Yes, you heard that right.
If you remember the massive thread:
http://www.sailnet.com/forums/gear-m...olar-wind.html
Brian was true to his word, and left me to play with a complete SolarStik. The first thing I have to say, is that if you've ever spent any time getting metal fabrication done, the photos we've seen of this totally do not get you ready to see the real thing. It looks like something that either fell off the ISS and survived the fall to earth, or something craftily stolen from a nuclear sub's powerplant. "Tim the Toolman" would go gaga over it.
Massively overbuilt, incredibly beautiful strong welds, and every part is either captive or attached with a fastpin and/or vinyl-covered steel leash. No tools required for assembly, nothing to drop overboard, lots of attention to separating the stainless and aluminum with Delrin(?) sleeves and washers to prevent bi-metal corrosion problems.
We were all wondering why a couple of solar panels and a pole would cost so much money. The answer is, that "pole" would probably cost more to fabricate in your local metal shop. Does anyone need or want that much overkill? Well...maybe. On a 40-60 footer, sure. I'm just saying there's a tremendous amount of expensive metalwork and design behind this, the "pole" is probably stronger than the mast or boom of many 28' boats.
I know, that was only half the question, whether the thing was overpriced. The other big issue was how come users were claiming to get more power out of it than most of us seem to think is possible anywhere on this planet. I've got answers for PART of that, and it seems to be that those wild claims aren't totally wild.
The SolarStik ships with a BlueSky SolarBoost "MPPT" charge controller. Big deal, a regulator is a regulator, right? Wrong. Part of that we figured out in the other thread. It turns out that MPPT controllers aren't just regulators--they take overvoltage from the solar panels, and convert it down to higher amperage at the voltage the batteries really need. There's some loss in the MPPT controller, and some variation among makers, and more variation by time of day, but apparently an MPPT controller can account for 5-10% "more power than those panels are capable of putting out". Not literally more power--but more useable
amperage instead of dumping the extra voltage.
Then, it turns out there's another effect of MPPT controllers that even BlueSky wasn't talking about. MPPT controllers put out PWM (pulse width modulated) DC, not plain DC power. PWM-DC is more like an AC signal, it is simply not the same kind of power that a straight solar panel, or a panel with a conventional regulator, puts out.
One of their competitors (Morningstar) did some tests with/for Sandia Labs, who spend some of our tax dollars looking very closely at things like solar panels. See:
Addendum to Why PWM?
for their report, and there's a URL in there that links back to Sandia for some more unbiased reports that aren't quite as easy to read. Apparently when you use PWM instead of pure DC, and especially if you use it with AGM batteries, you can charge the battery more thoroughly and faster, as the "spikes" of DC don't cause local gassing the way a pure DC charger would. In their results, they showed batteries accepting higher capacity, up to 20% higher than even three-stage DC chargers.
In other words, use any PWM charger, including MPPT controllers, and if your battery was holding 200AH, you might see it holding 230-240AH after a few charge cycles from the MPPT controller.
The MPPT controller itself is using the solar panel's power more effectively (gaining 5-10% more amperage) and the PWM output from the controller is stuffing more amps into the battery (10-20% more) so yes, in theory, you could see folks "reading the meter" on the charge controller and concluding that they were getting 30% more power than they "should" be getting from solar panels, based on hooking up plain unregulated panels.
That magic doesn't apply just to the SolarStik--it apparently applies to all MPPT controlled solar panels, and the folks who make the controllers just aren't talking about it much. Unless you find Morningstar's web site or their tests with Sandia.
To make things a little bit more complex...you can't just "measure" PWM-DC with a plain multimeter. It isn't AC, it isn't DC, it's a special pulsating DC and regular meters are not designed to read that accurately. So, when the BlueSkies controller displayed voltage in/out, and displayed amperage into the batteries, I found it typically about 4% higher than my own "pretty good but not NIS-lab-calibrated" multimeter. The 4% difference is neither here nor there--for a
boater reading the thing like a gas gauge. Whether the BlueSky controller was a bit optimistic (it consistently rounded UP to three figures, my meter uses four digits) or just needed calibration, dunno. BS will recalibrate their controllers for any original owner during the warranty period if that really concerns you. I figure, if you are trying to charge a battery bank near 50% cycle depth...a couple of percent either way really is not a concern.
So with a PWM controller pushing perhaps 20-30% more charge into the batteries, and a chance that the "meter" is misleading the user by another 4-5%?
Yeah, I can see that some owners would be reporting incredible amp-hour claims for the SolarStik. Without having any idea why those numbers were happening, but swearing quite postively that those numbers WERE REAL.
It has been a very enlightening bit of testing for me. When I go solar, at some point, I don't know that I'd want a SolarStik. It's just massive, and while it probably would survive a rollover and cartwheel...I just don't know. I'm kinda hoping that Brain comes out with a "SolarStik Jr." for the rest of us, same quality, but maybe with some college engineering class figuring out how to pare it down to half the mass while still making it "strong enough". (Heck, even the finger grips in the carrying handle are half-inch-deep rounded and polished INDENTS sticking out above a piece of one-inch aluminum tubing.)
Now, what I haven't been able to get around to yet, and may not be able to finish up on, is clocking the output in real low sun angles, i.e. 6-10AM and 5-8PM. We all questioned how much that might affect the total output. From what I saw, aiming and rotating the panels every hour or so to track the sun made some difference. And the locks and adjusters and arm supports and all on the SolarStik
do make that easy, again with a lot of expensive top quality metalwork.
(Apparently the same equipment, with a terrestial tripod base, is being sold to military and emergency/disaster operations centers--and they've got no complaints about how rugged it is either.)
So yes, Brian dared me. Yes, he kept his word. And even if I'm not all done and don't have a full set of "pure" percents to come out with? I've got to say I can totally understand the price point, based on the fab job alone.
The radical output numbers? Not so surprising. Apparently MPPT and PWM are just "out there" and you've got to pull teeth to find out that they are inherently different--and the only way to go.
Aside from wishing for a "Junior" model
my only concern would be on the BlueSky controller. It looks nicely made, but it doesn't seem to be "conformal coated" or really designed for use in salt air environments. It took three reeadings through the manuals to be sure of what and how I was setting things up, because they're very flexible but a bit confusing. And oddly enough, you can't just set the controller for "AGM" or "Wet Lead", you need to find the specs on your own batteries, and then go match them up through a menu system that takes a half dozen tries before you get the knack of it.
I don't know how BlueSky compares to Outback, Morningstar, and the couple of other companies producing MPPT controllers in overall terms or quality, efficiency, price...a whole other kettle of fish. And properly installed down below with the other electronics the BlueSky controller probably is fine--but considering the massive overkill on every other part of the SolarStik, I'd like to see "SolarStik Jr." ship with an MPPT controller that was designed for use in salt air, either potted or coated.
This is not at all your father's Oldsmobile!