Cash incentives for choosing green energy

Near-Field Thermophotovoltaics captures radiated energy across a nanoscale gap, using thin-film photovoltaic cells and indium gallium arsenide to boost power density and efficiency, enabling compact Army portable power from emitters via radiative heat transfer.

Key Points

A nanoscale TPV method capturing near-field photons for higher power density at lower emitter temperatures.

✅ Nanoscale gap boosts radiative transfer and usable photon flux

✅ Thin-film InGaAs cells recycle sub-band-gap photons via reflector

✅ Achieved ~5 kW/m2 power density with higher efficiency

With the addition of sensors and enhanced communication tools, providing lightweight, portable power has become even more challenging, with concepts such as power from falling snow illustrating how diverse new energy-harvesting approaches are. Army-funded research demonstrated a new approach to turning thermal energy into electricity that could provide compact and efficient power for Soldiers on future battlefields.

Hot objects radiate light in the form of photons into their surroundings. The emitted photons can be captured by a photovoltaic cell and converted to useful electric energy. This approach to energy conversion is called far-field thermophotovoltaics, or FF-TPVs, and has been under development for many years; however, it suffers from low power density and therefore requires high operating temperatures of the emitter.

The research, conducted at the University of Michigan and published in Nature Communications, demonstrates a new approach, where the separation between the emitter and the photovoltaic cell is reduced to the nanoscale, enabling much greater power output than what is possible with FF-TPVs for the same emitter temperature.

This approach, which enables capture of energy that is otherwise trapped in the near-field of the emitter is called near-field thermophotovoltaics or NF-TPV and uses custom-built photovoltaic cells and emitter designs ideal for near-field operating conditions, alongside emerging smart solar inverters that help manage conversion and delivery.

This technique exhibited a power density almost an order of magnitude higher than that for the best-reported near-field-TPV systems, while also operating at six-times higher efficiency, paving the way for future near-field-TPV applications, including remote microgrid deployments in extreme environments, according to Dr. Edgar Meyhofer, professor of mechanical engineering, University of Michigan.

"The Army uses large amounts of power during deployments and battlefield operations and must be carried by the Soldier or a weight constrained system," said Dr. Mike Waits, U.S. Army Combat Capabilities Development Command's Army Research Laboratory. "If successful, in the future near-field-TPVs could serve as more compact and higher efficiency power sources for Soldiers as these devices can function at lower operating temperatures than conventional TPVs."

The efficiency of a TPV device is characterized by how much of the total energy transfer between the emitter and the photovoltaic cell is used to excite the electron-hole pairs in the photovoltaic cell, where insights from near-light-speed conduction research help contextualize performance limits in semiconductors. While increasing the temperature of the emitter increases the number of photons above the band-gap of the cell, the number of sub band-gap photons that can heat up the photovoltaic cell need to be minimized.

"This was achieved by fabricating thin-film TPV cells with ultra-flat surfaces, and with a metal back reflector," said Dr. Stephen Forrest, professor of electrical and computer engineering, University of Michigan. "The photons above the band-gap of the cell are efficiently absorbed in the micron-thick semiconductor, while those below the band-gap are reflected back to the silicon emitter and recycled."

The team grew thin-film indium gallium arsenide photovoltaic cells on thick semiconductor substrates, and then peeled off the very thin semiconductor active region of the cell and transferred it to a silicon substrate, informing potential interfaces with home battery systems for distributed use.

All these innovations in device design and experimental approach resulted in a novel near-field TPV system that could complement distributed resources in virtual power plants for resilient operations.

"The team has achieved a record ~5 kW/m2 power output, which is an order of magnitude larger than systems previously reported in the literature," said Dr. Pramod Reddy, professor of mechanical engineering, University of Michigan.

Researchers also performed state-of-the-art theoretical calculations to estimate the performance of the photovoltaic cell at each temperature and gap size, informing hybrid designs with backup fuel cell solutions that extend battery life, and showed good agreement between the experiments and computational predictions.

"This current demonstration meets theoretical predictions of radiative heat transfer at the nanoscale, and directly shows the potential for developing future near-field TPV devices for Army applications in power and energy, communication and sensors," said Dr. Pani Varanasi, program manager, DEVCOM ARL that funded this work.

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PG&E Public Safety Power Shutoff reduces wildfire risk during extreme winds, triggering de-energization across the North Bay and Sierra Foothills under red flag warnings, with safety inspections and staged restoration to improve grid resilience.

Key Points

A utility protocol to de-energize lines during extreme fire weather, reducing ignition risks and improving grid safety.

✅ Triggered by red flag warnings, humidity, wind, terrain

✅ Temporary de-energization of transmission and distribution lines

✅ Inspections precede phased restoration to minimize wildfire risk

PG&E purposefully shut off electricity to nearly 60,000 Northern California customers Sunday night, aiming to mitigate wildfire risks from power lines during extreme winds.

Pacific Gas and Electric planned to restore power to 70 percent of affected customers in the North Bay and Sierra Foothills late Monday night. As crews inspect lines for safety by helicopter, vehicles and on foot, the remainder will have power sometime Tuesday.

While it was the first time the company shut off power for public safety, PG&E announced its criteria and procedures for such an event in June, said spokesperson Paul Doherty. After wildfires devastated Northern California's wine country last October, he added, PG&E developed its community wildfire safety program division to make power grids and communities more resilient, and prepares for winter storm season through enhanced local response. 

Two sagging PG&E power lines caused one of those wildfires during heavy winds, killing four people and injuring a firefighter, the California Department of Forestry and Fire Protection determined earlier this month. Trees or tree branches hitting PG&E power lines started another four wildfires in October 2017. Altogether, the power company has been blamed for igniting 13 wildfires last year.

"We're adapting our electric system our operating practices to improve safety and reliability," Doherty said of the safety program. "That's really the bottom line for us."

Turning off power to so many customers was a "last resort given the extreme fire danger conditions these communities are experiencing," Pat Hogan, senior vice president of electric operations, said in a statement. Conditions that led the company to shut off power included the National Weather Service's red flag fire warnings, humidity levels, sustained winds, temperature, dry fuel and local terrain, Doherty said, amid possible rolling blackouts during grid strain.

The company de-energized more than 78 miles of transmission lines and more than 2,150 miles of distribution power lines Sunday night. Many schools in the area were closed Monday because of the planned power outage, highlighting unequal access to electricity across communities.

Late Saturday and early Sunday, PG&E warned 97,000 customers in 12 counties that the shut off might go into effect. Through automated calls, texts and emails, the company encouraged customers to have drinking water, canned food, flashlights, prescriptions and baby supplies on hand.

Power was also turned off in Southern California on Monday.

San Diego Gas & Electric turned off service to about 360 customers near Cleveland National Forest, where multiple fires have scorched large swaths of land in recent years.

SDG&E has pre-emptively shut off power to customers in the past, most recently in December when 14,000 customers went without power.

Southern California Edison, the primary electric provider across Southern California — including Los Angeles — has a similar power shutoff program. As of Monday night, SCE had yet to turn off power in any of its service areas, a spokesperson told USA TODAY.

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Alberta Electricity Market Reforms aim to boost grid reliability and efficiency through a day-ahead market, transmission policy changes, clearer pricing signals, AESO oversight, and smarter siting near existing infrastructure to lower consumer costs.

Key Points

Policies add a day-ahead market and transmission fees to modernize the grid and improve reliability.

✅ Day-ahead market for clearer pricing and scheduling

✅ Up-front, non-refundable transmission payments by generators

✅ AESO to draft new rules by end of 2025

The Alberta government is implementing significant electricity policy changes to its electricity market to enhance system reliability and efficiency. These reforms aim to modernize the grid, accommodate growing energy demands, and align with best practices observed in other jurisdictions.

Proposed Market Reforms

The government has outlined several key initiatives:

• Day-Ahead Market Implementation: Introducing a day-ahead market is intended to provide clearer pricing signals and improve the scheduling of electricity generation. This approach allows market participants to plan and commit to energy production in advance, enhancing grid stability.

• Transmission Policy Revisions: The government proposes reforms to transmission policies, including the introduction of up-front and non-refundable transmission payments from new power generators. These payments would vary based on the proximity of new generators to existing transmission lines with available capacity. As part of a broader market overhaul, this strategy encourages the development of power plants in areas where existing infrastructure can be utilized, potentially reducing costs for consumers and businesses.

Government's Objectives

Minister of Affordability and Utilities, Nathan Neudorf, emphasized that these changes are necessary to meet growing energy demands and modernize Alberta’s electricity system. The government's goal is to create a more reliable and efficient electrical system that benefits both consumers and the broader economy.

Industry Reactions

The proposed reforms have elicited mixed reactions from industry stakeholders amid profound sector change across Alberta:

• Renewable Energy Sector Concerns: The Canadian Renewable Energy Association (CanREA) has expressed concerns about the potential for punitive market and transmission changes, and some retailers have similarly urged caution. They advocate for policies that support the integration of renewable energy sources and ensure fair treatment within the market.

• Regulatory Oversight: The Alberta Electric System Operator (AESO) is tasked with preparing restructured energy market rules by the end of 2025. This timeline reflects the government's commitment to a thorough and consultative approach to market reform.

Implications for Consumers

The Alberta government's proposed market changes aim to enhance the reliability and efficiency of the electricity system by considering measures such as a Rate of Last Resort to provide additional stability. By encouraging the development of power plants in areas with existing infrastructure, the reforms seek to reduce costs for consumers and businesses. However, the success of these initiatives will depend on careful implementation and ongoing engagement with all stakeholders to balance the diverse interests involved.

Alberta's proposed electricity market reforms represent a significant step toward modernizing the province's energy infrastructure. By introducing a day-ahead market and revising transmission policies, the government aims to create a more reliable and efficient electrical system and promote market competition more effectively. While these changes have generated diverse reactions, they underscore the government's commitment to addressing the evolving energy needs of Alberta's residents and businesses.

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Municipal Renewable Energy Procurement surged as cities contracted 3.7 GW of solar and wind, leveraging green tariffs, community solar, and utility partnerships across the Southeast, led by Houston, RMI, and WRI data.

Key Points

The process by which cities contract solar and wind via utilities or green tariffs to meet climate goals.

✅ 3.7 GW procured in 2020, nearly 25% year-over-year growth

✅ Houston runs city ops on 500 MW solar, a record purchase

✅ Southeast cities use green tariffs and community solar

Cities around the country bought more renewable energy last year than ever before, reflecting how renewables may soon provide one-fourth of U.S. electricity across the grid, with some of the most remarkable projects in the Southeast, according to new data unveiled Thursday.

Even amid the pandemic, about eight dozen municipalities contracted to buy nearly 3.7 gigawatts of mostly solar and wind energy — enough to power more than 800,000 homes. The figure is almost a quarter higher than the year before.

Half of the cites listed as “most noteworthy” in Thursday’s release —  from research groups Rocky Mountain Institute and World Resources Institute — are in the region that stretches from Texas to Washington, D.C. 

Houston stands out for the sheer enormity of its purchase: In July, it began powering city operations entirely from nearly 500 megawatts of solar power — the largest municipal purchase of renewable energy ever in the United States, as renewable electricity surpassed coal nationwide.

The groups also feature smaller deals in North Carolina and Tennessee, achieved through a utility partnership called a green tariff.

“We wanted to recognize that Nashville and Charlotte were really blazing a new trail,” said Stephen Abbott, principal at the Rocky Mountain Institute.

And the nation’s capital shows how renewable energy can be a source of revenue: It’s leasing out its public transit station rooftops for 10 megawatts of community solar.

All of these strategies will be necessary for scores of U.S. cities to meet their ambitious climate goals, researchers believe. An interactive clean energy targets tracker shows all 95 clean energy procurements from the year in detail.

Tracker 
Even before former President Donald Trump promised to remove the United States from the Paris Climate Accord, a lack of federal action on climate left a void that some cities and counties were beginning to fill, as renewables hit a record 28% in a recent month. In 2015, the first year tracked by researchers at the Rocky Mountain Institute and the World Resources Institute, municipalities contracted to buy more than 1 gigawatt of wind, solar and other forms of clean energy. 

But when Trump officially set in motion the withdrawal from the climate agreement, the ranks of municipalities dedicated to 100% clean energy multiplied. Today there are nearly 200 of them. The growth in activity last year reflects, in part, that surge of new pledges.

“It takes a while to get city staff up to speed and understand the options, and create the roadmap and then start executing,” Abbott said. “There is a bit of a lag, but we’re starting to see the impact.”

Even in Houston — one of the earliest to begin procuring renewable energy — there has been a steep learning curve as market forces change and prices drop, including cheaper solar batteries shaping procurement strategies, said Lara Cottingham, Houston’s chief of staff and chief sustainability officer.

No matter how well resourced and educated their staff, cities have to clear a thicket of structural, political and economic challenges to procure renewable energy. Most don’t own their own sources of power. Nearly all face budget constraints. Few have enough land or government rooftops to meet their goals within city limits.

“Cities face a situation where it’s a square peg in a round hole,” Cottingham said.

The hurdles are especially steep in much of the Southeast, where only publicly regulated utilities can sell electricity to retail customers, even large ones such as major cities. That’s where a green tariff regime comes in: Cities can purchase clean energy from a third party, such as a solar company, using the utility as a go-between.

Early last year, Charlotte became the largest city to use such a program, partnering with Duke Energy and two North Carolina solar developers to build a solar farm 50 miles north in Iredell County. At first, the city will pay a premium for the energy, but in the latter half of the 20-year contract, as gas prices rise, it will save money compared to business as usual.

“Over the course of 20 years, it’s projected we would save about $2 million,” Katie Riddle, sustainability analyst with Charlotte, told the Energy News Network last year.

The growing size of projects, innovative partnerships like green tariff programs, and the improving economics all give Abbott hope that renewable energy investments from cities will only grow — even with the Trump presidency over and the country back in the Paris agreement.

And when cities meet their goals for procuring renewable energy for their own operations, they must then turn to an even bigger task: reducing the carbon footprint of every person in their jurisdiction with broader decarbonization strategies and community engagement.

“The city needs to do its part for sure,” said Houston’s Cottingham. “Then we have this challenge of how do we get everyone else to.”

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Germany Nuclear Phase-Out reflects a decisive energy policy shift, retiring reactors as firms shun new builds amid high costs, radioactive waste challenges, climate goals, insurance gaps, and debate over small modular reactors and subsidies.

Key Points

Germany's policy to end nuclear plants and block new builds, emphasizing safety, waste, climate goals, and viability.

✅ Driven by safety risks, waste storage limits, and insurance gaps

✅ High capital costs and subsidies make new reactors uneconomic

✅ Political debate persists; SMRs raise cost and proliferation concerns

A year has passed since Germany deactivated its last three nuclear power plants, marking a significant shift in its energy policy.

Nuclear fission once heralded as the future of energy in Germany during the 1960s, was initially embraced with minimal concern for the potential risks of nuclear accidents. As Heinz Smital from Greenpeace recalls, the early optimism was partly driven by national interest in nuclear weapon technology rather than energy companies' initiatives.

Jochen Flasbarth, State Secretary in the Ministry of Development, reflects on that era, noting Germany's strong, almost naive, belief in technology. Germany, particularly the Ruhr region, grappled with smog-filled skies at that time due to heavy industrialization and coal-fired power plants. Nuclear energy presented a "clean" alternative at the time.

This sentiment was also prevalent in East Germany, where the first commercial nuclear power plant came online in 1961. In total, 37 nuclear reactors were activated across Germany, reflecting a widespread confidence in nuclear technology.

However, the 1970s saw a shift in attitudes. Environmental activists protested the construction of new power plants, symbolizing a generational rift. The 1979 Three Mile Island incident in the US, followed by the catastrophic Chornobyl disaster in 1986, further eroded public trust in nuclear energy.

The Chornobyl accident, in particular, significantly dampened Germany's nuclear ambitions, according to Smital. Post-Chernobyl, plans for additional nuclear power plants in Germany, once numbering 60, drastically declined.

The emergence of the Green Party in 1980, rooted in anti-nuclear sentiment, and its subsequent rise to political prominence further influenced Germany's energy policy. The Greens, joining forces with the Social Democrats in 1998, initiated a move away from nuclear energy, facing opposition from the Christian Democrats (CDU) and Christian Social Union (CSU).

However, the Fukushima disaster in 2011 prompted a policy reversal from CDU and CSU under Chancellor Angela Merkel, leading to Germany's eventual nuclear phase-out in March 2023, after briefly extending nuclear power amid the energy crisis.

Recently, the CDU and CSU have revised their stance once more, signaling a potential U-turn on the nuclear phaseout, advocating for new nuclear reactors and the reactivation of the last shut-down plants, citing climate protection and rising fossil fuel costs. CDU leader Friedrich Merz has lamented the shutdown as a "black day for Germany." However, these suggestions have garnered little enthusiasm from German energy companies.

Steffi Lemke, the Federal Environment Minister, isn't surprised by the companies' reluctance, noting their longstanding opposition to nuclear power, which she argues would do little to solve the gas issue in Germany, due to its high-risk nature and the long-term challenge of radioactive waste management.

Globally, 412 reactors are operational across 32 countries, even as Europe is losing nuclear power during an energy crunch, with the total number remaining relatively stable over the years. While countries like China, France, and the UK plan new constructions, there's a growing interest in small, modern reactors, which Smital of Greenpeace views with skepticism, noting their potential military applications.

In Germany, the unresolved issue of nuclear waste storage looms large. With temporary storage facilities near power plants proving inadequate for long-term needs, the search for permanent sites faces resistance from local communities and poses financial and logistical challenges.

Environment Minister Lemke underscores the economic impracticality of nuclear energy in Germany, citing prohibitive costs and the necessity of substantial subsidies and insurance exemptions.

As things stand, the resurgence of nuclear power in Germany appears unlikely, with economic factors playing a decisive role in its future.

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US-Canada Electricity Tariff Dispute intensifies as proposed tariffs spur Canadian threats to restrict hydroelectric exports, risking cross-border energy supply, grid reliability, higher electricity prices, and clean energy goals in the Northeast and Midwest.

Key Points

Trade clash over tariffs and hydroelectric exports that threatens power supply, prices, and grid reliability.

✅ Potential export curbs on Canadian hydro to US markets

✅ Risks: higher prices, strained grids, reduced clean energy

✅ Diplomacy urged to avoid retaliatory trade measures

In early February 2025, escalating trade tensions between the United States and Canada have raised concerns about the future of electricity exports from Canada to the U.S. The potential imposition of tariffs by the U.S. has prompted Canadian officials to consider retaliatory measures, including restricting electricity exports and pursuing high-level talks such as Ford's Washington meeting with federal counterparts.

Background of the Trade Dispute

In late November 2024, President-elect Donald Trump announced plans to impose a 25% tariff on all Canadian products, citing issues related to illegal immigration and drug trafficking. This proposal has been met with strong opposition from Canadian leaders, who view such tariffs as unjustified and detrimental to both economies, even as tariff threats boost support for Canadian energy projects among some stakeholders.

Canada's Response and Potential Retaliatory Measures

In response to the proposed tariffs, Canadian officials have discussed various countermeasures. Ontario Premier Doug Ford has threatened to cut electricity supplies to 1.5 million Americans and ban imports of U.S.-made beer and liquor. Other provinces, such as Quebec and Alberta, are also considering similar actions, though experts advise against cutting Quebec's energy exports due to reliability concerns.

Impact on U.S. Energy Supply

Canada is a significant supplier of electricity to the United States, particularly in regions like the Northeast and Midwest. A reduction or cessation of these exports could lead to energy shortages and increased electricity prices in affected U.S. states, with New York especially vulnerable according to regional assessments. For instance, Ontario exports substantial amounts of electricity to neighboring U.S. states, and any disruption could strain local energy grids.

Economic Implications

The imposition of tariffs and subsequent retaliatory measures could have far-reaching economic consequences. In Canada, industries such as agriculture, manufacturing, and energy could face significant challenges due to reduced access to the U.S. market, even as many Canadians support energy and mineral tariffs as leverage. Conversely, U.S. consumers might experience higher prices for goods and services that rely on Canadian imports, including energy products.

Environmental Considerations

Beyond economic factors, the trade dispute could impact environmental initiatives. Canada's hydroelectric power exports are a clean energy source that helps reduce carbon emissions in the U.S., where policymakers look to Canada for green power to meet targets. A reduction in these exports could lead to increased reliance on fossil fuels, potentially hindering environmental goals.

The escalating trade tensions between the United States and Canada, particularly concerning electricity exports, underscore the complex interdependence of the two nations. While the situation remains fluid, it highlights the need for diplomatic engagement to resolve disputes and maintain the stability of cross-border energy trade.

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