GE looks to taller tower technology

PG&E Wind Shutdown and Renewable Reliability examines PSPS strategy, wildfire risk, transmission line exposure, wind turbine cut-out speeds, grid stability, and California's energy mix amid historic high-wind events and supply constraints across service areas.

Key Points

An overview of PG&E's PSPS decisions, wildfire mitigation, and how wind cut-out limits influence grid reliability.

✅ Wind turbines reach cut-out near 55 mph, reducing generation.

✅ PSPS mitigates ignition from damaged transmission infrastructure.

✅ Baseload diversity improves resilience during high-wind events.

According to the official, widely reported story, Pacific Gas & Electric (PG&E) initiated power shutoffs across substantial portions of its electric transmission system in northern California as a precautionary measure.

Citing high wind speeds they described as “historic,” the utility claims that if it didn’t turn off the grid, wind-caused damage to its infrastructure could start more wildfires.

Perhaps that’s true. Perhaps. This tale presumes that the folks who designed and maintain PG&E’s transmission system are unaware of or ignored the need to design it to withstand severe weather events, and that the Federal Energy Regulatory Commission (FERC) and North American Electric Reliability Corp. (NERC) allowed the utility to do so.

Ignorance and incompetence happens, to be sure, but there’s much about this story that doesn’t smell right—and it’s disappointing that most journalists and elected officials are apparently accepting it without question.

Take, for example, this statement from a Fox News story about the Kincade Fires: “A PG&E meteorologist said it’s ‘likely that many trees will fall, branches will break,’ which could damage utility infrastructure and start a fire.”

Did you ever notice how utilities cut wide swaths of trees away when transmission lines pass through forests? There’s a reason for that: When trees fall and branches break, the grid can still function, and even as the electric rhythms of New York City shifted during COVID-19, operators planned for variability.

So, if badly designed and poorly maintained infrastructure isn’t the reason PG&E cut power to millions of Californians, what might have prompted them to do so? Could it be that PG&E’s heavy reliance on renewable energy means they don’t have the power to send when a “historic” weather event occurs, especially as policymakers weigh the postponed closure of three power plants elsewhere in California?

Wind Speed Limits

The two most popular forms of renewable energy come with operating limitations, which is why some energy leaders urge us to keep electricity options open when planning the grid. With solar power, the constraint is obvious: the availability of sunlight. One doesn’t generate solar power at night and energy generation drops off with increasing degrees of cloud cover during the day.

The main operating constraint of wind power is, of course, wind speed, and even in markets undergoing 'transformative change' in wind generation, operators adhere to these technical limits. At the low end of the scale, you need about a 6 or 7 miles-per-hour wind to get a turbine moving. This is called the “cut-in speed.” To generate maximum power, about a 30 mph wind is typically required. But, if the wind speed is too high, the wind turbine will shut down. This is called the “cut-out speed,” and it’s about 55 miles per hour for most modern wind turbines.

It may seem odd that wind turbines have a cut-out speed, but there’s a very good reason for it. Each wind turbine rotor is connected to an electric generator housed in the turbine nacelle. The connection is made through a gearbox that is sized to turn the generator at the precise speed required to produce 60 Hertz AC power.

The blades of the wind turbine are airfoils, just like the wings of an airplane. Adjusting the pitch (angle) of the blades allows the rotor to maintain constant speed, which, in turn, allows the generator to maintain the constant speed it needs to safely deliver power to the grid. However, there’s a limit to blade pitch adjustment. When the wind is blowing so hard that pitch adjustment is no longer possible, the turbine shuts down. That’s the cut-out speed.

Now consider how California’s power generation profile has changed. According to Energy Information Administration data, the state generated 74.3 percent of its electricity from traditional sources—fossil fuels and nuclear, amid debates over whether to classify nuclear as renewable—in 2001. Hydroelectric, geothermal, and biomass-generated power accounted for most of the remaining 25.7 percent, with wind and solar providing only 1.98 percent of the total.

By 2018, the state’s renewable portfolio had jumped to 43.8 percent of total generation, with clean power increasing and wind and solar now accounting for 17.9 percent of total generation. That’s a lot of power to depend on from inherently unreliable sources. Thus, it wouldn’t be at all surprising to learn that PG&E didn’t stop delivering power out of fear of starting fires, but because it knew it wouldn’t have power to deliver once high winds shut down all those wind turbines

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SaskPower-Flying Dust flare gas power deal advances a 20 MW, 20-year Power Purchase Agreement, enabling grid supply from FNPA-backed generation, supporting renewable strategy, lower carbon footprint targets, and First Nation economic development in Saskatchewan.

Key Points

A 20 MW, 20-year PPA converting flare gas to grid power, with SaskPower buying from Flying Dust First Nation via FNPA.

✅ 20 MW of flare gas generation linked to Saskatchewan's grid

✅ 20-year term; about $300M total value to SaskPower

✅ FNPA-backed project; PPA targeted in 6-12 months

An agreement signed between SaskPower, which reported $205M income in 2019-20, and Flying Dust First Nation is an important step toward a plan that could see the utility buy $300 million worth of electricity from Flying Dust First Nation, according to Flying Dust's chief.

"There's still a lot of groundwork that needs to be done before we get building but you know we're a lot closer today with this signing," Jeremy Norman told reporters Friday.

Norman's community was assisted by the First Nations Power Authority (FNPA), a non-profit that helps First Nations get into the power sector, with examples like the James Bay project showing what Indigenous ownership can achieve.

The agreement signed Friday says SaskPower will explore the possibility of buying 20 megawatts of flare gas power from FNPA, which it will look to Flying Dust to produce.

#google#

20-year plan

The proposed deal would span 20 years and cost SaskPower around $300 million over those years, as the utility also explores geothermal power to meet 2030 targets.

The exact price would be determined once a price per metawatt is brought forward.

"We won't be able to do this ourselves," Norman said.

Flare gas power generation works by converting flares from the oil and gas sector into electricity. Under this plan, SaskPower would take the electricity provided by Flying Dust and plug it into the provincial power grid, complementing a recent move to buy more power from Manitoba Hydro to support system reliability.

"This is a great opportunity as we advance our renewable strategy, including progress on doubling renewables by 2030, and try to achieve a lower carbon footprint by 2030 and beyond," Marsh said.

Ombudsman report details dispute between senior with breathing disorder, SaskPower

Norman said the business deal presents an opportunity to raise money to reinvest into the First Nation for things like more youth programming.

For the next steps, both parties will need to sign a power purchase agreement that spells out the exact prices for the power generation.

Marsh expects to do so in the next six to 12 months, with development of the required infrastructure to take place after that.

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UK Energy Networks Coronavirus Contingency outlines ESO's lockdown electricity demand forecast, reduced industrial and commercial load, rising domestic use, Ofgem guidance needs, grid resilience, control rooms, mutual aid, and backup centers.

Key Points

A coordinated plan with ESO forecasts, safeguards, and mutual aid to keep power and gas services during a lockdown.

✅ ESO forecasts lower industrial use, higher domestic demand

✅ Control rooms protected; backup sites and cross-trained staff

✅ Mutual aid and Ofgem coordination bolster grid resilience

National Grid ESO is predicting a reduction in electricity demand, consistent with residential use trends observed during the pandemic, in the case of the coronavirus spread prompting a lockdown across the country.

Its analysis shows the reduction in commercial and industrial use would outweigh an upsurge in domestic demand, mirroring Ontario demand data seen as people stayed home, according to similar analyses.

The prediction was included in an update from the Energy Networks Association (ENA), in which it sought to reassure the public that contingency plans are in place, reflecting utility disaster planning across electric and gas networks, to ensure services are unaffected by the coronavirus spread.

The body, which represents the UK's electricity and gas network companies, said "robust measures" had been put in place to protect control rooms and contact centres, similar to staff lockdown protocols considered by other system operators, to maintain resilience. To provide additional resilience, engineers have been trained across multiple disciplines and backup centres exist should operations need to be moved if, for example, deep cleaning is required, the ENA said.

Networks also have industry-wide mutual aid arrangements, similar to grid response measures outlined in the U.S., for people and the equipment needed to keep gas and electricity flowing.

ENA chief executive, David Smith, said, echoing system reliability assurances from other markets: "The UK's electricity and gas network is one of the most reliable in the world and network operators are working with the authorities to ensure that their contingency plans are reviewed and delivered in accordance with the latest expert advice. We are following this advice closely and reassuring customers that energy networks are continuing to operate as normal for the public."

Utility Week spoke to a senior figure at one of the networks who reiterated the robust measures in place to keep the lights on, even as grid alerts elsewhere highlight the importance of contingency planning. However, they pleaded for more clarity from Ofgem and government on how its workers will be treated if the coronavirus spread becomes a pandemic in the UK.

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Proton Conducting Fuel Cells enable reversible hydrogen energy storage, coupling electrolyzers and fuel cells with ceramic catalysts and proton-conducting membranes to convert wind and solar electricity into fuel and back to reliable grid power.

Key Points

Proton conducting fuel cells store renewable power as hydrogen and generate electricity using reversible catalysts.

✅ Reversible electrolysis and fuel-cell operation in one device

✅ Ceramic air electrodes hit up to 98% splitting efficiency

✅ Scalable path to low-cost grid energy storage with hydrogen

If we want a shot at transitioning to renewable energy, we’ll need one crucial thing: technologies that can convert electricity from wind, sun, and even electricity from raindrops into a chemical fuel for storage and vice versa. Commercial devices that do this exist, but most are costly and perform only half of the equation. Now, researchers have created lab-scale gadgets that do both jobs. If larger versions work as well, they would help make it possible—or at least more affordable—to run the world on renewables.

The market for such technologies has grown along with renewables: In 2007, solar and wind provided just 0.8% of all power in the United States; in 2017, that number was 8%, according to the U.S. Energy Information Administration. But the demand for electricity often doesn’t match the supply from solar and wind, a key reason why the U.S. grid isn't 100% renewable today. In sunny California, for example, solar panels regularly produce more power than needed in the middle of the day, but none at night, after most workers and students return home.

Some utilities are beginning to install massive banks of cheaper solar batteries in hopes of storing excess energy and evening out the balance sheet. But batteries are costly and store only enough energy to back up the grid for a few hours at most. Another option is to store the energy by converting it into hydrogen fuel. Devices called electrolyzers do this by using electricity—ideally from solar and wind power—to split water into oxygen and hydrogen gas, a carbon-free fuel. A second set of devices called fuel cells can then convert that hydrogen back to electricity to power cars, trucks, and buses, or to feed it to the grid.

But commercial electrolyzers and fuel cells use different catalysts to speed up the two reactions, meaning a single device can’t do both jobs. To get around this, researchers have been experimenting with a newer type of fuel cell, called a proton conducting fuel cell (PCFC), which can make fuel or convert it back into electricity using just one set of catalysts.

PCFCs consist of two electrodes separated by a membrane that allows protons across. At the first electrode, known as the air electrode, steam and electricity are fed into a ceramic catalyst, which splits the steam’s water molecules into positively charged hydrogen ions (protons), electrons, and oxygen molecules. The electrons travel through an external wire to the second electrode—the fuel electrode—where they meet up with the protons that crossed through the membrane. There, a nickel-based catalyst stitches them together to make hydrogen gas (H2). In previous PCFCs, the nickel catalysts performed well, but the ceramic catalysts were inefficient, using less than 70% of the electricity to split the water molecules. Much of the energy was lost as heat.

Now, two research teams have made key strides in improving this efficiency, and a new fuel cell concept brings biological design ideas into the mix. They both focused on making improvements to the air electrode, because the nickel-based fuel electrode did a good enough job. In January, researchers led by chemist Sossina Haile at Northwestern University in Evanston, Illinois, reported in Energy & Environmental Science that they came up with a fuel electrode made from a ceramic alloy containing six elements that harnessed 76% of its electricity to split water molecules. And in today’s issue of Nature Energy, Ryan O’Hayre, a chemist at the Colorado School of Mines in Golden, reports that his team has done one better. Their ceramic alloy electrode, made up of five elements, harnesses as much as 98% of the energy it’s fed to split water.

When both teams run their setups in reverse, the fuel electrode splits H2 molecules into protons and electrons. The electrons travel through an external wire to the air electrode—providing electricity to power devices. When they reach the electrode, they combine with oxygen from the air and protons that crossed back over the membrane to produce water.

The O’Hayre group’s latest work is “impressive,” Haile says. “The electricity you are putting in is making H2 and not heating up your system. They did a really good job with that.” Still, she cautions, both her new device and the one from the O’Hayre lab are small laboratory demonstrations. For the technology to have a societal impact, researchers will need to scale up the button-size devices, a process that typically reduces performance. If engineers can make that happen, the cost of storing renewable energy could drop precipitously, thereby moving us closer to cheap abundant electricity at scale, helping utilities do away with their dependence on fossil fuels.

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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 Storage for Microgrids enables renewables integration via ESS, boosting resilience and reliability while supporting solar PV and wind, innovative financing, and business models, with strong growth forecast across Asia-Pacific and North America.

Key Points

Systems that store energy in microgrids to integrate renewables, boost resilience, and optimize distributed power.

✅ Integrates solar PV and wind with stable, dispatchable output

✅ Reduces costs via new financing and service business models

✅ Expands reliable power for remote, grid-constrained regions

A new report from Navigant Research examines the global market for energy storage for microgrids (ESMG), providing an analysis of trends and market dynamics in the context of the evolving digital grid landscape, with forecasts for capacity and revenue that extend through 2026.

Interest in energy storage-enabled microgrids is growing alongside an increase in solar PV and wind deployments. Although not required for microgrids to operate, energy storage systems (ESSs) have emerged as an increasingly valuable component of distributed energy networks, including virtual power plants that coordinate distributed assets, because of their ability to effectively integrate renewable generation.

“There are several key drivers resulting in the growth of energy storage-enabled microgrids globally, including the desire to improve the resilience of power supply both for individual customers and the entire grid, the need to expand reliable electricity service to new areas, rising electricity prices, and innovations in business models and financing,” says Alex Eller, research analyst with Navigant Research. “Innovations in business models and financing will likely play a key role in the expansion of the ESMG market during the coming years.”

One example of microgrid deployment for resilience is the SDG&E microgrid in Ramona built to help communities prepare for peak wildfire season.

According to the report, the most successful companies in this industry will be those that can unlock the potential of new business models to reduce the risk and upfront costs to customers. This is particularly true in Asia Pacific and North America, which are projected to be the largest regional markets for new ESMG capacity by far, a trend underscored by California's push for grid-scale batteries to stabilize the grid.

The report, “Market Data: Energy Storage for Microgrids,” outlines the key market drivers and barriers within the global ESMG market. The study provides an analysis of specific trends, including evolving grid edge trends, and market dynamics for each major world region to illustrate how different markets are taking shape. Global ESMG forecasts for capacity and revenue, segmented by region, technology, and market segment, extend through 2026. The report also briefly examines the major technology issues related to ESSs for microgrids.

Google made energy storage news recently when its parent company Alphabet announced it is hoping to revolutionize renewable energy storage using vats of salt and antifreeze. Alphabet’s secretive research lab, simply named “X,” is developing a system for storing renewable energy that would otherwise be wasted. The project, named “Malta,” is hoping its energy storage systems “has the potential to last longer than lithium-ion batteries and compete on price with new hydroelectric plants and other existing clean energy storage methods, according to X executives and researchers,” reports Bloomberg.

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