Taking the solar plunge

[Maineah]

Nice panel! I believe the stick ons are amorphous. My aluminum glass harbor freights constantly get naysayers but I challenge anyone to make 3 amps on 45 watts like they do. Watts aren't everything; amps flow while watts are just pressure. Ideally you want high amperage too don't forget. I've seen huge wattage claimed with small amperage... Suspect . I love that 12 volt 68 watt at $99. Is it 3.xx amp?

amps X volts =watts it's math you can't have one with out the other watts/volts=amps. (45 watts/12=3.75 amps.

[Eve "n" Stephen]

Don't forget, all these panels are designed to charge 12V battery systems, that means they do not put out 12V! Most are over 15V and open circuit more like 21V. It takes at least 15V to fully charge a 12V battery, depending on the temperature. If you are doing an equalizing charge, it needs to go up around 21V, depending on the battery type and temperature both. 68 watt / 21 volt = 3.23 Amp.

Their specs (Uni-Solar 68 watt) claim an open circuit V of 21.1, max power 15.4V @3.4Amp

Steve

[stamar]

Ill look up before I say for sure but on my dolphin there's. 4 vents. The frige vent goes out the side.

So the space for 4stickems is on the drivers side and ppasseneger side of the 3 vents that are in a row

[stamar]

I think new motorhomes do come with a trickle charge solar panel

[Maineah]

Don't forget, all these panels are designed to charge 12V battery systems, that means they do not put out 12V! Most are over 15V and open circuit more like 21V. It takes at least 15V to fully charge a 12V battery, depending on the temperature. If you are doing an equalizing charge, it needs to go up around 21V, depending on the battery type and temperature both. 68 watt / 21 volt = 3.23 Amp.

Their specs (Uni-Solar 68 watt) claim an open circuit V of 21.1, max power 15.4V @3.4Amp

Steve

That's correct Steve but the math is still the same. That's why a controller is pretty much mandatory on a solar setup. Open circuit collectors make a lot of voltage they look good until you load them! The best way to see what you have is to dead end them into a amp meter. The higher voltage allows less voltage drop issues with wire runs.

[stamar]

They'll do a fast charge before testing a 'starter' battery. I'm no expert, but I'm not sure how complete a charge this would do to a deep-cycle battery and if 'forcing' it would damage it. I wouldn't expect the 'counter monkeys' at O'Reileys or AutoZone to be 'Experts' either.

Ok so autozone does a 1 hour charge. This is just a test to see if it takes a charge.

Oreilly does a full trickle charge that can take up to 24 hours.

The guy said it usually takes 12 hours.

Oreilly is definitely your free battery charging place. I left the light on again ran the battery sort of low. Ran the engine an hour again, now charging it to full.

[bajadulce]

Always envisioned rigid solar panels making an ideal awning/window shade that flips up/down above your windows esp. for those w/ limited roof space. When traveling or for night use being flipped down they would cover the window providing some insulation and keep prying eyes out of camper (easy to clean too). Guess the best thing would be a flexible solar panel that was integrated into the awning canvas itself and thus could roll up.

Kinda slightly off topic:

I think there was a guy on the site that posted about a portable wind generator? Anyone have any experience w/ one? I once saw an old timer many years ago w/ a homebuilt contraption made out of an old bicycle wheel. No idea how much power it put out, but it sure was cool looking.

Not all places have constant wind like they do sun, but some places are definitely windier than others (coast for instance)

[Totem]

I have a small wind turbine. have yet to try it though... the HF solar panels more than bring my bank up to 100% each day even in rain.

[WME]

I have a small wind turbine. have yet to try it though... the HF solar panels more than bring my bank up to 100% each day even in rain.

Thats the magic formula. panels match battery bank and load. Thats why one size doesn't fit all uses. Without facts its just a SWAG

[Totem]

Thats the magic formula panels match battery bank and load. Thats why one size doesn't fit all uses. Without facts its just a SWAG

I guess so... my "bank" is only the regular marine coach battery; the inverter is only a 400w that's only running an lcd monitor and wii occasionallyor charging cell phones ; otherwise just LEDs and furnace blower when I am in dryboon mode. maybe sometimes i run 12 volt trucker fan. not much of a load.

[stamar]

I believe it takes longer to charge two deep cycles with the same load than one. This I'm absorbing from reading about everyones set up. The top charge always take the longest its the cream or the last breath into the balloon

[Maineah]

Yes it does take longer because the combined output is greater. 2 group 27's 160 amp one 80, greater internal resistance. A hint do not draw/charge two batteries from one battery in other words connect both together but draw/charge from the positive post on one and the negative on the other don't complete the + - from the same battery this assures charge/discharge in both batteries..

[stamar]

solar blvd doesnt seem to have any more of those.

this one seems an even better deal per dollar but is 18 feet long. would work on the same pipe but just needs a longer wire.

http://www.ebay.com/...2951#vi-content

seems like an asap steal to me.

uni solar is aparently out of business.

not only are these the cheapest and the best for our purposes.... they might not be made again anytime soon .

[stamar]

im going to buy these right after tnxgivings either one or two

if someone could be so kind as to direct link all the other equipment needed to connect these to a deep cycle on a toyhome id appreciate it.

a controller for 150 watts and wires. i dont really think this requires real solar wires actually so the cheapest ones that work would be best

http://www.amazon.com/Controller-Regulator-Charging-Automatic-Functions/product-reviews/B008I0IZ7O/ref=dp_top_cm_cr_acr_txt?ie=UTF8&showViewpoints=1

pencilled in this one

to the best of my knowledge a 10 amp controller can have up to 240 watts, so that would cover one of these panels but not two. so this one is 30 amp could easily handle 3 or more

[Totem]

I used trailer light wire (available in a spool or from an old set of magnetic turn lights from harbor freight that can be trimmed down and stuck to cargo carrier). had 4 wires in a ribbon i just peeled two off.

[zero]

im going to buy these right after tnxgivings either one or two

if someone could be so kind as to direct link all the other equipment needed to connect these to a deep cycle on a toyhome id appreciate it.

a controller for 150 watts and wires. i dont really think this requires real solar wires actually so the cheapest ones that work would be best

http://www.amazon.co...howViewpoints=1

pencilled in this one

to the best of my knowledge a 10 amp controller can have up to 240 watts, so that would cover one of these panels but not two. so this one is 30 amp could easily handle 3 or more

Not all controllers are the same even though they are sold with the same ratings. You have to read the full spec sheets. Some 30 amp controllers can handle surges at twice the 30 amp rating some can barely handle a 10% overload. A solar panel will rarely put out what it is rated at. A 120 watt panel rated at 7 amps in bright sun will be lucky to put out 5 amps. The 7 amp rating is a "best possible case scenario." But in extreme cold weather in areas with bright snow cover - a 120 watt panel can spike up to 10 amps.

Solar charger wiring is nothing special. DC current is DC current. Does not matter if from a battery, alternator, or a solar panel. Generally speaking a panel up to 15 watts can be direct hooked to a battery with no controller. Anything bigger needs one. You do not have to size a panel wattage to your battery bank or battery. The controller takes care of that. All depends on how much power you want from solar. My entire house and farm runs from 5400 watts of solar panels and I live in a dark area of NY. My cabin in the Adirondacks with lights, 40" TV, DVD, electric water pump and electric tool useage does well enough with 1000 watts in solar panels.

To hook a solar panel to an RV battery - if bigger than 15 watts, you need a controller, wire, and a fuse or circuit breaker. Solar panels have built-in reverse-flow diodes and cannot drain a battery when the sun isn't shining (like they did years ago).

[Totem]

wow jde... how many batteries you got running that house? how often do you got to water them?

I want to take me house off the grid; problem is most of my homes stuff is electrical (hot water heater, dryer, stove). I heard I could setup a solar piping system that would dump right into my old electric hot water tank where the element used to plug in at.

I live in a high wind area also. Local ACE hardware has some interesting wind turbines that are HUGE ducted fans that look like overgrown ten speed bike wheels with magnets on the tires; the store owner said they take standard bicycle bearings also so there is no expensive alternator/stator/generator to replace brushes etc on.

I need to get some of those devices that waiter mentioned... kill a watt or something that tell how much juice stuff uses to plot out my requirements.

I have a VERY similar controller to the one Stamar linked in my toyhome. It neatly tucks into my stock charger/converter box access panel and I wired it right into the panel box itself and fused it as another 12 accessory. works great.

[zero]

wow jde... how many batteries you got running that house? how often do you got to water them?

I want to take me house off the grid; problem is most of my homes stuff is electrical (hot water heater, dryer, stove). I heard I could setup a solar piping system that would dump right into my old electric hot water tank where the element used to plug in at.

I live in a high wind area also. Local ACE hardware has some interesting wind turbines that are HUGE ducted fans that look like overgrown ten speed bike wheels with magnets on the tires; the store owner said they take standard bicycle bearings also so there is no expensive alternator/stator/generator to replace brushes etc on.

I need to get some of those devices that waiter mentioned... kill a watt or something that tell how much juice stuff uses to plot out my requirements.

I have a VERY similar controller to the one Stamar linked in my toyhome. It neatly tucks into my stock charger/converter box access panel and I wired it right into the panel box itself and fused it as another 12 accessory. works great.

My house has a 48 volt battey bank with 8 batteries. But they are the HD Rolls/Surette batteries. Each is about twice the size of a Trojan T-105 and are around 120 lbs. each.. But let me add I only use the batteries during power-outages. I have a grid-tie system. The battery bank can run my house for three days with no recharge from anything. So if the grid goes down, and the sun never shines - after three days I'll have to fire up a diesel generator to run my 48 volt battery charger to keep the batteries up. So far that has never happened. The grid was down for 8 days not long ago and we did fine. But the sun had come out once in awhile.

I check the battery water once a year and they do take a bit. When I changed over to solar I got one of the plug-in watt meters and checked everything. We yanked out the electric hot water heater and I installed propane. I rarely sets used though. I heat all our domestic hot water with a wood furnace in the winter and in the summer - I have solar passive water heating that does 3/4 of what we need. The propane does the rest. We also took out our electric clothes dryer and use a propane dryer in the winter. With a 5400 watt solar array we have been making around 120% of our annual useage.

Living with solar and no grid-tie can be problematic. There will be times when you are making three times the power you need and it all goes to waste. NO way to "save it for later." On the upside - off-grid electronics is MUCH cheaper that grid-tie certified stuff. Our cabin in the Adirondacks is off grid.

[stamar]

I am only going to power a lower power type laptop than I have and led lights and a cell phone.

I do want to have it stay on 12 to 24 hours a day

. So I chose 250 watts solar panel wamorphous ith the regular alternator charge( upgrading it to 120 amp alternator). And 200 amp hr battery bank

Two regular 27 size deep cycles

This was all rounded math or. Based on some rver that works it. Trying to do it without a generator but also without just running the engine in place ever.

[Totem]

My house has a 48 volt battey bank with 8 batteries. But they are the HD Rolls/Surette batteries. Each is about twice the size of a Trojan T-105 and are around 120 lbs. each.. But let me add I only use the batteries during power-outages. I have a grid-tie system. The battery bank can run my house for three days with no recharge from anything. So if the grid goes down, and the sun never shines - after three days I'll have to fire up a diesel generator to run my 48 volt battery charger to keep the batteries up. So far that has never happened. The grid was down for 8 days not long ago and we did fine. But the sun had come out once in awhile.

I check the battery water once a year and they do take a bit. When I changed over to solar I got one of the plug-in watt meters and checked everything. We yanked out the electric hot water heater and I installed propane. I rarely sets used though. I heat all our domestic hot water with a wood furnace in the winter and in the summer - I have solar passive water heating that does 3/4 of what we need. The propane does the rest. We also took out our electric clothes dryer and use a propane dryer in the winter. With a 5400 watt solar array we have been making around 120% of our annual useage.

Living with solar and no grid-tie can be problematic. There will be times when you are making three times the power you need and it all goes to waste. NO way to "save it for later." On the upside - off-grid electronics is MUCH cheaper that grid-tie certified stuff. Our cabin in the Adirondacks is off grid.

wow your state must be much more progressive than Michigan. We voted down mandatory requirements for renewable energy and current law states that one must get electric company sign off before enabling solar etc on grid tie. of course when a michigander inquires about whats needed the bills and permits stack up quickly; must pay for county, federal and UL inspection , pass and then pass electric company inspection and pay all those fees. also must be inspected to make sure its up to "code". basically at that point you are re-wiring your entire home in my case as my home is very old. Do you mind if I ask how much your system cost to implement jde>?

[zero]

wow your state must be much more progressive than Michigan. We voted down mandatory requirements for renewable energy and current law states that one must get electric company sign off before enabling solar etc on grid tie. of course when a michigander inquires about whats needed the bills and permits stack up quickly; must pay for county, federal and UL inspection , pass and then pass electric company inspection and pay all those fees. also must be inspected to make sure its up to "code". basically at that point you are re-wiring your entire home in my case as my home is very old. Do you mind if I ask how much your system cost to implement jde>?

I've got two houses in northern Michigan and am aware of their regs (Presque Isle and Alpena counties).. Pretty much the same as here in NY. If you install solar-grid-tie, you must get the new work inspected; NOT the old work. My house was built in 1820 and it was first wired ifor electricity in 1940. Parts of the house still have knob and tube wiring and that had nothing to do with the new solar and the new inspection. The specific requirements for the actual hookup and the AC output of the inverters are established by the power company you are dealing with. In my case - in Michigan - it would be Presque Isle Power and Light. To get any state incentive money (from NY) you are forced to use only certain panels and only state-certified installers. Solar panels are required to be UL certified. One difference between NY and MIchigan with grid-tie is . . . or at least was . . . that in Michigan the power company gets all your excess power, sells it, and pockets the proceeds. There was a lot of unhappiness over that maybe it's been changed. I haven't checked recently.

My system was more expensive that a conventional grid-tie system. A conventional grid-tie solar electric system cannot be used during a power outage. I find that to be silly. So, I designed my own with a battery bank and it can be used when the grid is down. I've had it 5 years now and when I did it - it was unusual. Now - it's becoming more comon. Also keep in mind that 5 years ago, UL certified solar panels are selling for $6 per watt. Now they can be found for 50 cents a watt if you buy in quantity.

My system had a sticker-price of somewhere around $40,000. When all done and all Federal and State incentives paid back to me - it cost me $8000 out-of-pocket.

[stamar]

http://www.ebay.com/...=item3f1c62b03d

im going with this one. it is obviously better than anything available in the us at the moment.

I have a personal recomendation from an rver with 3 x 100 watt panels.

Im getting one 138 watt panel, amorphous, and then hopefully a second one if i like how it works. its 18 feet long so its twice the length of the one pictured in this thread. im going ot have it go over the overhead curve on my dolphin, which i anticipate will work better than haing it all face up.

http://www.ebay.com/...=item337e048576

at the last moment i might go for this one

http://www.ebay.com/itm/10A-20A-30A-PMW-solar-panel-charger-controller-regulator-12V-auto-switch-to-24V-/110893873743?pt=LH_DefaultDomain_0&var=410115719742&hash=item19d1ca3a4f

[Totem]

just curious; are you using a 24 volt battery bank? how to you intend to scale down the power to 12 if not?

[stamar]

All solar controllers do that.

In fact I. Don't think most of them charge 24 volt batteries although the fancy one I listed might.

I haven't seen a solar charger that doesn't work with 24 volt panels at this point even the 10 dollar ones.

Basically that's what its for 24 volt panel and 12 volt batteries, for an rv or boat situation..

A 12 volt panel is more for.. well for rv use only more likely a smaller thing for battery tending.

Edit further review shows all of the solar controllers I looked at are for 12 volt batteries and 24 volt panels

None are compatible with 24 volt batteries.

[Totem]

My question was based on output of the 24 volt panel (max 33volt).

As I understand these controllers are preset to 12 or 24 charging.

Being that they probably have some form of step down for each.

Thus a "12 volt" rated panel will be putting out like 19 volts tops and a "24 volt" panel 33...

Of course I could be wrong I am merely trying to learn something here. Maybe Steven could chime in here....

My setup has a controller that I believe is only going to charge a 12 volt bank; it very well may handle 24 but I think that would be a dipswitch or something and would only change the expected input and output. My hunch is that a controller in 24 volt mode would be dumping a way too high voltage to a 12 volt battery alone and thus may require some sort of step down.

(not trying to drive you crazy here stamar just trying to learn...)

[stamar]

so far as I know

all of the panels say they take in up to 33 volts, and put out up to 14.7 volts

none of them would take in 33 volts and put out 33 volts to your 12 volt battery

it is china though

in general the majority of people buying this thing has 24 volt panels and 12 volt batteries.

all of these ones sold that ive even looked at are for rv and boat use, so the battery involved is always 12 volts. thery even have a picture of your deep cycle battery on them, connect this to your battery yankee

so all of them wouldnt fry a 12 volt battery, whether they connect to 24 volts or not.

and the electronics of halving the voltage to increase the amps costs .0001 cents in copper so i bet they all work. no guarantee though

there is a 10 amp charger for less than 10$

and a lot of the 3 amp chargers might only work with 12 volts in the first place.

the ones for 24 volt batteries are for your cabin or whatever. not even in this price range usually

so to get to the root of the question theres nothing else to get its plug and play to any controller large enough for a 136 watt panel is also going to work with 24 watt panels and 12 volt batteries.

nothing else to think about.

[stamar]

I dont have a long term plan put together yet for what Im going to use until I see these stick on panels.If its possible to

cut them in half im ordering a total of 4-8

even if you cant i think im going with 4, putting two on the sides lengthwise.

in the event thats not enough Im penciling in 3 125 watt polycrytalines set sideways between the vents. pointed at an angle. that would generate power regardless of the time of day even i might have the polys pointed 2 different ways even.

that would be, in a long term project, a 900 watt solar powered toyhome. That has to be more than enough.

im going to experiment with the panel i get before sticking it on.

believe it or not I think I will get more power during a day from a panel wrapped top wise across the top and the back as opposed to flat on the roof. then also the two on the roof will go over the overhang, so there will be a panel covering all 4 ends of the rectangle horizontal and vertical.

. the ones on the side get the max early the ones on the roof get the max closer to noon.

( then depending on the angle, the ones on the other side get it later.

[zero]

so far as I know

all of the panels say they take in up to 33 volts, and put out up to 14.7 volts

You kind of lost me the way you worded that. Solar panels don't "take in" any volts. They take in light and make power that can make a certain voltage. Voltage in itself is kind of meaningless. Voltage express with current is what matters. A solar panel with no load on produces what's called a "nominal" voltage. With a 12 volt panels, that's usually 17-20 volts. As soon as any sort of load is put on panel, the voltage drops down. The more load, the more drop. jSame reasoning why a starter motor in a Toyota truck is designed to work at 9 volts and not 12 volts - even though the system is called "12 volts." Unless you live somewhere with extremely constant and bright sun, you can use up to a 15 watt, 17-20 nominal volt panel to charge a full-size battery with no controller at all. Some controllers have a fixed input and output (e.g. 17-20 volts coming in and 12-14 regulated volts coming out). Some controllers have a variable input and a fixed output (e.g. 17-200 volts in and 12-14 regulated volts out). And yet others have a variable input and a 2-3 choices output.

You mentioned the possibility of using 900 watts in panels. I have a cabin in the woods with 1000 watts in panels. It is in deep woods in the Adirondack mountains. I mounted half the panels facing morning sun and the other half facing afternoon sun. Hooked to a 12 volt battery bank - we use the cabin for weeks at at time - running an 8 cubic foot DC refrigerator, 32" TV and DVD player, lights, DC water pump, 1000 watt microwave - and I also use power tools off and on every day since I'm buidling. 15 amp saw, 13 amp sawzall, electric drills, 18 volt screwguns that I have to keep recharging, etc. The 1000 watts with poor sun exposure has been more then enough for summer use.

I have an RV with two 120 watt panels that work fine for my uses. Not mounted on the roof though. There are too many times I'm camped under trees with no sun overhead. Very easy to just set them up outside on stands and fact towards the sun.

[Totem]

this answers my question then; 24 volt panels are aok with 12 volt controllers. Thanks JDE.

[stamar]

These are amorphous panels that will do better in shade. Definitely better for never being aimed directly at the sun. I don't plan on ever aiming or messing with solar panels.

Even if I throw some polycrystaline panels on someday I would never set up a stand and aim them id have them because they are smaller and fit.

Stick em panels

Are perfect for rv purposes. Id be more interested in peoples advice that have them as far as aiiming them but the truth is there mmight not be a lot of them.

For the most part not aimed a amorphous solar panel will get a lot more real life power.

In that one sentence iit shoudlsay solar controller not panel.

Impossible to get lost unless you're really trying.

[stamar]

These are amorphous panels that will do better in shade. Definitely better for never being aimed directly at the sun. I don't plan on ever aiming or messing with solar panels.

Even if I throw some polycrystaline panels on someday I would never set up a stand and aim them id have them because they are smaller and fit.

Stick em panels

Are perfect for rv purposes. Id be more interested in peoples advice that have them as far as aiiming them but the truth is there mmight not be a lot of them.

For the most part not aimed a amorphous solar panel will get a lot more real life power.

In that one sentence iit shoudlsay solar controller not panel.

Impossible to get lost unless you're really trying.

My actual set up is going to start with one 138 watt panel on the roof and the cabover

And likely expand to two, so 272 watts and a 30 amp controller.

Anything else I wrote about more is down the road just theorizing

These panels are 18 feet long so I can't picture where to put too many

The next two I would put on the sides 12 feet on the sides and 6 feet on the back so mounted vertically

I feel a rush to at least buy two as they are selling a lot on ebay and the company unisolar is gone now.

[zero]

These are amorphous panels that will do better in shade. Definitely better for never being aimed directly at the sun.

The amorphous panels do a little better in partial shade then the poly panels. That being said, any panel left in partial shade is pretty much a waste of money. Overall though the amorphous are much less efficient and also shorter-lived. As far as amorphous being better when not partially shaded but not aimed directly at the sun? That's something I've never come across in any test specs I've read. None of my solar setups are in good sun, for the most part. I live in a part of New York where it's cloudy and gloomy much of the time. I researched specs on a lot of panels and never came across anything as cost-efficient as polycrystaline. Overall the monos beat them in efficiency and space-saving - but not when it comes to how much energy you get per dollar.

[stamar]

Cost effective there is nothing that beats the stick em panels I directly linked.

What they are is large. Work much better in the shade and indirect sunlight.

If there is something out there that could compete with them make sure to direct link it.

The panels I linked are normally in the 700 dollars range, normally much more expensive.

I hope someone other than me gets a chance to get some before they sell out.

[Totem]

it would be sweet to have enough of them to run a swamp cooler or AC... but VERY expensive and heavy (due to the battery bank needed to run the inverter

[stamar]

well i chose amorphous panels first because they happen to be the cheapest in the world, whereas normally they are the most expensive, more a luxury item.

but mostly because I dont forsee ever using up the roof space i have with solar panels. Thats the least of my worries, so amorphous panels biggest down side is they are the largest panels.

a 125 watt polycrystaline panel is much smaller but doesnt really generate much unless its pointed at the sun.

I have a lot of experience with polycrystaline panels actually, in a set up like im looking for and they just wont make the cut.

Howvever if youre buying so many panels that your roof is full of them switch to poly panels.

I just had a epihpany that if I used a panel on the awning side i would have to remove my awning, so thats out. for some reason when I had that idea I was only looking at the other side.

for a complete roof cover project I do believe I would cover the entire roof with these stick em panels. I believe you can cut them however peices smaller than 9 feet arent making the 12 volts and need to be wired together.

I think 4 batteries would run a window ac well. I havent personally rved in the desert yet so Ill jump that cliff when I get there. My rv doesnt have the roof ac right now.

I feel like 2 batteries is the right amount but i could see 4 with 2 under the couch and 2 near the converter box.