A Clean Grid Is Also the Cheapest Grid

A comprehensive new analysis has concluded that Massachusetts can meet its peak electricity demand in 2050 with a power mix that is entirely free of combustion-based generation — and that this clean pathway represents the least-cost option for the state's ratepayers. The finding upends conventional wisdom in the utility industry, where natural gas peaker plants have long been considered essential insurance against the highest-demand days of the year.

The report models multiple scenarios for meeting the state's projected peak demand, accounting for the electrification of heating and transportation that will significantly increase electricity consumption over the coming decades. In every scenario analyzed, the combination of renewable energy, battery storage, long-duration energy storage, demand response, and regional grid imports proved cheaper than pathways that include new gas-fired generation or maintain existing combustion plants.

What Replaces Gas Peakers

The combustion-free power mix identified by the analysis relies on several complementary technologies working in concert. Solar and offshore wind provide the bulk of energy generation, while lithium-ion batteries handle short-duration peaks lasting four to eight hours. For extended periods of low renewable generation — the multi-day winter cold snaps that represent the grid's most challenging moments — long-duration energy storage technologies such as iron-air batteries and compressed air systems fill the gap.

Demand response plays a crucial role in the model's findings. By shifting flexible electricity consumption — such as electric vehicle charging, water heating, and industrial processes — to periods when renewable generation is abundant, the peak demand that the grid must serve at any given moment is reduced significantly. Smart thermostats, time-of-use pricing, and automated load management systems enable this flexibility without requiring consumers to sacrifice comfort or productivity.

  • The combustion-free pathway saves ratepayers an estimated $2.4 billion compared to the next cheapest alternative through 2050
  • Offshore wind and solar provide approximately 80 percent of total energy generation in the model
  • Battery storage capacity of 15-20 gigawatt-hours is needed to manage daily peak demand cycles
  • Long-duration storage of 50+ hours addresses the most extreme multi-day low-renewable events

The Economics Have Shifted

The report's most striking conclusion is not merely that a combustion-free grid is feasible — that has been argued by clean energy advocates for years — but that it is now the economically optimal choice. The cost declines in solar panels, wind turbines, and particularly lithium-ion batteries over the past decade have fundamentally altered the comparative economics of clean versus fossil-fuel generation.

Natural gas peaker plants, while relatively cheap to build, are expensive to operate because they run only during the highest-demand hours. Their fuel costs, carbon compliance costs, and maintenance expenses make them increasingly uncompetitive against batteries that can be charged with cheap renewable electricity and dispatched during peak periods at near-zero marginal cost.

The analysis also accounts for the cost of maintaining gas infrastructure — pipelines, compressor stations, and delivery systems — that would be needed to support peaker plants even if they operate only a few hundred hours per year. Eliminating this infrastructure represents a significant cost savings that is often overlooked in simpler comparisons between individual generation technologies.

Implications Beyond Massachusetts

While the report is specific to Massachusetts, its findings have relevance for grid planning across the northeastern United States and beyond. The state's climate — with cold winters that drive heating demand, moderate solar resources, and excellent offshore wind potential — is representative of many temperate regions facing similar decarbonization challenges.

If the least-cost pathway to meeting peak demand in a cold-climate state with significant heating electrification is combustion-free, the implication is that warmer regions with better solar resources face an even stronger economic case for eliminating fossil fuel generation. The report effectively removes one of the last technical and economic arguments for maintaining gas infrastructure as part of a long-term grid strategy.

Utility regulators and grid planners in other states are likely to take notice. Integrated resource plans — the documents that guide utility investment decisions over multi-decade horizons — increasingly reflect the declining costs of clean energy technologies. The Massachusetts analysis provides rigorous modeling support for planners who are already leaning toward clean energy pathways but face resistance from stakeholders with interests in the continued use of natural gas.

Challenges Ahead

Realizing the combustion-free pathway requires sustained policy support, continued technology cost reductions, and significant infrastructure investment. Permitting timelines for offshore wind, transmission upgrades, and energy storage facilities must be shortened to match the pace of deployment the model assumes. Workforce development in clean energy installation and maintenance is another critical enabling condition.

The report acknowledges that its projections depend on technology cost trajectories that, while consistent with historical trends, are not guaranteed. A slowdown in battery cost reductions or delays in long-duration storage commercialization could alter the economic calculus. However, the margin of savings identified in the analysis provides a substantial buffer against such contingencies, suggesting that the clean pathway remains the best bet even under less optimistic assumptions.

This article is based on reporting by Utility Dive. Read the original article.