Electric utilities in the U.S. are being inundated with applications from customers requesting to connect their rooftop solar systems to the grid. This flood in solar interconnection requests has created a new challenge for utilities because each application received requires a technical evaluation to assess the potential grid impacts of the new solar installation. Utilities are evaluating interconnection applications manually, a burden that can be lifted with a new tool that performs fast and automated interconnection assessments and seamlessly integrates with the existing business interconnection workflow.

The time-consuming nature of photovoltaic interconnection evaluation is addressed with PRECISE —PREconfiguring and Controlling Inverter SEt-points. The system developed by grid researchers at the U.S. National Renewable Energy Laboratory (NREL) and the Sacramento Municipal Utility District (SMUD) reduces evaluation time by instantly determining optimal inverter settings for a given location.

PRECISE performs fast and automated interconnection assessments. Source: NREL

PRECISE automates the modeling of all of SMUD's low-voltage distribution systems connected to houses and rooftop solar and targets advanced metering infrastructure data as required. The tool also uses local irradiance measurements across SMUD's service area and creates mathematical models of each incoming photovoltaic system. PRECISE automates an assessment of what size system the grid can accommodate and how advanced inverter functions can support approval.

For every residential solar PV interconnection application, PRECISE assesses the impact of the interconnection proposal and evaluates the need to use smart inverter functions.