Maxim presents its Cell-String Optimizer as the first IC to perform MPPT (maximum power point tracking) at low level in a panel; it allows photovoltaic (PV) panels to harvest significantly more energy and simplifies design complexity for solar installation projects. by Graham Prophet @ edn-europe.com
Maxim’s cell-string optimizers are highly integrated DC-DC converters that replace the bypass diode and perform maximum power point tracking (MPPT) deep inside the PV module. By replacing each diode with a MPPT device, the on-off response to performance mismatch is eliminated; every cell-string contributes maximum power without interfering with the power production capability of others. This enhanced degree of flexibility leads to increased energy production; eliminating collateral performance loss due to module mismatch, degradation, soiling, localized shading, and row shading loss mechanisms.
PV cell string optimizer boosts solar panel output up to 30% – [Link]
Well,
I have done a little work in this area and almost any low cost power converter can do the same with a simple storage cap.
At low light levels any normal converter would normally be very inefficient. But the additions of a storage cap (electrolytic) allows the converter to run at a high power level for a short period of time. During this interval the converter runs at high efficiency. I simple peak detector can be used to turn the converter on with the cap voltage reach a MPPT point.
Check out the http://www.sunduino.com site there is support for solar panels with lots of useful documentation.
Bob K.