Posted: 4/30/2013 10:59:02 PM EDT
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Seems like a rember a few guys/gals here have some solar set ups here in AR. I'm looking at adding some at my home and need some general info. Right now I have a battery setup with a rectifier systems and invertor. I have my important electronics(alarm, Uverse, wifi, comp, cameras and a few other small things. The basic set up stuff is plugged into the inverter that is powered from the rectifier that can switch to battery with no loss/ interruption of service. Once a month or so I cut power to the rectifier to switch to bat to about 50% drain takes about 16 hours with the current load. When I had the freezer drops to 10 hrs or so.
So I have a gen set in a long outage I can connect the gen set to the rectifiers and charge the batteries and the rectifier and the true sine inverter gives me good clean power. But what I would really like to have is some solor panels in place that could really extend then the time from having to run the gen set to charge the batteries in extended outages. Any ideals or linkes to good sites would be great. And if you close to central ark if I could come take a look at your set up that would be really cool. I'm a more hands on guy anyway. From my iPhone |
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I really don't have a lot of experience with 48v set-ups, sorry..
I do have a similar size set up, running on 12v though. It is the poor man's verson of a bank: 
It lives in a $100 wallyworld Lifetime box on the deck. 5 122 AH deep cycle batts, bus bars, and 2 30 Amp charge controllers..... 
I am replacing a couple of the batteries this week, but this is the set-up. I have 2 banks of 3, 120W, 12v panels, each putting out about 7.5 Amps going into each charge controller. The best deal in 12v panels used to be the DM solar 2 pack from Amazon, as long as you have a prime (or even a 30 day trial membership ) membership so as not to get hit with the $120 shipping charge. I know that people were using them in 24v systems with pretty good results, I do not know about 48 V though.. I am sure there are others here with much better set-ups and advice, wish I could be more help... Cheers, CT |
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First off, that's a nice setup, Clastac. Given the will and adequate research, we can all engineer a 90% solution for quite a bit less than it can be bought for.
On the OP's question, much will depend on the load you want to support and on how long you want to support it. If you have the capability to measure the load that would be an excellent start. I previously had my home network, with a low-power NAS, powered by solar. I have a couple 50W panels that I used to charge a pair of 100Ah deep-cycle batteries, and a small voltage regulator board I built to power the devices directly. Converting to A/C is fairly lossy, so if you can power any of your devices directly with D/C that would provide a fair bump in system efficiency. Any D/C load, that is pretty much anything with a wall wart, can be more efficiently powered through a cheap solid-state regulator (buck-boost, switch-mode, etc). My setup was fairly low-power, consuming about 550Wh per 24 hours. During high-solar periods the two 50W panels and batts provided the full power needed, with a few days worth of storage for low-solar periods. If it wasn't t-shirt and shorts weather, though, I had a scooter charger on a timer set to run for a few hours each night to fill the gap. Since moving from Kentucky to the River Valley my panels have been in the garage sitting idle, though. I don't know why, but I seem much less apt to poke holes in my own house than in the rental I was in before moving :) Anyways, if you're not far from the River Valley area (R'ville) I'd like to have a look at your setup and help plan out the upgrades over a beer or two :) Laters, Jason |
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Quoted:
I really don't have a lot of experience with 48v set-ups, sorry.. I do have a similar size set up, running on 12v though. It is the poor man's verson of a bank: http://i991.photobucket.com/albums/af39/clastac/batt014_zpsa7be9098.jpg It lives in a $100 wallyworld Lifetime box on the deck. 5 122 AH deep cycle batts, bus bars, and 2 30 Amp charge controllers..... http://i991.photobucket.com/albums/af39/clastac/batt012_zps781addb0.jpg I am replacing a couple of the batteries this week, but this is the set-up. I have 2 banks of 3, 120W, 12v panels, each putting out about 7.5 Amps going into each charge controller. The best deal in 12v panels used to be the DM solar 2 pack from Amazon, as long as you have a prime (or even a 30 day trial membership ) membership so as not to get hit with the $120 shipping charge. I know that people were using them in 24v systems with pretty good results, I do not know about 48 V though.. I am sure there are others here with much better set-ups and advice, wish I could be more help... Cheers, CT What all do you/can you power with that setup? |
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Here is a diagram of my current set up. Everything I show stays connected to the inverter all the time so in the event of an outage it goes strait to battery back up with no loss of service. I am still doing some reading with the Kill a watt to get better long term usage with the freezer and and ice box. I just added the kill a watt to this circuit this morning.
I would like to add a nice solar array to charge the batteries in an event of long term outage. I have a gen that I could plug the rectifier into to recharge the batts but I hate having to do this due to the noise and having to mess with when it is needed. A short test today. Batt 15:00 100% @ 275w 16:00 98.2% @ 255w 17:00 95.8% @ 213w 18:00 94.4% @ 132w 19:00 92.2% @ 361w 20.00 90.3% @ 248w 
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Quoted:
Quoted:
I really don't have a lot of experience with 48v set-ups, sorry.. I do have a similar size set up, running on 12v though. It is the poor man's verson of a bank: http://i991.photobucket.com/albums/af39/clastac/batt014_zpsa7be9098.jpg It lives in a $100 wallyworld Lifetime box on the deck. 5 122 AH deep cycle batts, bus bars, and 2 30 Amp charge controllers..... http://i991.photobucket.com/albums/af39/clastac/batt012_zps781addb0.jpg I am replacing a couple of the batteries this week, but this is the set-up. I have 2 banks of 3, 120W, 12v panels, each putting out about 7.5 Amps going into each charge controller. The best deal in 12v panels used to be the DM solar 2 pack from Amazon, as long as you have a prime (or even a 30 day trial membership ) membership so as not to get hit with the $120 shipping charge. I know that people were using them in 24v systems with pretty good results, I do not know about 48 V though.. I am sure there are others here with much better set-ups and advice, wish I could be more help... Cheers, CT What all do you/can you power with that setup? I can power just about anything in the house, except the well pump or big AC. I have several DC devices, and I am not sayin' that I have used an inverter and back-fed through the main panel.'cause that would be a no-no...........but IF I ever did, and used good power management, could power smaller window AC's, or blower motor for the fireplace insert....refidge or freezer..........Right now the only connected dedicated items are down in the bunker... 
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So for the last five days I have been running some power consumption test the items I use most to better gage how much back up power I will need in an extended power outage.
The refrigerator and freezer for the last 121 hrs used 19.94KWH so that should equate to 164.80 watts per hour on avg. My office with a iMac, Laptop with external monitor, external hard drive, Alarm system, small switch, Mac Time Machine, DVR, uVerse modem, and a battery charging station for my CR123 batts, iPhones & iPads for the 121 hrs used 15.35 KWH so that comes to 127.02 watts avg. I also have been looking hard into solar panels, charge controllers and the one common thread I have noticed is it almost like buying a safe! Always double what you think you need. As my system is set up right now my inverter is running the above mentions items 24/7 so in the case of an outage the inverter will automatically switch to the batteries with no loss in power to these items. I think I am going to add another battery bank and wire them in parallel to double my available amp hours to 250. I will also be setting them up with a A,B, A+B switch so that I can switch between the banks. My thinking is during normal operation they would be set up in A+B for the full 250 amp hour configuration. But in extended power outages I would like the solar panels connected to one bank charging them while I use the other bank. I know I can use them both while they are charging via the solar panels but the one thing I am having problems with is not knowing for sure if the charge from the charger controller would back ffed into my rectifiers and mess them up in any way. I would have to take a $300.00 charger controller and damage my $1000.00 + rectifier set up. Everything I see says it would not but I worked hard for that money and don't want to chance it. Anyway Ill be adding more as I learn more. Sooner or later ill post pics of the completed set up along with an updated wiring schematic. |
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I think your thought process is right on the money. Double what you think you will need in batteries, then quadruple what you think you need in panels . I do not have any experience with rectifiers, but with charge controllers and inverters, implementing a bus bar or two, helps eliminate a lot of headaches.....
I look forward to your updates and pictures..... |
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Ok, so it looks like your load is about 7.2KWh/day.
Given that charging a battery bank and then pulling power out later is not as efficient as immediate use, I'd build out with between 8.5 and 9 KW of solar. Considering 5 hours of solar per day, you're looking at about 1.75KW of solar panels to support the load. Considering that you don't want to deplete your storage array too deeply, too often, I'd go with 3 to 5 times the daily load in storage. That makes 30KWh to 50KWh of storage. It gets a bit expensive, as you already know, but if you've got the will and the means the cost really isn't that much of an issue. There are several places to geek out on solar, a few of them I've enjoyed are... http://www.freesunpower.com/designtools.php http://www.yourgreendream.com http://www.builditsolar.com/Projects/PV/pv.htm |
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