Charging with Solar and Wind

[mtnsapo]

Hello All! I have 310W of solar and a rutland 913 wind gen on board right now. Can both of these be charging tha bateries at the sme time? It appears that the high voltage on the solar regulator is fooling the wind regulator into thinking the batteries are fully charged. Am I correct, does one charging system win out over the over? It there a way to wire the system so that batteriss acn be charged from both at the same time?

I bought another rutland 913 to add, but now thinking it may not do much good during teh day???


Thanks!

Brian

[Bash]

it is certainly okay to have both systems charging at the same time, as long as they don't overcharge the battery bank. You should be able to adjust the voltage at which each system will shut itself down. I've adjusted my system so that the wind generator turns itself off before the solar does.

[daddle]

My fancy "smart" charger on the engine's alternator would go to the lowest charge rate if it detected another charger on the batteries, i.e. they were at a voltage greater than their quiescent voltage. Stupid, as any sunshine at all would stop the charging even if the batteries were way down. Swapped the smart regulator out for a plain old stupid automobile regulator. All is good now. I rarely charge with the alternator anyway as I rarely motor.

[SaucySailoress]

I have never seen wind generators in action. Feedback I have had from sailors who have seen them in use, is that they're rubbish. Heavy, inconvenient, and inefficient.

Bash - you clearly have one... how does it compare to solar? How efficient is it? Would you recommend it?

[mtnsapo]

Hello! I want both of them to charge if the batteries are not 100%, but I think the wind gen reg is reading the 14.4V that the solar reg is putting out and putting the wind gen in idle mode. neither regulator has a capibility to change the shutdown voltage. the wind gen is a rutland HRSi charge controller, and the solar controller is a sunsaver 20.....

Thanks!

Brian

[BlueWaterSail]

If the sun's out solar will always put out more than wind. Do you have separate house and starting batts? If so consider hard-wiring the wind to the starter and making the solar manually switchable between house and starter. Since there's more draw on the house, the alternator could be charging that bank exclusively.

If you have only one bank, I would not worry too much about the solar overriding the wind - that's essentially the way it should be, the stronger charging current takes priority. At night and on overcast days, the wind provides the trickle charge. Adding another wind gen is unlikely to make any difference because of the relatively low ouput to begin with.

BWS

[Captain Bill]

The secret to doing this is to have a charge controller designed to work both with wind and solar outputs so that they keep the current flowing from both devices. So far I have only found one controller designed to do this. It's the Blue Sky 3024il DUO. It combines a diversion type controller for use with the wind genny and an MPPT photovoltaic controller. It keeps the wind genny at full output and diverts part of it's energy to keep the batteries at the proper voltage for the charge state while at the same time regulating the PV's to a matching voltage so that both charge. When the batteries get full it diverts any power coming out of the wind genny and shuts down the PVs. I am not saying that this is the only controller that can do this, but it's the only one I've found. The only issue is where to divert the power when the batteries are at full charge. They suggest a resistance load such as a water heater element since the power available will vary with battery charge state.

This product is a recent addition to their line so there's probably not a lot of real world experience with it yet. I've been trying to figure out how to do this for a while and this is the first time I've seen a controller designed to work with both types of power in the same system. Now if they would only add a module for my engine alternators that would coordinate with the solar and wind modules I'ld have a complete charge management system. What a concept!! No affiliation with Blue Sky by the way.

[Mark Johnson]

This is absolutely no problem, if your charge controller has multiple inputs like mine does. I used to do exactly this, until I realized that my wind generator was frequently creating a dark shadow on my best solar panel, knocking it's power down 90%. Then I got rid of the wind generator, and my Amp Hours / day went UP!

Mark

[Captain Bill]

Originally Posted by Mark Johnson

This is absolutely no problem, if your charge controller has multiple inputs like mine does. I used to do exactly this, until I realized that my wind generator was frequently creating a dark shadow on my best solar panel, knocking it's power down 90%. Then I got rid of the wind generator, and my Amp Hours / day went UP!

Mark

Mark, would you mind sharing the brand and model of your charge controller?

[Bash]

Originally Posted by Saucy Sailoress

Bash - you clearly have one... how does it compare to solar? How efficient is it? Would you recommend it?

Funny you should ask. I'm anchored out right now. It was cloudy yesterday, with fog and drizzle moving in around 1300h. I might have been lucky to charge 10 amps through the solar bank yesterday. Rained all night last night, and it's still raining this morning, but my batteries are still 80% topped off because my wind generator thrives on rain, and darkness, and even fog. And it works the entire month of January.

My biggest draw comes during an all-night passage, a point when the solar is worthless. I run radar, dual chartplotters, an autopilot, navigation lights, et cetera. This time of year I'm often running a diesel furnace as well. Those of us who choose to sail, at night, rather than run the engine, find a wind generator to be indispensable. (You might wonder what this says about the folks who have been advising you. Daysailors, fair-weather sailors, or Motorsailors?)

I would not value my wind generator as much if I only sailed during the summer, or only took the boat out of its slip on sunny days, or only sailed low latitudes. Were I the type of sailor who always tends to motorsail at night, rather than sail, I would not find the wind machine to be nearly so essential.

When they come up with solar panels that work at night, or in the rain, I will surely get rid of my wind generator.

[S/V Alchemy]

Both have their uses. On passage as crew, the skipper stowed the rail-mounted panels (too "temporary" for use outside of an anchorage) and relied entirely on the wind gen. As we had nine days out of 11 with 20 knots, rising to 40 in the squalls, the thing would whir like crazy much of the time, but would cut out and freewheel nearly silently (well, I assume, as the wind itself was howling) when the banks were full.

So on that trip, when the plotter and the large Grunert fridge were on, the wind gen did the trick 24/7.

A simple method of dealing with a non-multiple MPPT input charge controller would be to run the two charge sources into a combiner before the charge controller, or simply to use switches to choose sources, would it not? I would also suggest a diode switched solution, except I'd have to sketch it out.

That said, Bash and Capt Bill seem to get it. One's battery capacity, usage pattern and mode of sailing and anchoring dictates one's need and indeed preference for one over the other. There are even clever ideas like the Duo-Gen setup, a wind gen you can troll behind a boat for massive generation (and drag, too, but if you have more wind than you can use, the water flow is going to be far more efficient and won't slow down a boat much that is already showing a bone in her teeth).

Solar is wonderful, but both "cover" you in ways that meet my criterion of never, or only in an extreme pinch, switching on the diesel just to make alternator amps.

[sailorboy1]

I would really like to read more here from those that have combined wind/solar chargers as I read somewhere else about how they really don't work well.

Other than that do people really feel they are losing a lot of charging by the wind generator shutting down during the sunny aftrernoon?

[Bash]

Originally Posted by Don Lucas

I would really like to read more here from those that have combined wind/solar chargers as I read somewhere else about how they really don't work well.

Other than that do people really feel they are losing a lot of charging by the wind generator shutting down during the sunny aftrernoon?

Honestly, I'd rather have it shut down on a sunny afternoon. But at that point, the solar panels are also usually shutting down. Usually.

In the summer, when it's sunny, my battery banks will be full by about 1100h. But that's not why I have so much charging capacity. I also want to keep the banks full on cloudy days, or during the winter, or....

Solar panels don't lengthen their life expectancy by shutting down once the bank is full. A wind generator does. This is the primary reason I'd rather have the wind machine shut down first once the house bank is getting close to being topped off.

None of these systems are perfect. When I'm going to weather, the wind generator can completely charge my batteries faster than the Balmar 110-amp alternator will. The generator will run for no more than half an hour, depending on wind strength, and then shut itself down until the house bank has once again drawn down. However, when I'm running downwind, the wind generator may run constantly because the apparent wind, which it runs on, is so much lighter.

So, I think that most cruisers build their systems around the charging capacity they'll need in less-than-ideal conditions. The passage maker and/or the person who spends extended periods on the hook has totally different needs than the weekend sailor on the one-week-per-summer cruiser has. I have no doubt that this latter group will fail to see the benefit of a combined wind/solar system.

[Mark Johnson]

Capt Bill,
This is the model I have: (Trace Engineering C-35) = for Max of 35 amps. They also have a C40 and C60. It has worked great for the last 12 years. It is VERY "smart", has three stages, (adjustable at each stage), and can equalize wet batteries if you want to. It is therefore adaptable to any type batteries.

If by chance I am having a memory problem about the multiple use feature, it doesn't really matter. I didn't set up my system that way.

Here is how I wired my system for maximum simplicity and reliability, rather than sophistication. I had 4 charge sources. The alternator, the dockside charger, the wind generator, and the solar panels. They ALL had their own charge controllers, and all 4 sources went to the house batteries only... (two Trojan L-16s = 380 AH). I have since gone smaller to Trojan L-14s. (= 340 AH.)

Since the MUCH smaller engine battery, needed a different charge regimen, I have a Blue Sea battery combiner that I usually keep switched on, (so this battery gets the spillover once the house bank is up to 13V, but juice can't go the other way and drain itself). When motoring all day, I flip a switch and disable the feature, once the engine battery is topped off, so that the engine battery doesn't get overcharged while the last little bit of the house bank is getting charged. My 55A alternator has a dumb regulator that could potentially do this, although it has never been a problem.

The above scenario avoids the old diode way of sending current equally to each bank, which has problems of its own.

I use an E-Meter now called Link 10 monitor, and it tells me exactly what state of charge the house bank is in, by counting the amps going in or out. It is very accurate.

The only thing about multiple charge controller / voltage regulators, is that when the batteries are near the very top, and voltage is getting really high, the controllers with the lowest shut off settings will stop contributing to the cause at this point. With wet batteries, this is a moot point, because no matter how much amperage you shove at them, when they are near the top, they will only accept a small amount of that amperage.

When my batteries are really low, all charge sources do stay on.

Having said that... Most books say you can take batteries down to 50% regularly without damage, this is true. In my case I was going for longevity of batteries, (10 years), and a good reserve for EXTREMELY cloudy days. Normally I only take my house bank down 14% each day, so recharge HAS to be slow anyway. With my 280W of solar alone, I usually have them back up, from -40 Amps down, to FULL, by just after noon!

This maximizes battery life! On a REALLY dark, overcast day, I still get topped off, but it takes all day.

When at sea and doing overnighters, our consumption really goes up, and I crank the engine for an hour, each morning at about 5AM, when they are the lowest and can accept the strongest of my charging sources. This short engine run brings back about 40% of what I need, and the solar takes over and tops them off over the day.

Other than the perhaps 30 days a year that we do overnighters, our solar panels keep us running the entire rest of the time.

The key with solar is to have a large enough battery bank to have a good reserve, and after figuring your NORMAL days Amp Hour usage, you need almost TWICE this amount of average Amp Hour solar production.

For our "at anchor" 30 to 40 amp hour per day use, we have enough panels to produce 50 to 60 Amp Hours. This keeps us covered, even on dark days! Totally cloudy, NO sun, but really bright days that make you squint, will result in almost normal solar production.

Try to orient the panels for the least DARK shadows from something within 10'. Even in a small area, this really knocks them down! You might want multiple panels like we did, to always have most of them in the sun. If you do, inclusion of a Shotkey one way diode in the + wire of each panel is a good idea. (regardless of the .5 V drop)

Good luck, Mark

PS, Everything has worked great for from 11 to 15 years with no problems, EXCEPT... we have been through 5 Xantrex dockside chargers! They are REALLY smart, but sensitive to lightning anywhere around, as well as AC line spikes. Their flat rate fee replacement is what we normally do.

[CarinaPDX]

I have solar panels, a wind generator, and an alternator. Of course all of the regulators will respond to voltage changes from the other regulators - a minor annoyance more than anything else. Typically the solar panels will trip the smart regulator on the alternator, causing the engine to load/unload every few seconds when under power. I have shut-down switches rigged for both the solar panels and wind generator, and have threatened to add one to the alternator as well. When the batteries are charged I tend to shut off the wind generator and go with the solar panels - the wind generator cycling on/off is noisy. I like the idea of a single smart regulator for both the wind and solar but I don't like the single point of failure; by my way of thinking keeping the systems separate increases the likelihood that at least one charging system will work.

BTW the regulator interaction problem extends to the "smart" Isotherm refrigerator. If the boat is running on a modest solar panel system as the voltage rises the Isotherm turns on (thinking that the batteries are being charged so there is ample power) which in turn loads down the system and drops the voltage, which causes the fridge to cut out. IIRC early versions just kept cycling but more modern ones stop after a few cycles and turn on the warning LED (after which the fridge is effectively off: i.e. a small problem becomes a major one). The short-term fix is to switch to manual operation of the fridge; the long term fix is to get rid of the over-engineered, unreliable design and go back to a simple thermostat. End of rant...

I reckon that I have about the same investment in solar panels and wind generator. The solar panels have easily generated more power through the years than the wind generator, but I want both. For the two Atlantic crossings made on Carina there was precious little sun but the wind was strong. OTOH most anchorages are protected from the wind so the solar panels come into their own there.

The older wind generator designs either put out too little power or had scary large propellers. The Airmarine series from Southwest Windpower changed all that, and is justifiably the most popular among modern cruisers. I believe there is a similar design from a German company now.

Bottom line is that I recommend to first make the boat as energy-efficient as possible, then install solar panels and a smart regulator on the alternator, and finally for long distance cruising add a wind generator (currently the Airmarine Breeze would be my choice). And avoid amorphous silicon solar panels like the plague...