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BajaBlanca
Select Nomad
Posts: 13242
Registered: 10-28-2008
Location: La Bocana, BCS
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solar power info request
Hi folks, we just moved into our new house and it has solar power. we are newbies at using solar and could use some insight as to YOUR experience:
how many panels?
do you use some kind of automatic sun tracker so that the panels are always facing the sun?
how many watts of solar panels are needd for charging eight 6 volt golf cart batteries?
Folks, these are my husband's questions and I told him for sure there would be some expert advice here. I just want everything to work. Pics of the
new house later - it is STUNNING.
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DavidE
Ultra Nomad
Posts: 3814
Registered: 12-1-2003
Location: Baja California México
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Mood: 'At home we demand facts and get them. In Mexico one subsists on rumor and never demands anything.' Charles Flandrau,
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BajaBlanca please U2U me. I have done solar voltaic installations to 10 KW in size. People have said I pretty much know what I am doing. Glad to help.
A Lot To See And A Lot To Do
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Bajajorge
Ultra Nomad
Posts: 2604
Registered: 10-13-2005
Location: Topaz Lake, NV/San Felipe
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I'm not a solar guru, but I have a medium sized solar setup at my place. Nearest electric pole is about a mile away. I have 6 T105 batteries, with
500watts worth of solar panels, no tracker. During Spring/early Summer they recharge from 12.2v to full charge by 10AM. During Fall/Winter they go
back to full charge by about 1-2PM.
As for how much you need is up to you. With my set up I have to forget using an electric coffee pot, toaster, microwave and AC. When I want to use
stuff like that I fire up my 4000watt generator.
It's all in what you want to do.
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larryC
Super Nomad
Posts: 1499
Registered: 8-11-2008
Location: BoLA
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Bajablanca
Your question is not nearly as easy as most would think.
Is your system wired as 12v, 24v or 48v? Easy way to tell is by the model # on your inverter. Should tell you the voltage. You should have somewhere
near 800 to 1000 watts of panels to get a good charge on those batteries according to the Trojan web site. Panels are so cheap right now I don't think
I would mess with a tracker, just buy more panels.
Here is Trojans web address for info on charging batteries properly. http://www.trojanbattery.com/BatteryMaintenance/Charging.asp...
Hope this helps
Larry
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willardguy
Elite Nomad
Posts: 6451
Registered: 9-19-2009
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anything davidE can't help you with, northern arizona wind and sun can. its a great forum from beginner to pro.
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rts551
Elite Nomad
Posts: 6700
Registered: 9-5-2003
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Have Les check with all your friends in La Beliza. Systems from whole house 220 ($$$$) to minimal 12 volt lighting.
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ncampion
Super Nomad
Posts: 1238
Registered: 4-15-2006
Location: Loreto
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Mood: Retired and Loving it
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You should always work backwards when sizing solar projects. First figure out what your daily use is, get inverters to cover that and sufficient
batteries to manage the load at night. Only then do you get panels and controllers with sufficient wattage to recharge the batteries. Oh and BTW
figure at least 50% safety margine on everything. I have a 6000 watt system for our off grid home in Loreto and we use AC at night with no generator
run. It can be done.
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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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no...you cannot run an ac unit on solar without draining the batteries at night
even the smallest ac unit uses 5 amps...that will drain the batteries in about 6 hours
for ac you need a generator
i have a question about your solar system...
did you buy the batteries yet
inverter...charge controlers...panels
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DavidE
Ultra Nomad
Posts: 3814
Registered: 12-1-2003
Location: Baja California México
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Mood: 'At home we demand facts and get them. In Mexico one subsists on rumor and never demands anything.' Charles Flandrau,
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5,000 BTU 488 run watts 87% conversion efficiency factor of the inverter, limited by 50% amp hour drawdown limit on flooded lead acid batteries.
530 amp hours X2 = 1,060 amp hours 12 hours continuous. Ten GC-220 batteries dedicated to running the A/C only and absolutely nothing else. CEF losses
and total watt hours/day determine the size of the array. The presence of an MPPT controller, and wire line losses also must be factored. Same for
temperature compensation of the electrolyte for quiescent charge loss. Equalization adds to the panel capacity demand. There is always error in
theoretical workups.
All of this, meaning the chemistry going on in the battery, has to be understood and managed without overwhelming the end user. No one wants to be a
slave to a bunch of batteries, array of panels and an inverter. Guesswork means heartbreak, and disappointment coupled with a flat wallet. The user
has to be audited and the system has to be intelligently sized. Protection against salt air is crucial. It's not hard to do, but salt air will ruin a
system in months.
I've seen cloud edging utterly destroy a five hundred dollar controller in minutes. "But it was sized correctly!" was the wail from the installer.
Blanca is smart asking for help. A wrong solar system is worse than a hole to throw money in.
The ONLY WAY to determine the success of a system is if and when it delivers that maximum amount of service over the longest period of time, for the
least amount of money.
A Lot To See And A Lot To Do
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ncampion
Super Nomad
Posts: 1238
Registered: 4-15-2006
Location: Loreto
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Mood: Retired and Loving it
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| Quote: | Originally posted by Bob and Susan
no...you cannot run an ac unit on solar without draining the batteries at night
even the smallest ac unit uses 5 amps...that will drain the batteries in about 6 hours
for ac you need a generator
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Bob, next time you are in Loreto, stop in and see me. I'll let you sleep in one of our air conditioned (1 ton mini-split)guest rooms that we have
been using for two summers now using only power from our panels and battery bank. It's all a matter of doing the math.
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captkw
Ultra Nomad
Posts: 3850
Registered: 10-19-2010
Location: el charro b.c.s.
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Mood: new dog/missing the old 1
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ncampion
Hola,not sure as I get your name ?? but ,yes IT can be done,,but not the normal system !! and you are right..It is in the math AND money!!!! and
sometimes to the end user/owner I recommend a true sine wave unit with a GOOD genset..to keep up during Low Lu periods....K & T
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El Camote
Senior Nomad
Posts: 514
Registered: 9-7-2003
Location: Above the clouds
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Mood: y Blues
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| Quote: | Originally posted by Bajajorge
With my set up I have to forget using an electric coffee pot, toaster, microwave and AC. When I want to use stuff like that I fire up my 4000watt
generator.
It's all in what you want to do. |
BJ, we had a similar size system in the Baja house except the panels were only 450 watts. I found an electric drip coffee maker that used an
insulated carafe rather than glass carafe and heating element. The only electric it needed was about 3 minutes to heat the water. Worked great with
our system. On those rare winter mornings when the voltage was too low, I would just heat the water on the stove top then pour through the filter
into the insulated carafe. This is the type
I mean although not the same model.
Also used a toaster and microwave. No problem at all just not at the same time! I mounted a voltmeter in the kitchen so I could keep track of the
batteries.
Knowledge is good. - Emil Faber
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Bob and Susan
Elite Nomad
Posts: 8813
Registered: 8-20-2003
Location: Mulege BCS on the BAY
Member Is Offline
Mood: Full Time Residents
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here is my experience with solar powering ac...
the neighbor lived in a trailer
he had 16 six volt trojans
outback inverter and controler
16- 185w solar panels
one panel for each battery
the 5000btu ac unit ran all night but the batteries were dead in the morning
he was able to raise the charge partially by the evening but had to turn off the unit during the day...during that time the trailer heated up
remember the math used in the example is at 70f not 108f
batteries and panels do weird things when its hot
heat kills batteries
the batteries could not power a house and the ac unit
the continues large draw lowers the voltage and drains the batteries
lower voltage increases the temp (amps) in the inverter...
he even had one inverter fail...we figured it overheated...
outback waranted it
nchampion...what does your hydrometer say in the morning
remember voltage is ONLY an indicator that you CAN charge the batteries
[Edited on 7-1-2012 by Bob and Susan]
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DavidE
Ultra Nomad
Posts: 3814
Registered: 12-1-2003
Location: Baja California México
Member Is Offline
Mood: 'At home we demand facts and get them. In Mexico one subsists on rumor and never demands anything.' Charles Flandrau,
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Whoa Hoss, I'm a retired battery design engineer. Elevated thermal issues on a flooded lead antimony battery do not degrade performance, period.
Charging has to cease when electrolyte temperature approaches 50C, that's 122F
A dozen of anything is meaningless, unless all the batteries were in good condition, started out fully charged, and then one can start to wonder about
additional loads like lights, fans, and water pumps. This isn't guesswork. it is hard, cold, cruel, engineering science. I had to crunch numbers for
decades, resolving issues like antimonial poisoning of negative plates, plate paste composition on time delivery issues, greening ambient temperature
and humidity, and most of all certifying test results using NIST documented apparati and criteria.
My company subcontracted to Trojan, US Battery, ABC, Ramcar, Globe Union, and was in contact with Johnson Controls when I had to close it down due to
my getting ill.
Exide used to run Skipjack submarines, for many hours on stupid 7% antimony lead acid batteries seventy years ago. Fairbanks Morse engines, and
Westinghouse motor generators.
When I wrote above, that 10 GC-220 golf car batteries, fully charged, will operate a 5,000 BTU A/C with at least a 9.6 EEF for 12 hours without
discharging the batteries more than 50 percent I did not stutter. The subject of recharging the batteries, according to the Peukert Factor assigned to
the discharge has to due entirely with the CEF, the Charge Efficiency Factor. It must correlate with the design of the battery. The battery must not
remain discharged for any length of time or risk crystallization of sulfates on the plates. When appropriate the cell must be equalized or desulfated.
This process is specialized and CAN NOT BE DONE AUTOMATICALLY. It is a regimen of using 5% of total amp hour capacity applied in constant AMPERAGE to
a fully charged sulfated battery until one of the following happens.
The electrolyte specific gravity reverts to OEM density
16.0 volts is attained
50C or 122C is reached
The charge shall be terminated
This is appropriate for a .110" positive plate 5% antimonial flooded lead acid battery.
end
A Lot To See And A Lot To Do
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edm1
Senior Nomad
Posts: 568
Registered: 8-23-2006
Location: Oak Hills, Ca
Member Is Offline
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| Quote: | Originally posted by DavidE
5,000 BTU 488 run watts 87% conversion efficiency factor of the inverter, limited by 50% amp hour drawdown limit on flooded lead acid batteries.
530 amp hours X2 = 1,060 amp hours 12 hours continuous. Ten GC-220 batteries dedicated to running the A/C only and absolutely nothing else. CEF losses
and total watt hours/day determine the size of the array. The presence of an MPPT controller, and wire line losses also must be factored. Same for
temperature compensation of the electrolyte for quiescent charge loss. Equalization adds to the panel capacity demand. There is always error in
theoretical workups.
All of this, meaning the chemistry going on in the battery, has to be understood and managed without overwhelming the end user. No one wants to be a
slave to a bunch of batteries, array of panels and an inverter. Guesswork means heartbreak, and disappointment coupled with a flat wallet. The user
has to be audited and the system has to be intelligently sized. Protection against salt air is crucial. It's not hard to do, but salt air will ruin a
system in months.
I've seen cloud edging utterly destroy a five hundred dollar controller in minutes. "But it was sized correctly!" was the wail from the installer.
Blanca is smart asking for help. A wrong solar system is worse than a hole to throw money in.
The ONLY WAY to determine the success of a system is if and when it delivers that maximum amount of service over the longest period of time, for the
least amount of money. |
Good info. You know wgat you're talking about David.
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edm1
Senior Nomad
Posts: 568
Registered: 8-23-2006
Location: Oak Hills, Ca
Member Is Offline
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| Quote: | Originally posted by Bob and Susan
. . . .
the 5000btu ac unit ran all night but the batteries were dead in the morning . . .
[Edited on 7-1-2012 by Bob and Susan] |
This would not happen if the system was designed properly, unless the inverter malfunctioned, and they rarely do. When they malfunction, they usually
turn off the system and that would not cause (rather protect from) a dead battery bank in the morning.
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captkw
Ultra Nomad
Posts: 3850
Registered: 10-19-2010
Location: el charro b.c.s.
Member Is Offline
Mood: new dog/missing the old 1
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DAVID E
Hola,,You like me must get frustrated when talking to most folk's..I think I can safely say, most people do not read/study about batt's and belive a
lot of wife tells..and the technoligy is rapidly changeing..I have to keep on my toe's with the new stuff !! never boring..thats for sure..btw good
info!!! me,I learn every day and try not to fall behind....K&T  PS.am I
correct in saying sulfate on the plates is the leading batt fail?? and cold is WOSRE than heat in general ???
[Edited on 7-1-2012 by captkw]
[Edited on 7-2-2012 by captkw]
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BajaBlanca
Select Nomad
Posts: 13242
Registered: 10-28-2008
Location: La Bocana, BCS
Member Is Offline
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wow...so much information. thank you. I will pass all this information onto Les ... thank goodness we are on the Pacific side and will more likely
need a heater once in while in the winter rather than an air conditioner. ever. But I would like to be able to use a microwave, the TV, internet.
I don't mind sideline questions at all - in my opinion it just adds to general knowledge. so anyone, pls feel free to ask any generator or solar
power related question.
panels really are cheap right now, aren't they ? we got a really good deal and it looks like we should have gotten more of them. oh well ! we may
have to make a trip up north.
we did have the generator on for a while last night and there were popping noises, loud ones, in various locations thorughout the house and then the
smell of burnt rubber. It was panic time since we have NO water pump, it decided to conk out. we did go get the fire extinguishers from the B&B,
but the smell eventually went away. Although we searched for burned wires today, we found nada.
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maspacifico
Nomad
Posts: 317
Registered: 4-22-2008
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BajaBlanca! I'm not an electrician but live on solar. Popping noises and the smell of burnt rubber isn't normal solar living. Something is wrong. Shut
it down and move back into where you were til you get an electrician out there! Really.
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DavidE
Ultra Nomad
Posts: 3814
Registered: 12-1-2003
Location: Baja California México
Member Is Offline
Mood: 'At home we demand facts and get them. In Mexico one subsists on rumor and never demands anything.' Charles Flandrau,
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Bajablanca, keep me supplied with cold water and I'll come out and check your system if you wish. Is the road badly washboarded? My
piece-of-you-know-what car will commit seppuko if it endures too much ondas de terreceria. Hour and a half? How many kilometers?
Do not attempt to use the genset agreeing with the comments above.
You will need a PURE SINE WAVE inverter to make the microwave work like it does on generator power. The inverter must be rated at a higher wattage
than the microwave. Some use a thousand watts, others use twelve hundred watts. The other type of inverter is called a Modified Sine Wave inverter.
They are much more common and less expensive. I can bake a large potato in 6 minutes with house power or a pure sine wave inverter. A MSW inverter
requires double the time. A MSW inverter will also blow out electric blanket controls. I recommend getting a PSW inverter just to operate the stuff
that absolutely needs one. Use your existing inverter for everything else. A pure sine wave inverter makes better electricity than any generator short
of a critical use generator that costs as much as your house. The problem is called "harmonic distortion". All but inverter type small generators have
problems in this area as well as with voltage and frequency. I believe your generator did something evil and the voltage went way up. Your system may
have lost neutral with a 240 volt output or the voltage regulator may have said "adios".
"Loud Pops" sounds distressingly like capacitors blowing in various electronic circuits, like TV, VCR, Microwave, etc. (sigh).
Ain't nothing like that smell or fried automatic transmission, clutch or brakes. Eewww!
A Lot To See And A Lot To Do
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