Combine solar and wind charge controllers?

[Argyle38]

I'm installing 48W of solar this spring and am looking for a charge controller. I'm looking mainly at the MPPT variety and I'll probably expand capacity eventually to not more than about 150W total of solar.

I also plan on getting a wind-charger, perhaps next year. My favorite so far is the Rutland 913 due to quiet operation and low wind speed start up. It's maximum output is rated at 300W.

My question: is it possible to get a higher charge controller right now that will be able to handle all my needs going into the future, both solar and wind, or, are the two power sources sufficiently different that they both require individual attention?

 

[Stu Jackson]

From what I've gleaned at www.cruisersforum.com, Electrical section, it would be wise to consider separate controllers.

 

[Bill Roosa]

An interesting dilemma
The solar needs to be treated just like a battery and the wind generator needs to be treated like a, well, generator you can't turn off.
Wind generators need to be able to dump to a diverter load so they don't self destruct. You have to ALWAYS have a load on a wind generator. Solar is not so much.
So your controller would have to have as a very minimum a load diverter. The solar will not care if there is a load or not so you can actually connect the two together.
Not that I'd recommend that route due to the two fighting (I got more volts than you) each other resulting in one simply not contributing. Exactly like connecting a six volt battery into a 12 volt system (with a diode to prevent current charging the 6 volt of course) and expecting to get the 6 volt to do anything. It just sits there till you discharge the 12 volts down to totally dead 6 volts. The voltages on solar and wind are closer so you get a more frequent and rapid back and forth thing going. It does not really hurt anything but it is not very efficient given you paid a lot of money for the units and you can’t get full output all the time.
What you really want is the full Monty “wind and solar” controller. It takes care of the dumping the output of the generator to an external load (water heater???) and adjust the voltages between the two devices to get max output at all times in accordance with the batter SOC.
Yes they are expensive.

 

[Stu Jackson]

There was a discussion about this on sailnet recently. Here's one, with a link from one of my posts to an even earlier discussion. The two are each pretty long but have some good information.

http://www.sailnet.com/forums/elect...t-breaker-wiring-design-relays-dump-load.html

 

[Maine Sail]

There are controllers that will do both and can have a "dump load" but they are often very expensive and no better built or performing than two separate devices specifically designed for their intended usage. The Xantrex "C" series will do both wind and solar and a dump zone but are not on my "favorites" list. Marlec also makes a solar/wind controller as do others..

As for MPPT and a small panel there is little benefit until you break the 150W - 200W range. Genasun has come up with MPPT controllers that are specifically designed for small panels to effect the most current from them. A Genasun GV-10 would cover you to 150W and run $165.00.

Alternatively the Morningstar PS-15 is an excellent PWM controller that works well with smaller panels.

Personally I like to pick controllers for each use but this can cost more and take up more space. Many of the new wind gens already come with controllers too....

 

[Argyle38]

Thanks guys. I was starting to come to the same conclusion, I just wanted to get some more opinions. I do remember seeing the Marlec unit some time ago (same folks that make the Rutland) but had forgotten about it. It looks like that unit can do the job, but may not be as efficient with my smaller solar panels.

I'll likely end up with the Genasun controller for solar. The price isn't bad and with a 38' boat, I have plenty of space for separate controllers.