A Future So Bright It's Electric

Greg Nielson is the lead solar technology researcher at Sandia National Labs. His group recently announced successfully using micro-scale manufacturing to create "glitter" -- solar cells that can measure as little as one-quarter of a millimeter in diameter. The potential of glitter and other breakthroughs like it could revolutionize the solar energy market. Here's a taste of why:

WVW: I recently tested a $50 solar battery charger. It took all day in bright sunlight to charge one pair of AA batteries. That seems absurd. Given that just the charger costs $50, I found myself asking, “What are we doing here? No one is going to pay for this.” Can your technology help improve our daily electronics experience?

Nielson: A couple of things. You can buy a backpack with PV built into it to charge a cell phone or whatever. The cost of those compared to the power output is pretty high. Just for reference, I’ve examined some of those in the past, and you’re looking at about $40 per watt at peak production, under the brightest sunlight. On the other hand, with the solar systems that people put on their houses, the cost is much lower.

For portable electronics, we’re excited about that. The flexible PV [photovoltaics] that people are using on bags are about 4% to 5% efficient, so really poor. Building stuff on a flexible substrate is really hard to do in a way that’s robust, but we think we have a way to do flexible PV at much higher efficiencies. Right now, we could do flexible PV with our cells at even 15% efficiency, and silicon has been demonstrated to be over 25% efficient. If we could get into that range, we could increase the power output of those electronics—charging bags and things—by a factor of five. That’s pretty significant.

Now, on the rooftop solar power side, we also think we can have a big impact. One particular reason is the fact that we’re using much less silicon to produce the same amount of power. Silicon is, for the cells and the modules, definitely the biggest cost driver. So if we can reduce that significantly, then the biggest cost component goes down. In our case, it essentially goes away because we’re reducing the silicon by a factor of like 100.