Summaries of State 100% Clean Energy Plans

Below are links to the 100% clean energy plans and reports for seven states, along with summaries of each report's objectives, information on how it was produced and organized, what its key conclusions/recommendations are, and key takeaways about the report.


Massachusetts 2050 Decarbonization Roadmap

Authors: Massachusetts Executive Office of Energy and Environmental Affairs, The Cadmus Group

Publishing Organization: Massachusetts Executive Office of Energy and Environmental Affairs

Date Published: December 2020

Number of Pages: 92 plus stand-alone, sector-specific technical appendices


Report Objective

In January 2020, Massachusetts Governor Charlie Baker committed the Commonwealth to “net zero” greenhouse gas emissions by 2050 during the annual State of the Commonwealth address. Shortly thereafter, the Secretary of Energy and Environmental Affairs, as authorized by the 2008 Global Warming Solutions Act, set the statewide 2050 emissions limit at net-zero with a minimum of 85% reduction in economy-wide greenhouse gas emissions by 2050. This goal strengthened Massachusetts’ previous commitment to achieve an 80 percent emissions reduction by 2050.

EEA commissioned the 2050 Decarbonization Roadmap Study to understand the short- and long-term strategies necessary for Massachusetts to achieve net-zero emissions by 2050. The Roadmap Study also seeks to illuminate various tradeoffs Massachusetts may face to achieve this deep decarbonization goal and provide guidance on interim 2030 emissions reduction goals. The report, Massachusetts 2050 Decarbonization Roadmap, was released in December 2020 along with 6 technical appendices. It seeks to answer a core question: “How can the Commonwealth [of Massachusetts] achieve Net Zero while maintaining a healthy, equitable, and thriving economy?”

The report synthesizes the results of study’s integrated, cross-sector energy modeling of eight distinct pathways for Massachusetts to achieve net-zero emissions by 2050, their economic and health impacts, more sector-specific analyses of deep decarbonization, and the carbon sequestration potential of Massachusetts’ natural and working lands. Recognizing that the transition to a low-carbon economy over the next several decades will necessarily entail change and uncertainty, the report emphasizes flexibility and seeks to identify “no-regret” actions Massachusetts can take.

How the Report Was Produced

EEA served as the lead state agency for the report and worked with consultants from The Cadmus Group. The Global Warming Solutions Act Implementation Advisory Committee and working groups of that committee contributed to the report’s analysis. Additional partners, including a range of analytic contributors, a technical steering committee of 21 university affiliates, and staff representing seven state agencies, provided analytical and advisory support throughout the development of the report. Stakeholder engagement consisted of a combination of in-person and virtual public meetings, online public comment opportunities, and feedback sessions with a representative range of stakeholders.

Report’s Organization and Modeling Approach

The report starts by discussing the context and motivation behind Massachusetts’ net-zero greenhouse gas emissions goal, then provides an overview of the modeling approach and stakeholder engagement process, discusses the existing Massachusetts emissions portfolio, proposes strategic recommendations across multiple sectors for the state to achieve its goal, and identifies policy implications and other action items for Massachusetts to pursue moving forward. The report emphasizes the importance of a systems engineering analytical approach, one that considers the interactive dynamics among constituent parts of a complex broader system and touches upon the importance of equity considerations and addressing environmental justice.

Two modeling approaches were utilized to develop the report, including: (1) an “integrated, regional, cross-sector energy system pathways analysis consisting of results from eight differing high-level pathways,” and (2) sector-specific analysis for the buildings, transportation, non-energy, and land sectors and an economic and health impacts analysis. These sector-specific and impact analyses were published as supplementary technical reports.

With the first approach, an integrated cross-sector energy modeling platform was used to identify the physical and technological interdependencies across the Commonwealth’s energy system and economy.  A regional lens was taken to accurately represent the Commonwealth’s energy system and economy, and to consider the impacts of the broader Northeast’s decarbonization efforts on Massachusetts’ strategy and interactive effects associated with regional coordination. This integrated pathways modeling approach explicitly looked at the necessary technologies for Massachusetts to achieve its net-zero emissions by 2050 goal based on eight pathways that each balanced hourly energy supply and demand at minimum cost. These eight pathways primarily differ in their built-in model assumptions regarding the scale of deployment, as determined by resource cost and availability, including ones that consider breakthroughs in certain technologies, constraints in other energy resources, a grid powered fully by renewable energy, and emphasis on pipeline gas or regional coordination. By pursuing this pathways approach, Massachusetts sought to develop a more thorough, holistic understanding of “different technological evolutions, advancements, and constraints” as well as the “costs, benefits, risks, opportunities, and tradeoffs associated with different decarbonization strategies” in order to identify “no-regret” actions that Massachusetts should take regardless of technological or policy uncertainties.

In contrast, the supplementary sector-specific modeling allowed for more detailed analysis of sectoral transitions, especially through 2030. By relying on more granular data specific to Massachusetts, these analyses were able to explore specific policy measures that could accelerate progress on the strategies identified in the integrated pathways modeling analysis and understand socioeconomic and equity implications of such pathways.

Based on this modeling analysis, the report proposes a detailed range of specific strategies for light-duty transportation; medium- and heavy-duty transportation, aviation, and shipping; residential and commercial buildings; electricity and energy; non-energy and industry; natural carbon sequestration; and additional carbon dioxide removal. For each of these focus areas, the report outlines its current contribution to Massachusetts’ emissions, strategies associated with its decarbonization transition, near-term implications, areas of further research, and case studies.

Overall, the technical analysis of the report aimed to achieve five objectives:

  • “Start with the technical to enable policy and implementation”
  • “Explore multiple pathways to Net Zero to support the development of robust and resilient decarbonization strategies”
  • “Create optionality for the Commonwealth”
  • “Use ‘back-cast’ modeling,” which involves starting with the 2050 goals and working backwards to understand the transformations that would be needed to reach those goals
  • “Produce granular data to unlock and enable policy implementation and market action”

Report Key Recommendations and Conclusions

  • There exist multiple viable pathways for Massachusetts to affordably and equitably achieve its goal of net-zero emissions by 2050 while growing its economy.
  • These pathways will all yield significant economic and health benefits for Massachusetts.
  • Regional collaboration is critical: how Massachusetts’ neighbors pursue climate action may dramatically impact costs, risks, and impacts of Massachusetts’ approach. Massachusetts cannot practically achieve its net-zero emissions goal through state-level policies alone, absent a broader regional strategy.
  • Massachusetts does not need to wait around: the core technologies and techniques necessary for Massachusetts to achieve its goals are already known and largely commercialized.
  • The four key pillars comprising Massachusetts’ strategy for reducing emissions are to:
    • Transition energy “end-uses” (including buildings and vehicles) away from fossil fuels
    • Deploy more energy efficiency and load flexibility
    • Decarbonize the energy supply
    • Remove carbon from the atmosphere
  • Key constraints for Massachusetts to achieve its goal include land use, bioenergy availability, and low- and zero-carbon fuels.
  • The most cost-effective and feasible strategies for Massachusetts to achieve near-term emissions reductions include increased regional coordination on decarbonization strategies, particularly on transportation fuels and energy system planning, and electrification of building heating and passenger vehicles.
  • New, transformed, and expanded markets, shaped by intentional redesign and/or indirect responses to policy or regulatory measures, will be instrumental in Massachusetts achieving its net-zero goal.

Notable Takeaways

The Roadmap consists of a core report with supplemental sections on certain topics, including transportation, buildings, non-energy emissions, and land use. Such an approach allows for a broad view of how Massachusetts fits in with the climate actions of other New England states, while going into greater depth for key sectors.

The sectoral studies serve to offer guidance to policymakers on how they could craft climate policies for specific sectors that may not be well-treated with an overarching policy, such as a carbon tax or cap and trade. It also gives an opportunity for those sectors to provide detailed input to the policies, such as on how fluorinated gases are used and how they can be phased out.

Building on the Roadmap, Massachusetts adopted Senate Bill 9, “An Act Creating a Next Generation Roadmap for Massachusetts Climate Policy,” in March 2021. The law sets interim targets of at least 50 percent reductions by 2030, and at least 75 percent by 2040, on the way to at least net-zero emissions by 2050.  It also “significantly increases protections for Environmental Justice communities across Massachusetts, authorizes the Administration to implement a new, voluntary energy efficient building code for municipalities, and allows the Commonwealth to procure an additional 2,400 Megawatts (MW) of clean, reliable offshore wind energy by 2027.”

The law further directs the EEA to set sectoral greenhouse gas limits for electric power, transportation, commercial and industrial heating and cooling, residential heating and cooling, industrial processes, and natural gas distribution and service.

The figure below (page 24 of the Roadmap report) shows the fuel types projected to be used for energy and the energy sources projected to be used for electricity generation from 2020 to 2050.

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State Seven