Distributed energy resources

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New technologies and lower costs mean growing opportunities for distributed energy resources (DERs), such as energy efficiency, distributed generation, demand response, and energy storage. E3 helps utilities, regulators, technology developers, and large energy users find beneficial applications for these technologies. We are also examining the impact of transportation electrification on the grid and assessing the potential for electric vehicles to provide grid services.

E3 has been at the forefront of DER assessment since our founding in 1989. We developed the methods and models that utilities and state regulators throughout North America use to evaluate the cost effectiveness of utility investments in DERs. E3 has also developed tools that help utilities quantify DER location benefits and optimize siting. As our international client base grows, our consultants are disseminating these tools and best practices in India, Africa, and China.

Our distributed energy resources evaluation services include:

  • Avoided cost assessment
  • Cost-effectiveness evaluation
  • Best practice assessment
  • Program design and evaluation
  • DER potential estimation
  • Retail rate design to maximize DER cost effectiveness
  • Evaluation of electric vehicle smart charging
  • Evaluation of DER impacts on utility rates and financial health
  • Zero net energy building evaluation and cost-effectiveness analysis
  • Building energy code evaluation
  • Net energy metering cost-effectiveness analysis
  • Assessing the participation of energy storage and non-generation resources in energy and AS markets
  • Non-wires alternatives and local integrated resource plans
  • Regulatory support and expert testimony


Distributed energy resources projects

Energy Storage Market Update and Long Duration Storage Study | Massachusetts Clean Energy Center, 2023

In collaboration with the Massachusetts Clean Energy Center (MassCEC) and Department of Energy Resources (DOER), E3 conducted a study that assesses the current state of energy storage in the Commonwealth, the market outlook for emerging mid- and long-duration storage (LDES) technologies, and potential applications of mid- and long-duration storage, all in the context of providing benefits to ratepayers and achieving the state’s ambitious decarbonization goals.

The study included several modeling and stakeholder engagement elements. Leveraging E3’s pro forma financial model of storage technology costs and a custom-built storage dispatch model, the project team analyzed several storage use cases to help the state understand impacts of current incentive programs. Assessment of future storage value involved loss-of-load probability modeling of the entire ISO-NE footprint using E3’s RECAP model. E3 engaged stakeholders throughout the study process through interviews with more than 50 key stakeholders and two public stakeholder workshops. In the study, E3 shows that the role of energy storage changes to suit grid needs, but that storage requires well-designed state support to encourage deployment and innovation that targets these needs. In addition to writing a report providing study findings, the team worked with DOER to translate findings into policy recommendations for the state.

Read the detailed project description.

New York City Long-Term Energy Plan | New York City Mayor’s Office of Climate and Environmental Justice, 2022-2023

E3 led a team completing an inclusive, year-long study to identify the policies and programs needed to achieve the New York City’s decarbonization goals. E3’s analysis involved both examining policies and programs to meet the city’s long-term goals as well as providing specific recommendations for actions to be taken during the current administration. The study included eight research branches focused on the performance and cost of heat pumps in new buildings; the affordability of electrification retrofits in rent-regulated housing; the opportunities for electric school bus managed charging and vehicle-to-grid; the potential for in-city wind energy; a screening of public lands for new clean energy development; an assessment of the electric grid readiness for increasing heat pump and EV charging loads; and an evaluation of how bulk energy storage could reduce reliance on in-city fossil generation. Based on E3’s study, New York City published PowerUp NYC, the city’s first Long-Term Energy Plan, which includes 29 clean energy initiatives focused on the city’s energy grid, its buildings, and its transportation sector. Many aspects of the PowerUp NYC, from research topic selection to recommendations, were developed in collaboration with the public, and with the public’s interest at the forefront of the decision-making process. The recommendations of the LTEP are aligned with long-term energy and equity policy mandates from both the city and state and revolve around the needs of NYC residents.

Read the detailed project description.

Advanced Metering Infrastructure Filing Support | National Grid, 2018 – 2022

E3 supported to National Grid, beginning in 2018, with developing and progressing their Advanced Metering Infrastructure (AMI) and Grid Modernization Plan (GMP) filings in New York, Rhode Island, and most recently in Massachusetts. In addition to developing both a detailed business case and benefit-cost analysis for the meter installations, E3 worked with National Grid’s AMI team to engage internal stakeholders in the development of the filings. and to coordinate filing approaches with Eversource Energy’s Massachusetts team. E3 also worked with National Grid to align the proposed Massachusetts AMI implementation timeline with National Grid’s approved New York AMI implementation plan to maximize the cost savings of codeployment. National Grid’s final AMI proposal was approved by the Massachusetts Department of Public Utilities in December 2022.

New York Electricity Grid Emission Factors | NYSERDA, 2020-22

E3 supported NYSERDA in developing a new methodology for calculating greenhouse gas emission factors for New York’s electricity grid. Greenhouse gas emission factors measure the emissions intensity of grid power (the amount of emissions produced per unit of energy generated, such as in metric tons per megawatt-hour). E3 calculated future marginal grid emission factors for carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) for New York State for 2023 through 2040, on a month-hour and annual basis. E3 worked together with NYSERDA to write a white paper describing the methodology, results, and recommended applications of the new emission factors, as well as an accompanying database of emission factors for use by stakeholders.

Read the detailed project description.

New York Distributed Solar Roadmap | NYSERDA, 2021

Working with the New York Department of Public Service (DPS) and the New York State Energy Research and Development Authority (NYSERDA), E3 supported the development of a new roadmap for New York to achieve the installation of at least 10 Gigawatts of distributed solar by 2030. The roadmap lays out a path that will expand renewable energy in New York, generating enough clean energy to power 700,000 additional homes, while also prioritizing an equitable expansion of New York’s distributed solar infrastructure. E3 contributed to the distributed solar framework by providing analysis that informed the plan’s policy recommendations. E3 developed a supply curve model for distributed solar projects in New York and used this model to evaluate program costs for different incentive program options. The analysis was used to inform the roadmap’s ultimate recommendation to extend the current NY-Sun Megawatt Block incentive program to help achieve the 10 GW target.

Read the detailed project description.

Electrification of Transportation Rate Design and Infrastructure Applications | Hawaiian Electric Company, 2020-2021

E3 supported the Hawaiian Electric Company (HECO) on four transportation electrification filings. First, E3 and its subcontractors Anser Advisory and Black & Veatch designed a program for HECO to build the make-ready infrastructure for electric buses to support electrification of transportation for transit, tourism, and other bus operators. Second, E3 designed two new electric vehicle charging rates, EV-J and EV-P, for commercial electric vehicle charging sites. E3 developed a rate design calculator and performed cost-benefit assessments to evaluate different rate designs and propose final rates that will support low-cost public EV charging in Hawaii. Third, E3 and its subcontractor Anser Advisory supported HECO in developing its Charge Ready Hawaii pilot program to deploy make-ready charging infrastructure for commercial and multi-unit dwelling locations. Finally, E3 and its subcontractors Anser Advisory and Atlas Public Policy supported HECO in developing a proposal to expand its public DC fast charging (DCFC) infrastructure pilot to build out 150 DCFC ports and 150 dual-port Level 2 charging stations across its service territory. These programs – three of which have been approved by the Hawaii Public Utilities Commission with the fourth project (DCFC program expansion) under review in 2022 – build on HECO’s Electrification of Transportation Roadmap and allow for HECO to support its customers in electrifying their vehicles and fleets.

Cost-effective pathways to Hawai‘i’s 100 percent RPS goal

n 2015, Hawai‘i passed unprecedented legislation, Act 97, which requires its investor-owned utility, Hawaiian Electric Company (HECO), to meet a 100 percent renewable portfolio standard (RPS) by the end of 2045. Strengthening the state’s economy depends on moving away from imported fossil fuels for both electricity and transportation and increasing reliance on its abundant renewable […]

  • Read the Case Study
  • Transportation electrification assessment | CalETC, 2014–16

    E3 analyzed the grid impacts of charging light-, medium-, and heavy-duty electric vehicles (EVs) for the California Electric Transportation Coalition (CalETC), a consortium of automakers and utilities. To quantify the distribution system upgrades needed to accommodate residential charging of light-duty EVs, we mapped vehicle registration data with utility distribution system and load data for more than 81,000 circuits and feeders and 2,200 substations; we then modeled costs under different rate and charging scenarios.

    Even with clustered EV adoption, distribution impacts were modest, and we found that managed charging reduced distribution upgrade costs by 60 percent. For most technologies studied, we showed that EV adoption can actually reduce rates for utility customers while providing net economic, environmental, and societal benefits for California. CalETC’s member utilities used our study to educate regulators and stakeholders about the benefits of EV adoption prior to seeking authorization to invest ratepayer funds in charging infrastructure and customer outreach.


    Net energy metering tariff evaluation tool | CPUC, 2015

    E3 created a public tool for the California Public Utilities Commission (CPUC) to inform the development of a successor to existing net energy metering (NEM) tariffs for eligible customer-sited renewable generators. This tool helped the CPUC and stakeholders balance legislative directives to design tariffs that maintain sustainable growth of such generation and ensure that total benefits to customers are approximately equal to total costs.

    The tool lets users evaluate different rate designs, simulating their impact on adoption of customer-sited PV and on bills for all ratepayers, while accounting for feedback effects on future rates and life-cycle cost-effectiveness. Providing a common model to all parties allowed the CPUC and stakeholders to focus on fundamental differences in proposals and scenarios, rather than on disagreements and confusion over model differences.

    Time-dependent valuation for building codes | CEC, 1999–present

    E3 supports the California Energy Commission (CEC) in implementing the state building energy code by maintaining the economic framework for energy standard requirements and allowed trade-offs for new construction. We have worked with the CEC and its stakeholders since 1999 to continually refine a time-dependent valuation (TDV) methodology, and we are now under contract to support the 2025 Title 24 Update. The TDV methodology uses a 30-year forecast of the social cost of energy that varies hourly and by location to account for shifts in system peaks over time, and regional variations in climate and grid utilization. . E3’s initial study investigated a shift to a value-based standard that accounts for the time and geographic differences in energy costs seen in California energy prices, natural gas and propane markets, as well as in the costs of electric utility distribution and transmission systems. TDV was initially adopted in 2005, and E3 supported the updates in 2008, 2013, 2016, 2019, and 2022.


    Distributed resources planning tool development | Con Edison, 2014

    E3 built on a collaboration with Con Edison going back to 2000 to develop an integrated demand-side management (IDSM) model that expands the utility’s distribution planning capabilities. Using detailed data on customer populations, the tool assesses market potential for dispatchable distributed energy resources (DERs) within local electric networks, enabling Con Edison to identify lower-cost ways to alleviate local distribution constraints.

    Con Edison has integrated the IDSM tool into its distribution planning practices and is using it to help realize the New York State Public Service Commission’s Reforming the Energy Vision initiative. The E3 team continues to refine and enhance the tool, which won the 2014 Utility Analytics Institute Innovation Award.

    Avoided Cost Model for evaluating DER programs | CPUC, 2004–present

    Since 2004, the California Public Utilities Commission (CPUC) has used E3’s Avoided Cost Model (ACM) to estimate the benefits of energy efficiency, distributed generation, energy storage, and other distributed energy resources (DERs). The ACM has evolved along with energy markets and policy in the West, and it currently projects avoided costs for energy, losses, generation capacity, ancillary services, subtransmission and distribution capacity, renewable portfolio standard purchases, carbon allowances, and other air permit costs. The 30-year hourly forecast is differentiated across California’s 16 climate zones. Since 2019, E3 has provided ongoing support to refine the CPUC’s cost-effectiveness framework for distributed energy resources, expanding the applications of the Avoided Cost Calculator to include the cost-effectiveness of California’s entire DER portfolio.

    The CPUC approves over $1 billion in annual funding for DERs using these avoided costs for its cost-effectiveness tests. The ACM is suitable for stakeholder processes and contentious regulatory proceedings because it uses robust methods and publicly available input data. E3 also allows the download of the ACM so that all stakeholders can audit any of the calculations.