Projects & Case Studies

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CASE STUDY

Investigating the Economic Value of Flexible Solar Plants

CASE STUDY

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

CASE STUDY

Modeling California’s 50 Percent Renewables Portfolio Standard

Pacific Northwest Resource Adequacy Study | Pacific Northwest Utilities, 2018-19

E3 was retained by a consortium of public and private utilities in the Pacific Northwest to evaluate regional resource adequacy under a resource mix that, for both economic and public policy reasons, is transitioning toward higher levels of renewable energy and storage and away from coal. The study used E3’s RECAP model to examine the reliability of different portfolios and reliability contributions of individual resources such as wind, solar, hydro, and energy storage. The study examined both near-term (2030) and long-term (2050) systems. The results found that the Northwest region needs new capacity in the near term to meet growing loads and compensate for planned coal retirements. In the long term, E3 found that deep decarbonization could be achieved if sufficient firm capacity was retained for reliability during times of low wind, solar, and hydro generation. While wind, solar, hydro, and battery storage could provide reliability benefits to the system, replacing all carbon-emitting firm resources with these alternatives was found to be impractical due to the large overbuild required. Study sponsors included the Public Generating Pool (PGP), a consortium of publicly owned utilities in Washington and Oregon; Avista Corporation; Puget Sound Energy; and Northwestern Energy.

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Long-Run Resource Adequacy Under Deep Decarbonization Pathways for California | Calpine, 2018-19

Building on E3’s prior work for the California Energy Commission, this study examines which resources will be needed to maintain resource adequacy in a future California electricity system that is deeply decarbonized and heavily dependent on renewable energy and electric energy storage to meet California’s economy-wide 2050 greenhouse gas reduction goal. Whereas E3’s previous work identified resources California should build to meet GHG and renewable energy targets, this study takes an in-depth look at electric system reliability requirements – and specifically which resources are needed to maintain acceptable long-run reliability in a cost-effective manner. After examining resource adequacy through loss-of-load-probability (LOLP) modeling across thousands of simulated years using its RECAP model, E3 found that achieving economy-wide goals does not require full decarbonization of the electricity sector and that the least-cost electricity portfolio to meet 2050 economy-wide goals includes very large quantities of solar + storage and retains 17 GW to 35 GW of firm natural gas capacity for reliability.

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Flexibility assessment for wind integration | Portland General Electric, 2014–15

After Oregon set renewable portfolio standard (RPS) goals of 25 percent by 2015 and 50 percent by 2040, Portland General Electric (PGE) turned to E3 to study the flexible generation capacity necessary to meet wind integration needs. Our studies considered the variability, uncertainty, and timing of renewable energy output, and we considered alternative resources such as flexible combined cycle gas turbine plants, frame and aero-derivative combustion turbines, reciprocating engines, and energy storage. Our analysis informed the resource procurement strategy in PGE’s 2016 integrated resource plan. The studies found that PGE’s need for within-hour operational flexibility is not a significant driver of the value or need for new gas resources, even at a 50 percent RPS.

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Least-cost planning for achieving Hawai‘i’s 100 percent RPS | HECO, 2015–present

With more than two decades of experience in Hawai‘i, E3 is now helping the Hawaiian Electric Company (HECO) plan for the grid transformation needed to reach 100 percent renewable generation by 2045. Our long-term analysis supported development of the utility’s Power System Improvement Plan (PSIP), with modeling centered on individual island plans and interisland transmission. The study develops least-cost expansion plans for each island using a variety of policy cases and fuel price forecasts. E3 used its Renewable Energy Solutions model (RESOLVE) to explore the economic trade-off between renewable curtailment and investments in storage, and to develop least-cost expansion plans consistent with each scenario. We also solicited and incorporated stakeholder input. HECO filed the PSIP, including testimony and support from E3, with the Hawai‘i Public Service Commission in December 2016.

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Investigating a higher RPS for California | LADWP, PG&E, SMUD, SDG&E, and SCE, 2013–14

On behalf of California’s five largest electric utilities, E3 evaluated the challenges, costs, and potential solutions for achieving a 50 percent renewables portfolio standard (RPS) by 2030. Using our Renewable Energy Flexibility Model (REFLEX), we performed detailed operational studies of power system dispatch flexibility constraints under high levels of wind and solar generation. We found that achieving a 50 percent RPS is feasible and that California’s power system can remain reliable as long as renewable resources can be dispatched in response to grid needs. Our study recommended strategies for integrating higher levels of renewables, including greater regional coordination, renewables portfolio diversity, flexible generation capacity, flexible loads, and energy storage. We found that deploying these strategies would reduce the need to curtail renewables, lowering the cost of reaching 50 percent RPS.

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Procurement and rate design | Lower Valley Energy, 2001–16

E3 has provided procurement and rate-making advice to Wyoming’s Lower Valley Energy (LVE) since 2001. Our long-term procurement plans have carefully addressed LVE’s need to mitigate cost increases due to changes in either market prices of energy or Bonneville Power Administration’s rates. We have also helped LVE assess the merits of different rate structures and compare the value of building generation in its own service territory with the costs of building new transmission facilities to access alternative power sources. Most recently, we provided an independent evaluation of the costs and benefits of a potential merger with a neighboring co-op utility.

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