20kw Sustainable Farm System - Input neededWaste? Do you know that the average age of a farmer is almost 60 yrs old in the US? We are a group in our mid thirties and the owner of the farm just had to declare bankruptcy after his wife died and left medical bills up the ying yang - I would be careful how you judge.
I'm not judging. What I'm pointing out is that I see somebody who has an idea about running a farm on renewable power. And it can be done, but not the way you got it laid out. You have taken ideas from off-grid home setups and tried to apply it to a farming operation. That doesn't work. Period.
There are viable energy programs for farms for which you can get assistance. USDA REAP:
http://www.rurdev.usda.gov/energy.html
But if you start talking wind turbines you will find out that there are only a couple that qualify for assistance (Bergey Excel, Jacobs 31-20). Solar projects qualify, but only if done by a certified installer, etc, etc, etc..
The most common renewable systems being put in for farms are manure digesters with natural gas generators. There are two of them in this area - one a Caterpillar 750 kW unit owned by the farmer and he powers his farm and sells power back to the utility with it. The other a GE 1.2 MW gas turbine set owned by Dairyland Power and operated on a dairy farm with a digester.
There are other programs such as peak rate power programs where you install a diesel standby generator and get a break on your utility rates in return for running your generator at peak load times to reduce demand on the utility. These programs are VERY common and there is not a farm that I know of anywhere within 100 miles of here that does not have a diesel generator. Some of them, like ours, are for off-grid prime power for three-phase systems because there is no three-phase power anywhere around here. Some are for irrigation systems. Some are just for standby power. Common sizes for most farms in the area here are from 75 to 350 kVA with a few larger than 500 kVA.
There are also eligible programs to update old grain dryers to newer more energy efficient models, as an example (again USDA REAP).
So, basically when I see a renewable energy "plan" for a farm laid out with a $5,000 wind turbine with dump load controllers and some solar panels and whatnot, it is so far-fetched that it's almost beyond belief. That is all small-time stuff for homes.
If you don't know where to start in having a certified auditor with experience with farm power systems come to your place and lay out a system that both qualifies and works, then go to your county FSA office and have them get the list from the state office. Every state only has two or three that do this kind of work - and they usually do it in cooperation with the electric utility. I highly doubt anybody here can help you put a system together for this. There are too many unknowns, as you evidently don't even have an operating farm, or any of the coolers or freezers you are talking about installed! You are way in over your head with this. It might seem simple reading about it on the internet. But in practice it's not. You need to hire an expert that is both familiar with farm power systems, and what programs alternative sources are eligible for.Once we know we have the load right we can then move on to the best system to build.
Basically, I looked at the (proposed) loads and you are into piston engine generator territory. Your budget is not big enough to even buy the solar panels required to operate those loads on 99% RE, much less buy the inverters and associated equipment. That's assuming you're going to get 7 kWh/kW installed capacity per day. A wind turbine? Forget it. A 20 kW Jacobs 31-20 is going to produce about 30,000 kWh/year on a good wind site. But you're going to spend $150,000 to install it. A Bergey Excel, which is the next smaller size suitable for farms, is going to cost $80,000 for roughly 18,000-20,000 kWh/year. Anything smaller is not worth even kicking the dirt and saying "this is where I want to put it".
I once had a wild pie-in-the-sky idea about powering our equipment shop with a Jacobs 23-10 that I rebuilt. Let's just say that wind turbines don't work that way. Diesel generators work every single time. If you want to make it "renewable", figure out a way to run it on biofuel.
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Chris -
Re: 20kw Sustainable Farm System - Input needed
Some of the dairy farmers have used methane generators.
gww
Dang Chris, you beat me to the punch. -
Re: 20kw Sustainable Farm System - Input needed
I went thru your loads in detail and made some assumptions on what's going to be running and when. And I think some of them are a little light on your estimation. But basically, this is where it shakes out - you are running a lot of refrigeration systems. 19 years experience working for Cummins on gensets before I came back here dictates that you need a generator with a 50kW standby rating and 45kW prime.
Some of these things appear to be house loads. But the business end loads cannot be interrupted even during a power outage. In homes you can afford to shut down non-essential items to "get by" with a smaller generator. Not for business. Estimating the starting draw of the compressors, along with normal running amps with some running and some not, and some starting while others are running, comes out to 50kW is the smallest unit that's going to work. And, basically, that's a 200 amp 120/240V split-phase service.
Now, to put this in perspective from a renewable energy standpoint, and costs:
Our home's off grid system has 6 kW of solar capacity - cost about $9,000 at today's prices by the time you buy wiring and racks/mounting systems, combiners, controllers, etc.. We have 7.5 kW of wind capacity - cost about $15,000 in three turbines by the time you buy wiring, put in foundations and towers, and buy controllers - and I built the turbines myself. Our battery bank is 58 kWh - cost $9,600. Our inverter and related systems cost $5,000. The inverter is only part of it - there's conduit boxes, breakers and wiring, service panels, control panel, auto-gen start, etc.. It all adds up. We have about $5,000 in generators with wiring and panels and breakers and suitable housing for them.
Let's add all that up - $43,600. Isn't that about your budget for this?
Now, here's reality:
We use 25-30 kWh/day in our house. 25% of it year 'round used to come from our standby genset on peak load power. However - we have never had AC in our house. We installed a central AC unit this year. The solar and wind runs it fine during the day when the sun is out and the wind is blowing, along with other normal loads. But we had to put in a small diesel prime power genset to run the AC at night (and sometimes during the day when it's cloudy). That AC unit ALONE consumes 25 kWh/day - and we don't even live in a hot climate compared to down south.
So there's reality with renewable power - we live off-grid, have over $40,000 invested in equipment - and we STILL cannot produce 75% of our power from solar and wind. And I've been at this off-grid game for 11 years and one month.
So that, in a nutshell, is what somebody with experience sees wrong with your proposed setup.
You'll spend around $30,000 on a real 45 kVA prime power genset, brand new, installed. If it were me, that's where I'd spend my money if the power goes out for 6 hours at a time. You CAN use a prime genset like this as a co-generation set. They are capable of being adapted to driving heat pumps besides gen heads, as well as using heat recovery systems for building heating (maybe not important where you are). I also have extensive experience with that. So if you consider something along those lines, feel free to email me and I'll be happy to tell you all I know about it.
--
Chris -
Re: 20kw Sustainable Farm System - Input neededAs for getting a certified consultant - anyone have a recommendation?
I'm trying to find as much information on this as I can for you - this is the national standards for farm energy audits:
http://extension.purdue.edu/renewable-energy/docs/S612_JUL2009.pdf
And it wasn't that difficult to find out how to request one in Arizona - here is your contact person in your state's Dept of Ag:
Tiffany H. Ground
Environmental Program Coordinator/Conservationist
Arizona Department of Agriculture
Agricultural Conservation and Training
1688 W Adams St
Phoenix, AZ 85007
Phoenix Phone: 602.542.0873
Avondale Phone: 623.535.5055 ext 123
And this is where you can download, fill out and fax in your state's Farm Energy Audit Application:
http://www.azda.gov/act/Energy_Audit_Request_Form.pdf
Jumping thru all the hoops will get you a state-licensed engineer that will come to your place and put the pencil to it.
--
Chris -
Re: 20kw Sustainable Farm System - Input needed
I am not sure where to go with this post -
If there is anyone interested in helping us create this system, if it would be fun, interesting, challenging then please get in touch.
We would be willing to bring an experienced, passionate, solar enthusiast out to the farm to help on site. We are looking at mid October for the install.
If there is anyone in the Phoenix area we would love to take you out to lunch.
kyle@farmergoose.com
480-267-6577
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