Audits aimed toward energy efficiency

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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SunCrate Solar Microgrid delivers resilient, plug-and-play renewable power to Puerto Rico schools, combining Canadian Solar PV, Tesla Powerwall battery storage, and Black & Veatch engineering to ensure off-grid continuity during outages and disasters.

Key Points

A compact PV-and-battery system for resilient, diesel-free power and microgrid backup at schools and clinics.

✅ Plug-and-play, modular PV, inverter, and battery architecture

✅ Tesla Powerwall storage; Canadian Solar 325 W panels

✅ Scales via daisy-chain for higher loads and microgrids

Eleven months since their three-building school was first plunged into darkness by Hurricane Maria, 140 students in Puerto Rico’s picturesque Yabucoa district have reliable power. Resilient electricity service was provided Saturday to the SU Manuel Ortiz school through an innovative scalable, plug-and-play solar system pioneered by SunCrate Energy with Black & Veatch support. Known as a “SunCrate,” the unit is an effective mitigation measure to back up the traditional power supply from the grid. The SunCrate can also provide sustainable power in the face of ongoing system outages and future natural disasters without requiring diesel fuel.

The humanitarian effort to return sustainable electricity to the K-8 school, found along the island’s hard-hit southeastern coast, drew donated equipment and expertise from a collection of North American companies. Additional support for the Yabucoa project came from Tesla, Canadian Solar and Lloyd Electric, reflecting broader efforts to build a solar-powered grid in Puerto Rico after Hurricane Maria.

“We are grateful for this initiative, which will equip this school with the technology needed to become a resilient campus and not dependent on the status of the power grid. This means that if we are hit with future harmful weather events, the school will be able to open more quickly and continue providing services to students,” Puerto Rico Secretary of Education Julia Keleher said.

The SunCrate harnesses a scalable rapid-response design developed by Black & Veatch and manufactured by SunCrate Energy. Electricity will be generated by an array of 325-W CS6U-Poly modules from Canadian Solar. California-based Tesla contributed advanced battery energy storage through various Powerwall units capable of storing excess solar power and delivering it outside peak generation periods, with related experience from a virtual power plant in Texas informing deployment.  Lloyd Electric Co. of Wichita Falls, Texas, partnered to support delivery and installation of the SunCrate.

“As families in the region begin to prepare for the school year, this community is still impacted by the longest U.S. power outage in history,” said Dolf Ivener, a Midwestern entrepreneur who owns King of Trails Construction and SunCrate Energy, which is donating the SunCrate. “SunCrate, with its rapid deployment and use of renewable energy, should give this school peace of mind and hopefully returns a touch of long-overdue normalcy to students and their parents. When it comes to consistent power, SunCrate is on duty.”

The SunCrate is a portable renewable energy system conceived by Ivener and designed and tested by Black & Veatch. Its modular design uses solar PV panels, inverters and batteries to store and provide electric power in support of critical services such as police, fire, schools, clinics and other community level facilities.

A SunCrate can generate 23 to 156 kWh per day, and store 10 kWh to 135 kWh depending on configuration. A SunCrate’s power generation and storage capacity can be easily scaled through daisy-chained configurations to accommodate larger buildings and loads. Leveraging resources from Tesla, Canadian Solar, Lloyd Electric and Lord Electric, the unit in Yabucoa will provide an estimated 52 kWh of storable power without requiring use of costlier diesel-powered generators and cutting greenhouse gas emissions. Its capabilities allow the school to strengthen its function as a designated Community Emergency Response Center in the event of future natural disasters.

“Canadian Solar has a long history of using solar power to support humanitarian efforts aiding victims of social injustice and natural disasters, including previous donations to Puerto Rico after Hurricane Maria,” said Dr. Shawn Qu, Chairman and Chief Executive Officer of Canadian Solar. “We are pleased to make the difference for these schoolchildren in Yabucoa who have been without reliable power for too long.”

The SunCrate will also substantially lower the school’s ongoing electricity costs by providing a reliable source of renewable energy on site, as falling costs of solar batteries improve project economics overall.

“Through our experience providing engineering services in Puerto Rico for nearly 50 years, including dozens of specialized projects for local government and industrial clients, we see great potential for SunCrate as a source of resilient power for the Commonwealth’s remote schools and communities at large, underscoring the importance of electricity resilience across critical infrastructure,” said Charles Moseley, a Program Director in Black & Veatch’s water business. “We hope that the deployment of the SunCrate in Yabucoa sets a precedent for facility and municipal level migro-grid efforts on the island and beyond.”

SunCrate also has broad potential applications in conflict/post-conflict environments and in rural electrification efforts in the developing world, serving as a resilient source of electricity within hours of its arrival on site and could enable peer-to-peer energy within communities. Of particular benefit, the system’s flexibility cuts fuel costs to a fraction of a generator’s typical consumption when they are used around the clock with maintenance requirements.

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San Francisco Battery-Electric Ferries will deliver zero-emission, high-speed passenger service powered by Wartsila electric propulsion, EPMS, IAS, batteries, and shore power, advancing maritime decarbonization under the REEF program and USCG Subchapter T standards.

Key Points

They are the first US zero-emission high-speed passenger ferries using integrated electric propulsion and shore power

✅ Dual 625 kW motors enable up to 24-knot service speeds

✅ EPMS, IAS, DC hub, and shore power streamline operations

✅ Built to USCG Subchapter T for safety and compliance

Wartsila, a global leader in sustainable marine technology, has been selected to supply the electric propulsion system for the United States' first fully battery-electric, zero-emission high-speed passenger ferries. This significant development marks a pivotal step in the decarbonization of maritime transport, aligning with California's ambitious environmental goals, including recent clean-transport investments across ports and corridors.

A Leap Toward Sustainable Maritime Transport

The project, commissioned by All American Marine (AAM) on behalf of San Francisco Bay Ferry, involves the construction of three 150-passenger ferries, reflecting broader U.S. advances like the Washington State Ferries hybrid upgrade now underway. These vessels will operate on new routes connecting the rapidly developing neighborhoods of Treasure Island and Mission Bay to downtown San Francisco. The ferries are part of the Rapid Electric Emission Free (REEF) Ferry Program, a comprehensive initiative by San Francisco Bay Ferry to transition its fleet to zero-emission propulsion technology. The first vessel is expected to join the fleet in early 2027.

Wärtsilä’s Role in the Project

Wärtsilä's involvement encompasses the supply of a comprehensive electric propulsion system, including the Energy and Power Management System (EPMS), integrated automation system (IAS), batteries, DC hub, transformers, electric motors, and shore power supply. This extensive scope underscores Wärtsilä’s expertise in providing integrated solutions for emission-free marine transportation. The company's extensive global experience in developing and supplying integrated systems and solutions for zero-emission high-speed vessels, as seen with electric ships on the B.C. coast operating today, was a key consideration in the selection process.

Technical Specifications of the Ferries

The ferries will be 100 feet (approximately 30 meters) in length, with a beam of 26 feet and a draft of 5.9 feet. Each vessel will be powered by dual 625-kilowatt electric motors, enabling them to achieve speeds of up to 24 knots. The vessels will be built to U.S. Coast Guard Subchapter T standards, ensuring compliance with stringent safety regulations.

Environmental and Operational Benefits

The transition to battery-electric propulsion offers numerous environmental and operational advantages. Electric ferries produce zero emissions during operation, as demonstrated by Berlin's electric ferry deployments, significantly reducing the carbon footprint of maritime transport. Additionally, electric propulsion systems are generally more efficient and require less maintenance compared to traditional diesel engines, leading to lower operational costs over the vessel's lifespan.

Broader Implications for Maritime Decarbonization

This project is part of a broader movement toward sustainable maritime transport in the United States. San Francisco Bay Ferry has also approved the purchase of two larger 400-passenger battery-electric ferries for transbay routes, further expanding its commitment to zero-emission operations. The agency has secured approximately $200 million in funding from local, state, and federal sources, echoing infrastructure bank support seen in B.C., to support these initiatives, including vessel construction and terminal electrification.

Wartsila’s involvement in this project highlights the company's leadership in the maritime industry's transition to sustainable energy solutions, including hybrid-electric pathways like BC Ferries' new hybrids now in service. With a proven track record in supplying integrated systems for zero-emission vessels, Wärtsilä is well-positioned to support the global shift toward decarbonized maritime transport.

As the first fully battery-electric high-speed passenger ferries in the United States, these vessels represent a significant milestone in the journey toward sustainable and environmentally responsible maritime transportation, paralleling regional advances such as the Kootenay Lake electric-ready ferry entering service. The collaboration between Wärtsilä, All American Marine, and San Francisco Bay Ferry exemplifies the collective effort required to realize a zero-emission future for the maritime industry.

The deployment of these battery-electric ferries in San Francisco Bay not only advances the city's environmental objectives but also sets a precedent for other regions to follow. With continued innovation and collaboration, the maritime industry can look forward to a future where sustainable practices are the standard, not the exception.

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US Nuclear Generating Costs 2017 show USD33.50/MWh for nuclear energy, the lowest since 2008, as capital expenditures, fuel costs, and operating costs declined after license renewals and uprates, supporting a reliable, low-carbon grid.

Key Points

The 2017 US nuclear average was USD33.50/MWh, lowest since 2008, driven by reduced capital, fuel, and operating costs.

✅ Average cost USD33.50/MWh, lowest since 2008

✅ Capital, fuel, O&M costs fell sharply since 2012 peak

✅ License renewals, uprates, market reforms shape competitiveness

Average total generating costs for nuclear energy in 2017 in the USA were at their lowest since 2008, according to a study released by the Nuclear Energy Institute (NEI), amid a continuing nuclear decline debate in other regions.

The report, Nuclear Costs in Context, found that in 2017 the average total generating cost - which includes capital, fuel and operating costs - for nuclear energy was USD33.50 per megawatt-hour (MWh), even as interest in next-generation nuclear designs grows among stakeholders. This is 3.3% lower than in 2016 and more than 19% below 2012's peak. The reduction in costs since 2012 is due to a 40.8% reduction in capital expenditures, a 17.2% reduction in fuel costs and an 8.7% reduction in operating costs, the organisation said.

The year-on-year decline in capital costs over the past five years reflects the completion by most plants of efforts to prepare for operation beyond their initial 40-year licence. A few major items - a series of vessel head replacements; steam generator replacements and other upgrades as companies prepared for continued operation, and power uprates to increase output from existing plants - caused capital investment to increase to a peak in 2012. "As a result of these investments, 86 of the [USA's] 99 operating reactors in 2017 have received 20-year licence renewals and 92 of the operating reactors have been approved for uprates that have added over 7900 megawatts of electricity capacity. Capital spending on uprates and items necessary for operation beyond 40 years has moderated as most plants are completing these efforts," it says.

Since 2013, seven US nuclear reactors have shut down permanently, with the Three Mile Island debate highlighting wider policy questions, and another 12 have announced their permanent shutdown. The early closure for economic reasons of reliable nuclear plants with high capacity factors and relatively low generating costs will have long-term economic consequences, the report warns: replacement generating capacity, when needed, will produce more costly electricity, fewer jobs that will pay less, and, for net-zero emissions objectives, more pollution, it says.

NEI Vice President of Policy Development and Public Affairs John Kotek said the "hardworking men and women of the nuclear industry" had done an "amazing job" reducing costs through the institute's Delivering the Nuclear Promise campaign and other initiatives, in line with IAEA low-carbon lessons from the pandemic. "As we continue to face economic headwinds in markets which do not properly compensate nuclear plants, the industry has been doing its part to reduce costs to remain competitive," he said.

"Some things are in urgent need of change if we are to keep the nation's nuclear plants running and enjoy their contribution to a reliable, resilient and low-carbon grid. Namely, we need to put in place market reforms that fairly compensate nuclear similar to those already in place in New York, Illinois and other states," Kotek added.

Cost information in the study was collected by the Electric Utility Cost Group with prior years converted to 2017 dollars for accurate historical comparison.

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PGE Residential Energy Storage Pilot aggregates 525 home batteries into a virtual power plant, enabling distributed energy resources, smart grid control, renewable energy optimization, demand response, and backup power across Portland General Electric's area.

Key Points

A PGE program aggregating 525 batteries into a utility-run virtual power plant for renewables support and backup power.

✅ Up to 4 MW aggregated capacity from 525 residential batteries

✅ Monthly credits: $40 ($20 with solar) for grid services

✅ Enhances smart grid, DERs, resilience, and outage backup

Portland General Electric Company is set to launch a pilot program that will incentivize installation and connection of 525 residential energy storage batteries that PGE will dispatch, contributing up to four megawatts of energy to PGE's grid. The distributed assets will create a virtual power plant made up of small units that can be operated individually or combined to serve the grid, adding flexibility that supports PGE's transition to a clean energy future. When the program launches this fall, incentives will be available to residential customers across PGE's service area. Rebates will be available to customers within three neighborhoods participating in PGE's Smart Grid Test Bed, and income-qualified customers participating in Energy Trust of Oregon's Solar Within Reach offer.

PGE will study the full benefits of energy storage that these distributed energy assets can provide the grid while also increasing resiliency for each participating customer. PGE will operate and test the benefits of using homes' batteries, each capable of storing 12 to 16 kWh of energy, to optimize the use of renewable energy and grid capabilities. In the event of a power outage, participating customers can rely on them as a backup power resource.

"Our vision for clean energy relies on a smart, integrated grid. One of the ways that we'll achieve that is through creative partnerships and diversified energy resources, including those behind-the-meter," said Larry Bekkedahl, vice president of Grid Architecture, Integration and Systems Operation. "This pilot project will allow PGE to integrate even more intermittent renewable energy and enhance grid capabilities while also giving participating customers peace of mind in the event of an outage."

Energy storage maximizes renewables and the grid, improves power quality

Energy storage, including long-duration energy storage solutions, is vital to help capture and store energy from renewable power sources, such as wind and solar, that are more variable. As a virtual power plant, the residential battery storage pilot will create a single resource that can help the grid balance energy production with energy demand, freeing up the generation resources that are typically held on standby, ready to kick in when the wind doesn't blow or the sun doesn't shine. As a clean energy option that takes the place of standby resources, the virtual power plant also gives customers access to reliable energy, even in the event of system outages.

The test program will also allow PGE to test new smart-grid control devices across its distribution system that will more effectively allow a two-way exchange between PGE and pilot participants. The new controls will more actively manage the way that electricity is distributed across PGE's system to incorporate energy that customers generate, such as through solar panels, while also meeting power demand that is less predictable, such as for charging electric vehicles, supporting EVs for grid stability strategies. The controls will allow PGE to more actively manage power distribution to improve power quality for all customers.

Select rebates and incentives will be available to participants, aligned with electric vehicle programs that encourage transportation electrification

When it launches in fall 2020, participation in the program will be available to residential customers, including:

* Those across PGE's service area who already have or are installing a qualifying battery. Participation will require an application, and in exchange for allowing PGE to operate their battery for grid services, similar to programs where EV owners selling power back for compensation, participating customers will receive a monthly bill credit of $40, or $20 if the battery is charged with solar power.

* Customers across PGE's service area who are participating in the Solar Within Reach offering from Energy Trust of Oregon. Participants will be eligible for a $5,000 instant rebate in addition to the monthly bill credits.

* Those living within the PGE Smart Grid Test Bed who purchase a battery will be eligible for an instant rebate, in addition to the monthly bill credit of $40 or $20, which will allow PGE to test the localized grid impact of having a large concentration of battery storage devices available on one substation and explore interfaces with vehicle-to-grid pilots in the region.

PGE is working with Energy Trust to cost-effectively procure the residential battery storage systems, as utilities invest in advanced storage solutions across the region, by leveraging the existing Solar incentive program infrastructure and trade ally contractor network. Customers who participate in the program will own their battery systems, and rebates will only be available for systems installed by an Energy Trust solar trade ally. The program may also accept customers with a qualifying battery that is was previously installed, following a process to ensure safe operation.

More information about Portland General Electric's energy storage program is available at PortlandGeneral.com/energystorage and will be updated with details about the residential battery storage pilot program.

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B.C. EV Charging Rebates boost CleanBC incentives as NRCan and ZEVIP funding covers up to 75% of Level 2 and DC fast-charger purchase and installation costs for homes, workplaces, condos, apartments, and fleet operators.

Key Points

Incentives in B.C. cover up to 75% of Level 2 and DC fast charger costs for homes, workplaces, and fleets.

✅ Up to 75% back; Level 2 max $5,000; DC fast max $75,000 for fleets.

✅ Eligible sites: homes, workplaces, condos, apartments, fleet depots.

✅ Funded by CleanBC with NRCan ZEVIP; time-limited top-up.

The Province and Natural Resources Canada (NRCan) are making it more affordable for people to install electric vehicle (EV) charging stations in their homes, businesses and communities, as EV demand ramps up across the province.

B.C. residents, businesses and municipalities can receive higher rebates for EV charging stations through the CleanBC Go Electric EV Charger Rebate and Fleets programs. For a limited time, funding will cover as much as 75% of eligible purchase and installation costs for EV charging stations, which is an increase from the previous 50% coverage.

“With electric vehicles representing 13% of all new light-duty vehicles sold in B.C. last year, our province has the strongest adoption rate of electric vehicles in Canada. We’re positioning ourselves to become leaders in the EV industry,” said Bruce Ralston, B.C.’s Minister of Energy, Mines and Low Carbon Innovation. “We’re working with our federal partners to increase rebates for home, workplace and fleet charging, and making it easier and more affordable for people to make the switch to electric vehicles.”

With a $2-million investment through NRCan’s Zero-Emission Vehicle Infrastructure Program (ZEVIP) to top up the Province’s EV Charger Rebate program, workplaces, condominiums and apartments can get a rebate for a Level 2 charging station for as much as 75% of purchase and installation costs to a maximum of $5,000. As many as 360 EV chargers will be installed through the program.

“We’re making electric vehicles more affordable and charging more accessible where Canadians live, work and play,” said Jonathan Wilkinson, federal Minister of Natural Resources. “Investing in more EV chargers, like the ones announced today in British Columbia, will put more Canadians in the driver’s seat on the road to a net-zero future and help achieve our climate goals.”

Through the CleanBC Go Electric Fleets program and in support of B.C. businesses that own and operate fleet vehicles, NRCan has invested $1.54 million through ZEVIP to top up rebates. Fleet operators can get combined rebates from NRCan and the Province for a Level 2 charging station as much as 75% to a maximum of $5,000 of purchase and installation costs, and 75% to a maximum of $75,000 for a direct-current, fast-charging station. As many as 450 EV chargers will be installed through the program.

CleanBC is a pathway to a more prosperous, balanced and sustainable future. It supports government’s commitment to climate action to meet B.C.’s emission targets and build a cleaner, stronger economy.

Quick Facts:

• A direct-current fast charger on the BC Electric Highway allows an EV to get 100-300 kilometres of range from 30 minutes of charging.
• Faster chargers, which give more range in less time, are coming out every year.
• A Level 2 charger allows an EV to get approximately 30 kilometres of range per hour of charging.
• It uses approximately the same voltage as a clothes dryer and is usually installed in homes, workplaces or for fleets to get a faster charge than a regular outlet, or in public places where people might park for a longer time.
• A key CleanBC action is to strengthen the Zero-Emission Vehicles Act to require light-duty vehicle sales to be 26% zero-emission vehicles (ZEVs) by 2026, 90% by 2030 and 100% by 2035, five years ahead of the original target.
• At the end of 2021, B.C. had more than 3,000 public EV charging stations and almost 80,000 registered ZEVs.

Learn More:

To learn more about home and workplace EV charging-station rebates, eligibility and application processes, visit: https://goelectricbc.gov.bc.ca/   

To learn more about the Fleets program, visit: https://pluginbc.ca/go-electric-fleets/    

To learn more about Natural Resources Canada’s Zero-Emission Vehicle Infrastructure Program, visit:
https://www.nrcan.gc.ca/energy-efficiency/transportation-alternative-fuels/zero-emission-vehicle-infrastructure-program/21876

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