Posted on 09/27/2016 10:23:34 AM PDT by artichokegrower
Excellent advice.
Heck, by the time one learns enough to cut through the political and sales talk mumbo jumbo one’s learned enough to DIY!
Just looking to do a stealth camping/other van build which would need to run small fridge, lighting, 12v devices, etc.
I sort of have a basic understanding of the PWM vs. MPPT(higher amps vs. higher volts)when it comes to wiring size/length, efficiency, limitations...that said, am I better off wiring all 5 panels in series into the MPPT(or should I ask, can it be done safely), or series/parallel or just parallel through the PWM for this small solar/vehicle setup?
Forklift battery?
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Yes, Forklift or lift truck battery. 3000 lbs each. I bought 4, 36V batteries and converted them into 4, 48V batteries. I took the cells out of their cases, each cell weighs about 120 lbs with water, that is 72 cells. Takes up a lot of room in my basement. It took me several days to get them all down to my basement. I hope someone else carries them out.
The steel case they were in weighted about 400 lbs. I used a lift in my garage to lift each cell out and then sent the boxes to the scrap yard. Yes, it was a job.
As with any new technology, new adopters must OVERpay in order to make the technology affordable for the masses. Remember back in the beginning of flat-panel televisions, simple 27” versions were selling for thousands of dollars, and seatbelts and airbags were initially available in only Mercedes and BMW’s. Buy early and pay development costs of the new industry - if you have the money.
Thanks for reply. I have my generator in a covered area behind my workshop/toolshed, with an extension cord running to the house to provide power to the workshop. During power outages, I run the extension cords into the house from the generator. Been too lazy to hook up the switching panel which would provide power to the whole house. Can't run a dedicated line to the workshop because of toolshed rules here, the way I built it. Your solution to back feed sounds great otherwise.
Wow! Serious manual labor.
The only reason your economics are so good for you personally is federal and state laws make it so. Your little power plant needs backup power to get you through the night and times of little solar production. You are not paying for that backup power...the rest,of,us are. You are not paying for your share of the transmission and distribution infrastructure you use...the rest,of us are. Without laws distorting markets, you would NEVER pay what your system fully costs.
The contract for the roofing job had a clause that installing solar panels voids the warranty.
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That’s a concern for me also ,, I wouldn’t do it unless I was re-roofing in metal (special attachment hardware that doesn’t penetrate the roof system is available) or if I placed panels on a unattached garage or similar roof structure.
See my post #82, appreciate any advice.
I think the greatest expense and headache is the storage batteries. They require maintainence and do not last as long as the panels.
I keep a couple of golf cart batteries charged up for short term emergency hurricane lighting of my home, using an inverter and LED bulbs. Those batteries last a max of five years in my experience.
Bullspit. I pay $10/month for infrastructure maintenance, because that’s what the Utility proved it costs. I did get a one-time Federal tax credit, but even without it I would still be paying about 10% less than my previous bill, and locked constant while the power rates will increase at minimum 5% per year. I got ZERO tax credit from the State.
Rooftop solar is a moneymaker for the Utility currently, as it allows deferral of construction for increased capacity. Solar provides daytime power when it is needed throughout the grid, and my house uses baseline grid capacity at night. Without an increased daytime influx from rooftop solar, the Utility would have to increase baseline capacity, much of which would be idled at night.
Rooftop solar will be especially beneficial when they shut down the last remaining nuclear power plant in California in a couple of years with much lower construction cost for a smaller natural gas replacement.
I can see how that would be the case, most of the other stuff is solid state, and if it is in a dry, properly maintained environment with the wiring properly done, most of the other stuff would likely last a while.
So, yeah...that makes sense to me.
LOL, I am a noob compared to you, you sound like you have been poking at it a bit.
I have to figure out how to convince my wife I can build something that will work as an electricity backup if the power goes out, and to let me take the money out of savings to do it...she respects me, but...well...probably thinks I’ll cut my fingers off or something.
There's a guy over on SolarPanelTalk that seems to know his stuff, though he does tend to treat newbies like ignoramuses(which, in the solar/electronic world, I resemble that remark).
Anyway, I'll let you know if I burn my van down...
...unless I was in it...
...in which case I probably won't.
Heheheheh...in that case, I do hope to hear from you...:)
thx interesting thread and comments
One of the problems with solar and camping is that in camping weather you usually try to locate yourself into shade.
500 watts is not much power considering you won’t have them at their best angle but it is a whole lot more than nothing. That being said you need to realize that you will not get 500 watts except on very sunny days in cool to cold weather. You will never want to take your batteries past 50% of charge. You can if you are willing to get a short life from your batteries but if you intend them to last you will not.
It would be wise to get a camping refrigerator that uses both cycles, that is electric and propane. During the day when the refrigerator gets a lot of use use the battery electricity but at night use propane. The propane will be slow to recover but can hold temperatures just fine.
Your battery is rated at 20 hours but you should calculate everything based on 10 and subtract 10% off the top for losses. I wouldn’t count on more than about 10KW to get you down to 50%. If your refrigerator pulls 2000W then that gives you about 5 hours of run time without charging the batteries. The refrigerator will run a lot until it gets everything in it cool and then will only run about 25% of the time after that if you don’t leave the door open.
Since you have 500 watts and you could potentially have it 5 hours a day that 2500W total, with losses you should be able to just about keep up on your refrigerator without running a generator to charge the batteries. If you add lighting you will likely have to run a generator a couple hours each day.
If your refrigerator is 12V and your system is 12V you are more efficient and could get a little more than going through your inverter first. LED lighting is the only lighting you should consider, you will be able to do a lot with 20W.
You have enough to do what you want if you are careful, very careful. You must make sure your panels are at the best angle, never in the shade and that you get in and out of the frig quickly and don’t open unless you absolutely have to.
My expectation is that you will probably have to run the generator each day at least an hour or two to make sure you never go below 50% unless you don’t care about the life of the batteries. Most people are more concerned with having a good time than they are managing their electricity.
bump
I picked up a small fridge/freezer at a thrift store for about $10, it's just a couple of cu. ft. I plugged it into a Kill-o-watt and let it run for 24hrs., simulating a typical usage by opening/closing a few times during the day, it netted about 30W/.71 kwH in that(temperature controlled environment)time period, 'course that wouldn't likely be the case on the road.
I'm sure going with 12V/propane would be the more efficient way to go.
Oh, and yeah, I realize there are quite a few factors that reduce actual power input/output for these type of setups. Mine is more of a project right now to get a general sense of how these things work, what I should(and shouldn't)expect from them as far as their usage/limitations.
....meaning at this time I have no plans on going for a full off-grid setup(on the homestead anyway), just trying to gain a little knowledge...not to mention preparing for a bug-out when the zombie apocalypse hits(should illiary be elected).
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