Venerable lighthouse gets a new holiday look

Nighttime Thermoelectric Generator converts radiative cooling into renewable energy, leveraging outer space cold; a Stanford-UCLA prototype complements solar, serving off-grid loads with low-power output during peak evening demand, using simple materials on a rooftop.

Key Points

A device converting nighttime radiative cooling into electricity, complementing solar for low-power evening needs.

✅ Uses thermocouples to convert temperature gradients to voltage.

✅ Exploits radiative cooling to outer space for night power.

✅ Complements solar; low-cost parts suit off-grid applications.

Two years ago, one freezing December night on a California rooftop, a tiny light shone weakly with a little help from the freezing night air. It wasn't a very bright glow. But it was enough to demonstrate the possibility of generating renewable power after the Sun goes down.

Working with Stanford University engineers Wei Li and Shanhui Fan, University of California Los Angeles materials scientist Aaswath Raman put together a device that produces a voltage by channelling the day's residual warmth into cooling air, effectively generating electricity from thin air with passive heat exchange.

"Our work highlights the many remaining opportunities for energy by taking advantage of the cold of outer space as a renewable energy resource," says Raman.

"We think this forms the basis of a complementary technology to solar. While the power output will always be substantially lower, it can operate at hours when solar cells cannot."

For all the merits of solar energy, it's just not a 24-7 source of power, although research into nighttime solar cells suggests new possibilities for after-dark generation. Sure, we can store it in a giant battery or use it to pump water up into a reservoir for later, but until we have more economical solutions, nighttime is going to be a quiet time for renewable solar power. 

Most of us return home from work as the Sun is setting, and that's when energy demands spike to meet our needs for heating, cooking, entertaining, and lighting.

Unfortunately, we often turn to fossil fuels to make up the shortfall. For those living off the grid, it could require limiting options and going without a few luxuries.

Shanhui Fan understands the need for a night time renewable power source well. He's worked on a number of similar devices, including carbon nanotube generators that scavenge ambient energy, and a recent piece of technology that flipped photovoltaics on its head by squeezing electricity from the glow of heat radiating out of the planet's Sun-warmed surface.

While that clever item relied on the optical qualities of a warm object, this alternative device makes use of the good old thermoelectric effect, similar to thin-film waste-heat harvesting approaches now explored.

Using a material called a thermocouple, engineers can convert a change in temperature into a difference in voltage, effectively turning thermal energy into electricity with a measurable voltage. This demands something relatively toasty on one side and a place for that heat energy to escape to on the other.

The theory is the easy part – the real challenge is in arranging the right thermoelectric materials in such a way that they'll generate a voltage from our cooling surrounds that makes it worthwhile.

To keep costs down, the team used simple, off-the-shelf items that pretty much any of us could easily get our hands on.

They put together a cheap thermoelectric generator and linked it with a black aluminium disk to shed heat in the night air as it faced the sky. The generator was placed inside a polystyrene enclosure sealed with a window transparent to infrared light, and linked to a single tiny LED.

For six hours one evening, the box was left to cool on a roof-top in Stanford as the temperature fell just below freezing. As the heat flowed from the ground into the sky, the small generator produced just enough current to make the light flicker to life.

At its best, the device generated around 0.8 milliwatts of power, corresponding to 25 milliwatts of power per square metre.

That might just be enough to keep a hearing aid working. String several together and you might just be able to keep your cat amused with a simple laser pointer. So we're not talking massive amounts of power.

But as far as prototypes go, it's a fantastic starting point. The team suggests that with the right tweaks and the right conditions, 500 milliwatts per square metre isn't out of the question.

"Beyond lighting, we believe this could be a broadly enabling approach to power generation suitable for remote locations, and anywhere where power generation at night is needed," says Raman.

While we search for big, bright ideas to drive the revolution for renewables, it's important to make sure we don't let the smaller, simpler solutions like these slip away quietly into the night.

This research was published in Joule.

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Nuclear Power for Net-Zero Grids anchors reliable baseload, integrating renewables with grid stability as solar, wind, and battery storage scale. Advanced reactors complement hydropower, curb natural gas reliance, and accelerate deep decarbonization of electricity systems.

Key Points

Uses nuclear baseload and advanced reactors to stabilize power grids and integrate higher shares of variable renewables.

✅ Provides firm, zero-carbon baseload for renewable-heavy grids

✅ Reduces natural gas dependence and peaker emissions

✅ Advanced reactors enhance safety, flexibility, and cost

Declining solar, wind, and battery technology costs are helping to grow the share of renewables in the world’s power mix to the point that governments are pledging net-zero emission electricity generation in two to three decades to fight global warming.

Yet, electricity grids will continue to require stable baseload to incorporate growing shares of renewable energy sources and ensure lights are on even when the sun doesn’t shine, or the wind doesn’t blow. Until battery technology evolves enough—and costs fall far enough—to allow massive storage and deployment of net-zero electricity to the grid, the systems will continue to need power from sources other than solar and wind.

And these will be natural gas and nuclear power, regardless of concerns about emissions from the fossil fuel natural gas and potential disasters at nuclear power facilities such as the ones in Chernobyl or Fukushima.

As natural gas is increasingly considered as just another fossil fuel, nuclear power generation provides carbon-free electricity to the countries that have it, even as debates over nuclear power’s outlook continue worldwide, and could be the key to ensuring a stable power grid capable of taking in growing shares of solar and wind power generation.

The United States, where nuclear energy currently provides more than half of the carbon-free electricity, is supporting the development of advanced nuclear reactors as part of the clean energy strategy.

But Europe, which has set a goal to reach carbon neutrality by 2050, could find itself with growing emissions from the power sector in a decade, as many nuclear reactors are slated for decommissioning and questions remain over whether its aging reactors can bridge the gap. The gap left by lost nuclear power is most easily filled by natural gas-powered electricity generation—and this, if it happens, could undermine the net-zero goals of the European Union (EU) and the bloc’s ambition to be a world leader in the fight against climate change.

U.S. Power Grid Will Need Nuclear For Net-Zero Emissions

A 2020 report from the University of California, Berkeley, said that rapidly declining solar, wind, and storage prices make it entirely feasible for the U.S. to meet 90 percent of its power needs from zero-emission energy sources by 2035 with zero increases in customer costs from today’s levels.

Still, natural gas-fired generation will be needed for 10 percent of America’s power needs. According to the report, in 2035 it would be possible that “during normal periods of generation and demand, wind, solar, and batteries provide 70% of annual generation, while hydropower and nuclear provide 20%.” Even with an exponential rise in renewable power generation, the U.S. grid will need nuclear power and hydropower to be stable with such a large share of solar and wind.

The U.S. Backs Advanced Nuclear Reactor Technology

The U.S. Department of Energy is funding programs of private companies under DOE’s new Advanced Reactor Demonstration Program (ARDP) to showcase next-gen nuclear designs for U.S. deployment.

“Taking leadership in advanced technology is so important to the country’s future because nuclear energy plays such a key role in our clean energy strategy,” U.S. Secretary of Energy Dan Brouillette said at the end of December when DOE announced it was financially backing five teams to develop and demonstrate advanced nuclear reactors in the United States.

“All of these projects will put the U.S. on an accelerated timeline to domestically and globally deploy advanced nuclear reactors that will enhance safety and be affordable to construct and operate,” Secretary Brouillette said.

According to Washington DC-based Nuclear Energy Institute (NEI), a policy organization of the nuclear technologies industry, nuclear energy provides nearly 55 percent of America’s carbon-free electricity. That is more than 2.5 times the amount generated by hydropower, nearly 3 times the amount generated by wind, and more than 12 times the amount generated by solar. Nuclear energy can help the United States to get to the deep carbonization needed to hit climate goals.

Europe Could See Rising Emissions Without Nuclear Power

While the United States is doubling down on efforts to develop advanced and cheaper nuclear reactors, including microreactors and such with new types of technology, Europe could be headed to growing emissions from the electricity sector as nuclear power facilities are scheduled to be decommissioned over the next decade and Europe is losing nuclear power just when it really needs energy, according to a Reuters analysis from last month.

In many cases, it will be natural gas that will come to the rescue to power grids to ensure grid stability and enough capacity during peak demand because solar and wind generation is variable and dependent on the weather.

For example, Germany, the biggest economy in Europe, is boosting its renewables targets, but it is also phasing out nuclear by next year, amid a nuclear option debate over climate strategy, while its deadline to phase out coal-fired generation is 2038—more than a decade later compared to phase-out plans in the UK and Italy, for example, where the deadline is the mid-2020s.

The UK, which left the EU last year, included support for nuclear power generation as one of the ten pillars in ‘The Ten Point Plan for a Green Industrial Revolution’ unveiled in November.

The UK’s National Grid has issued several warnings about tight supply since the fall of 2020, due to low renewable output amid high demand.

“National Grid’s announcement underscores the urgency of investing in new nuclear capacity, to secure reliable, always-on, emissions-free power, alongside other zero-carbon sources. Otherwise, we will continue to burn gas and coal as a fallback and fall short of our net zero ambitions,” Tom Greatrex, Chief Executive of the Nuclear Industry Association, said in response to one of those warnings.

But it’s in the UK that one major nuclear power plant project has notoriously seen a delay of nearly a decade—Hinkley Point C, originally planned in 2007 to help UK households to “cook their 2017 Christmas turkeys”, is now set for start-up in the middle of the 2020s.

Nuclear power development and plant construction is expensive, but it could save the plans for low-carbon emission power generation in many developed economies, including in the United States.

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Minnesota Electric Cooperatives are driving grid innovation with smart meters, time-of-use pricing, demand response, and energy storage, including iron-air batteries, to manage peak loads, integrate wind and solar, and cut costs for rural members.

Key Points

Member-owned utilities piloting load management, meters, and storage to integrate wind and solar, cutting peak demand.

✅ Time-of-use pricing pilots lower bills and shift peak load.

✅ Iron-air battery tests add multi-day, low-cost energy storage.

✅ Smart meters enable demand response across rural co-ops.

Minnesota electric cooperatives have quietly emerged as laboratories for clean grid innovation, outpacing investor-owned utilities on smart meter installations, time-based pricing pilots, and experimental battery storage solutions.

“Co-ops have innovation in their DNA,” said David Ranallo, a spokesperson for Great River Energy, a generation and distribution cooperative that supplies power to 28 member utilities — making it one of the state’s largest co-op players.

Minnesota farmers helped pioneer the electric co-op model more than a century ago, similar to modern community-generated green electricity initiatives, pooling resources to build power lines, transformers and other equipment to deliver power to rural parts of the state. Today, 44 member-owned electric co-ops serve about 1.7 million rural and suburban customers and supply almost a quarter of the state’s electricity.

Co-op utilities have by many measures lagged on clean energy. Many still rely on electricity from coal-fired power plants. They’ve used political clout with rural lawmakers to oppose new pollution regulations and climate legislation, and some have tried to levy steep fees on customers who install solar panels.

Where they are emerging as innovators is with new models and technology for managing electric grid loads — from load-shifting water heaters to a giant experimental battery made of iron. The programs are saving customers money by delaying the need for expensive new infrastructure, and also showing ways to unlock more value from cheap but variable wind and solar power.

Unlike investor-owned utilities, “we have no incentive to invest in new generation,” said Darrick Moe, executive director of the Minnesota Rural Electric Association. Curbing peak energy demand has a direct financial benefit for members.

Minnesota electric cooperatives have launched dozens of programs, such as the South Metro solar project, in recent years aimed at reducing energy use and peak loads, in particular. They include:

Cost calculations are the primary driver for electric cooperatives’ recent experimentation, and a lighter regulatory structure and evolving electricity market reforms have allowed them to act more quickly than for-profit utilities.

“Co-ops and [municipal utilities] can act a lot more nimbly compared to investor-owned utilities … which have to go through years of proceedings and discussions about cost-recovery,” said Gabe Chan, a University of Minnesota associate professor who has researched electric co-ops extensively. Often, approval from a local board is all that’s required to launch a venture.

Great River Energy’s programs, which are rebranded and sold through member co-ops, yielded more than 101 million kilowatt-hours of savings last year — enough to power 9,500 homes for a year.

Beyond lowering costs for participants and customers at large, the energy-saving and behavior-changing programs sometimes end up being cited as case studies by larger utilities considering similar offerings. Advocates supporting a proposal by the city of Minneapolis and CenterPoint Energy to allow residents to pay for energy efficiency improvements on their utility bills through distributed energy rebates used several examples from cooperatives.

Despite the pace of innovation on load management, electric cooperatives have been relatively slow to transition from coal-fired power. More than half of Great River Energy’s electricity came from coal last year, and Dairyland Power, another major power wholesaler for Minnesota co-ops, generated 70% of its energy from coal. Meanwhile, Xcel Energy, the state’s largest investor-owned utility, has already reduced coal to about 20% of its energy mix.

The transition to cleaner power for some co-ops has been slowed by long-term contracts with power suppliers that have locked them into dirty power. Others have also been stalled by management or boards that have been resistant to change. John Farrell, director of the Institute for Local Self-Reliance’s Energy Democracy program, said generalizing co-ops is difficult. 

“We’ve seen some co-ops that have got 75-year contracts for coal, that are invested in coal mines and using their newsletter to deny climate change,” he said. “Then you see a lot of them doing really amazing things like creating energy storage systems … and load balancing [programs], because they are unique and locally managed and can have that freedom to experiment without having to go through a regulatory process.”

Great River Energy, for its part, says it intends to reach 54% renewable generation by 2025, while some communities, like Frisco, Colorado, are targeting 100% clean electricity by specific dates. Its members recently voted to sell North Dakota’s largest coal plant, but the arrangement involves members continuing to buy power from the new owners for another decade.

The cooperative’s path to clean power could become clearer if its experimental iron-air battery project is successful. The project, the first of its kind in the country, is expected to be completed by 2023.

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California Wildfire Smoke Impact on Solar reduces photovoltaic output, as particulate pollution, soot, and haze dim sunlight and foul panels, cutting utility-scale generation and grid reliability across CAISO during peak demand and heatwaves.

Key Points

How smoke and soot cut solar irradiance and foul panels, slashing PV generation and straining CAISO grid operations.

✅ Smoke blocks sunlight; soot deposition reduces panel efficiency.

✅ CAISO reported ~30% drop versus July during peak smoke.

✅ Longer fire seasons threaten solar reliability and capacity planning.

Smoke from California’s unprecedented wildfires was so bad that it cut a significant chunk of solar power production in the state, even as U.S. solar generation rose in 2022 nationwide. Solar power generation dropped off by nearly a third in early September as wildfires darkened the skies with smoke, according to the US Energy Information Administration.

Those fires create thick smoke, laden with particles that block sunlight both when they’re in the air and when they settle onto solar panels. In the first two weeks of September, soot and smoke caused solar-powered electricity generation to fall 30 percent compared to the July average, according to the California Independent System Operator (CAISO), which oversees nearly all utility-scale solar energy in California, where wind and solar curtailments have been rising amid grid constraints. It was a 13.4 percent decrease from the same period last year, even though solar capacity in the state has grown about 5 percent since September 2019.

California depends on solar installations for nearly 20 percent of its electricity generation, and has more solar capacity than the next five US states trailing it combined as it works to manage its solar boom sustainably. It will need even more renewable power to meet its goal of 100 percent clean electricity generation by 2045, building on a recent near-100% renewable milestone that underscored the transition. The state’s emphasis on solar power is part of its long-term efforts to avoid more devastating effects of climate change. But in the short term, California’s renewables are already grappling with rising temperatures.

Two records were smashed early this September that contributed to the loss of solar power. California surpassed 2 million acres burned in a single fire season for the first time (1.7 million more acres have burned since then). And on September 15th, small particle pollution reached the highest levels recorded since 2000, according to the California Air Resources Board. Winds that stoked the flames also drove pollution from the largest fires in Northern California to Southern California, where there are more solar farms.

Smaller residential and commercial solar systems were affected, too, and solar panels during grid blackouts typically shut off for safety, although smoke was the primary issue here. “A lot of my systems were producing zero power,” Steve Pariani, founder of the solar installation company Solar Pro Energy Systems, told the San Mateo Daily Journal in September.

As the planet heats up, California’s fire seasons have grown longer, and blazes are tearing through more land than ever before, while grid operators are also seeing rising curtailments as they integrate more renewables. For both utilities and smaller solar efforts, wildfire smoke will continue to darken solar energy’s otherwise bright future, even as it becomes the No. 3 renewable source in the U.S. by generation.

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Power Grid Attacks surge across substations and transmission lines, straining critical infrastructure as DHS and FBI cite vandalism, domestic extremists, and cybersecurity risks impacting resilience, outages, and grid reliability nationwide.

Key Points

Power Grid Attacks are deliberate strikes on substations and lines to disrupt power and weaken grid reliability.

✅ Physical attacks rose across multiple states and utilities.

✅ DHS and FBI warn of threats to critical infrastructure.

✅ Substation security and grid resilience upgrades urged.

Even before Christmas Day attacks on power substations in five states in the Pacific Northwest and Southeast, similar incidents of attacks, vandalism and suspicious activity were on the rise.

Federal energy reports through August – the most recent available – show an increase in physical attacks at electrical facilities across the nation this year, continuing a trend seen since 2017.

At least 108 human-related events were reported during the first eight months of 2022, compared with 99 in all of 2021 and 97 in 2020. More than a dozen cases of vandalism have been reported since September.

The attacks have prompted a flurry of calls to better protect the nation's power grid, with a renewed focus on protecting the U.S. power grid across sectors, but experts have warned for more than three decades that stepped-up protection was needed.

Attacks on power stations on the rise 
Twice this year, the Department of Homeland Security warned "a heightened threat environment" remains for the nation, including its critical infrastructure amid reports of suspected Russian breaches of power plant systems. 

At least 20 actual physical attacks were reported, compared with six in all of 2021. 
Suspicious-activity reports jumped three years ago, nearly doubling in 2020 to 32 events. In the first eight months of this year, 34 suspicious incidents were reported.
Total human-related incidents – including vandalism, suspicious activity and cyber events such as Russian hackers and U.S. utilities in recent years – are on track to be the highest since the reports started showing such activity in 2011.

Attacks reported in at least 5 states
Since September, attacks or potential attacks have been reported on at least 18 additional substations and one power plant in Florida, Oregon, Washington and the Carolinas. Several involved firearms.

• In Florida: Six "intrusion events" occurred at Duke Energy substations in September, resulting in at least one brief power outage, according to the News Nation television network, which cited a report the utility sent to the Energy Department. Duke Energy spokesperson Ana Gibbs confirmed a related arrest, but the company declined to comment further.
• In Oregon and Washington state: Substations were attacked at least six times in November and December, with firearms used in some cases, local news outlets reported. On Christmas Day, four additional substations were vandalized in Washington State, cutting power to more than 14,000 customers.
• In North Carolina: A substation in Maysville was vandalized on Nov. 11. On Dec. 3, shootings that authorities called a "targeted attack" damaged two power substations in Moore County, leaving tens of thousands without power amid freezing temperatures.
• In South Carolina: Days later, gunfire was reported near a hydropower plant, but police said the shooting was a "random act."

It's not yet clear whether any of the attacks were coordinated. After the North Carolina attacks, a coordinating council between the electric power industry and the federal government ordered a security evaluation.

FBI mum on its investigations
The FBI is looking into some of the attacks, including cyber intrusions where hackers accessed control rooms in past cases, but it hasn't said how many it's investigating or where. 

Shelley Lynch, a spokesperson for the FBI's Charlotte field office, confirmed the bureau was investigating the North Carolina attack. The Kershaw County Sheriff's Office reported the FBI was looking into the South Carolina incident.

Utilities in Oregon and Washington told news outlets they were cooperating with the FBI, but spokespeople for the agency's Seattle and Portland field offices said they couldn't confirm or deny an investigation.

Could domestic extremists be involved?
In January, the Department of Homeland Security said domestic extremists had been developing "credible, specific plans" since at least 2020, including a Neo-Nazi plot against power stations detailed in a federal complaint, and would continue to "encourage physical attacks against electrical infrastructure."

In February, three men who ascribed to white supremacy and Neo-Nazism pleaded guilty to federal crimes related to a scheme to attack the grid with rifles.

In a news release, Timothy Langan, assistant director of the FBI’s Counterterrorism Division, said the defendants "wanted to attack regional power substations and expected the damage would lead to economic distress and civil unrest."

Why is the power grid so hard to protect?
Industry experts, federal officials and others have warned in one report after another since at least 1990 that the power grid was at risk, and a recent grid vulnerability report card highlights dangerous weak points, said Granger Morgan, an engineering professor at Carnegie Mellon University who chaired three National Academies of Sciences reports.

The reports urged state and federal agencies to collaborate to make the system more resilient to attacks and natural disasters such as hurricanes and storms. 

"The system is inherently vulnerable, with the U.S. grid experiencing more blackouts than other developed nations in one study. It's spread all across the countryside," which makes the lines and substations easy targets, Morgan said. The grid includes more than 7,300 power plants, 160,000 miles of high-voltage power lines and 55,000 transmission substations.

One challenge is that there's no single entity whose responsibilities span the entire system, Morgan said. And the risks are only increasing as the grid expands to include renewable energy sources such as solar and wind, he said. 

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Pacific Northwest Transmission Bottleneck slows clean energy progress as BPA's aging grid constrains renewable interconnections, delaying wind, solar, and data center growth; decarbonization targets depend on transmission upgrades, new substations, and policy reform.

Key Points

An interconnection and capacity shortfall on BPA's aging grid that delays renewables and impedes clean energy goals.

✅ BPA approvals lag: 1 of 469 projects since 2015.

✅ Yakama solar waits for substation upgrades until 2027.

✅ Data centers and decarbonization targets face grid constraints.

Oregon and Washington have set ambitious targets to decarbonize their power sectors, aiming for 100% clean electricity in the coming decades. However, a significant obstacle stands in the way: the region's aging and overburdened transmission grid, underscoring why 100% renewables remain elusive even as momentum builds.

The Grid Bottleneck

The BPA operates a transmission system that is nearly a century old in some areas, and its capacity has not expanded sufficiently to accommodate the influx of renewable energy projects, reflecting stalled grid spending in many parts of the U.S., according to recent analyses. Since 2015, 469 large renewable projects have applied to connect to the BPA's grid; however, only one has been approved—a stark contrast to other regions in the country. This bottleneck has left numerous wind and solar projects in limbo, unable to deliver power to the grid.

One notable example is the Yakama Nation's solar project. Despite receiving a $32 million federal grant under the bipartisan infrastructure law as part of a broader grid overhaul for renewables, the tribe faces significant delays. The BPA estimates that it will take until 2027 to complete the necessary upgrades to the transmission system, including a new substation, before the solar array can be connected. This timeline poses a risk of losing federal funding if the project isn't operational by 2031.

Economic and Environmental Implications

The slow pace of grid expansion has broader implications for the region's economy and environmental goals. Data centers and other energy-intensive industries are increasingly drawn to the Pacific Northwest due to its clean energy potential, while interregional projects like the Wyoming-to-California wind link illustrate how transmission access can unlock supply. However, without adequate infrastructure, these industries may seek alternatives elsewhere. Additionally, the inability to integrate renewable energy efficiently hampers efforts to reduce greenhouse gas emissions and combat climate change.

Policy Challenges and Legislative Efforts

Efforts to address the grid limitations through state-level initiatives have faced challenges, even as a federal rule to boost transmission advances nationally. In 2025, both Oregon and Washington considered legislation to establish state bonding authorities aimed at financing transmission upgrades. However, these bills failed to pass, leaving the BPA as the primary entity responsible for grid expansion. The BPA's unique structure—operating as a self-funded federal agency without direct state oversight—has made it difficult for regional leaders to influence its decision-making processes.

Looking Ahead

The Pacific Northwest's renewable energy aspirations hinge on modernizing its transmission infrastructure, aligning with decarbonization strategies that emphasize grid buildout. While the BPA has proposed several projects to enhance grid capacity, the timeline for completion remains uncertain. Without significant investment and policy reforms, the region risks falling behind in the transition to a clean energy future. Stakeholders across Oregon and Washington must collaborate to advocate for necessary changes and ensure that the grid can support the growing demand for renewable energy.

The Pacific Northwest's commitment to clean energy is commendable, but achieving these goals requires overcoming substantial infrastructure challenges, and neighboring jurisdictions such as British Columbia have pursued B.C. regulatory streamlining to accelerate projects. Addressing the limitations of the BPA's transmission system is critical to unlocking the full potential of renewable energy in the region. Only through concerted efforts at the federal, state, and local levels can Oregon and Washington hope to realize their green energy ambitions.

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