SBIR Phase I: Low Cost, Low Weight, and Low Profile Microinverter for Photovoltaic Solar

Partoe Inc., Menlo Park CA

Investigators

Abstract

This Small Business Innovation Research (SBIR) Phase 1 project is concerned with photovoltaic (PV) solar technology. Microinverters are presently sold as separate boxes that are bolted either onto the racking or the panel frame and still require DC cables, connectors and the junction box. Partoe?s Tiger 1 microinverter is a low cost, low weight, low profile, microinverter for direct integration onto the panel?s backsheet, thereby eliminating DC cables, connectors and the junction box and enabling a significantly simpler installation/commissioning of PV systems at lower cost. Tiger 1 deploys a proprietary thermal management technology to keep any heat generated by the electronics away from the backsheet, as any excess heat (over ambient) reaching the solar cells results in a reduction in PV efficiency. The Company has validated its product concept with a number of customers both within the US and in Asia. Hardware prototypes are completed. Objectives of this research include: Complete algorithm/software development and characterize the current pushed to the utility grid, thermal characterization of the panel backsheet, under different microinverter operating conditions, and optimization of Partoe?s mesh-network-radio-based reporting/diagnostic software. If successful, the results of the research will place the Company in a position to address certification and preproduction issues. The boarder impact/commercial potential of this project is a reduction of the cost of solar PV electricity, at a time when our dependence on fossil fuel has proven to be quite problematic. Partoe is targeting an $8.5B (2014 estimate) solar inverter market. Entirely eliminating DC cables, connectors, junction box, and enabling a solar panel that produces AC power (PVAC) from the onset, sets our differentiation from our competitors. Another differentiation is our mesh-network radio technology. Our competitors use Power Line Communication (PLC) for monitoring. PLC generally dissipates more power than a mesh-network-enabled-radio technology (100s of mW vs. 10s of mW). Everything else being equal, this results in a higher DC/AC conversion efficiency for Tiger 1. The long term impacts of low-cost solar electricity not only address oil-related geopolitical issues, but also are environmental and societal. On longer term, Tiger 1 can be interfaced with smart meters (which are radio-enabled in the US) and send/receive instructions, for example, for delivering reactive power to the grid for voltage regulation, micro-grid operations, etc. Objectives of this proposal are stepping stones toward these longer term directions for Partoe.