A new report coauthored by Berkeley Lab summarizes different approaches states are taking for grid planning. State Engagement in Electric Distribution System Planning documents activities in 16 states. The report covers planning and investment strategies, analyzing non-wires alternatives to traditional distribution system solutions, identifying the capacity of distribution systems to integrate distributed energy resources (DERs) such as rooftop solar, energy storage, and demand response, and assessing th e benefits of these resources by location.
Distribution system planning is focused on assessing needed physical and operational changes to the local grid to maintain safe, reliable, and affordable service. While electric utilities have always engaged in this activity, the planning horizon has typically been short and involvement by state utility regulators minimal.
Reliability and affordability are top objectives for deeper state engagement in longer-term distribution system planning. Other drivers are proposed utility investments to replace aging infrastructure and modernize grids, opportunities to improve distribution system efficiency, enabling consumers to have greater control over energy costs and sources, and integrating higher levels of DERs.
The report provides a snapshot of current state engagement in distribution system planning:
- Part 1 describes activities in states that have adopted some advanced elements of integrated distribution system planning and analysis (see figure): California, Hawaii, Massachusetts, Minnesota, and New York. It summarizes the impetus for early action, goals, regulatory requirements, additional state activities related to distribution system planning, and next steps.
- Part 2 covers a broader array of state approaches. For example, some states have longstanding distribution reliability and performance codes, requiring regulated utilities to report regularly on poor-performing circuits and propose investments for improvements. Other states require regulated utilities to make filings related to proposed grid modernization investments.
Integrated planning and analysis: transmission, distribution, and customer/third-party domains
A growing number of states are beginning to consider comprehensive distribution system planning processes. The report documents activities in eight states with statutory or public utility commission requirements for distribution system plans or grid modernization plans, plus four jurisdictions with proceedings on such requirements underway or planned (see table).
The report also covers activities in several additional states to provide a more accurate picture of the significant variation in approaches, in part stemming from differences in electricity market structure — states with restructured markets versus states where all utilities remain vertically integrated.
Common emerging distribution system planning elements include DER forecasting, assessing DER locational value, analyzing hosting capacity, assessing non-wires alternatives, and engaging stakeholders (including third-party service providers) to comment on proposed planning processes and filed utility plans and help identify least-cost solutions to distribution system needs.
Some states also are exploring new procurement mechanisms, such as competitive solicitations, to consider DERs as non-wires alternatives for load relief and other distribution system needs.
State Activities on Electric Distribution System Planning
Among the specific reasons PUCs are adopting these new planning and procurement practices are to facilitate higher penetration levels of DERs, harness these resources to provide grid services for customers, enable greater consumer engagement, and improve review of utility investments in distribution systems, particularly with respect to grid modernization.
States can learn from each other and tailor successful approaches to their unique circumstances. Reviewing the broad range of legislative and public utility commission activities described in this report is a useful starting point.
Report authors are Juliet Homer and Alan Cooke, Pacific Northwest National Laboratory;
Lisa Schwartz and Greg Leventis, Berkeley Lab; and Francisco Flores-Espino and Michael Coddington, National Renewable Energy Laboratory. The U.S. Department of Energy’s Grid Modernization Initiative funded the report through the Office of Electricity Delivery and Energy Reliability and Office of Energy Efficiency and Renewable Energy – Solar Energy Technologies Office.