As California’s electric companies begin developing strategies to meet the state’s 50% by 2030 Renewable Portfolio Standard (RPS), microgrids could play an expanded role in integrating higher levels of distributed solar photovoltaics (PV), energy storage and other distributed energy resources (DER) to reduce emissions and achieve other policy goals. Utilities, regulators and grid operators will need to evaluate whether microgrids represent a viable option for reducing emissions in addition or as an alternate to building utility-scale renewable energy projects that often require transmission upgrades to deliver power to load centers. Meeting local demand with local generation capacity could result in greater emissions reductions by reducing cycling and ramping at larger power plants, and may provide an easier entry into renewables than investing in large-scale renewable energy projects. Innovative technologies and operational strategies will need to be implemented to ensure that increasing levels of distributed PV and storage capacity are fully utilized to provide maximum benefits to ratepayers, project developers, utilities and society at large.
This report examines the environmental impacts and cost-effectiveness of microgrid deployment across California as a strategy for achieving the 50% by 2030 RPS using bulk power system modeling techniques. Microgrid deployment scenarios are compared against a baseline scenario that relies on utility-scale renewable energy deployment to evaluate the emissions reductions and total system costs associated with each RPS compliance strategy. EPRI’s Electric Generation Expansion Analysis System (EGEAS version 12.0) software was used to model greenhouse gas (GHG) emissions reductions under the two RPS compliance strategies. EGEAS is used by the Midcontinent Independent System Operator (MISO), and many states and utilities within the MISO market, for bulk power system capacity planning. These users could benefit from novel uses of the software to integrate distribution-level capacity into integrated resource planning (IRP).
This report seeks to provide a better understanding of those issues and identify future research projects where EGEAS could contribute to integrating microgrids and other distributed resources into long-term planning applications. Results from this study will contribute to better understanding of the EGEAS model’s capabilities for incorporating microgrids and other DER technologies into long-term capacity planning, and will inform microgrid technology assessment for achieving environmental policy goals.