Considering solar installation

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Considering solar installation

March 02, 2012, 07:01:49 pm

The prices on panels is compelling me to go ahead and do an install. I've read over a fair amount of info on installing panels but most guides are written with eking the last ounce of performance out of a solar installation, typically aimed at never having to plug in or use a genset. That's not critical for me, I figure I'm carrying around a diesel genset, why not use it from time to time. What I'd like to know, if anyone can advise me, is if I could do something as simple as this:

Install approx 600 Watts worth of panels, (or more, it seems the panel price is low enough to engage in some overkill) wire them properly with heavy gauge wire to a charge controller, thence to batteries. I assume there would need to be a pull block disconnect or something similar in line. What I don't want to do is replace my Heart 2500 charger/inverter which has a good quality remote data display and works well. Could it be as simple as this or is there some reason why the massive equipment list typically used is required? Am I overlooking some aspect such as transfer switches which would be a deal breaker for a simple install? Appreciate your thoughts, Chuck

Re: Considering solar installation

Reply #1 – March 02, 2012, 07:17:20 pm

That's pretty much it. You'll need a device on the rooftop that all the panels plug into and then aggregates the current and moves that down to the charge controller near the batteries. Your inverter will work as usual. I am planning to do the same thing, myself.

There are details like determining between tilting mounts or non-tilting, routing the cables, etc., but solar panels are not rocket science. Essentially you connect them to the batteries. In fact, I have often just hooked them up and then watched the battery voltage with a digital volt meter unhooking them (or turning them away from the sun) when the batteries are fully charged.

Craig

Re: Considering solar installation

Reply #2 – March 02, 2012, 08:36:34 pm

Solar installations can be relatively simple. I write several blogs/boat/brand of boat/and my RV. In the 'brand of boat'/I wrote years ago of my installation of 6-85 watt panels (total 510 watts) added in 2 arrays of 3 panels each. The 3 panels in each array, were tied in series, like Christmas lights so that each 12v panel added voltage. Output was then in 36 volts. (yes, I'm making this simple for discussion sake) Could often get

Each array of 3 panels each were then brought into a simple Circuit breaker box and then into a 'Controller' which took the 2 arrays together, near or above 30 amps put into battery bank. !!rays of 36 voltage each, now in parralel and the controller a MPPT unit (more later on this unit) and converted the panels output to 12 v for charging. It is a powerful and easy system to build and If you're not comfortable in doing it yourself i'm sure there are plenty of reasonable businesses out there capable.

A MPPT controller can take your input and thru algorithyms transform the output into a more usable VA or WATT configuration so that as simply as can be said, offers more input at the beginning or end of any day, as the sun sets or during low light (like cloudy) days. this can be done with up to a 30% increase of output.

Only one of my arrays is adjustable and it TOO makes a big difference in output, but...............get solar panels up there and wired in to good batteries thru a good converter.

Check out Back woods Solar online for lots of good info.

I bought my gear thru the "Alternative Energy Store" and other I will think tomorrow.......I hope

We lived for 7 years cruising(a boat can be very similar to a MH) on rain and sun. Only filled up tanks for $ 2x in 7 years. Rain kept our tanks full.

We did modify our sun collection for times of NO sun, by adding a Honda eu2000i inexpensive gas generator to top off batteries and refrigerations systems i built, but that is another story probably not needed here.

link for old post of mine CSY Sailboats: Then and Now: Solar for Cruisingne on solar panels..

great info, service and prices too at

http://www.altestore.com/learn/
and.............Solar electric power components and solar panels

Re: Considering solar installation

Reply #3 – March 03, 2012, 12:45:43 am

Chuck, your design is all there is for solar. No one uses transfer switches or eliminates a battery charger or generator.

A roof top two-bus combiner box with separate pairs of #10 cables from each panel allows removal of one panel, serial wired panel option and simple wiring.

Having a larger capacity controller leaves room for expansion and insurers maximum output from existing panels. Using a two-circuit breaker box to easily disconnect controller from batteries and from panels will come in handy and gives your protection on in & out circuits.

We have 4 Kyocera 130 and a Morningstar MPPT-60 controller, #10 solar wires,

6 wires to controller and to batteries.

Re: Considering solar installation

Reply #4 – March 03, 2012, 06:37:58 am

After researching and shopping around for almost a year, I went to AM Solar (recommended by many forumites) for my solar gear. The charge controller kits make it simple, as all the cables, terminals, labels, screws, heat shrink tubing, circuit breaker, etc are included, saving numerous trips chasing down bits and pieces. I also decided to go with their 150 watt panels as well; up to yesterday they were offering free shipping. My panels should arrive this coming week.

In putting the plan together, I took some cardboard and taped/cut four pieces the same size as the panels, then climbed on the roof and started laying it all out. Saved a lot of time fussing around and guessing.

Steve

Re: Considering solar installation

Reply #5 – March 03, 2012, 08:19:18 am

I used AM solar about 9 years ago. They were great to deal with.

Re: Considering solar installation

Reply #6 – March 03, 2012, 08:28:04 am

What's the payback period for this level of solar installation?

Re: Considering solar installation

Reply #7 – March 03, 2012, 10:35:23 am

The payback is about the same as the payback on your coach...

Re: Considering solar installation

Reply #8 – March 03, 2012, 12:34:18 pm

For those willing to piece together a system, Sun Elec in Miami has a number of 17.x Vmp panels (up to 180W) for a buck a watt. Kyoceras are still in the $2.50 a watt range. The cheaper ones also have junction boxes which allow you to avoid the added cost of special connectors.

http://www.sunelec.com/solar-panels-c-5.html

These are known as '12V' panels and allow you to buy the cheaper MPPT controllers if you are fine with a smaller system.

Re: Considering solar installation

Reply #9 – March 03, 2012, 07:27:10 pm

there is no real payback time as Dave said BUT it does give you a whole lot more oppurtunities of places to go. In Mexico I did not use my generater once (friends there would have gone mad if I had) and we had lots of power for Ruth to do all the baking etc she wanted plus the regular stuff. Today I did a trip to Lowes here in Nac' and bought the black fridge a few others have got. We lose some cabinet space from the side by side but we will manage. There will be about a 10" space down the right side that I will make another cabinet with slide out shelves once we get home. It is being delivered to Xtreme on monday as we are there for ins' work and we just leave it by the buffet till home but will plug it in to the 1000w extra inverter I put in a while ago, as we need a fridge and been without one now for over a week. Will be interesting to see power use.
John H

Re: Considering solar installation

Reply #10 – March 03, 2012, 08:38:21 pm

The only downside to solar is that it pretty much precludes spending a lot of time in the dense forests we have in the PNW unless you also have either a genset or a hookup. This also makes me worry about going to a household fridge (2A average is a LOT of power use from my old-school thinking). On the other hand my best cut at full solar ended with the panels becoming useless due to UV. This was in 1985, mind you. The seller, who had turned to selling toys when I called him about the "lifetime warranty" on the 4-year-old panels told me that he'd give me toys in exchange but it was mostly my fault... I left 'em out in the sun too much.

If John Haygarth thinks an all-electric fridge will do the job with solar, who am I to argue?

Craig

Re: Considering solar installation

Reply #11 – March 04, 2012, 11:06:11 pm

Alright then, this is sounding good. I appreciate all the straight forward advice. So, it's sounding like the MPPT controller coupled to some higher voltage panels will simplify wiring and allow for easier maintenance as they aren't series wired. Would it be correct to assume that this arrangement (panels wired parallel to combiner) will also limit the negative effects of having one panel shaded? As far as wire routing goes, what about using some low profile surface mount plastic wiremold? Would it be feasible to put the combiner close to the controller and batteries? The thinking here is that it would be easier to route multiple #10 wires down from roof than say a pair of #4 or larger.

Dave Head's source for panels at 1.00/watt is going to be hard to beat. As far as I've seen, none of the panels are warrantied when installed on a vehicle. Seems like most of them have CE rated manufacturers. I wonder if there's much physical difference in construction between the panels which would make one more durable than the other. Water leakage is what would concern me most.

Once again, thanks to all for lending the voice of experience.

Chuck

Re: Considering solar installation

Reply #12 – March 04, 2012, 11:39:47 pm

If you haven't already, I suggest you call AMSolar and have them give you a quote and talk you through your questions - they are great to work with. You might decide to buy some or all your parts from them, and in any event they can give you a wealth of information.

here is the link Welcome to AM Solar_Your RV Solar Specialists since 1987

Re: Considering solar installation

Reply #13 – March 05, 2012, 08:23:15 am

Quote from: Chuck Pearson – March 04, 2012, 11:06:11 pm

Dave Head's source for panels at 1.00/watt is going to be hard to beat. As far as I've seen, none of the panels are warrantied when installed on a vehicle.

Chuck

G'day Chuck,

I noticed that, and the warranty wasn't very good either. Most panels I've looked at are not warranted in a mobile installation. Something to factor into the purchasing decision.

Lots of good info on AM Solar's site, even if you shop elsewhere.

Steve

Re: Considering solar installation

Reply #14 – March 08, 2012, 08:00:09 pm

If a person had a 200 watt solar system on their coach, what would that power, or what could you use off that system? I know almost nothing about solar systems!
Thanks.

Re: Considering solar installation

Reply #15 – March 08, 2012, 09:47:32 pm

it also depends on what batteries you have and how much holding power they give. You can charge up many batteries with 200 watts and if you have many then you can do almost anything you want but do not expect them to charge the depleted batteries up very quick ( in fact it will take many hours, even days, to do it of sunlite, depending on how many or big you have.
Panels charge the batteries so the more the better(quicker) and the batteries hold the power for when you need it. The amp hours capacity of them is what gives the power and for how long. I think that is the way it is. I have 600watts of panel and 3 8D AGM and it is just enough to do most things you do in a day, but you need sun the next to recharge them ( or generator).
john h

Re: Considering solar installation

Reply #16 – March 09, 2012, 11:06:02 am

John Haygarth is spot on with his advice. You have to balance battery power, charging power, and load. Factored into this would be whether you can tilt the panels (direct sunlight is the best), how you are aligned with the sun's path across the sky (sometimes you can't park perfectly), and - of course - how much sun you will get. It's difficult to get enough solar panels on top of a coach to make you completely self-sufficient under all possible conditions. A 200-watt solar panel will do a lot of battery charging but it won't get you off the grid. 800 watts will pretty much keep you off the grid (especially in areas where there is a lot of sun each day).

You could use a 200-watt panel like a carry-out satellite dish; set it up in the morning and every few hours go over and tweak it to follow the sun. This will maximize your solar power and will greatly extend your ability to go without running a generator (or plugging in to power).

Craig

Re: Considering solar installation

Reply #17 – March 09, 2012, 12:00:49 pm

Just a thought. I have been working with Drew Schultz at Arizona wind and sun and have been very impressed with his willingness to help and answer questions. Plan to order the first two solar panels (270 watts) next week with a planned additional two later. He has provided complete specifications down to wire sizes and junction boxes. Really a very nice experience so far.

Re: Considering solar installation

Reply #18 – March 09, 2012, 05:51:25 pm

Thanks, John and Craig for the info. Now I know a little

Re: Considering solar installation

Reply #19 – March 09, 2012, 06:29:33 pm

May do the solar route, if I can justify cost. The one question I have not seen anyone address is how to do an automatic tilt to follow the sun. Don't know if this is even possible. I do not go on the roof unless absolutely needed.

Could someone let me know if auto tilting is available.? Much appreciated.

Re: Considering solar installation

Reply #20 – March 09, 2012, 09:50:19 pm

Jeff,

From what I hear, auto tilting is available but a more practical approach is to just add an extra panel to get the added output. To be really effective, and allow some flexibility in parking (not having to align the coach to East and West), tilt mechanisms would have to work through two axis. Most people build their own gizmos but keeping em running would be an issue.

Re: Considering solar installation

Reply #21 – March 09, 2012, 10:26:25 pm

I have seen auto tracking systems made for stationary installations, but not mobile ones. I looked into building something, but the complexity and the weight made this impractical. I've settled for flat-mounted panels with tilt capability.

From what I've read, you'll never see the power the panels are rated at. Their numbers come from lab testing under ideal conditions. Nonetheless, it is an energy source that works whenever the sun is out. I felt it a worthwhile investment.

Steve

Re: Considering solar installation

Reply #22 – March 10, 2012, 03:12:27 am

There was a fellow in Quartzsite selling a remote tilting solar panel setup that he had designed himself. Looked like it worked, and it tilted both directions using electric screw actuators, but it looked heavy and bulky, and you would need all the tilting panels in a row, or have a separate tilt mechanism for each panel or group of panels. As I recall, the cost was around $1500 for each tilt frame. Sorry I didn't get any contact info. As others have mentioned, probably a lot cheaper to just get more panels and keep them flat.

Re: Considering solar installation

Reply #23 – March 10, 2012, 12:38:38 pm

Like the others, the only automated sun-following system I've seen was on a house and was complicated, and big, and heavy. I have done both wind power and solar power and the most endearing trait of solar is its relative simplicity. Make sure they're clean and nothing is shading them and they are pretty much "set and forget".

Craig

Re: Considering solar installation

Reply #24 – March 10, 2012, 08:45:23 pm

wait till I get home to finish my drawing on a tilt mechanism with a rotating base so you can set them up in an arc to follow the suns path during the day. This will not be powered and each panel will be rotated slightly more than the next one at first set up to do what I have just described. They will be compact and lite (aluminum) and have one per panel. I have been working on it in my brain for awhile so hope to get one made in the next month or so to try.
John H

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