National Semi: Now Touting Solar Stuff

Hardly a day goes by without another tech name becoming a solar technology inventor. Yesterday’s debut was from National Semiconductor (NSM), a long-time maker of humble analog circuitry sold into numerous electronic devices. The company put out a press release this afternoon about a new technology to aid solar panel design, and Briefing.com notes that the stock was up 36 cents, almost 2%, after hours, at $20.90, after National’s chief executive, Brian Halla, appeared on CNBC after market close.

National’s “SolarMagic,” as the part is called, is not itself a solar panel technology, rather its a chip that can, as National puts it, recoup 50% of energy that’s typically lost in solar cells when dust or shadow falls across the panel. There’s not a lot of detail on the press release about how this magical device works, but I assume we’ll be hearing much more about it.

Comments

[H. T. Love:]

How it works i simple, really. Just as one weak battery in a pack will draw current from good ones (higher voltage potential pushes juice to lower voltage potential, same for water pressure, air pressure, etc.), a solar panel that is shaded (shadows, dust coatings, etc.) have lower voltage than ones that are not. So some current would tend to flow towards the underperforming panels. Net effect is overall lower effective voltage from the array. That translates into lower current flow from the array to where it is needed.

By having circuitry that is equivalent to voltage monitoring, diodes to prevent current flow in "reverse" directions, isolation circuits, etc. the array is "balanced" to maintain overall effective output by preventing these "sapping" effects.

BTW, for accuracy's sake, the PR said as hihg as 44%, not 50% and a lab environment yielded an overall 12% gain.

Certainly a useful result.

The more important effect is that it increases the coverage to installations that may not have previously met minimum qualifications for use of PV arrays. That effect *may* provide enough gain in price points (through higher volumes and more wats per $ at less-optimal sites) to provide a noticable acceleration in PV usage growth. Depends on how widespread the adoption of the device is among installtions.

2008 Jul 02 10:47 AM

[TinyTim:]

I could see it for panel mismatches, which should be equalized out during the original install, but why don't all the panels get shaded or dirty at the same time?
I would think this technology more appropriate to correct mismatches in the individual modules that make up a panel as they age.

2008 Jul 02 01:36 PM

[OldFart Peter:]

I don't think Tiny Tim has ever watched a shadow! It is perfectly clear why shading could affect only some panels. I have arranged for the ones to be installed on my roof to dodge the shadow of the TV antenna, at least in summer, but the optimum panel position on my daughter's house has a small area shaded by a neighbor's tree, which moved during the day. And the last time birds pooped on my car, it was over a small portion of it, not all over.

2008 Jul 16 02:17 PM