NREL and LBNL reports on PV system pricing

On December 4th, 2012 the US Department of Energy's (DOE) National Renewable Energy Laboratories (NREL, Golden, Colorado, US) and DOE's Lawrence Berkeley National Laboratory (LBNL, Berkeley, California, US) jointly released two reports looking at solar photovoltaic (PV) pricing in the United States. 

The first report looks at historical progress for PV price reductions, as well as providing future projections, finding that system prices are likely to continue to fall through 2012 and into 2013. 

The second report looks at the components of "soft" costs for PV systems.

"There is often confusion when interpreting estimates of PV system prices," said NREL Solar Technology Financial Analyst David Feldman. 

"This report helps to clarify this confusion by bringing together data from a number of different sources and clearly distinguishing among past, current and near-term projected estimates."

PV prices tracked against SunShot goal:

"Photovoltaic (PV) pricing trends: historical, recent and near-term projections" looks at progress in price reduction in relation to the goals of the DOE's SunShot program to reduce the installed cost of PV systems by roughly 75% between 2010 and 2020. This report indicates that while data sources, assumptions and methods differ between the bottom-up analysis and the reported price analysis, the results support the validity of both analyses. The report draws on multiple ongoing NREL research activities.

Presentation of DOE analysis on soft cost:

The second report, "Benchmarking non-hardware balance of system (soft) costs for US photovoltaic systems using a data-driven analysis from PV installer survey results", presents results from the first DOE-sponsored data collection and analysis of such costs. 

The report finds that these costs made up 40-50% of residential and commercial US PV prices in 2010. The study benchmarks four particular categories of soft costs, looking at customer acquisition, permitting, inspection and interconnection, installation labor, and labor associated with arranging third-party financing.

NREL and LBNL found that these costs alone comprised 23% of residential PV system prices, 17% of small commercial system prices and 5% of large commercial system prices. 

 

Bubble tracking in PV systems

Concentrating solar photovoltaic (PV) systems cut system costs by reducing the area of PV cells for a specified electrical output, but the precise mechanical tracking systems needed to keep a concentrator aimed at the sun can raise the system cost, to little advantage. As a result, researchers are looking at nonmechanical ways to finely track the sun (coarse tracking could still be left to a lower-cost mechanical tracker).

A group at the École Polytechnique Fédérale de Lausanne (Lausanne, Switzerland) has developed an optofluidic waveguide coupling mechanism in which focused light heats liquid in a waveguide to form a bubble of vapor that scatters the incoming sunlight into the waveguide, which carries the light to a concentrating PV cell. The experimental efficiency of a system coupling laser light through an off-the-shelf axicon lens pair into a methanol-containing waveguide was greater than 40%. Two lasers were used: one emitting at 460 nm to represent the visible part of the solar spectrum, and an infrared (IR) laser diode to simulate the IR spectral portion. When focused on the IR-absorbing glass that helps form the waveguide, the light produces a bubble that varies between 160 and 300 μm in diameter for IR power between 40 and 100 mW. The bubble-tracking technique could reach at least 90% efficiency with better optics, say the researchers.

Advanced single-junction, tandem-junction and triple-junction PV cells

Altatech, a subsidiary of Soitec, announced today that it has introduced a multi-chamber chemical vapor deposition (CVD) system that enables photovoltaic (PV) cell manufacturers to develop and optimize their solar cell designs using advanced thin-film deposition of amorphous silicon and other materials. By performing all deposition processes within a single system, the new AltaCVD Solarlab™ tool reduces cycle times and materials consumption in fabricating advanced single-junction, tandem-junction and triple-junction PV cells.

Using the AltaCVD Solarlab, customers can deposit transparent conducting oxide (TCO) films that deliver the superior optical characteristics, high doping mobility and smooth, defect-free surfaces needed to optimize efficiency of their solar cells. 

"Extending our core CVD technology for use in solar cell development presents an additional market opportunity for us," said Jean-Luc Delcarri, general manager of Soitec's Altatech subsidiary. "Reducing the amount of material used in cells and improving photovoltaic conversion performance will be the keys to growth in the next few years. We look forward to continuing to apply our deposition expertise in both Research and Development and commercial applications for the renewable-energy industry."

In creating its newest CVD system, Soitec's Altatech subsidiary leveraged its patented chamber architecture and deposition technology, which enables the use of new precursor gases to achieve extremely high film uniformity and tightly controlled stoichiometry. These capabilities have been production-proven on the company's AltaCVD platform, which has been used in both engineering and volume manufacturing of advanced semiconductor devices since 2008.

The AltaCVD Solarlab system has the versatility to perform standard thermal CVD processing as well as plasma-enhanced CVD and atomic-layer deposition. These processes can be run over a wide spectrum of temperatures, from 100° C to 800° C, to create photosensitive films that can maximize the efficiency of PV cells in converting sunlight to electricity. In addition, the system can handle a variety of substrates, including transparent glass and both round or square silicon wafers with thicknesses ranging from 150 microns to several centimeters.

Soitec plans to begin shipping AltaCVD Solarlab systems to customers by the end of this year.

Read more here: http://www.sacbee.com/2012/10/01/4870913/altatech-launches-new-cvd-system.html#storylink=cpy