Stretching wire generates current

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Researchers at Georgia Tech have developed a new type of electric power generator able to produce AC current through cyclical stretching and releasing of zinc oxide wires. The new “flexible charge pump” generator is the fourth generation of devices designed to produce electrical current by using the piezoelectric properties of zinc oxide structures to harvest mechanical energy from the environment.

“The flexible charge pump offers yet another option for converting mechanical energy into electrical energy,” says Zhong Lin Wang, director of the Center for Nanostructure Characterization at the Georgia Institute of Technology. The generator can produce an oscillating output voltage of up to 45 millivolts. To boost the current produced, arrays of the flexible charge pumps could be constructed and connected in series. Multiple layers of the generators could also be stacked to form modules that could be implanted in the human body to power blood pressure sensors or other devices.

When the modules are mechanically stretched and released, the zinc oxide material generates a piezoelectric potential that alternately builds up and then is released. The wires are encapsulated in a flexible plastic substrate with two bonded ends; a Schottky barrier controls the alternating flow of electrons, and the piezoelectric potential is the driving force of the charge pump.

To measure generated electric energy in tests, researchers subjected the substrate and attached zinc oxide wires to periodic mechanical bending created by a motor-driven mechanical arm. Bending induces tensile strain, which creates a piezoelectric potential field along the laterally packaged wires. That in turn drives a flow of electrons into an external circuit, creating the alternating charge and discharge cycle – and corresponding current flow. Wang envisions a family of small-scale generators enabling development of a new class of self-powered wireless sensing systems that could gather, store, and transmit information without an external power source.

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Turning thermal energy into electricity

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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Energy Vault Lands $110M From SoftBank’s Vision Fund for Gravity Storage

Energy Vault Gravity Storage uses crane-stacked concrete blocks to deliver long-duration, grid-scale renewable energy; a SoftBank Vision Fund-backed, pumped-hydro analog enabling baseload power and a lithium-ion alternative with proprietary control algorithms.

 

Key Points

Gravity-based cranes stack blocks to store and dispatch power for hours, enabling grid-scale, low-cost storage.

✅ 4 MW/35 MWh modules; ~9-hour duration

✅ Estimated $200-$250/kWh; lower LCOE than lithium-ion

✅ Backed by SoftBank Vision Fund; Cemex and Tata support

 

Energy Vault, the Swiss-U.S. startup that says it can store and discharge electrical energy through a super-sized concrete-and-steel version of a child’s erector set, has landed a $110 million investment from Japan’s SoftBank Vision Fund to take its technology to commercial scale.

Energy Vault, a spinout of Pasadena-based incubator Idealab and co-founded by Idealab CEO and billionaire investor Bill Gross, unstealthed in November with its novel approach to using gravity to store energy.

Simply put, Energy Vault plans to build storage plants — dubbed “Evies” — consisting of a 35-story crane with six arms, surrounded by a tower consisting of thousands of concrete bricks, each weighing about 35 tons.

This plant will “store” energy by using electricity to run the cranes that lift bricks from the ground and stack them atop of the tower, and “discharge” energy by reversing that process. It’s a mechanical twist on the world’s most common energy storage technology, pumped hydro, which “stores” energy by pumping water uphill, and lets it fall to spin turbines when electricity is needed, even as California funds 100-hour long-duration storage pilots to expand flexibility worldwide.

But behind this simplicity lies some heavy-duty software to orchestrate the cranes and blocks, with a "unique stack of proprietary algorithms" to balance energy supply and demand, volatility, grid stability, weather elements and other variables.

CEO and co-founder Robert Piconi said in a November interview with GTM that the standard array would deliver 4 megawatts/35 megawatt-hours of storage, which translates to nearly 9 hours of duration — the equivalent of building the tower to its height, and then reducing it to ground level. It can be built on-site in partnership with crane manufacturers and recycled concrete material, and can run fully automated for decades with little deterioration, he said.

And the cost, which Piconi pegged in the $200 to $250 per kilowatt-hour range, with room to decline further, is roughly 50 percent below the upfront price of the conventional storage market today, and 80 percent below it on levelized cost, he said, a trend utilities see benefits in as they plan resources.

The result, according to Wednesday’s statement, is a technology that could allow “renewables to deliver baseload power for less than the cost of fossil fuels 24 hours a day,” in applications such as community microgrids serving low-income housing.

Wednesday’s announcement builds on a recent investment from Mexico's Cemex Ventures, the corporate venture capital unit of building materials giant Cemex, along with a promise of deployment support from Cemex's strategic network, and also follows project financing for a California green hydrogen microgrid led by the company. Piconi said in November that the company had sufficient investment from two funding rounds to carry it through initial customer deployments, though he declined to disclose figures.

This is the first energy storage investment for Vision Fund, the $100 billion venture fund set up by SoftBank founder Masayoshi Son. While large by startup standards, it’s in keeping with the capital costs that Energy Vault will face in scaling up its technology to meet its commitments, amid mounting demand in regions like Ontario energy storage that face supply crunches. Those include a 35 megawatt-hour order with Tata Power Company, the energy-producing arm of the Indian industrial conglomerate, first unveiled in November, as well as plans to demonstrate its first storage tower in northern Italy in 2019.

For Vision Fund, it’s also an unusual choice for a storage investment, given that the vast majority of venture capital in the industry today is being directed toward lithium-ion batteries, and even Mercedes-Benz energy storage ventures targeting the U.S. market. Lithium-ion batteries are limited in terms of how many hours they can provide cost-effectively, with about 4 hours being seen as the limit today.

The search for long-duration energy storage has driven investment into flow battery technologies such as grid-scale vanadium systems deployed on utility networks, compressed-air energy storage and variations on gravity-based storage, including a previous startup backed by Gross and Idealab, Energy Cache, whose idea of using a ski lift carrying buckets of gravel up a hill to store energy petered out with a 50-kilowatt pilot project.

 

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Drought, lack of rain means BC Hydro must adapt power generation

BC Hydro drought operations address climate change impacts with hydropower scheduling, reservoir management, water conservation, inflow forecasting, and fish habitat protection across the Lower Mainland and Vancouver Island while maintaining electricity generation from storage facilities.

 

Key Points

BC Hydro drought operations conserve water, protect fish, and sustain hydropower during extended heat and low inflows.

✅ Proactive reservoir releases protect downstream salmon spawning.

✅ Reduced flows at Puntledge, Coquitlam, and Ruskin/Stave facilities.

✅ System relies on northern storage to maintain electricity supply.

 

BC Hydro is adjusting its operating plans around power generation as extended heat and little forecast rain continue to impact the province, a report says.

“Unpredictable weather patterns related to climate change are expected to continue in the years ahead and BC Hydro is constantly adapting to these evolving conditions, especially after events such as record demand in 2021 that tested the grid,” said the report, titled “Casting drought: How climate change is contributing to uncertain weather and how BC Hydro’s generation system is adapting.”

The study said there is no concern with BC Hydro being able to continue to deliver power through the drought because there is enough water at its larger facilities, even as issues like crypto mining electricity use draw scrutiny from observers.

Still, it said, with no meaningful precipitation in the forecast, its smaller facilities in the Lower Mainland and on Vancouver Island will continue to see record low or near record low inflows for this time of the year.

“In the Lower Mainland, inflows since the beginning of September are ranked in the bottom three compared to historical records,” the report said.

The report said the hydroelectric system is directly impacted by variations in weather and the record-setting, unseasonably dry and warm weather this fall highlights the impacts of climate change, while demand patterns can be counterintuitive, as electricity use even increased during Earth Hour 2018 in some areas, hinting at challenges to come.

It noted symptoms of climate change include increased frequency of extreme events like drought and intense storms, and rapid glacial melt.

“With the extremely hot and dry conditions, BC Hydro has been taking proactive steps at many of our South Coast facilities for months to conserve water to protect the downstream fish habit,” spokesperson Mora Scott said. “We began holding back water in July and August at some facilities anticipating the dry conditions to help ensure we would have water storage for the later summer and early fall salmon spawning.”

Scott said BC Hydro’s reservoirs play an important role in managing these difficult conditions by using storage and planning releases to provide protection to downstream river flows. The reservoirs are, in effect, a battery waiting to be used for power.

While the dry conditions have had an impact on BC Hydro’s watersheds, several unregulated natural river systems — not related to BC Hydro — have fared worse, with rivers drying up and thousands of fish killed, the report said.

BC Hydro is currently seeing the most significant impacts on operations at Puntledge and Campbell River on Vancouver Island as well as Coquitlam and Ruskin/Stave in the Lower Mainland.

To help manage water levels on Vancouver Island, BC Hydro reduced Puntledge River flows by one-third last week and on the Lower Mainland reduced flows at Coquitlam by one-third and Ruskin/Stave by one quarter.

However, the utility company said, there are no concerns about continued power delivery.

“British Columbians benefit from BC Hydro’s integrated, provincial electricity system, which helps send power across the province, including to Vancouver Island, and programs like the winter payment plan support customers during colder months,” staff said.

Most of the electricity generated and used in B.C. is produced by larger facilities in the north and southeast of the province — and while water levels in those areas are below normal levels, there is enough water to meet the province’s power needs, even as additions like Site C's electricity remain a subject of debate among observers.

The Glacier Media investigation found a quarter of BC Hydro's power comes from the Mica, Revelstoke and Hugh Keenleyside dams on the Columbia River. Some 29% comes from dams in the Peace region, including the under-construction Site C project that has faced cost overruns. At certain points of the year, those reservoirs are reliant on glacier water.

Still, BC Hydro remains optimistic.

Forecasts are currently showing little rain in the near-term; however, historically, precipitation and inflows show up by the end of October. If that does not happen, BC Hydro said it would continue to closely track weather and inflow forecasts to adapt its operations to protect fish, while regional cooperation such as bridging with Alberta remains part of broader policy discussions.

Among things BC Hydro said it is doing to adapt are:

Continuously working to improve its weather and inflow forecasting;
Expanding its hydroclimate monitoring technology, including custom-made solutions that have been designed in-house, as well as upgrading snow survey stations to automated, real-time snow and climate stations, and;
Investing in capital projects — like spillway gate replacements — that will increase resiliency of the system to climate change.

 

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Romania enhances safety at Cernavoda, IAEA reports

IAEA OSART Cernavoda highlights strengthened operational safety at Romania’s Cernavoda NPP, citing improved maintenance practices, simulator training, and deficiency reporting, with ongoing actions on spare parts procurement, procedure updates, and chemical control for nuclear compliance.

 

Key Points

An IAEA follow-up mission confirming improved operational safety at Cernavoda NPP, with remaining actions tracked.

✅ Enhanced simulator training and crew performance

✅ Improved field deficiency identification and reporting

✅ Ongoing upgrades to procedures, spares, and chemical control

 

The International Atomic Energy Agency (IAEA) said yesterday that the operator of Romania’s Cernavoda nuclear power plant had demonstrated "strengthened operational safety" by addressing the findings of an initial IAEA review in 2016. The Operational Safety Review Team (OSART) concluded a five-day follow-up mission on 8 March to the Cernavoda plant, which is on the Danube-Black Sea Canal, about 160 km from Bucharest.

The plant's two 706 MWe CANDU pressurised heavy water reactors, reflecting Canadian nuclear projects, came online in 1996 and 2007, respectively.

The OSART team was led by Fuming Jiang, a senior nuclear safety officer at the IAEA, which recently commended China's nuclear security in separate assessments.

"We saw improvements in key areas, such as the procurement of important spare parts, the identification and reporting of some deficiencies, and some maintenance work practices, as evidenced by relevant performance indicators," Jiang said, noting milestones at nuclear projects worldwide this year.

The team observed that several findings from the 2016 review had been fully addressed, including: enhanced operator crew performance during simulator training; better identification and reporting of deficiencies in the field; and improvement in maintenance work practices.

More time is required, it said, to fully implement some actions, including: further improvements in the procurement of important spare parts with relevance to safety; further enhancement in the revision and update of some operating procedures, drawing on lessons from Pickering NGS life extensions undertaken in Ontario; and control and labelling of some plant chemicals.

Dan Bigu, site vice president of Cernavoda NPP, said the 2016 mission had "proven to be very beneficial", adding that the current follow-up mission would "provide further catalyst support to our journey to nuclear excellence".

The team provided a draft report of the mission to the plant's management and a final report will be submitted to the Romanian government, which recently moved to terminate talks with a Chinese partner on a separate nuclear project, within three months.

OSART missions aim to improve operational safety by objectively assessing safety performance, even as the agency reports mines at Ukraine's Zaporizhzhia plant amid ongoing risks, using the IAEA's safety standards and proposing recommendations and suggestions for improvement where appropriate. The follow-up missions are standard components of the OSART programme and, as the IAEA has warned of risks from attacks on Ukraine's power grids, are typically conducted within two years of the initial mission.

 

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Russia Builds Power Lines to Reactivate Zaporizhzhia Plant

Zaporizhzhia Nuclear Plant Restart signals new high-voltage transmission lines to Mariupol, Rosatom grid integration, and IAEA-monitored safety amid occupied territory risks, cooling system shortfalls after the Kakhovka dam collapse, and disputed international law.

 

Key Points

A Russian plan to reconnect and possibly restart ZNPP via power lines, despite IAEA safety, cooling, and legal risks.

✅ 80 km high-voltage link toward Mariupol confirmed by imagery

✅ IAEA warns of safety risks and militarization at the site

✅ Cooling capacity limited after Kakhovka dam destruction

 

Russia is actively constructing new power lines to facilitate the restart of the Zaporizhzhia Nuclear Power Plant (ZNPP), Europe's largest nuclear facility, which it seized from Ukraine in 2022. Satellite imagery analyzed by Greenpeace indicates the construction of approximately 80 kilometers (50 miles) of high-voltage transmission lines and pylons connecting the plant to the Russian-controlled port city of Mariupol. This development marks the first tangible evidence of Russia's plan to reintegrate the plant into its energy infrastructure.

Strategic Importance of Zaporizhzhia Nuclear Power Plant

The ZNPP, located on the eastern bank of the Dnipro River in Enerhodar, was a significant asset in Ukraine's energy sector before its occupation. Prior to the war, the plant was connected to Ukraine's national grid, which later saw resumed electricity exports, via four 750-kilovolt lines, two of which passed through Ukrainian-controlled territory and two through areas under Russian control. The ongoing conflict has damaged these lines, complicating efforts to restore the plant's operations.

In March 2022, Russian forces captured the plant, and by 2023, all six of its reactors had been shut down. Despite this, Russian authorities have expressed intentions to restart the facility. Rosatom, Russia's state nuclear corporation, has identified replacing the power grid as one of the critical steps necessary for resuming operations, even as Ukraine pursues more resilient wind power to bolster its energy mix.

Environmental and Safety Concerns

The construction of new power lines and the potential restart of the ZNPP have raised significant environmental and safety concerns, as the IAEA has warned of nuclear risks from grid attacks in recent assessments. Greenpeace has reported that the plant's cooling system has been compromised due to the destruction of the Kakhovka Reservoir dam in 2023, which previously supplied cooling water to the plant. Currently, the plant relies on wells for cooling, which are insufficient for full-scale operations.

Additionally, the International Atomic Energy Agency (IAEA) has expressed concerns about the militarization of the plant. Reports indicate that Russian forces have established defensive positions and trenches around the facility, with mines found at ZNPP by UN inspectors, raising the risk of accidents and complicating efforts to ensure the plant's safety.

International Reactions and Legal Implications

Ukraine and the international community have condemned Russia's actions as violations of international law and Ukrainian sovereignty. Ukrainian officials have argued that the construction of power lines and the potential restart of the ZNPP constitute illegal activities in occupied territory. The IAEA has called for a ceasefire to allow for necessary safety improvements and to facilitate inspections of the plant, as a possible agreement on power plant attacks could underpin de-escalation efforts.

The United States has also expressed concerns, with President Donald Trump reportedly proposing the inclusion of the ZNPP in peace negotiations, which sparked controversy among Ukrainian and international observers, even suggesting the possibility of transferring control to American companies. However, Russia has rejected such proposals, reaffirming its intention to maintain control over the facility.

The construction of new power lines to the Zaporizhzhia Nuclear Power Plant signifies Russia's commitment to reintegrating the facility into its energy infrastructure. However, this move raises significant environmental, safety, and legal concerns, and a proposal to control Ukraine's nuclear plants remains controversial among stakeholders. The international community continues to monitor the situation closely, urging for adherence to international laws and standards to prevent potential nuclear risks.

 

 

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Renewable energy now cheapest option for new electricity in most of the world: Report

Renewable Energy Cost Trends highlight IRENA data showing solar and wind undercut coal, as utility-scale projects drive lower levelized electricity costs worldwide, with the Middle East and UAE advancing mega solar parks.

 

Key Points

They track how solar and wind undercut new fossil fuels as utility-scale costs drop and investment accelerates.

✅ IRENA reports renewables cheapest for new installations

✅ Solar and wind LCOE fell sharply since 2010

✅ Middle East and UAE scale mega utility projects

 

Renewable energy is now the cheapest option for new electricity installation in most of the world, a report from the International Renewable Energy Agency (IRENA) on Tuesday said.

Renewable power projects have undercut traditional coal fuel plants, with solar and wind power costs in particular falling as record-breaking growth continues worldwide.

“Installing new renewables increasingly costs less than the cheapest fossil fuels. With or without the health and economic crisis, dirty coal plants were overdue to be consigned to the past, said Francesco La Camera, director-general of IRENA said in the report.

In 2019, renewables accounted for around 72 percent of all new capacity added worldwide, IRENA said, following a 2016 record year that highlighted the momentum, with lowering costs and technological improvements in solar and wind power helping this dynamic. For solar energy, IRENA notes that the cost for electricity from utility-scale plants fell by 82 percent in the decade between 2010 and 2019, as China's solar PV growth underscored in 2016.

“More than half of the renewable capacity added in 2019 achieved lower electricity costs than new coal, while new solar and wind projects are also undercutting the cheapest and least sustainable of existing coal-fired plants,” Camera added.

Costs for solar and wind power also fell year-on-year by 13 and 9 percent, respectively, with offshore wind costs showing steep declines as well. In 2019, more than half of all newly commissioned utility-scale renewable power plants provided electricity cheaper than the lowest cost of a new fossil fuel plant.

The Middle East

In mid-May, a report by UK-based law firm Ashurst suggested the Middle East is the second most popular region for renewable energy investment after North America, at a time when clean energy investment is outpacing fossil fuels.

The region is home to some of the largest renewable energy bets in the world, with Saudi wind expansion gathering pace. The UAE, for instance, is currently developing the Mohammed Bin Rashid Solar Park, the world’s largest concentrated solar power project in the world.

Around 26 percent of Middle East respondents in Ashurst’s survey said that they were presently investing in energy transition, marking the region as the most popular for current investment in renewables, while 11 percent added that they were considering investing.

In North America, the most popular region, 28 percent said that they were currently investing, with 11 percent stating they are considering investing.

 

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