The Ellsworth Dam, located just upstream from the scenic Union River Bridge in downtown Ellsworth, is often overlooked by those passing by, as its significant structure is concealed by nearby vegetation and a bend in the river. The flow into the dam is managed by another dam situated upstream.
Without the presence of these two dams, which form the Ellsworth Hydroelectric Project, the surrounding community would present a notably different landscape. Instead of the lakes that currently grace the area, there would be rivers, leaving homes that once enjoyed lakefront views with hundreds of feet separating them from the water’s edge.
However, the historical significance of these dams does not ensure their operation will persist. The corporate owners of the Ellsworth Dam are currently entrenched in a prolonged legal dispute regarding a state water quality certification. This certification is essential for the continued functionality of the turbines for future decades and is presently being contested in the Maine Supreme Court.
The situation in Ellsworth raises broader issues that Brookfield, the Canadian multinational investment company that owns most hydroelectric facilities in Maine, is grappling with alongside communities throughout the state. As Maine’s aging dams demand substantial investments to comply with strict environmental regulations and remain operational, there looms a crucial question: will the owners commit to the necessary upgrades, or will local opposition and state regulations lead to the retirement of these critical energy sources?
These decisions have gained urgency as Maine approaches its renewable energy targets, necessitating the expansion of wind and solar projects as part of its energy mix. Amidst this, the state’s policies governing water quality and fish passage are gaining prominence, with advocates for aquatic habitat restoration rallying to advocate for dam removal in public forums regarding dam operation licenses.
The fate of Maine’s dams could have significant repercussions for communities historically shaped by these structures, as well as for the state’s renewable energy strategy. While the state has made strides in other renewable sectors, hydropower remains vital, accounting for 30 percent of Maine’s renewable energy output last year, continuously outpacing other renewable sources.
The state’s 124 operational hydroelectric dams have historically dominated Maine’s energy landscape, shaping renewable energy benchmarks before formal standards were set. However, with an average operational age of 104 years, these dams are increasingly overshadowed by investments in newer energy technologies. In fact, wind energy overtook hydropower as the state’s primary renewable electricity source for the first time in 2021, complementing solar energy, which is also expected to expand significantly under state law.
At present, the active hydroelectric dams in Maine are maximizing their energy output, while their corporate operators navigate the growing burden of operational expenses. After Maine released its draft for a roadmap to achieve 100 percent clean electricity by 2040, indications show an emphasis on wind, battery systems, and solar as the main components of the future energy mix.
The potential of hydropower in Maine is bolstered by the state’s extensive network of over 30,000 miles of rivers, where many waterways lead into the Atlantic Ocean. Despite recent challenges such as drought exacerbated by climate change, Maine benefits from a consistent annual precipitation rate of 40 to 50 inches alongside the snowpack that replenishes lakes and rivers.
For decades, hydroelectric facilities have supplied Maine with reliable renewable energy. In 2023, the state’s 51 hydroelectric plants produced 726 megawatts of electricity free from fossil fuels, accounting for about 31 percent of Maine’s total electricity generation and nearly 47 percent of its renewable energy generation — a value that has remained relatively stable over the years.
Overall renewable sources, which include hydro, wind, solar, wood, and biomass, represented 65 percent of in-state electricity generation in 2023, as reported by the U.S. Energy Information Administration. This ratio has to increase to 80 percent by 2030 and reach 100 percent by 2050, as mandated by bipartisan legislation signed into law by Governor Janet Mills in 2019.
Proponents of hydropower argue that the abundance of rivers in Maine, charged by an immense amount of rain, can sustain continuous energy generation. Dams also provide a crucial advantage in restoring energy to the grid after widespread outages, as they can instantly generate electricity without needing an external power source to restart. This is particularly beneficial when electricity demand surges, like during cold, overcast winter days when other renewable sources struggle to meet consumer needs.
As Maine seeks to reduce its dependence on natural gas plants—while they are reliable, they emit greenhouse gases—hydropower stands out as the state’s most viable emissions-free resource, according to Tom Welch, a former chair of the Maine Public Utilities Commission. He emphasized the importance of maximizing production from existing hydro facilities, stating, “Getting as much production as you can out of hydro facilities is crucial, because once they’re operational, they contribute significantly.”
Welch articulated that improving the efficiency of existing hydro plants represents a cost-effective route to enhancing grid reliability and pursuing renewable energy goals, suggesting that investing in upgrades for these established facilities would yield substantial benefits compared to the costs associated with developing new energy sources.
Significantly, much of New England heavily relies on hydroelectric power, with a notable share of this energy being transmitted from Quebec’s extensive hydropower network. According to statistics, Hydro-Quebec supplied 24 percent of Vermont’s electricity in 2022, showcasing the critical importance of hydro within the northeastern energy framework.
A recent report on Maine’s Renewable Portfolio Standard advised supporting ongoing renewable energy projects, particularly those facing expensive maintenance and replacement needs due to aging infrastructure. Key legislative advancements came in 2019, when Maine revamped credit classifications in the renewable energy market to benefit hydroelectric electricity producers more.
However, policymakers in Maine have exhibited caution regarding direct investments in hydropower. The regulatory body overseeing non-federal dams is notably underfunded, with only two engineers overseeing the safety of over 500 dams. Additionally, despite the favorable 2019 credit update, larger dams continue to be excluded from the preferred credit class while significant financial support flows into the offshore wind sector.
Fortunately, a recent uptick in federal funding could provide the necessary backing for Maine’s dams to navigate regulatory challenges. The federal government has allocated $33.8 million from the Bipartisan Infrastructure Law to 21 privately owned hydroelectric projects in Maine for maintenance tasks, fish passage enhancements, and energy efficiency improvements. This marks the largest investment in the region and signals federal recognition of the enduring relevance of hydropower in the energy sector.
As near to 135 dams in the Northeast will undergo federal relicensing processes by the end of the decade, the fate of these applications, which constitute around 46 percent of the total relicensing requests nationwide, is critical. The Federal Energy Regulatory Commission’s (FERC) decisions will dictate the operational future of these dams, hinging greatly on their capacity to satisfy rigorous water quality requirements and provide safe passage for migratory fish.
The expenses associated with upgrading existing facilities, such as the Shawmut Dam on the Kennebec River—which FERC estimates will require around $6.3 million to comply with fish passage protocols—are considerable. Notably, Shawmut is positioned to receive $4.8 million from the Infrastructure Law funding, although details remain uncertain concerning how these funds will be utilized given the dam is in a lengthy relicensing process.
Maine’s commitment to maintaining its hydro resources underscores the importance of these facilities within the state’s clean energy framework, as underscored by Afton Vigue, a spokesperson for the Governor’s Energy Office, who noted that preserving existing hydro facilities is essential for achieving balanced clean energy goals alongside other renewable sources.
Historically, Maine’s rivers have shaped local communities, with early European settlers leveraging river energy in the 1600s for various industries, subsequently displacing Indigenous peoples who had relied on these natural resources. By the mid-1800s, then-Governor Joshua L. Chamberlain commissioned a comprehensive evaluation of Maine’s rivers to identify their potential for hydroelectric energy generation.
The subsequent report by Walter Wells in 1869 highlighted the long-term reliability of Maine’s hydropower resources in contrast to fossil fuels, emphasizing their capacity for sustainable energy production. Wells’ enthusiastic findings set the stage for an era brimming with hydroelectric advancements, including the establishment of the first hydroelectric facilities in the U.S. across several river systems.
In the decades that followed, hydroelectric power significantly transformed the energy landscape, with the construction of numerous dams to harness river currents for electricity generation. However, over the years, the industry has faced declines, as many dams and their infrastructure have aged, and new energy developments have overshadowed traditional hydropower systems.
Currently, while approximately 730 megawatts of power capacity from existing hydroelectric dams remains stable since the late 1990s, opportunities for expansion are limited. A 2015 analysis indicated that few sites possess viable potential for development, rendering significant investments in new hydro projects unlikely.
As Maine aims to achieve its ambitious renewable energy targets, it is largely focusing on wind and solar technologies, intending to bolster its mix with substantial offshore wind capacity and battery storage solutions. Legislative mandates have set specific targets for developing thousands of megawatts of wind energy and numerous solar arrays by 2040, alongside a parallel goal of enhancing energy storage capacity.
Recent substantial investments in battery technology, including the funding awarded to an 85-megawatt project touted as a groundbreaking storage facility, reflect Maine’s strategic shift towards diversifying its energy sources while maintaining existing hydroelectric power. Nonetheless, community opposition against solar developments and proposed regulations on land use may pose challenges to this trajectory.
Efforts towards offshore wind development have also faced setbacks, highlighted by a missed federal funding opportunity for constructing a port essential for turbine assembly. Despite these hurdles, state officials remain optimistic about harnessing wind energy, emphasizing the region’s untapped potential.
As opposition to large-scale hydropower gains momentum following contemporary environmental movements, the complexities of balancing ecological concerns with energy generation persist. For instance, dam removal campaigns aimed at enhancing fish passage and river health are increasingly prevalent, steering communities to reassess the ecological impacts of existing dams.
The enduring legacy of hydroelectric dams prompts discussions among stakeholders about their value versus costs, as each dam presents both community attachment and ecological considerations. The intricate dynamics surrounding the future of Maine’s dams reflect a complicated interplay of historical reliance and modern environmental advocacy, leaving policymakers and communities at a crossroads for the future of this vital resource.
From water quality certifications to environmental compliance, the future of hydroelectric power in Maine will ultimately depend on collaborative efforts and investments that consider both energy needs and ecological stewardship. The outcome will influence not just the power landscape but the very fabric of communities built around these waterways.