Distributed Energy Resources

Glint Photonics is developing an inexpensive solar concentrating PV (CPV) module that tracks the sun’s position over the course of the day to channel sunlight into PV materials more efficiently. Conventional solar concentrator technology requires complex moving parts to track the sun’s movements. In contrast, Glint’s inexpensive design can be mounted in a stationary configuration and adjusts its properties automatically in response to the solar position.

Yale University is developing a system to generate electricity using low-temperature waste heat from power plants, industrial facilities, and geothermal wells. Low-temperature waste heat is a vast, mostly untapped potential energy source. Yale’s closed loop system begins with waste heat as an input. This waste heat will separate an input salt water stream into two output streams, one with high salt concentration and one with low salt concentration. In the next stage, the high and low concentration salt streams will be recombined.

The University of California, Santa Cruz (UC Santa Cruz) is developing an optical device that enables the use of concentrated solar energy at locations remote to the point of collection. Conventional solar concentration systems typically use line of sight optical components to concentrate solar energy onto a surface for direct conversion of light into electricity or heat. UC Santa Cruz’s innovative approach leverages unique thin-film materials, processes, and structures to build a device that will efficiently guide sunlight into an optical fiber for use away from the point of collection.

Applied Materials is working with ARPA-E and the Office of Energy Efficiency and Renewable Energy (EERE) to build a reactor that produces the silicon wafers used in solar panels at a dramatically lower cost than existing technologies. Current wafer production processes are time consuming and expensive, requiring the use of high temperatures to produce ingots from molten silicon that can be sliced into wafers for use in solar cells. This slicing process results in significant silicon waste—or “kerf loss”—much like how sawdust is created when sawing wood.

1366 Technologies is developing a process to reduce the cost of solar electricity by up to 50% by 2020—from $0.15 per kilowatt hour to less than $0.07. 1366's process avoids the costly step of slicing a large block of silicon crystal into wafers, which turns half the silicon to dust. Instead, the company is producing thin wafers directly from molten silicon at industry-standard sizes, and with efficiencies that compare favorably with today's state-of-the-art technologies.

The University of Rochester along with partners Arzon Solar and RPC Photonics will develop a micro-CPV system based on Planar Light Guide (PLG) solar concentrators. The PLG uses a top lenslet layer to focus and concentrate sunlight towards injection facets. These facets guide and redirect light, like a mirror, towards a PV cell at the edge of the device. Combined, these methods lead to higher efficiency over conventional FPV systems. At fewer than 3 mm thick, the system will be thin and flat, similar to traditional FPV panels.

Texas Engineering Experiment Station (TEES) and their partners will build a micro-CPV system that incorporates waveguide technology. A waveguide concentrates and directs light to a specific point. TEES's system uses a grid of waveguides to concentrate sunlight onto a set of coupling elements which employ a 45 degree turning mirror to further concentrate the light and increase the efficiency of the system. Each coupling element is oriented to direct its specific beam of light towards high-efficiency, multi-junction solar cells.

University of Arizona will develop a micro-CPV system that combines a CPV cell with dual-sided FPV panels to capture direct, diffuse, and reflected sunlight. The team's system will feature lenses that focus sunlight onto a horizontal waveguide, which further concentrates the light onto high-performance micro-CPV solar cells. Dual-sided solar panels, attached beneath the CPV cells, enable diffuse light collection on one side and reflected light collection on the other side. The system will be mounted on a two-axis tracker that will allow for optimal collection of sunlight throughout the day.

Palo Alto Research Center (PARC), along with Sandia National Laboratory (SNL) will develop a prototype printer with the potential to enable economical, high-volume manufacturing of micro-PV cell arrays. This project will focus on creating a printing technology that can affordably manufacture micro-CPV system components. The envisioned printer would drastically lower assembly costs and increase manufacturing efficiency of micro-CPV systems.

Panasonic Boston Laboratory will develop a micro-CPV system that features a micro-tracking subsystem. This micro-tracking subsystem will eliminate the need for bulky trackers, allowing fixed mounting of the panel. The micro-tracking allows individual lenses containing PV cells to move within the panel. As the sun moves throughout the day, the lenses align themselves to the best position to receive sunlight, realizing the efficiency advantages of CPV without the cumbersome tilting of the entire panel.