I don't have any myself but have heard good things and have them in my "wish list" to get a couple with my tax refund (if I get one). My plan is to do a mini experiment and see if I can set up a simple battery bank that I can run a fridge off of, 100% by the sun. This might sound like kids' play to folks who have had solar panels at their homes for a long time, but for me it will be a good learning experience.

I think panel prices are going to continue to drop now that the urgency of the expiring federal tax credit has been pushed down the road a few years. I also had a recent conversation with a local installer and PowerWalls and other compact home battery systems are probably going to improve dramatically and come down in price in the next few years as well.

If you do get panels and you live in a heavily populated area, be sure and secure them somehow. They will walk off - panel theft is a growing issue.

If you end up buying them, let us know how they work out. Good luck!

 

I am planning on buying some this week. I asked a seller for specifics on a midnite solar kid, 30 amp, but have not heard back from them. I have 12 new golf cart batteries [couldn't pass them up for the price] My project to will be an experiment. they will be mounted on my roof, so theft should not be an issue. Plus you won't see them from yard/road. My research is looking into inverters specifically for solar with a low voltage shut down feature. Possibly propower 2000 watt. LED lights and non heating appliances will be main use. I've been looking at PV in my area, not a lot, but snow will be an issue. I won't be going up to clean them off in the winter, just not safe at all. I am also looking at the possibilty of hot water from solar panels feeding dc elements in a small hot water tank 5 gallon, which I got new for free. an office ordered it, it did not fulfill their needs and they couldn't return it. they bought a larger tank. I have the dc pump/water supply to operate it in an emergency.

 

Yes, I have this exact panel. To the best of my knowledge, they are the best panels on the market. They are durable, packed well, and output what they are rated for in bright sunshine.

 

I also have the Renogy panels, 10 of them as a matter of fact.

4 panels max for one charge controller, at peak they will give you about 27 amps.
I mounted mine on rolling carts that I keep in my shop which I can pull out when I need them. $125 is a very good price for the panels, but you should get at least 1 with a charge controller for every set of four. I have been meaning to get a couple more for spares, thanks for the heads up.:thumb:

 

The number of panels you can place on a single charge controller depends on the amperage rating of the controller. You can get controllers as small as 3 amps (probably even smaller) or much, much larger. Amazon sells at least one that is 80 amps.

At maximum output, a 100 watt panel will output 8.33 amps. Practically speaking, you'll probably never quite achieve that in most places in the country, so an 80 amp charge controller could handle 1000 watts worth of panels.

Also, when looking at multiple panels, it's ALWAYS a good investment to get the more expensive but FAR more efficient MPPT charge controllers rather than the cheaper PWM models. You'll get a lot more usable energy out of the MPPT controllers.

 

Why not get the most powerful panels you can? Ive seen them as high as 340 watts. I get that they are more expensive. Just save your money. I would think unless you live in the perfect environment, I dont, you'd want all the power you could get.

 

This seems pretty smart to me, too, especially if there is a lot of cost in installation.

 

if you are short on space get the max watts/panel.

Otherwise I would optimize the best price/watt (this is what I did). Usually the highest watt panels are cutting edge technology and so the price/watt is much higher.

 

I've had two of them on the RV roof for over a year. They work very well and are
very sturdy. I have them cabled to a MPPT 20A controller.

 

I bought that panel with a controller and wires from amazon about a year and a half ago for $160. I put it on my tent trailer. It works great. I may buy a second one at that price.

 

Could you guys recommend a good "Stand Alone" household inverter for a Cabin type 12 v System ?

 

That all depends on several things. A, how much draw are you using at any time? B, what size bank are you drawing from? C, are you intending to run electronics or just basic lighting and such? There are pure sine wave inverter which you'll need for a computer or other electronics, or modified sine wave for basic electrical supply. Also, you need to consider the wattage you're drawing and calculate it against the storage capacity. A 3000w inverter is useless if your bank is wiped out in 5 minutes of use. It's easier to suggest something with more details about what you're wanting to do.

 

2 100 Watt Panels (PV array ) 4 6V Trojan Golf Cart style Deep Cycle Batteries (Storage) for a SMALL "stand alone" Cabin style system and minimal usage of 12 v lighting , 30 inch or smaller TV for short periods (Less than 3 Hours) And/or a Small Gas/Electric Fridge And/or a small Laptop.

 

In your situation, spending many hundreds of dollars for a pure sine wave inverter is a waste of money IMHO. I've run many electronics, including a high end laptop, from an affordable modified sine wave inverter with zero problems. Anything with a DC converter (that black box on the end or middle of the power cord) runs perfectly fine from modified sine wave power since it's converting it to DC power anyway.

An 800 watt inverter (buy at least two for insurance) should be plenty big enough for your situation. And even then, you shouldn't be drawing 1600 watts for long. That would be well over 100 amps and would drain your four golf cart batteries in two to three hours at most.

 

First thing you want to do is check the wattage for what you want to run. A 30" flat screen is probably in the 100-150 watt range, laptop is likely about the same. Not sure about the fridge. They're all probably listed in ac amps and volts. Multiply one by the other to get watts. 120 volt at .5 amps is 60 watt draw, and so on. With your batteries, you'll need to know what kind of amp hours you have. That will tell you what kind of run time you'll get with the draw you figured from the watt calculations. As for the 2 100w panels, figure about 5 hours of good charging ability per day with good sun--so about a kilowatt. With monocrystal panels you'll get some charge with indirect sun or even overcast, the 5 hour is just a safe minimum to go on. It's a simple formula to convert amp hours into x watts for y time that I can't for the life of me remember, but a quick search online will reveal it.

Your laptop should be fine on modified sine wave if it has the little box in the power cord, that is there to clean up the power. The tv may be okay or it may not. Pure sine wave inverters are more expensive, but also more efficient by about 20%. It all depends on the math.

Another thing with the fridge, they don't always run. It depends on how they cycle. It may show a 600w draw, but only really run for 20 minutes per hour. That would make your peak 600 watts, but only 200 watts of draw on your bank per hour. It will effect how you calculate your run time on your bank.

 

I have Renogy pnels and serm to hold up well. I have a novice question. Can I connect the panels to 48v by combining 4 of them to feed my morningstar 40amp MPPT charge controller which acceps upto 48v to charge my 12 volt batteries? I am not sure if the battery banks need to be same as input to the charge controller.
Thanks

 

I have Renogy pnels and seem to hold up well. I have a novice question. Can I connect the panels to 48v by combining 4 of them to feed my morningstar 40amp MPPT charge controller which acceps upto 48v to charge my 12 volt batteries? I am not sure if the battery banks need to be same as input to the charge controller.
Thanks

Short answer - maybe.

I have a MPPT charge controller that accepts up to 100vdc input from panels. It outputs 13.8vdc to charge my batteries.

The Renogy panels put out over 18vdc (22vdc unloaded) so I wouldn't series 4 of them. Series/parallel them. 2 each in parallel, then series the two groups.

 

What is the efficiency of the Renogy panels? Panasonic and Sanyo have some at 22%, just wondering.

 

Efficiency really doesn't matter, unless you don't have the space to put more panels, there is a cost trade off, higher efficiency panels cost more per watt.

Rancher

 

I have 8 of these 100 watt panels on the roof of my shop. They are configured in two strings of 48 volts going into a Midnite Kidd 30 amp controller. I am charging 4 6 volt golf cart batteries for a final output of 24 volts.

So far I am pretty happy with them but I don't think they put out the advertised power that they are supposed to. Yesterday it was a nice sunny day and at the most I was getting 20 plus amps out of the system or 550 watts. I have seen them put out close to 650 watts but the sun has to be perfect.

Some on here have asked-Why not buy the 340 watt solar panels?
SHIPPING my friends is a killer. If you live where you can pick these big panels up at the store then they are a great deal. I live in Kansas with no stores close and the shipping costs are about 50% of the cost of the big panels. I can get these shipped free. They are also easier to handle and install.

https://www.flickr.com/photos/135955182@N02/shares/9T4EhL

All in all I think they are great for the money. I am planning on 4 more batteries for more storage and maybe a Morningstar controller because I think they work better.

 

So far I am pretty happy with them but I don't think they put out the advertised power that they are supposed to. Yesterday it was a nice sunny day and at the most I was getting 20 plus amps out of the system or 550 watts. I have seen them put out close to 650 watts but the sun has to be perfect.

All solar panels are rated based on optimal conditions. February is not an optimal condition. That would be July in Arizona on a perfectly cloudless day with optimal angling toward the sun and tracking to maintain it.

 

I looked at Renogy panels, they seemed fine; Ended up buying some BP brand instead for about $0.85/watt(190watt panels) delivered(from 1000 miles away, minimum order was 10).

The prices posted seem a tad on the expensive side to me; This might be the current market, but I've seen plenty polycrystalin panels as low as $0.65/watt; and crappy thinfilm for half that.

http://www.ebay.com/itm/New-Lot-of-...-10-Astroenergy-UL-Listed-245-Watt-24-Volt-Solar-Panels-CHSM6610P-/311480318702
Lacks detail but that would suggest $0.75/watt delivered anywhere in USA; vs $1.25 ....

The only reason to connect panels in series(unless you NEED higher voltage) is to reduce your copper needs and maybe number of charge controllers; Charge controllers are more efficient the closer the input voltage is to the output; Also parallel helps with partially shaded panels.

I have 4 85 Watt panels and 8 190 Watt installed; for Theft and light I positioned them on the building itself; Here is how I mounted the 85 Watt'ers(similar to Renogy 100's). 190's much the same just 2 per rack/larger and steel vs aluminum...

 

The brand of a panel means nothing to me. I lived at one place for years with an off-grid solar system and another place with grid-tie. Over the past 30 years I've paid as high as $9 per watt and as low as 80 cents per watt for a panel. No difference in quality from what I can perceive. I prefer low-voltage panels e.g. for 12 volt systems. Often the higher voltage panels are cheaper per watt but not as handy for my changing uses. I'd buy whatever is the cheapest. Same goes with controllers. I've had just as many high-priced Outback MX series controllers go bad as dirt-cheap stuff from China. I hate to say it but I've had similar luck with inverters. I've had cheap mod-wave inverters from Harbor Freight take as much abuse and work as well as name-brand "sine-wave" inverters. Few of the latter make a true sine-wave anyway. Not unless very expensive and certified for grid-tie. One thing I hate though - are the cheap inverters with cooling fans that run all the time. That drives me nuts. Get one with a thermal-activated cooling fan. One note. If you get in a situation where a 120 VAC smoke alarm or GFCI is required - likely a "sine wave" inverter will be needed or it will buzz.

 

I have 3 of the 100 watt Renogy panels. Very satisfied with them. My neighbor also has some and he said they fell over face down onto some rocks, didn't break, and still work perfectly. He was amazed.

Renogy also has an ebay store and a web site store: http://www.renogy-store.com/

They have a lot of other panels besides the ones they sell on Amazon. You can email them from the web site and ask their best price on a bulk deal, delivered and they will give a good price. Only reason I didn't go with them for my 5.2KW array is because my local supplier matched Renogy's price with some other brand of panels.

You can worry about efficiency numbers and stuff like that all day long, but in the end, as long as the panels don't have something wrong with them and are sold from a reputable manufacturer, they will work as advertised. If it is rated as a 240 watt panel, it is a 240 watt panel. If during testing they find that it didn't produce 240 watts, they might sell that batch as 220 watt panels. Et cetera. Like computer CPUs.

 

I am also very happy with my Renogy panels. Plan to get some more. Efficiency numbers aren't what I shop for either. It's dollars per watt. My first ones, CIGS, cost $4 per watt, my Renogy ones cost $1.50 per watt. Now I see they are down to $1.25 per watt. Progress.

(CIGS = Copper-Indium-Gallium-Selenide) supposed to be the savior of the world. Remember Solyndra?

Article on the process.

http://www.solarpowerworldonline.com/2014/01/cigs-solar-cells-simplified/

 

...my Renogy ones cost $1.50 per watt. Now I see they are down to $1.25 per watt. Progress....

If you email them and ask for a quote with shipping for a larger array, they get down to around $1 per watt.

But $1.25/watt is very good for a single panel!

 

Has anyone got panels more efficient than the Renology installed and is happy with them? I have a small space that is hard to get to. The panels must be efficient and durable.

 

I'd say you would first need to look at only mono-crystalline panels. Renogy also has the poly-crystalline type, but they are sometimes bigger. Not always though.

 

20% is about it. What they claim and what you get are two different things. Easy enough to do an online comparison of panel specs.

 

I noticed the Renogy went back up on Amazon