DIY Solar

Topic: DIY Solar (Read 1205 times) previous topic - next topic

DIY Solar

May 11, 2016, 12:29:58 am

Since we have gotten to the west we have been doing a bunch of dry camping. It's obvious that solar is the way to go. Not so much because of the cost to run the generator, just the noise.
Anyone diyed there own system be willing to share information details ect? Thinking of starting with 600 watts or so.

Re: DIY Solar

Reply #1 – May 11, 2016, 12:35:23 am

Interested as well, intend to install 400W.

Re: DIY Solar

Reply #2 – May 11, 2016, 08:31:51 am

Bruce (and Chuck),

You need to get with Jennifer (tothetrail). Their thread on solar install was very detailed, and demonstrated excellent planning and research. After studying their photos, I would say their "amateur" installation easily rivals the one we had done at AM Solar, and I'm sure it was considerably less expensive! I'd wager they could provide a lot of good advice!

Solar Installation Project

Re: DIY Solar

Reply #3 – May 11, 2016, 09:25:58 am

Quote from: Balcanthez – May 11, 2016, 12:35:23 am

Interested as well, intend to install 400W.

I have 400 watts, not enough to keep up. I would consider at least 600 watts.

Re: DIY Solar

Reply #4 – May 11, 2016, 10:09:01 am

Quote from: Darrell LeBeau – May 11, 2016, 09:25:58 am

I have 400 watts, not enough to keep up. I would consider at least 600 watts.

I agree. The previous owner installed 540 Watts and I can and will easily install one more panel to provide a total of 675. Even more would be better!

Re: DIY Solar

Reply #5 – May 11, 2016, 10:31:47 am

Before we did our PV install, I did a lot of reading. It seems there are two main schools of thought on "sizing" a PV installation.

Plan A. You can go the "intellectual" route, conduct a detailed energy audit, and calculate exactly how much solar will satisfy your particular needs. The link below might be helpful if this approach appeals to you:

Solar Design Worksheet

OR, Plan B. You can go the "More Is Better" route, and install as many panels as either, 1. you can afford, or 2. you can fit on your roof. Because our discretionary budget was limited, and I wanted to insure sufficient remaining room on our roof to safely walk around and work on stuff, we chose a modified Plan B. We laid out the max number of panels that left me comfortable room to walk around, determined that we could indeed afford that size system, and went for it.

In solar, ignoring all other factors, more is definitely better...too much is just enough.

Re: DIY Solar

Reply #6 – May 11, 2016, 11:59:48 am

Why diy? I've taken several people to this guy. He will install (better than anyone) a complete 500 watt (2 panels) and controller system for $1300. Or 750 watts (3 panels) and 100 amp controller for $1700.

All he does is RV's and he's 70 miles south of Palm Springs, California. Free camping. The install takes about 4-6 hrs. Then camp there for a while to test it out.

http://www.thesunworks.com/

Re: DIY Solar

Reply #7 – May 11, 2016, 01:45:08 pm

Consider installing a solar controller that has a maximum capacity much higher than initial plan, as many find they want to add future panels or move to a different coach with larger roof space, but their controller limits the power output.

We think that controllers that mount in the bay near the batteries, and have a remote readout panel for inside readout is a good idea. Some controllers can be accessed via Ethernet cable which some find helpful for setup, charge profile changes and monitoring.

Our Morningstar Tristar MPPT TS-MPPT-60, 600-watt controller works very well for us. We have 4 135-watt and 2 100-watt panels wired in parallel, 740 rated watts, nominal 12 volt system.

On sunny days, we get about 35 amps average, with 45 maximum amp output, colder the outside temp and more depleted the batteries, the higher solar output.

Leave room to walk from rear to front of motorhome roof. We mount panels on aluminum angles which bolt to aluminum angles mounted on roof. We used to tilt, but no longer tilt.

Each panel is wired to central waterproof roof mounted bus strips, and a pair of cables run from roof to bay wall near the batteries where our controller is mounted. Next to controller is a pair of circuit breakers, one for 12-volt positive cable from controller to batteries and the other on solar positive cable feeding controller.

Wire gauge matters, use large enough to help counteract some of the voltage drop. Important to put a breaker on solar cable to disconnect the voltage panel output if desired.

Re: DIY Solar

Reply #8 – May 11, 2016, 02:05:23 pm

I have about 450 Watts on the roof, and it's not enough to keep my batteries up with the 12-volt only marine refrigerator running (two compressors, one each for the refrigerator and the freezer). My 12 volt current drain runs from a minimum of 1A to 4A with one compressor running and 7A with both running. On a bright sunny day, I honestly get 350 Watts from the panels, not the full rated 452.

At Quartzsite last January, I needed to run the generator for a couple of hours after three days and nights with solar alone. I waited until the battery monitor indicated less than 20% remaining, then ran the generator until the inverter/charger tapered off from 104A to just under 50A, at which time the battery monitor indicated 80% battery charge. The battery monitor believes my batteries are only half of actual capacity, so even if I let them go to 0% indicated, they are actually at 50%.

My solar panels are than flexible ones that glue directly to the roof. No windage, and they "can" be walked on, so the manufacturer says. None the less, I left pathways on the roof for walking.

The charge controller is a Tracer-3215RN, rated at 30A. I will probably add another 200W to the roof since I currently use less than 20A most days, and only occasionally 23A. The charge controller can take up to 150 volts from the panels, so I have the panels wired in series, where they might get to 140 volts open circuit. When I add more panels, I will go with a series/parallel arrangement where like panels are wired in parallel, and unlike sets are wired in series.

Re: DIY Solarf

Reply #9 – May 11, 2016, 04:24:14 pm

I feel 800 is a minimum.. 2 batteries

My 900 watts gets me 2 days..before genny with 1 250ah battery (new from O'Reilly.. wish I had 1200 watts for 1 battery then I would get to 80% under reasonable sun... maybe I will replace a couple with higher output say 200 watts.. Oh...wait... I'll need to replace the charge controller... maxed @ 50A... lesson... as chuck said... figure this out.. future needs... maybe running an AC unit off battery... a mini split... designed in the future in maybe 2 years??

Don't forget sun loss without tipping the panels

Wyatt... where are you?

Re: DIY Solar

Reply #10 – May 11, 2016, 04:50:06 pm

We have 465 watts and have learned to live within that restriction. We're CAMPING and that means that we don't need all the stuff running all the time. Got two 8-D batteries and all is well. Coffee, fine; micro the breakfast rolls, OK; run the TV or the lights, no problem. Run the electric frying pan and that's too much. Just have to show a little sense.

Re: DIY Solar

Reply #11 – May 11, 2016, 09:38:47 pm

Bruce,

I started with 400 watts thinking I didn't want to spend so much. Then as most people find, there isn't such a thing as "too much solar".

Jim
02 320

with 900 watts and still think I want more.

Re: DIY Solar

Reply #12 – May 11, 2016, 09:56:21 pm

You can not have too much. I have 1200 watts and 4 8d agms, and a electric/ propane refrigerator. With no ac, can go a long, long time without gen. Even on cloudy/rainy days, 1200 watts will produce enough to charge batteries by the end of the day. On sunny days, will be topped off well before noon. With a battery combiner to charge start batteries, my only worry for extended dry camping, is propane for the fridge, and water for us.
With prices for solar below $1 a watt ,it is a good time to install as many panels as you can afford.

Re: DIY Solar

Reply #13 – May 11, 2016, 10:27:02 pm

We have 950 w and think it is right for us. Not much TV and very few minutes on computer suits us fine while travelling. Almost all LED in and out and Res Fridge on separate inverter. Almost never use the gen set, in fact in 7 yrs have run it about 10 hrs total and most of that is to keep it operational. We do not miss out on anything and forgot to say we hardly ever use AC, in fact hate it.
JohnH

Re: DIY Solar

Reply #14 – May 11, 2016, 10:40:21 pm

This guy is not very politically correct but he is living off grid and what he says works. Don't go if you are sensitive! And don't ask any dumb questions on his blog! LOL!

TOM

HandyBob's Blog « Making off grid RV electrical systems work

Re: DIY Solar

Reply #15 – May 11, 2016, 11:12:35 pm

Quote from: jcus – May 11, 2016, 09:56:21 pm

With prices for solar below $1 a watt, it is a good time to install as many panels as you can afford.

And, you get back 30% of every dollar spent on your PV installation, in the form of a tax credit when you file your federal tax return. If you can't use it all in one year, you can carry the remaining credit over to the next year. Sure helps ease the pain!

Re: DIY Solar

Reply #16 – May 12, 2016, 07:12:41 am

Listening to the collective advice, researching different solar options and found some enticing panels HERE. If I go this route, I'll be piecing my system from different manufacturers and will really have to research wisely. Would also have to ensure I buy with growth in mind (can't imagine ever needing 1400W, but things change).

3 315 Watt Astronergy panels (945W/26.4 Amps/107.5 Volts) would do nicely. Right price at .97/Watt.

Or, can go the 'Merican route with 3 285 Watt Suniva panels (855W/26.8 Amp/95.7 Volts) at $1.07/Watt.

Decisions......

Re: DIY Solar

Reply #17 – May 12, 2016, 09:37:09 am

Couple of things to consider while in the planning stage:

If you don't already have a really good inverter, include that in your upgrade package. It doesn't matter whether it is a combined inverter/charger, or a separate inverter and charger - that is a matter of personal preference. What IS important is that the inverter and charger play nice with the solar controller(s). You want the transition between different operating modes to be seamless and transparent. Whether you are dry camping on battery, running the generator, plugged into shore power, or cruising down the road on alternator - you want the addition and subtraction of power from your batteries to be handled, as much as possible, automatically without requiring a lot of manual input.

Mount the remote control panel for the inverter and the solar controller(s) together in one convenient location. Once you have the system correctly programed, you won't be doing much with the remotes, but it is fun (and educational) to use the monitor functions to watch what's going on.

Re: DIY Solar

Reply #18 – May 12, 2016, 12:37:24 pm

So I'm assuming so far that my original inverter/ charger is just fine working with solar? 600-900 watts is a good starting point, increase wire size from combiner box(s) to controller to reduce voltage loss, use a larger controller in case of future expansion. Also looks like if one was knowledgable you could put a decent system together themselves for about 1500 or so.

Re: DIY Solar

Reply #19 – May 12, 2016, 01:42:45 pm

Quote from: bbeane – May 12, 2016, 12:37:24 pm

So I'm assuming so far that my original inverter/ charger is just fine working with solar? 600-900 watts is a good starting point, increase wire size from combiner box(s) to controller to reduce voltage loss, use a larger controller in case of future expansion. Also looks like if one was knowledgable you could put a decent system together themselves for about 1500 or so.

Or less, using a Chinese mppt charge controller so you can series connect your panels using thinner wire, and going to EBay for the panels.

The oem inverter/charger is fine. Actually, great as a charger, ok as an inverter. It drains the batteries too rapidly when on but only lightly used. Some day I'll add another smaller inverter for the television and sparingly use the big one for the microwave, coffee maker, or hair dryer. My refrigerator is 12 volt only.

Last time we accidentally left the inverter on for half a day with nothing on other than a clock radio and microwave and tv on standby, I needed to run the generator to get enough battery charge for the night.

Re: DIY Solar

Reply #20 – May 12, 2016, 02:01:45 pm

Quote from: Tom Lang – May 12, 2016, 01:42:45 pm

Or less, using a Chinese mppt charge controller so you can series connect your panels using thinner wire, and going to EBay for the panels.

The oem inverter/charger is fine. Actually, great as a charger, ok as an inverter. It drains the batteries too rapidly when on but only lightly used. Some day I'll add another smaller inverter for the television and sparingly use the big one for the microwave, coffee maker, or hair dryer. My refrigerator is 12 volt only.

Last time we accidentally left the inverter on for half a day with nothing on other than a clock radio and microwave and tv on standby, I needed to run the generator to get enough battery charge for the night.

I bought a new outback psw 2800 watt inverter and measured amp draw with nothing using it, 68 watts in idle mode!
It has a search feature which allows it to shut down and search for current draw every so often, and go back on line when it sees a load, the problem is that it turns on every 30 seconds or so, to search, this was not good for my microwave. Same as plugging and unplugging microwave every 30 seconds.
Ended up buying small [300 watt] inverters for tv, sound system, computer etc. This small ones only draw about 3 to 5 watts at idle, lot easier on your battery bank. Use the big one only when you need it for big items like microwave, coffee pot etc.

Re: DIY Solar

Reply #21 – May 12, 2016, 03:34:19 pm

Tom our OEM inverter is like your 5-6 amps just in standby. It will work on batteries if left on.
I did call a company in Palm Springs another member recommended. For about 2k 750watts plus upgraded controller installed. By the time one pieces togather all the little trinkets necessary to complete the job, along with trying to do all this in a camp ground 2k would be a good deal.

Re: DIY Solar

Reply #22 – May 12, 2016, 06:54:08 pm

The Xantrex 3012 only draws 36 watts idle, charges at 150 amps if your battery bank supports it

Affiliate Notice