Another sign that renewable energy has hit a tipping point: Maxim Integrated Products, a maker of chip components, is piloting a cell-string optimizer that can give solar cell panels an additional 15% to 30% of power. It is one more tool in the toolbox that can make solar energy more affordable, and that could make a big difference for people around the world who now depend largely on fossil fuels to power their lives. Cell-string optimizers — a catch-all term for retrofitting solar panels — tend to involve ripping out the old string of chip circuits that are being used to make every solar cell.
They replace them with the kind of “top-off” circuit pins that are used in digital signals. (That’s the kind of circuit that lets a cell phone to switch from talking to texting.) Of course, this raises not only technical but environmental concerns. Here’s why: In the short run, the benefits of changing from solar cells to cell-string optimizers are likely to be as much on the environmental front as they are on the tech front. For example, there are solar panels with more than a gigawatt of capacity installed. And most of them are built in huge modules called solar concentrators. Here’s a sort of schematic showing a concentrator: The chip in that solar cell is a semiconductor — the transistor.
It typically does the task of driving the cell. This semiconductor is made up of 32 small blocks, and that blocks are connected by a wire that we have used for a long time to regulate electrical output. But the problem here is that the wires tend to wear out. The silicon inside each chip cell is indeed a renewable resource, but like all renewable resources it isn’t really abundant. And solar cells just don’t have the physical mass for a lot of use, and so it is the artificial-electrical inputs, which constitute the vast majority of power generated by solar panels, that account for most of the U.S.’s 26 gigawatts of solar capacity. The Maxim Optimizer then comes in and tweaks the chips to run at higher efficiency, with less wear and tear on the wire. The idea is to give solar cells a boost that makes up for what they have lost by not being able to absorb more light.
So while Maxim is just piloting this little tool for its solar-cell customers now, over time it could be sold for other commercial purposes, such as in rooftop or commercial solar-cell installation. Another key point about the Maxim Optimizer is that it requires no major investment in capital equipment, just a few minutes per system per year. This will be a big plus for lower-income homeowners and small-scale investors who want to put solar systems up for cash. Indeed, most solar developers would probably be very interested in using this new tool. Instead of getting a fancy solar farm at the price they might have paid for one of the very large utility-scale farms that have recently come online, they could put up a single solar array on a larger property.
That would offer energy savings at a more modest price, and it would be a possibility for even small communities, if the panels aren’t too expensive. Of course, the energy savings alone won’t be sufficient to make solar power cheap enough for the masses. But it will be a big help — a big clue about where solar is going.