Solar Power Optimizers – What are they? [Video]

This is my second round of interviews with John Shaw of Bella Energy in Louisville Colorado.

SolarDave: Solar Power Optimizers – What are they?

John Shaw: [transcript coming soon]

I got a comment from Don Ellingham that I wanted to include:

Hi Dave, two comments:
If I had to guess, NSC’s optimizers simulate the effect of MPP controllers for each panel. Without them, when as few as one panel is even a few% shaded, the current out of every panel in a whole string of panels is affected, maybe substantially. I believe that this device compensates for shading by converting the shaded panel’s output to a slightly lower voltage, and in return increases output current to balance with the rest of the panels. Getting the maximum current through the string of panels would produce the most power from the whole string. Since inverters are designed to work over a voltage range anyway, they don’t care about a few volts, and the system levels itself to the maximum power dynamically, as the day progresses. Sometimes just one part-shaded CELL can look as bad (1) as a large resistor in series with all the other panels and kill the system output. I have a friend who has an ice/snow problem. He cannot get at a couple of his panels and this very problem really affects his winter energy production.

The second one is, I don’t think NSC’s optimizers are all that cheap. While they CAN be used as an add-on to bump up your system output, as an add-on to a GOOD system, I wouldn’t expect more than MAYBE 5% improvement. On the other hand, if you have a poorly sited installation, as in (1) above with chimneys, gables, growing trees, ice etc. sometimes interfering with sunlight, it may make a substantial difference. One that you can’t get in any way except with optimizers or micro-inverters. Cheers, Don

It’s a good idea in (1) above, but on a new install, good siting, cost trade-offs against hi-Wattage panels, a good installer, (goes without saying) etc are all numbers that should be run first.

I have looked at National’s SolarMagic(TM) Power Optimizer product announcements and as John said (something like this) there’s magic in that box. National never really says WHAT they do, but I’m an engineer and know a bit about the field and solar cells, so thought I’d voice the most plausible technical explanation. And I believe it’s pretty much right on. I should dig through National’s patent apps and see if they applied for one that’s has been published on this.

A long time ago, I did a presentation at one of National Semi’s shareholder meetings, on a project National and I were working on together, and I had the pleasure of meeting Charlie Sporck, (possibly by then, ex-) CEO and one of Fairchild’s and National’s founders. A real legend, and a very approachable guy! Anyway, when I broached the subject of patents with him, he really surprised me and said something like “Patents? We don’t waste a lot of money of them. Instead of spending all that money on lawyers, I’d rather spend it in the lab. That way, by the time someone’s taken apart your last brainstorm, you’re already shipping your next one.”

There’s been lots of debate over that logic. And it may have been what kept National on top of the analog chip market for so many years. They owned it. TI and Motorola started selling off their semi business and National was still going strong. But like everything else, there comes a day when someone, in this case the Japanese, Maxim and Linear Technology, take your lunch (and some of your key people). And unlike TI and IBM who had HUGE patent portfolios that bring in cash continually, they didn’t. As a result, and most sadly, they almost went away. It’s great to see they’re coming back, and even better, in a field that really matters! If they can get the optimizers into a reasonable price range, they may have found their next hot new market.
Don