Managing Consultant
Charlie Duff

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Charlie Duff

Charlie Duff works in E3’s Planning and Markets group, where he helps clients identify high-renewable resource portfolios and make strategic decisions around asset valuation and power procurement. Recent projects include investigating alternative decarbonization strategies in PJM, supporting the California Public Utility Commission’s Integrated Resource Plan, and analyzing potential economic benefits of the Boulder Canyon Pumped Storage project, which would transform the Hoover Dam into one of the world’s largest energy storage resources.

Charlie’s graduate studies focused on energy optimization and power systems modeling. As an intern with the California Independent System Operator (CAISO), he analyzed how solar ramps might affect grid reliability and how variations in ramp rate design could affect the achievement of state RPS goals. At E3, he enjoys contributing to projects in the rapidly-changing energy industry and applying his skills in jurisdictions beyond California.

Charlie enjoys hiking and camping. A native of Wisconsin, he appreciates that the Bay Area’s climate allows him to get outdoors throughout the year.

Education: MS, civil and environmental engineering (atmosphere and energy), Stanford University; BS, mechanical engineering, University of Wisconsin

Projects

Hawaiʻi Pathways to Decarbonization | Hawaiʻi State Energy Office, 2023

E3 supported the Hawaiʻi State Energy Office in the development of a report to the State Legislature evaluating long-term pathways to economywide decarbonization in Hawaiʻi and recommending new policies to ensure the achievement of the state’s decarbonization goals. E3 supported the Hawaiʻi State Energy Office in this effort by developing long-term decarbonization scenarios using the PATHWAYS model to explore the tradeoffs between different pathways to achieving Hawaiʻi’s goals.

The report affirms and recommends maintaining the state’s economy-wide emissions reduction target of 50% by 2030, relative to 2005 levels. The analysis shows that while challenging to achieve, with high levels of energy efficiency and conservation, renewable energy, and natural carbon sinks, among other measures, this ambitious goal is within reach.

Read the detailed project description.

WRI United States Decarbonization Scenarios | World Resources Institute, 2021

E3 worked with the World Resources Institute (WRI) to develop four scenarios of increasing ambition to reduce greenhouse gas (GHG) emissions across all sectors of the United States economy using E3’s US PATHWAYS and RESOLVE models. E3 collaborated with WRI to develop robust scenario definitions, collect publicly available data and assumptions, and create interactive spreadsheet results. The goal of the study was to understand the effect of high-impact federal policies on achieving 50% emissions reduction by 2030 and net-zero emissions by 2050. The analysis demonstrates the importance of key near-term building blocks, including: 1) aligning economics for customers and companies to adopt clean energy technologies; 2) aligning policy and institutions to remove barriers to technology deployment; 3) increasing consumer awareness and education to unlock higher levels of adoption; and 4) creating a transition plan for fossil fuel jobs to ensure a smooth transition.

Read the detailed project description.

US Climate Alliance Greenhouse Gas Emissions Scenarios to Net Zero | US Climate Alliance, 2021

E3 provided modeling and scenario analysis to support the US Climate Alliance’s 2021 Annual Report. The report highlights the progress Alliance members have already made toward reducing greenhouse gas (GHG) emissions, and using E3’s modeling, details multiple scenarios of Alliance-wide GHG emissions through 2050. E3 evaluated Alliance-wide GHG emissions through 2050 using E3’s PATHWAYS and RESOLVE models. The GHG emissions scenarios E3 developed for the Alliance highlighted the gap between the GHG reductions that would be possible with proposed state and federal policies and the reductions necessary to meet established federal targets. E3 also modeled the emissions impacts of the collective actions that would help bridge that gap.

Read the detailed project description.

Integrated Resource Plan Support | Xcel Energy Upper Midwest, 2019

As part of its 2019 Integrated Resource Plan, Xcel Energy retained E3 to conduct two independent analyses to support its IRP: (1) an economy-wide study for the state of Minnesota examining what would be needed to meet deep decarbonization goals throughout the economy (e.g. 80% reductions by 2050); and (2) a portfolio optimization and reliability analysis for Xcel’s portfolio to examine the costs of meeting the utility’s carbon reduction goals (80% reductions by 2030; 100% carbon-free by 2050).

E3’s statewide pathways study provided Xcel with a novel perspective on future electricity loads in the context of an economy-wide carbon reduction effort, showing how decarbonization measures such as building and transportation electrification could lead to significant long-term increases in load. These findings were used to inform a sensitivity analysis conducted within Xcel’s internal IRP modeling.

E3’s portfolio and reliability analyses were conducted in parallel with Xcel’s internal work to develop a forward-looking resource plan, testing the notion that an independent expert using advanced industry-standard methods would come to similar conclusions. E3 used RECAP for sophisticated loss-of-load-probability analysis and RESOLVE for optimal capacity expansion to design reliable, least-cost portfolios to meet carbon reduction goals, ultimately corroborating the findings in Xcel’s plan.

Publications

Integrated Resource Plan | California Public Utilities Commission, 2021

E3 has provided comprehensive technical and advisory support to the Energy Division of the California Public Utilities Commission (CPUC) in its administration of the state’s IRP program, mandated by the passage of SB 350 in 2016.  E3 worked with CPUC staff to develop the structure of the IRP program including a three-year modeling cycle in which Staff prepares a system-wide plan that informs the California Independent System Operator (CAISO)’s annual Transmission Planning Process (TPP) and informs Load-Serving Entities integrated resource plans in alternate years.

E3 has helped the CPUC design an optimal “Preferred System Plan” for the combined utilities that incorporates the resource procurement plans of the LSEs and complies with the state’s clean energy policy requirements. In the 2020-2021 cycle, the policy requirements considered include a 60% RPS by 2030 and SB 100 by 2045, and a statewide greenhouse gas emissions target of 38 million metric tons (MMT) by 2030, while capturing the operational and reliability challenges encountered at high penetrations of variable renewable generation. E3 also supported the Energy Division’s development of a mid-term reliability order requiring the procurement of 11.5 GW of effective capacity by 2026. As part of this process, E3 evaluated dozens of scenarios reflecting alternative assumptions about load forecasts and electrification, resource costs, the availability of offshore wind and out-of-state wind, the ability of end-use loads to operate flexibly, and a variety of other input parameters.


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