Pompano
Elite Nomad
Posts: 8194
Registered: 11-14-2004
Location: Bay of Conception and Up North
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Mood: Optimistic
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Alternative Power Sources for AC at casa.
Got a question for any off-grid electrical-energy users and experts out there.
I have installed a four-ton, 220 volt, 3 head air-conditioning system at our casa. It takes quite a bit of power to run the system at maximum. Of
course we are a longs ways off the grid, so we supply our own power here.
These are the specs on the Mini-split AC unit...an LG.
48,000 BTU's
4700 watt
single phase
220 volt
60Hz
My new Honda EX5500 generator will run it, BUT there is not enough left over to run the charging feature on my 4500 watt Trace inverter/charger. I
have to drop the Trace's charge rate down to almost nothing..2-3 amps.. or the breaker goes off. This is not efficient as we will be running the AC
all summer long.
My solar system: 24 volts...4500 watt inverter...lots of battery storage hours. 28-30 amp power from solar array of 16 panels. Of course the solar
system I have will not run at 220 currently, but I am told I can 'stack' another inverter with my existing one and accomplish 220 volts..along with
another elect. device. I am not sure how much we would have to add to power these AC's by using strictly solar panels...if in fact we could at all.
Maybe some out there have powered large home AC's with their solar systems? I would appreciate any advice or experience.
The most likely solution appears to me to just get a larger genset...10-20KW. Now, the question would be...diesel or propane? I will discount gas
out of hand for various reasons, but mostly safety.
Any input on gensets in that power range? Recommendations on brands and suppliers? Gracias.
I do what the voices in my tackle box tell me.
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Pompano
Elite Nomad
Posts: 8194
Registered: 11-14-2004
Location: Bay of Conception and Up North
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Mood: Optimistic
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As long as I am on the subject of power...who has a great buy on 100-120 watt solar panels, Trace 4500 inverters, batts, all things solar.
I do what the voices in my tackle box tell me.
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oladulce
Super Nomad
Posts: 1625
Registered: 5-30-2005
Location: bcs
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A suggestion Pompano
Mr oladulce has posted many solar queries on this forum-
http://www.wind-sun.com/smf/index.php.
The guys who respond are very friendly and knowledgable and you'll probably get a couple of opinions and suggestions.
This is the Forum section for the place where we get most of our solar supplies- Northern AZ Wind & Sun.
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Mexray
Super Nomad
Posts: 1016
Registered: 8-30-2002
Location: California Delta
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Mood: Baja Time
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Roger...
Costco online has Cummins Gen sets...they have a 10kw propane for around $3800...
http://www.costco.com/Browse/Product.aspx?Prodid=10044991&am...
Don't know how economical it would be to run, however, versus diesel. I believe diesel would be cheaper to 'run', but purchase cost is much higher,
so you kinda have to factor all that into the picture to get a projected cost over, say 5-10 years, etc.
BTW...your AC load is about 22Amps....4700 / 220 = 21.3.
Even with two inverters and lots of batteries, that's a rather large load to maintain over time. AND, to recharge the battery bank takes lots of
time, as well, depending on your recharge capacities.
If you ran your 22 amp load for 24 hours, thats about 528amps from your battery bank - now you have to replace those amps...a true 100 amp charger
would take, in theory, 5-1/2 hours on the generator - most likely in reality about 8 hours (efficiency loss, heat, etc). Of course, those 24 hours on
the inverter would be reduced by the generator 'on' time, etc, etc...
To get max battery life, your bank needs to be 'sized' so that you only use about 50% of it's capacity during 'cycles'. An estimate, using 225 amp ,
6volt golf car batteries would be:
528amps * 2 (for 50% use) = 1056 / 225 (amp capc of 4 batt's in series for 24 volt inverter use) = 5 (4 battery groups)...or 5 groups * 4 batt's = 20
total batteries in system.
This doesn't allow for any 'safety' factor, or other electrical loads but the AC...so you'll have to add more batteries for the other ac voltage needs
- lights, TV, BLENDER, fans, refrigerator, etc., etc....and more gen charge time as well.
Your solar system will of course be used to moderate your generator time, depending on the actual capacity of the panels, etc, etc...
Too bad you couldn't get hold of that old diesel generator that was up on the hill there at 'Tiberon'...that set up just 'hummed' along all the time
before they ran the power up there. Remember that big 'hot tub' dug into the hill, up there full of drain oil from the gen set!
When we had our 'outback' property in northern Nevada, I bought an air cooled 6 KW diesel powered gen set for the small cabin we had. I'd dug a 150
well, and needed 220 volts to pump the water. Knowing how noisy that air cooled genny would be, I built a cement block house around it, away from the
cabin, to mute the sound - worked great. Kinda like your 'neighbors' the other side of Santispac with the large casa's - their diesel gennys being in
separate enclosed buildings away from the house.
All things considered...I believe a substantial solar/battery/inverter system to handle your 'normal' loads, and a permanent gen set installation in a
block enclosure for those times you need to run the AC cooling system, might be the best all around set-up.
According to my clock...anytime is \'BAJA TIME\' & as Jimmy Buffett says,
\"It doesn\'t use numbers or moving hands It always just says now...\"
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bajalou
Ultra Nomad
Posts: 4459
Registered: 3-11-2004
Location: South of the broder
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A outfit in Idaho had a lot of diesel gensets from the RR refigerator cars think some were in the 10KW range - at some pretty reasonable prices for
diesel. About $2200 as I recall about 2 years ago.
No Bad Days
\"Never argue with an idiot. People watching may not be able to tell the difference\"
\"The trouble with doing nothing is - how do I know when I\'m done?\"
Nomad Baja Interactive map
And in the San Felipe area - check out Valle Chico area |
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Bob and Susan
Elite Nomad
Posts: 8813
Registered: 8-20-2003
Location: Mulege BCS on the BAY
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Mood: Full Time Residents
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Roger
I just spent all Saturday morning at Solortron in Victorville CA
http://www.partsonsale.com/main.htm
They are VERY helpful.
If you stack two 4024 units you just get 8000W
You do need to buy some stuff....
gj250 breaker 159.90
4024 inverter 2145.00
swi/par box 282.90
and a swcb conduit box 77.08
2 battery cables thrown in
Out the door w/ tax 2871.41
The two inverters also need software above 4.01
so you need to check your old 4024 unit.
I now have 3-5500W 10hp China made diesel generators that I purchased locally in Carson CA
each cost $710
They only have a 15 amp breaker but have 220V and 110V but can cold start my washer here in Upland which most other generators can't.
It takes over 5000W to start the washer motor.
I figure I could have 10 of these for the price of one BIG guy.
Diesel is alot better fuel source and small units use way less fuel.
These units hold 6 gallons and run about 8hours on a tank of fuel.
They are noisy 85db...
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Pompano
Elite Nomad
Posts: 8194
Registered: 11-14-2004
Location: Bay of Conception and Up North
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Mood: Optimistic
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Thanks to all for the good advice and information. I am busy checking it all out right now.
That forum is a good one, oladulce. I am sure there will be lots of helpful posts found there.
Mexray.. yeah, me too. I figure to beef up the solar system anyway, but plan on running the AC load with a full-time generator for the hot times. A
neighbor of mine who owns a large dairy business in Ensenada runs his 30KW diesel constantly when he is here..and has for many years. We are not that
far away, but we never hear it running. I will want one like that for sure. Something in the 70's or less decibel range. I have a line on some
diesel units in northern Minnesota. Go figure, that is right next to our home Up North and we will be buying for Baja.
Bajalou..thanks for the tip and I will search around for those used RR units up in Idaho. Sounds like very good prices at $2200 or so per.
Bob y Susan..I will talk to those people and maybe we can work something out on additions to my existing solar system. Although in retrospect, I
doubt I will stack another inverter if I go with an AC generator. There would then be no need for the extra. Some panel replacements and a few more
storage batteries will be in order, though.
An odd note...we have a great washer..a Whirlpool we bought in La Paz..that runs fine with our 4500 Watt Trace inverter from just the solar array. I
wonder why the difference in power uses? Ours is a large unit and fires up with no problem on fewer watts.
I do what the voices in my tackle box tell me.
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Mexray
Super Nomad
Posts: 1016
Registered: 8-30-2002
Location: California Delta
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Mood: Baja Time
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Roger...
...sounds like your 'neighbor' with the 30K genny has a bit more capacity than he needs...ahem, an investment in a heavy duty, long extension cord
might be a real 'low bucks' solution...Midnight electrical supply...
[Edited on 2-6-2006 by Mexray]
According to my clock...anytime is \'BAJA TIME\' & as Jimmy Buffett says,
\"It doesn\'t use numbers or moving hands It always just says now...\"
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Bruce R Leech
Elite Nomad
Posts: 6796
Registered: 9-20-2004
Location: Ensenada formerly Mulege
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Mood: A lot cooler than Mulege
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Pompano I hate to tell you this but your 5500 gen set is going to melt down come warm weather.
buy a heavy duty diesel gen set with twice the capacity that you think you will ever draw. most are rated at 12 000 hours service life
my 30 KVA would use a half gallon per hour at 15 KVA draw
Bruce R Leech
Ensenada
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Bob and Susan
Elite Nomad
Posts: 8813
Registered: 8-20-2003
Location: Mulege BCS on the BAY
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Mood: Full Time Residents
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if they worked 5 days a week for 8 hours a day they would work 2080 hours a year...
so that's a life of 5.8 years
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Pompano
Elite Nomad
Posts: 8194
Registered: 11-14-2004
Location: Bay of Conception and Up North
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Mood: Optimistic
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Mexray..I will look into the 'extension cord' application! Buy fear I would be shot!
Bruce...don't worry, I already knew beforehand that the Honda EX5500 genset I have wouldn't be the one to run 24/7..especially during our hot summers.
It is meant to be a back-up genset in the event of a new install. Although I must say that this 5.5KW is one helluva good generator and super quiet.
It is used on movie sets a lot.
I tried a 8KW Coleman unit using a Briggs & Stratton engine a couple years ago but that genset failed in 2 days at fairly low temps. I should
have known...Briggs and Stratton make good small auger engines that we used for our grain farms back home, but for larger gensets, forget it. No
bueno. Now, while Honda is good, I will probably go with some larger diesel..14-20KW or so. Cummins make a good engine...bulletproof in my Dodge.
But there are many good mgfrs of industrial diesel gensets. Northstar Up North will be a good bet. Kohler, Northern Lights, etc.
Sob & Susan, I figure to run the AC about 6-8 hours daily for 14 weeks..thus over 680 hours every year. Using an average of 12,000 hours lifespan,
that is about 18 years of use. Longevity and economy of operation are the issues.
The solar application is becoming more and more attractive, nicht wahr? We are discussing that aspect over patiodrinks.
[Edited on 2-6-2006 by Pompano]
I do what the voices in my tackle box tell me.
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