Northern premiers look for green funds

US Summer Electricity Outlook 2022 projects rising renewable energy generation as utility-scale solar and wind capacity additions surge, while coal declines and natural gas shifts amid higher fuel prices and regional supply constraints.

Key Points

An EIA forecast of summer 2022 power: more solar and wind, less coal, and shifting gas use amid higher fuel prices.

✅ Solar +10 million MWh; wind +8 million MWh vs last summer

✅ Coal generation -20 million MWh amid supply constraints, retirements

✅ Gas prices near $9/MMBtu; slight national gen decline

In our Summer Electricity Outlook, a supplement to our May 2022 Short-Term Energy Outlook, we expect the largest increases in U.S. electric power sector generation this summer will come from renewable energy sources such as wind and solar generation. These increases are the result of new capacity additions. We forecast utility-scale solar generation between June and August 2022 will grow by 10 million megawatthours (MWh) compared with the same period last summer, and wind generation will grow by 8 million MWh. Forecast generation from coal and natural gas declines by 26 million MWh this summer, although natural gas generation could increase in some electricity markets where coal supplies are constrained.

For recent context, overall U.S. power generation in January rose 9.3% year over year, the EIA reports.

Wind and solar power electric-generating capacity has been growing steadily in recent years. By the start of June, we estimate the U.S. electric power sector will have 65 gigawatts (GW) of utility-scale solar-generating capacity, a 31% increase in solar capacity since June 2021. Almost one-third of this new solar capacity will be built in the Texas electricity market. The electric power sector will also have an estimated 138 GW of wind capacity online this June, which is a 12% increase from last June.

Along with growth in renewables capacity, we expect that an additional 6 GW of new natural gas combined-cycle generating capacity will come online by June 2022, an increase of 2% from last summer. Despite this increase in capacity, we expect natural gas-fired electricity generation at the national level will be slightly (1.3%) lower than last summer.

We forecast the price of natural gas delivered to electric generators will average nearly $9 per million British thermal units between June and August 2022, which would be more than double the average price last summer. The higher expected natural gas prices and growth in renewable generation will likely lead to less natural gas-fired generation in some regions of the country.

In contrast to renewables and natural gas, the electricity industry has been steadily retiring coal-fired power plants over the past decade. Between June 2021 and June 2022, the electric power sector will have retired 6 GW (2%) of U.S. coal-fired generating capacity.

In previous years, higher natural gas prices would have resulted in more coal-fired electricity generation across the fleet. However, coal-fired power plants have been limited in their ability to replenish their historically low inventories in recent months as a result of mine closures, rail capacity constraints, and labor market tightness. These coal supply constraints, along with continued retirement of generating capacity, contribute to our forecast that U.S. coal-fired generation will decline by 20 million MWh (7%) this summer. In some regions of the country, these coal supply constraints may lead to increased natural gas-fired electricity generation despite higher natural gas prices.
 

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Nuclear Power Resilience During COVID-19 shows low-carbon electricity supporting renewables integration with grid flexibility, reliability, and inertia, sustaining decarbonization, stable baseload, and system security while prices fell and demand dropped across markets.

Key Points

It shows nuclear plants providing reliable, low-carbon power and supporting grid stability despite demand declines.

✅ Low prices challenge investment; lifetime extensions are cost-effective.

✅ Nuclear provides inertia, reliability, and dispatchable capacity.

✅ Market reforms should reward flexibility and grid services.

The COVID-19 pandemic has transformed the operation of power systems across the globe, including European responses that many argue accelerated the transition, and offered a glimpse of a future electricity mix dominated by low carbon sources.

The performance of nuclear power, in particular, demonstrates how it can support the transition to a resilient, clean energy system well beyond the COVID-19 recovery phase, and its role in net-zero pathways is increasingly highlighted by analysts today.

Restrictions on economic and social activity during the COVID-19 outbreak have led to an unprecedented and sustained decline in demand for electricity in many countries, in the order of 10% or more relative to 2019 levels over a period of a few months, thereby creating challenging conditions for both electricity generators and system operators (Fig. 1). The recent Sustainable Recovery Report by the International Energy Agency (IEA) projects a 5% reduction in global electricity usage for the entire year 2020, with a record 5.7% decline foreseen in the United States alone. The sustainable economic recovery will be discussed at today's IEA Clean Energy Transitions Summit, where Fatih Birol's call to keep options open will be prominent as IAEA Director General Rafael Mariano Grossi participates.

Electricity generation from fossil fuels has been hard hit, due to relatively high operating costs compared to nuclear power and renewables, as well as simple price-setting mechanisms on electricity markets. By contrast, low-carbon electricity prevailed during these extraordinary circumstances, with the contribution of renewable electricity rising in a number of countries as analyses see renewables eclipsing coal by 2025, due to an obligation on transmission system operators to schedule and dispatch renewable electricity ahead of other generators, as well as due to favourable weather conditions.

Nuclear power generation also proved to be resilient, reliable and adaptable. The nuclear industry rapidly implemented special measures to cope with the pandemic, avoiding the need to shut down plants due to the effects of COVID-19 on the workforce or supply chains. Nuclear generators also swiftly adapted to the changed market conditions. For example, EDF Energy was able to respond to the need of the UK grid operator by curtailing sporadically the generation of its Sizewell B reactor and maintain a cost-efficient and secure electricity service for consumers.

Despite the nuclear industry's performance during the pandemic, faced with significant decreases in demand, many generators have still needed to reduce their overall output appreciably, for example in France, Sweden, Ukraine, the UK and to a lesser extent Germany (Fig. 2), even as the nuclear decline debate continues in Europe. Declining demand in France up to the end of March already contributed to a 1% drop in first quarter revenues at EDF, with nuclear output more than 9% lower than in the year before. Similarly, Russia's Rosatom experienced a significant demand contraction in April and May, contributing to an 11% decline in revenues for the first five months of the year.

Overall, the competitiveness and resilience of low carbon technologies have resulted in higher market shares for nuclear, solar and wind power in many countries since the start of lockdowns (Fig. 3), and low-emissions sources to meet demand growth over the next three years. The share of nuclear generation in South Korea rose by almost 9 percentage points during the pandemic, while in the UK, nuclear played a big part in almost eliminating coal generation for a period of two months. For the whole of 2020, the US Energy Information Administration's Short-Term Energy Outlook sees the share of nuclear generation increasing by more than one percentage point compared to 2019. In China, power production decreased during January-February 2020 by more than 8% year on year: coal power decreased by nearly 9%, hydropower by nearly 12%. Nuclear has proved more resilient with a 2% reduction only. The benefits of these higher shares of clean energy in terms of reduced emissions of greenhouse gases and other air pollutants have been on full display worldwide over the past months.

Challenges for the future

Despite the demonstrated performance of a cleaner energy system through the crisis - including the capacity of existing nuclear power plants to deliver a competitive, reliable, and low carbon electricity service when needed - both short- and long-term challenges remain.

In the shorter term, the collapse in electricity demand has accelerated recent falls in electricity prices, particularly in Europe (Fig. 4), from already economically unsustainable levels. According to Standard and Poor's Midyear Update, the large price drops in Europe result from not only COVID-19 lockdown measures but also collapsing demand due to an unusually warm winter, increased supply from renewables in a context of lower gas prices and CO2 allowances . Such low prices further exacerbate the challenging environment faced by many electricity generators, including nuclear plants. These may impede the required investments in the clean energy transition, with longer term consequences on the achievement of climate goals.

For nuclear power, maintaining and extending the operation of existing plants is essential to support and accelerate the transition to low carbon energy systems. With a supportive investment environment, a 10-20 year lifetime extension can be realized at an average cost of US $30-40/MW*h, making it among the most cost-effective low-carbon options, while also maintaining dispatchable capacity and lowering the overall cost of the clean energy transition. The IEA Sustainable Recovery report indicates that without such extensions 40% of the nuclear fleet in developed economies may be retired within a decade, adding around US$ 80 billion per year to electricity bills. The IEA note the potential for nuclear plant maintenance and extension programmes to support recovery measures by generating significant economic activity and employment.

The need for flexibility

New nuclear power projects can provide similar economic and environmental benefits and applications beyond electricity, but will be all the more challenging to finance without strong policy support and more substantive power market reforms, including improved frameworks for remunerating reliability, flexibility and other services. The need for flexibility in electricity generation and system operation - a trend accelerated by the crisis - will increasingly characterize future energy systems over the medium to longer term.

Looking further ahead, while generators and system operators successfully responded to the crisis, the observed decline in fossil fuel generation draws attention to additional grid stability challenges likely to emerge further into the energy transition. Heavy rotating steam and gas turbines provide mechanical inertia to an electricity system, thereby maintaining its balance. Replacing these capacities with variable renewables may result in greater instability, poorer power quality and increased incidence of blackouts. Large nuclear power plants along with other technologies can fill this role, alleviating the risk of supply disruptions in fully decarbonized electricity systems.

The challenges created by COVID-19 have also brought into focus the need to ensure resilience is built-in to future energy systems to cope with a broader range of external shocks, including more variable and extreme weather patterns expected from climate change.

The performance of nuclear power during the crisis provides a timely reminder of its ongoing contribution and future potential in creating a more sustainable, reliable, low carbon energy system.

Data sources for electricity demand, generation and prices: European Network of Transmission System Operators for Electricity (Europe), Ukrenergo National Power Company (Ukraine), Power System Operation Corporation (India), Korea Power Exchange (South Korea), Operador Nacional do Sistema Eletrico (Brazil), Independent Electricity System Operator (Ontario, Canada), EIA (USA). Data cover 1 January to May/June.

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Hourly Electricity Emissions Tracking maps grid balancing areas, embodied emissions, and imports/exports, revealing carbon intensity shifts across PJM, ERCOT, and California ISO, and clarifying renewable energy versus coal impacts on health and climate.

Key Points

An hourly method tracing generation, flows, and embodied emissions to quantify carbon intensity across US balancing areas.

✅ Hourly traces of imports/exports and generation mix

✅ Consumption-based carbon intensity by balancing area

✅ Policy insights for renewables, coal, health costs

In the United States, electricity generation accounts for nearly 30% of our carbon emissions. Some states have responded to that by setting aggressive renewable energy standards; others are hoping to see coal propped up even as its economics get worse. Complicating matters further is the fact that many regional grids are integrated, and as America goes electric the stakes grow, meaning power generated in one location may be exported and used in a different state entirely.

Tracking these electricity exports is critical for understanding how to lower our national carbon emissions. In addition, power from a dirty source like coal has health and environment impacts where it's produced, and the costs of these aren't always paid by the parties using the electricity. Unfortunately, getting reliable figures on how electricity is produced and where it's used is challenging, even for consumers trying to find where their electricity comes from in the first place, leaving some of the best estimates with a time resolution of only a month.

Now, three Stanford researchers—Jacques A. de Chalendar, John Taggart, and Sally M. Benson—have greatly improved on that standard, and they have managed to track power generation and use on an hourly basis. The researchers found that, of the 66 grid balancing areas within the United States, only three have carbon emissions equivalent to our national average, and they have found that imports and exports of electricity have both seasonal and daily changes. de Chalendar et al. discovered that the net results can be substantial, with imported electricity increasing California's emissions/power by 20%.

Hour by hour
To figure out the US energy trading landscape, the researchers obtained 2016 data for grid features called balancing areas. The continental US has 66 of these, providing much better spatial resolution on the data than the larger grid subdivisions. This doesn't cover everything—several balancing areas in Canada and Mexico are tied in to the US grid—and some of these balancing areas are much larger than others. The PJM grid, serving Pennsylvania, New Jersey, and Maryland, for example, is more than twice as large as Texas' ERCOT, in a state that produces and consumes the most electricity in the US.

Despite these limitations, it's possible to get hourly figures on how much electricity was generated, what was used to produce it, and whether it was used locally or exported to another balancing area. Information on the generating sources allowed the researchers to attach an emissions figure to each unit of electricity produced. Coal, for example, produces double the emissions of natural gas, which in turn produces more than an order of magnitude more carbon dioxide than the manufacturing of solar, wind, or hydro facilities. These figures were turned into what the authors call "embodied emissions" that can be traced to where they're eventually used.

Similar figures were also generated for sulfur dioxide and nitrogen oxides. Released by the burning of fossil fuels, these can both influence the global climate and produce local health problems.

Huge variation
The results were striking. "The consumption-based carbon intensity of electricity varies by almost an order of magnitude across the different regions in the US electricity system," the authors conclude. The low is the Bonneville Power grid region, which is largely supplied by hydropower; it has typical emissions below 100kg of carbon dioxide per megawatt-hour. The highest emissions come in the Ohio Valley Electric region, where emissions clear 900kg/MW-hr. Only three regional grids match the overall grid emissions intensity, although that includes the very large PJM (where capacity auction payouts recently fell), ERCOT, and Southern Co balancing areas.

Most of the low-emissions power that's exported comes from the Pacific Northwest's abundant hydropower, while the Rocky Mountains area exports electricity with the highest associated emissions. That leads to some striking asymmetries. Local generation in the hydro-rich Idaho Power Company has embodied emissions of only 71kg/MW-hr, while its imports, coming primarily from Rocky Mountain states, have a carbon content of 625kg/MW-hr.

The reliance on hydropower also makes the asymmetry seasonal. Local generation is highest in the spring as snow melts, but imports become a larger source outside this time of year. As solar and wind can also have pronounced seasonal shifts, similar changes will likely be seen as these become larger contributors to many of these regional grids. Similar things occur daily, as both demand and solar production (and, to a lesser extent, wind) have distinct daily profiles.

The Golden State
California's CISO provides another instructive case. Imports represent less than 30% of its total electric use in 2016, yet California electricity imports provided 40% of its embodied emissions. Some of these, however, come internally from California, provided by the Los Angeles Department of Water and Power. The state itself, however, has only had limited tracking of imported emissions, lumping many of its sources as "other," and has been exporting its energy policies to Western states in ways that shape regional markets.

Overall, the 2016 inventory provides a narrow picture of the US grid, as plenty of trends are rapidly changing our country's emissions profile, including the rise of renewables and the widespread adoption of efficiency measures and other utility trends in 2017 that continue to evolve. The method developed here can, however, allow for annual updates, providing us with a much better picture of trends. That could be quite valuable to track things like how the rapid rise in solar power is altering the daily production of clean power.

More significantly, it provides a basis for more informed policymaking. States that wish to promote low-emissions power can use the information here to either alter the source of their imports or to encourage the sites where they're produced to adopt more renewable power. And those states that are exporting electricity produced primarily through fossil fuels could ensure that the locations where the power is used pay a price that includes the health costs of its production.

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Electric Field-Induced Glass Softening reveals a Joule heating anomaly in silicate glass, where anode-side nanoscale alkali depletion drives ionic conduction, localized thermal runaway, melting, and evaporation, challenging homogeneity assumptions and refining materials processing models.

Key Points

An effect where electric fields lower glass softening temperature via nanoscale ionic migration and structural change.

✅ Anode-side alkali depletion creates extreme, localized heating

✅ Thermal runaway melts glass near the anode despite uniform bulk

✅ Findings refine Joule heating models and enable new glass processing

A team of scientists working with electrical currents and silicate glass have been left gobsmacked after the glass appeared to defy a basic physical law, in a field that also explores electricity-from-air devices for novel energy harvesting.

If you pass an electrical current through a material, the way that current generates heat can be described by Joule's first law. It's been observed time and time again, with the temperature always evenly distributed when the material is homogeneous (or uniform).

But not in this recent experiment. A section - and only a section - of silicate glass became so hot that it melted, and even evaporated. Moreover, it did so at a much lower temperature than the boiling point of the material.

The boiling point of pure silicate glass is 2,230 degrees Celsius (4,046 degrees Fahrenheit). The hottest temperature the researchers recorded in a homogeneous piece of silicate glass during the experiment was 1,868.7 degrees Celsius.

Say whaaaat.

"The calculations did not add up to explain what we were seeing as simply standard Joule heating," said engineer and materials scientist Himanshu Jain of Lehigh University.

"Even under very moderate conditions, we observed fumes of glass that would require thousands of degrees higher temperature than Joule's law could predict!"

Jain and his colleagues from materials science company Corning Incorporated were investigating a phenomenon they had described in a previous paper. In 2015, they reported that an electric field could reduce the temperature at which glass softens, by as much as a few hundred degrees, a line of inquiry that parallels work on low-cost heat-to-electricity materials in energy research. They called this "electric field-induced softening."

It was certainly a peculiar phenomenon, so they set up another experiment. They put pieces of glass in a furnace, and applied 100 to 200 volts in the form of both alternating and direct currents.

Next, a thin wisp of vapour emanated from the spot where the anode conveying the current contacted the glass.

"In our experiments, the glass became more than a thousand degrees Celsius hotter near the positive side than in the rest of the glass, which was very surprising considering that the glass was totally homogeneous to begin with," Jain said.

This seems to fly in the face of Joule's first law, so the team investigated more closely - and found that the glass wasn't remaining as homogeneous as it started out. The electric field changed the chemistry and the structure of the glass on nanoscale, in just a small section close to the anode.

This region heats faster than the rest of the glass, to the point of becoming a thermal runaway - where an increase in temperature further increases temperature in a blistering feedback loop.

As it turned out, that spot of structural change and dramatic heat resulted in a small area of glass reaching melting point while the rest of the material remained solid.

"Unlike electronically conducting metals and semiconductors, with time the heating of ionically conducting glass becomes extremely inhomogeneous with the formation of a nanoscale alkali-depletion region, such that the glass melts near the anode, even evaporates, while remaining solid elsewhere," the researchers wrote in their paper.

In other words, the material wasn't homogeneous any more, which means the glass heating experiment doesn't exactly change how we apply Joule's first law.

But it's an exciting result, since until now we didn't know a material could actually lose its homogeneity with the application of an electrical current, with possible implications for thin-film heat harvesters in electronics. (The thing is, no one had tried electrically heating glass to these extreme temperatures before.)

So the physical laws of the Universe are still okay, as a piece of glass hasn't broken them. But Joule's first law may need a bit of tweaking to take this effect into account, a reminder that unconventional energy concepts like nighttime solar cells also challenge our intuitions.

And, of course, it's another piece of understanding that could help us in other ways too, including advances in thermoelectric materials that turn waste heat into electricity.

"Besides demonstrating the need to qualify Joule's law," Jain said, "the results are critical to developing new technology for the fabrication and manufacturing of glass and ceramic materials."

The research has been published in Scientific Reports.

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Juba Power Distribution Expansion accelerates grid rehabilitation in South Sudan, adding concrete poles, medium and low voltage networks, and LED street lighting, funded by AfDB and executed by Power China for reliable, affordable electricity.

Key Points

A project to upgrade Juba's grid with concrete poles, MV-LV networks, and LED lighting for reliable, affordable power.

✅ 13,350 concrete poles produced locally for network rollout

✅ Medium and low voltage network rehabilitation and expansion

✅ LED street lighting and customer care improvements funded by AfDB

The South Sudan government has launched a factory producing concrete poles that will facilitate an ambitious project done by a Chinese company to rehabilitate and expand the Power Distribution System in Juba, its capital.

The Minister of Dams and Electricity, Dhieu Mathok, said that the factory, rented by Power China, will produce some 13,350 poles for the electricity distribution in the capital and other states.

"The main objective of this project is to increase the supply capacity and reliability of the power distribution system in Juba. Access to the grid will replace the use of generators by the population, allow supply of energy at more affordable price and, hence contribute toward economic growth and poverty eradication in South Sudan," Mathok said during the inauguration of the plant along the Yei road in Juba.

#google#

He disclosed that it will help solve the problem associated with non-availability of concrete poles for the project and to mitigate the risk of importing poles from other countries.

"This factory will create positive impact on the construction of the national grid in South Sudan. It is owned by South Sudanese business people but currently it has been taken over by Power China for a brief period of one year," he said.

South Sudan is largely generator driven economy with continued electricity blackout, and across the continent initiatives like Cape Town's municipal power build-out illustrate alternative approaches, in the wake of the collapse of the generator power plant operated by the South Sudan Electricity Corporation (SSEC) in 2013.

Wang Cun, an official with Power China said they got the contract to build the electricity project in June 2016 and that they will continue to support South Sudanese staff with skills and knowledge, drawing on advances such as PEM green hydrogen R&D that point to future low-carbon options, and also work with the government on several major power projects.

"We have achieved much from these projects and we also suffered much from the instability and continuous conflicts all these years, but we confirm and believe the year of 2018 will be a year of peace and development in South Sudan," Wang said, adding that the company has been operating in South Sudan since 2009.

He disclosed that Power China has conducted several projects before South Sudan won independence from Sudan in 2011 such as the peace road project from Renk to Malakal, Maridi water plant and Malakal municipal road projects.

Wang said they will immediately reorganize all necessary resources to increase post-production capacity and immediately shall commence the erection of these poles to all corners of Juba city and start the distribution.

"We shall do as we did before to recruit more local technicians, engineers and laborers during the construction period, so that they are there in place for similar projects in the near future. We shall make more efforts to improve these local staffs' working environment and to realize sustainable development of Power China and Sino-hydro in South Sudan," said Wang.

Power China has been committing itself in the economic development of South Sudan and has signed eight commercial contracts with the government of South Sudan since independence like the Juba-hydro power project and the Tharjiath thermal power plant project, while in China projects such as the Lawa hydropower station demonstrate ongoing hydropower expertise that can inform regional work.

Liu Xiaodong, the Charge d'Affaires at the Chinese embassy in South Sudan, said Power China has been working very hard in the engineering and procurement in the earlier stage of the project, and as China expands energy ties such as nuclear cooperation with Cambodia that demonstrate broader engagement, also thanked the South Sudan government and the African Development Bank for their strong support.

Liu added upon completion Juba will have an upgraded power distribution system with 2,250 lighting points along the main roads in the capital and lamps will be LED ones.

The project falls under the Juba Power Distribution System Rehabilitation and Expansion Project, which was funded by the African Development Bank (AfDB) and has undertaken an AfDB review of a Senegal power plant to inform regional energy decisions.

It comprises of five different lots like Rehabilitation of Diesel plant substation, Rehabilitation and Expansion of medium voltage network, low voltage network, and Rehabilitation and Expansion of street lighting and improvement of customer care.

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Air-gen Protein Nanowire Generator delivers clean energy by harvesting ambient humidity via Geobacter-derived conductive nanowires, generating continuous hydrovoltaic electricity through moisture gradients, electrodes, and proton diffusion for sustainable, low-waste power in diverse climates.

Key Points

A device using Geobacter protein nanowires to harvest humidity, producing continuous DC power via proton diffusion.

✅ 7 micrometer film between electrodes adsorbs water vapor.

✅ Output: ~0.5 V, 17 uA/cm2; stack units to scale power.

✅ Geobacter optimized via engineered E. coli for mass nanowires.

They found it buried in the muddy shores of the Potomac River more than three decades ago: a strange "sediment organism" that could do things nobody had ever seen before in bacteria.

This unusual microbe, belonging to the Geobacter genus, was first noted for its ability to produce magnetite in the absence of oxygen, but with time scientists found it could make other things too, like bacterial nanowires that conduct electricity.

For years, researchers have been trying to figure out ways to usefully exploit that natural gift, and they might have just hit pay-dirt with a device they're calling the Air-gen. According to the team, their device can create electricity out of… well, almost nothing, similar to power from falling snow reported elsewhere.

"We are literally making electricity out of thin air," says electrical engineer Jun Yao from the University of Massachusetts Amherst. "The Air-gen generates clean energy 24/7."

The claim may sound like an overstatement, but a new study by Yao and his team describes how the air-powered generator can indeed create electricity with nothing but the presence of air around it. It's all thanks to the electrically conductive protein nanowires produced by Geobacter (G. sulfurreducens, in this instance).

The Air-gen consists of a thin film of the protein nanowires measuring just 7 micrometres thick, positioned between two electrodes, referencing advances in near light-speed conduction in materials science, but also exposed to the air.

Because of that exposure, the nanowire film is able to adsorb water vapour that exists in the atmosphere, offering a contrast to legacy hydropower models, enabling the device to generate a continuous electrical current conducted between the two electrodes.

The team says the charge is likely created by a moisture gradient that creates a diffusion of protons in the nanowire material.

"This charge diffusion is expected to induce a counterbalancing electrical field or potential analogous to the resting membrane potential in biological systems," the authors explain in their study.

"A maintained moisture gradient, which is fundamentally different to anything seen in previous systems, explains the continuous voltage output from our nanowire device."

The discovery was made almost by accident, when Yao noticed devices he was experimenting with were conducting electricity seemingly all by themselves.

"I saw that when the nanowires were contacted with electrodes in a specific way the devices generated a current," Yao says.

"I found that exposure to atmospheric humidity was essential and that protein nanowires adsorbed water, producing a voltage gradient across the device."

Previous research has demonstrated hydrovoltaic power generation using other kinds of nanomaterials – such as graphene-based systems now under study – but those attempts have largely produced only short bursts of electricity, lasting perhaps only seconds.

By contrast, the Air-gen produces a sustained voltage of around 0.5 volts, with a current density of about 17 microamperes per square centimetre, and complementary fuel cell solutions can help keep batteries energized, with a current density of about 17 microamperes per square centimetre. That's not much energy, but the team says that connecting multiple devices could generate enough power to charge small devices like smartphones and other personal electronics – concepts akin to virtual power plants that aggregate distributed resources – all with no waste, and using nothing but ambient humidity (even in regions as dry as the Sahara Desert).

"The ultimate goal is to make large-scale systems," Yao says, explaining that future efforts could use the technology to power homes via nanowire incorporated into wall paint, supported by energy storage for microgrids to balance supply and demand.

"Once we get to an industrial scale for wire production, I fully expect that we can make large systems that will make a major contribution to sustainable energy production."

If there is a hold-up to realising this seemingly incredible potential, it's the limited amount of nanowire G. sulfurreducens produces.

Related research by one of the team – microbiologist Derek Lovley, who first identified Geobacter microbes back in the 1980s – could have a fix for that: genetically engineering other bugs, like E. coli, to perform the same trick in massive supplies.

"We turned E. coli into a protein nanowire factory," Lovley says.

"With this new scalable process, protein nanowire supply will no longer be a bottleneck to developing these applications."

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