Solar Experiences

[Nicholson58]

Originally Posted by Verities

Thank you everyone for your great input. I have completely rewired and reconfigured the DC system on the boat and do have a Blue Seas ACR isolating the house and starter banks. Works great. Replaces the charge to the starter almost immediately and ties in the house just after a few minutes. I will look at good charge regulators and check out all the advice here in regard to panels. The high output alternator has an external regulator (Balmar), I'll have to figure out where in the system to insert the charge. Cheers!

Balmar is a good one. I like ours. I had to add wire to be able to install at the nav station. Ours charges bank(s) according to the battery combiner and battery selector switches.

[hellosailor]

"He just says its overkill on small systems IF your panels are voltage matched to your batteries."
Ah, but how can you tell if they are voltage matched? How can you tell IF your panels are coincidentally operating at their MPP, and if thta happens at 10AM? Or from 1-3PM only? or?? As opposed to an MPPT controller, which is adjusting the impedance on the fly all day long, to keep the panels at their MPP.
I'd submit that even if your system is co-incidentally matched at some time (twice) during the day, it is not matched for most of the day. Since there are MPPT controllers for just over $100 these days (Genasun's smallest) it is no longer a question of "I've got $200 worth of panels, I'm not going to throw a $500 controller on them!". There are options all along the price scale, and I'd argue that a properly chosen MPPT controller is probably cheaper than 20-30% more wattage in the panels.

[Nicholson58]

For most of us with serious solar, the panels are large and the Voc is too high for anything except MPPT.

[Verities]

My calculation in wattage is based on possible future needs (inverter for computer, etc). I have all LED cabin clusters, water pump, chartplotter, radar, vhf, autohelm, bilge pumps and basic running light set-up. Real bare bones for a cruising rig. No frig or large amp eaters. Should I go smaller? Thanks!

[Nicholson58]

Originally Posted by Verities

My calculation in wattage is based on possible future needs (inverter for computer, etc). I have all LED cabin clusters, water pump, chartplotter, radar, vhf, autohelm, bilge pumps and basic running light set-up. Real bare bones for a cruising rig. No frig or large amp eaters. Should I go smaller? Thanks!

the lights hardley count. Your big one is probably the autohelm. I don't see AIS or radar. We added a 3watt Watchmate 850 and a Lawrence broadband radar. Not big users but important. I think you should install the most you have space for.

[Verities]

Looks like MPPT regulation is the way to go. I'm thinking one panel at this time. I'm moving my radar to the mast leaving my bimini shelf aft open for solar use. Seems to be a fairly unobstructed area given it's a sail rig and out of the way.

[GeoPowers]

Originally Posted by Cotemar

These are the lightest and most power output in watts for their size.
Sanyo 225 watts, 35 lbs 31x62inch
SunPower 230 watt, 33 lbs 31x61inch
Work great with a Blue Sky 3024i controller

I like these, but I think you can only run one with the 3024i (or iL) because of the high Voc and Vmp voltages. The iL goes to 540W only with a nominal 12v charge, if you go higher you can only have 400W max, right?

EDIT: (for a 12V battery system), 24V systems can go up to 800W

I have a 3024iL that I got for crazy cheap, trying to fit the best panels to go on my arch now...

Frank

[NorthPacific]

Almost afraid to ask.

Bought 2 100w solar panels with 2 diodes per panel. Plan to mount on cockpit rails.

So if I wire both panels to this controler then to the battery. Will it work?http://imgs.inkfrog.com/pix/welldone/160031-1.jpg

[Nicholson58]

Originally Posted by NorthPacific

Almost afraid to ask.

Bought 2 100w solar panels with 2 diodes per panel. Plan to mount on cockpit rails.

So if I wire both panels to this controler then to the battery. Will it work?http://imgs.inkfrog.com/pix/welldone/160031-1.jpg

Controllers & panels need to mate regarding volts and amps. If you have a 12 volt boat, nominal 12 volt panels and a nominal 12 volt controler it can work. Read the manual with your controler. If you are unsure, contact the help geeks. Most of the suppliers know most of the panels so they can help you along.

The big panels I have and some of the other posters have noted have very high open circuit voltage. My boat is 24 VDC and my panels are 54 volts. For that, I have to use an MPPT type charge controler. The advantage is better power management of the available power and the system will produce some usable power in marginal light conditions.

[Nicholson58]

Originally Posted by Cotemar

These are the lightest and most power output in watts for their size.
Sanyo 225 watts, 35 lbs 31x62inch
SunPower 230 watt, 33 lbs 31x61inch
Work great with a Blue Sky 3024i controller

I too found the Sun Power panels interesting. I was unable to find anyone to sell them to me. I finally talked directly to someone in their organization. I found phone numbers here along with specifications. Solar Panels For Your Home | Residential Solar Panels | SunPower I was told they were only interested in big time operators who were installing large solar power plants. Also, they only sell through licensed installer - distributors so I would have to hire their guys to evaluate my system and design and install it.

Did you find a way to buy Sun Power panels?

Practically, this leaves only Sanyo as the high efficiency panels available to people like us.

Note: if you use Blue Sky and your system is 24 volts you will probably need a 3048 model. I found this particular unit a bit complex as I read the manual and I didn't like having to use a VTVM to tune the potentiometers. I bought a Morningstar MPPT instead. We will be installing when the water becomes less stiff.

[NorthPacific]

Hi Nic 58,

Much smaller boat and smaller amp demands. SO I have 2 100w panels. Open voltage is 22volts each. So X 2 need a controller that can handle 44 volt? or another controler for the other panel?

MAx voltage 18.5 volts.

[Nicholson58]

Originally Posted by NorthPacific

Hi Nic 58,

Much smaller boat and smaller amp demands. SO I have 2 100w panels. Open voltage is 22volts each. So X 2 need a controller that can handle 44 volt? or another controler for the other panel?

MAx voltage 18.5 volts.

You don't generally wire panels in series unless you are in the wide open with ZERO chance of partial shading. Plan parallel. I asume two identical panels. I'd still talk to the brain trust that makes the controler before you plan your wiring. I can't recommend handy Bob's blog enough. It will take you several hours to get through. Take notes on the key points and devices. I bought a Bogart TM 2025RV battery monitor for each bank after reading and will modify my charge voltage and profile. If yoy take nothing else away from Bob - its to oversize the guage of all wires especially those carrying power.

[roverhi]

Installed two Kyocera 130 watt panels on the sides of the extended stern pulpit. Wired the panels in series for 24v nominal into a BZ Products MPPT controller. Sailed from SF to Hilo in 15 days with the first 10 days overcast. Didn't start the engine till I got to Hilo and batteries were fully charged on arrival. I'm a pretty low drain boat with no refrigeration but ran the Garmin 3206 GPS and AIS 24/7 and the running lights from dawn to dusk. Fairly liberal use of the SSB Ham radio and Pactor Modem everyday.

It's the wattage you have to be concerned about with your controller. The BZ controller is rated for 250 watts but handles the 2600 watt output of the panels. I'd be willing to bet the controller wattage rating is conservative, know the solar panel wattage is almost always wildly optimistic.

[SV Demeter]

Originally Posted by senormechanico

He sounds like a knowledgeable guy about most of the stuff he posts, but imho, he's still in the backwoods about MPPT controllers.
I've watched the input and output of mine enough to be convinced of its effectiveness.
Even on very cloudy days with very low solar irradiance (only one amp input), I get an average 15% boost from input to output current.

Plus 1 for the MPPT. Here is a photo of the display on my Outback controller with 400watts coming from 4 panels and a cloudy day. Note the input voltage and amperage and also the output voltage and amperage.

Sorry for the crummy photo./

[Nicholson58]

Originally Posted by SV Demeter

Plus 1 for the MPPT. Here is a photo of the display on my Outback controller with 400watts coming from 4 panels and a cloudy day. Note the input voltage and amperage and also the output voltage and amperage.

Sorry for the crummy photo./

I am encouraged! just received my panels 660 watts of Sanyo and morningstar MPPT. Panels waiting for less rigid water. I really need to leave the dock.