Grid Integration

Planning and Modeling for High-Penetration PV

Distributed PV systems are outside the scope of most utility planners and engineers, due to their small size and historically low market-penetration and utility personnel may not be familiar with the operational characteristics of these systems. In addition, due to the rapid growth in distributed PV systems, utility grid operation models and planning tools lack the ability to account for distributed PV generation technologies and resources. Problems also exist with the current methods for estimating solar resources and predicting PV system output. Existing solar resource models are based on lower resolution insolation data sets and usually provide only hourly resource values. Only with the emergence of higher concentrations of PV onto distribution feeders has there been a recognition that rapid changes in atmospheric conditions over relatively small areas can have significant impacts on the aggregated PV system output and on the associated electricity distribution system.

Existing methods for predicting and planning for high penetration PV limit the ability of utilities to strategically locate this technology within their T&D systems. New solar resource and utility planning models provide utilities with the means to identify optimal locations for high penetration levels of PV. As PV and other DG resources form a larger portion of the electricity generation mix, it will be increasingly important to have electric system planning, design, and operation modeling tools that provide utilities and others in the solar industry, with the ability to accurately assess and forecast energy output and account for distributed PV systems.

Testing and Development of Hardware and Software for High-Penetration PV

Successful grid integration of high-penetration PV requires robust grid, PV communications, control systems, and operational procedures. PV systems will need to be capable of dynamically interacting with varying frequency and voltage conditions on the grid including load and VAR (reactive power) control to improve reliability. New software and hardware tools will emerge in response to these needs. Field testing, and demonstrations are needed before these new tools can realize widespread market adoption.

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