Distribution Grid Electrification Model

What is the Distribution Grid Electrification Model (DGEM)?

The Public Advocates Office developed the Distribution Grid Electrification Model (DGEM) to estimate the cost of upgrading California’s electric distribution grids to support the state’s electrification goals and understand how those investments could affect electric rates.

As Californians increasingly use electric vehicles and electric appliances, electricity demand will grow and utilities will need to plan for upgrades to local distribution grids. DGEM examines how factors such as building electrification and electric vehicle (EV) charging behavior can affect future infrastructure needs, costs, and electric rates. The model is designed to illustrate a range of possible outcomes rather than provide a definitive forecast of future costs.

The Public Advocates Office first published DGEM in 2023, followed by supplemental analyses examining how the timing and location of EV charging could affect grid costs. We continued to refine and expand the model, releasing preliminary results from an updated version in 2024 and the completed DGEM 2025 study in October 2025. This page brings those studies and supporting materials together in one place.

DGEM 2025

DGEM 2025 is the Public Advocates Office’s latest completed DGEM study. Published in October 2025, it expands on DGEM 2023 with updated data and assumptions and nine scenarios that vary by the degree of building electrification and EV charging behavior.

DGEM 2025 Resources

• Study and Report (October 2025) – Full technical study, including methodology, assumptions, results, limitations, and findings.
• Q&A (October 2025) – Plain-language overview of the study and its main takeaways.
• Presentation (October 2025) – Slides summarizing the model, scenarios, results, and key findings.

How DGEM 2025 Builds on DGEM 2023

DGEM 2023 focused primarily on distribution grid upgrades needed to support transportation electrification through 2035. DGEM 2025 extends the analysis through 2040, incorporates building electrification, evaluates different EV charging behaviors, and uses updated data and assumptions.

The updated analysis also changes the estimated cost through 2035. DGEM 2023 projected approximately $26 billion in grid upgrade costs by 2035, while DGEM 2025 estimates approximately $14 billion by that year under the same assumptions, largely because of updated infrastructure cost data.

DGEM 2023

Published in August 2023, DGEM 2023 was the Public Advocates Office’s first completed DGEM study. It primarily examined the distribution grid upgrades needed to accommodate transportation electrification and other projected load growth through 2035.

DGEM 2023 Resources

• Study and Report (August 2023) – Full DGEM 2023 technical study and findings.
• Fact Sheet (August 2023) – Summary of the study and key findings.
• Presentation (August 2023) – Slides summarizing the DGEM 2023 analysis and results.

Supplemental Analyses to DGEM 2023

Following publication of DGEM 2023, the Public Advocates Office conducted additional analyses examining how both when EVs charge and where charging occurs can affect distribution grid infrastructure needs and costs.

• Supplemental Study – EV Charging Location and Potential Cost Impacts (July 2024) – Examines how the location of EV charging can affect infrastructure needs and potential costs.
• Supplemental Analysis – EV Charging Patterns (March 2024) – Examines how EV charging patterns can affect peak demand and distribution grid upgrade costs.

Preliminary and Earlier Materials

These materials document earlier stages of DGEM’s development and are provided for reference. For completed findings, see DGEM 2025 and DGEM 2023 above.

• DGEM 2.0 – Preliminary Results (October 2024) – Preliminary work leading to the completed DGEM 2025 study. The updated model was referred to as “DGEM 2.0” during development.
• Distribution Grid Electrification Model – Preliminary Results (June 2, 2023) – Preliminary analysis released before completion of DGEM 2023.
• Preliminary Fact Sheet (June 14, 2023) – Preliminary summary released while DGEM 2023 was being finalized.

Related Commentary

• Understanding Electrification and Downward Pressure on Rates (January 31, 2025)
• What Does California’s Power Grid Need to Handle the Coming Wave of Electric Vehicles? (August 29, 2023)