DOE grants aim to drive down inverter costs, advance PV fire prevention tech

Nine projects won grants totaling $14 million from a Department of Energy program aimed at boosting the U.S. solar manufacturing industry.

Several of the projects aim for lower costs for PV module materials or PV racking, or lower defect rates on module assembly lines. Another aims to prevent installed systems from catching on fire. Other projects are developing inverters for utility-scale PV that would eliminate the need for a transformer.

DOE also granted $25 million for a public-private consortium to advance grid-forming inverters, which allow solar and other inverter-based technologies to restart the grid without a spinning turbine at a fossil-fired generating unit. Grid-forming inverters will enable a high-renewables grid with little or no fossil generation.

Further grants of $6 million aim to provide better data to utilities about rooftop solar generation.

Here are descriptions of the nine solar manufacturing projects supported by DOE grants:

Lower-cost inverters

• Develop and commercialize a 1 MW inverter for utility-scale PV that eliminates the need for a transformer, accepting 1,000 volts of DC current and generating power directly to a 13kV AC medium-voltage grid (Imagen Energy, Milwaukee, Wisconsin).
• Improve and test a solar-plus-storage inverter for utility-scale PV that can send DC solar power to an energy storage device, or convert it to medium-voltage AC power, eliminating the need for a transformer (Toshiba and UT Austin, Houston).
• Design, build, test and validate a 400 kWh inverter system for the commercial and industrial PV market, that has four hours of energy storage and a grid-forming inverter that can island operation behind the meter (GE Research and partners, Niskayuna, New Yord).

Fire prevention

• Produce a PV electrical connector that predicts and prevents arc faults in a PV system, which can cause electrical fires, and disconnects the system in less than two seconds (Management Sciences and partners, Albuquerque, New Mexico).

Manufacturing cost reductions

•  De-risk a screen-printable copper-based metallization paste, for electrical connections within and among solar cells at lower cost than silver paste, and show its manufacturability (Bert Thin Films, Louisville, Kentucky).
• In a PV module assembly line, integrate a non-contact inspection tool developed by Tau Science to identify electrical and mechanical defects prior to cell-to-cell interconnection, thus increasing the yield of shipment-ready modules (Silfab Solar, Bellingham, Washington).
• Develop a new racking system for floating PV systems, and advance the manufacturing process to increase throughput (Accusolar and Nhu Energy, Tallahassee, Florida).
• Develop high-speed manufacturing of low-cost electrically conductive aluminum backsheets for silicon PV modules, to replace copper backsheets on which electrical connections are printed (Silfab Solar and SunFlex Solar, Bellingham, Washington).

Solar process heat

• Test and demonstrate the use of solar process heat instead of natural gas to dry municipal sewage sludge and produce fertilizer (Solar Dynamics, Broomfield, Colorado).

The Department of Energy further describes all of the funded projects here.