Shrink Nanotechnologies is one of several companies that is using bioplastics to find a new way of making devices that will minimize the use of increasingly-scarce rare metals.
The company’s OptiSol Solar Concentrator is billed as a nanotechnology-based plastic solar concentrator and solar film. Traditional silicon solar cells absorb only a small fraction of the total incident solar radiation potential, with a majority of the light either reflected or converted to thermal energy.
Based on electromagnetic non-optical principles and using a proprietary technology, the OptiSol enhances the capabilities and efficiency of existing solar cell designs by focusing and tuning the incident solar radiation from the sun for optimal silicon absorption, with less of the total spectrum lost as heat or reflection. The goal is to deliver immediate and significant improvements in efficiency and power output.
The product can also be made into clear view solar cells that can be used on windows and for exterior panel siding.
CleanTechies caught up with Shrink Nanotechnologies CEO Mark Baum for three questions.
CleanTechies: Do you have any working installations? Where and when were they deployed?
Mark Baum: We are currently building a final prototype functional OptiSol solar window with our working groups at UC Irvine and UC Merced. To our knowledge, this device — including the first two iterations — are the first functional quantum dot solar concentrators that do not rely on mirrors, lenses or tracking systems. They absorb ambient light at one wavelength and convert it into another (800-900 nm). We use very small amounts of silicon to absorb at the 8-900 nm wavelength, and the efficiency of the silicon is improved as a result of the window design system that the silicon cell is a part of. Our current designs absorb approximately 16% of the light shining onto it and are at an overall efficiency of 5.7%.
To our knowledge, the most efficient concentrator device ever made is at 7%. Relative to the present efficiency numbers we have achieved, the additional differences are in cost. The fact that our window designs are upgradable, allowing the consumer to benefit from better technologies over time, and environmental friendliness as we do not use harmful toxic elements to create these results.
CleanTechies: What’s the manufacturing cost compared to silicon? Are there any other price variables or durability issues with this?
Mark Baum: We use a fraction of the silicon required in a traditional solar cell. In fact, we use a very narrow 3 mm wide solar cell around the edge of the window, so the silicon we require in order to achieved a nearly 6% efficiency at the extremely low cost we are able to achieve is minimal. Our product designs are made to be “upgradable.” In this sense, we are firm believers that technology is only going to bring better efficiency and cost results and opportunities, respectively, to the consumer. We do not believe that there is any wisdom in buying a system that will become a legacy product as fast as we believe some of the current flat panel crystalline silicon solar cell system will. Therefore, we advice all purchasers of an OptiSol window to upgrade their systems at a very minimal cost over time in order to take advantage of this technology as it evolves.
CleanTechies: Why is the plastic corn-based?
Mark Baum: The films themselves can be made from PLA or other plastics. We do not have to use PLA. However, these forms of corn-based plastics are desirable to certain consumers for certain applications. In terms of performance, we have not determined a difference between using one plastic versus another. Additional testing will be required.
[photo credit: Shrink Nanotechnologies]