Two New National Lab Reports Introduce Innovative Concept to Support Near-term Distributed Solar Photovoltaic Deployment on Feeders with Limited Hosting Capacity
Researchers from the Lawrence Berkeley National Laboratory (LBNL) and the National Renewable Energy Laboratory (NREL), with staff from the Rhode Island Office of Energy Resources, National Grid, and Rocky Mountain Institute, have authored two NREL technical reports on work culminating from a project of the Solar Energy Innovation Network (SEIN). SEIN supports teams composed of diverse stakeholders that are developing transformative approaches to adopting solar energy.
The project, “Use of Operating Agreements and Energy Storage to Reduce Photovoltaic Interconnection Costs,” comprises two reports that explore one integrated concept designed to manage interconnection costs and streamline interconnection timelines to support near-term distributed solar energy deployment. Together, the reports describe a new agreement, designed to supplement an interconnection agreement, between renewable energy developers and utilities. The agreement defines the operational parameters for a distributed solar system with the primary goal of reducing distribution reliability risks and secondarily, increasing cost recovery and certainty to developers. This enables increased levels of distributed solar interconnection to support state clean energy targets without sacrificing grid reliability that could be adapted for other states.
The first of the two reports, titled the “Technical and Economic Analysis” report, presents an analytical methodology to identify alternative options to manage interconnection costs and streamline interconnection timelines for distribution system-connected PV systems not co-located with load. It details a technical analysis framework to identify time-based operational parameters for a DER system (an “Operating Envelope”), to mitigate potential violations on a utility distribution feeder. It then explores how an Operating Envelope may impact the economics of a solar project for a developer, comparing traditional distribution system upgrade costs and multiple technically viable options for abiding by the technical parameters of the Operating Envelope Agreement (OEA), including curtailment and the addition of a battery electric system. The analysis suggests that an OEA that specifies technical parameters by which a developer can avoid downsizing a proposed PV system and avoid paying expensive infrastructure upgrade costs can be an economically attractive option under select conditions.
The “Conceptual Framework” report describes the OEA between renewable energy developers and utilities, informed by the technical and economic analysis. The OEA defines the operational parameters for a renewable energy system, with the goal of reducing risk and cost to all parties. This work provides a foundation upon which other states and utilities may build proof of concept.
A webinar to discuss the reports’ findings and conclusions was recorded and is available here.
We appreciate the funding support of the U.S. Department of Energy Solar Energy Technologies Office in making this work possible.