The problem, as Dawn Weisz saw it back in the mid-2000s, was straightforward. She and other residents of Marin County wanted green power. But only 16 percent of the electricity that PG&E, the local utility, was delivering to its 250,000 customers was renewable.

Frustratingly, Weisz and other community members didn’t have any say about what went into that mix. The county government — for which Weisz worked at the time — had set ambitious decarbonization goals and had found that cleaning up their power supply would be the best first step forward. But they couldn’t force the utility to go green any faster.

So she and others organized to form a “community choice aggregator,” or CCA — a nonprofit that took over buying electricity for Marin from a variety of producers. Within a year they were providing 50 percent renewable power to nearly everyone in the county. Today, 10 years after its founding, Marin Clean Energy, (now known as MCE since they serve more than just Marin), has expanded to cover more than a million people and provides just over 60 percent renewable power.

“To double, and then triple the amount of renewable content people are getting really had a dramatic impact on our carbon footprint, and that was really our goal,” Weisz says.

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MCE’s CEO Dawn Weisz shakes hands with Jonathan Brito, a graduate of the RichmondBUILD program who worked on an MCE solar project. Credit: MCE

Marin is at the vanguard of a trend. The model of using CCAs as an environmental force has spread rapidly in recent years in the nine states where the law currently allows them; six other states are considering CCA legislation. Nationwide, some 100 CCAs are offering green electricity alternatives. The ones in California alone have 11 million customers.

“There is huge unmet demand for renewable energy,” says Kelly Trumbull, a researcher at UCLA who has analyzed California’s CCAs.  “Especially as the climate crisis gets worse, people are looking for ways to help move the transition forward.”

By popular demand

Polling confirms Trumbull’s point: Americans really, really want green energy. Pew Research Center surveys show that 79 percent of respondents, across political lines, want the U.S. to develop more alternative energy resources, such as solar and wind. That support has increased more than 15 percentage points since 2011.

Today, the power sector accounts for about 30 percent of U.S. greenhouse gas emissions. Its emissions have decreased about eight percent over the last decade, as coal plants retired and renewable sources grew, buoyed by their plummeting cost. Photovoltaic power, for example, has gotten 82 percent cheaper since 2010.

And yet the energy transition hasn’t been moving nearly fast enough to reach net-zero emissions by 2050 — the goal scientists say is necessary in order to keep the planet from warming beyond 1.5 degrees Celsius, and the goal the Biden administration has now adopted for the United States. Even in California, which in 2006 first instituted climate goals that forced utilities to increase renewable power generation every year, those increases have been slow compared to the rate scientists recommend and many concerned citizens are demanding.

“There’s definitely this grassroots interest in procuring renewable energy,” says Michelle Davis, a solar expert at energy research firm Wood Mackenzie. “Customers are really wanting to take more control over their power.”

Some who can afford it put solar panels on their homes, supplying their own electricity needs and perhaps even feeding some back to the grid. Others have banded together to form community solar “gardens” that do the same. But most Americans still have little ability to influence the greenness of their power, and by extension little clout with which to accelerate the transition from fossil fuels to renewables.

What’s a CCA?

In CCAs, Weisz and others like her have found a tool that can help. Community choice aggregation lets a city, county, or a group of them take over the role of buying power for the community.

In states like California with so-called regulated electricity, utilities such as PG&E have traditionally had three distinct roles: buying power from generating plants; building and maintaining the transmission lines; and providing service to consumers. In other states like Massachusetts, which have “restructured” systems, utilities run the transmission and customer-service sides, but customers can choose from different power suppliers.

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An MCE solar project, part of a system providing green energy for millions of Californians. Credit: MCE

In both regulated and restructured states, provided a state law allows it, CCAs can take over the power-buying part of the process. Once a local government chooses to form or join a CCA, everyone in the service territory is automatically opted in (though they can choose to leave if they like). By grouping together lots of customers, a CCA gets more negotiating leverage.

Unlike utilities, CCAs are nonprofits and are governed locally, which advocates say makes them more reflective of the community’s needs and desires. When they first emerged in the 1990s, they were mostly used to negotiate lower electricity rates; in states like Ohio and Illinois, that’s still the primary goal for many CCAs.

But in California, CCAs started to use them explicitly to forward climate goals.

At first, adoption was slow. MCE formed in 2010 despite vigorous opposition from utilities. The next to form was Sonoma Clean Power, in 2014. “There’s been almost exponential growth since then,” says Trumbull. Now, 23 CCAs across the state are in charge of buying power for more than 11 million people — nearly a third of California residents.

“It’s not just California — we’re seeing rapid growth in Massachusetts and other states,” including heavily populated New York, says Joseph Nyangon, an energy economist at the University of Delaware. Legislation that would enable CCAs is in discussion from Arizona to Maryland.

“I would bet that several more have this by next year, and that could be quite significant for the [renewables] market,” Nyangon says.

Emissions impacts

So, are CCAs accelerating the energy transition? A recent UCLA report led by Trumbull suggests that in California, the answer is yes.

In 2018 the state updated its renewables goals,  aiming to reach 100 percent carbon-free power by 2045, with an interim goal of 33 percent by 2020. Almost all the California CCAs exceeded that interim goal: In 2019, they provided an average of about 50 percent renewable power, whereas large utilities averaged less than 40 percent (though they too exceeded the state goal). The UCLA report found that CCAs indirectly nudged the utilities into a more renewables-heavy energy mix, primarily because as customers leave the utilities for CCAs, the utilities — which still have green power contracts in hand — end up with more renewable energy serving their smaller customer base.

In total, CCAs caused nearly 50 million megawatt hours of renewables to be used in place of fossil fuel sources between 2011 and 2019. That contribution is still relatively small — California uses about five times that much electricity each year — but it’s expected to grow quickly: By the end of 2021, more than 40 percent of the state’s customers will likely be part of a CCA.

Several of the newer CCAs, such as southern California’s Clean Power Alliance, default their customers into 100 percent renewable power. Some 93 percent of the Alliance’s three million customers stick with that option, which pushes up demand for renewables and helps to “put steel in the ground,” says Ted Bardacke, the executive director. Across the state, CCAs have contracted for about 6,000 megawatts of new solar, wind, and other renewables projects, according to the trade association CalCCA.

California is going to get to 100 percent renewables one way or another, but “it’s safe to say that the CCAs are going to accelerate that,” says Eric O’Shaughnessy, an energy researcher with Lawrence Berkeley National Laboratory.

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Wind turbines in Tehachapi Pass, California. Credit: Daxis / Flickr

Nationally, the scale of CCAs’ potential is less clear. They have become the primary tool people use to get greener power than that required by their own state, O’Shaughnessy and colleagues found in a 2019 analysis; in 2017, about 100 of the nation’s roughly 750 CCAs offered greener options than state baseline. Most of them were still focused on getting cheaper power rather than driving down emissions — though, as Nyangon notes, today those often go hand in hand.

If the states with CCA laws on the books continued to expand their green power customer base, and if the states considering CCA legislation pass it and follow in the same pattern, O’Shaughnessy and his colleagues calculated that they could provide about 20 to 30 million megawatt hours of extra renewable energy per year. That works out to about 2 percent of the national load.

Given the scale of the climate challenge, every nudge helps, says Bardacke. “I don’t think it’s an either-or situation,” he says. “It’s and, and.”

Value beyond carbon

Along with clean energy, many communities have been calling for equity in the energy transition. Some have demanded that CCAs provide local jobs while pursuing renewables, or help make rooftop solar and energy efficiency measures available to residents who can’t afford them.

Richmond, California, north of Berkeley on San Francisco Bay, is a good example: It wanted both local solar power and good jobs for community members. So the city government asked MCE to develop a 10.5-megawatt solar farm right in town. They negotiated a cheap lease of an unused 60-acre parcel at the Chevron refinery (Chevron offered it as part of a “modernization” effort undertaken a few years after a disastrous refinery fire). In the end, nearly 60 percent of the workers who built the “Solar One” plant lived within city limits — including 41 trainees from a low-income workforce training program called RichmondBUILD.

Today, the refinery’s rust-red tanks loom from a hill overlooking the solar farm. During peak sunshine hours, the high-pitched whine of inverters — like a constantly ringing fire alarm — signals that solar energy is being transformed into electricity, enough to power about 3,900 local homes. Turkeys strut and jackrabbits hop among the steel racks supporting the 78,000 panels, half of which follow the arc of the sun overhead.

The site accounts for only a few percent of MCE’s peak load, but for Fred Lucero, the director of RichmondBUILD, the value goes beyond the energy produced.  “With a project like Solar One, we were able to lift all the boats in the harbor,” he says.