Solar panels fool breeding insects

Hydroelectric retrofits for unpowered dams leverage turbines to add renewable capacity, bolster grid reliability, and enable low-impact energy storage, supporting U.S. and Canada decarbonization goals with lower costs, minimal habitat disruption, and climate resilience.

Key Points

They add turbines to existing dams to make clean power, stabilize the grid, and offer low-impact storage at lower cost.

✅ Lower capex than new dams; minimal habitat disruption

✅ Adds firming and storage to support wind and solar

✅ New low-head turbines unlock more retrofit sites

As countries race to get their power grids off fossil fuels to fight climate change, there's a big push in the U.S. to upgrade dams built for purposes such as water management or navigation with a feature they never had before — hydroelectric turbines. 

And the strategy is being used in parts of Canada, too, with growing interest in hydropower from Canada supplying New York and New England.

The U.S. Energy Information Administration says only three per cent of 90,000 U.S. dams currently generate electricity. A 2012 report from the U.S. Department of Energy found that those dams have 12,000 megawatts (MW) of potential hydroelectric generation capacity. (According to the National Hydropower Association, 1 MW can power 750 to 1,000 homes. That means 12,000 MW should be able to power more than nine million homes.)

As of May 2019, there were projects planned to convert 32 unpowered dams to add 330 MW to the grid over the next several years.

One that was recently completed was the Red Rock Hydroelectric Project, a 60-year-old flood control dam on the Des Moines River in Iowa that was retrofitted in 2014 to generate 36.4 MW at normal reservoir levels, and up to 55 MW at high reservoir levels and flows. It started feeding power to the grid this spring, and is expected to generate enough annually to supply power to 18,000 homes.

It's an approach that advocates say can convert more of the grid from fossil fuels to clean energy, often with a lower cost and environmental impact than building new dams.

Hydroelectric facilities can also be used for energy storage, complementing intermittent clean energy sources such as wind and solar with pumped storage to help maintain a more reliable, resilient grid.

The Nature Conservancy and the World Wildlife Fund are two environmental groups that oppose new hydro dams because they can block fish migration, harm water quality, damage surrounding ecosystems and release methane and CO2, and in some regions, Western Canada drought has reduced hydropower output as reservoirs run low. But they say adding turbines to non-powered dams can be part of a shift toward low-impact hydro projects that can support expansion of solar and wind power.

Paul Norris, president of the Ontario Waterpower Association, said there's typically widespread community support for such projects in his province amid ongoing debate over whether Ontario is embracing clean power in its future plans. "Any time that you can better use existing assets, I think that's a good thing."

New turbine technology means water doesn't need to fall from as great a height to generate power, providing opportunities at sites that weren't commercially viable in the past, Norris said, with recent investments such as new turbines in Manitoba showing what is possible.

In Ontario, about 1,000 unpowered dams are owned by various levels of government. "With the appropriate policy framework, many of these assets have the potential to be retrofitted for small hydro," Norris wrote in a letter to Ontario's Independent Electricity System Operator this year as part of a discussion on small-scale local energy generation resources.

He told CBC that several such projects are already in operation, such as a 950 kW retrofit of the McLeod Dam at the Moira River in Belleville, Ont., in 2008. 

Four hydro stations were going to be added during dam refurbishment on the Trent-Severn Waterway, but they were among 758 renewable energy projects cancelled by Premier Doug Ford's government after his election in 2018, a move examined in an analysis of Ontario's dirtier electricity outlook and its implications.

Patrick Bateman, senior vice-president of Waterpower Canada, said such dam retrofit projects are uncommon in most provinces. "I don't see it being a large part of the future electricity generation capacity."

He said there has been less movement on retrofitting unpowered dams in Canada compared to the U.S., because:

There are a lot more opportunities in Canada to refurbish large, existing hydro-generating stations to boost capacity on a bigger scale.

There's less growth in demand for clean energy, because more of Canada's grid is already non-carbon-emitting (80 per cent) compared to the U.S. (40 per cent).

Even so, Norris thinks Canadians should be looking at all opportunities and options when it comes to transitioning the grid away from fossil fuels, including retrofitting non-powered dams, especially as a recent report highlights Canada's looming power problem over the coming decades.

"If we're going to be serious about addressing the inevitable challenges associated with climate change targets and net zero, it really is an all-of-the-above approach."

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Hong Kong Typhoon Mangkhut Power Outages strain households with blackouts, electricity disruption, and humid heat, impacting Tin Ping Estate in Sheung Shui and outlying islands; contractor-led restoration faces fines for delays and infrastructure repairs.

Key Points

They are blackout events after Typhoon Mangkhut, bringing heat stress, food spoilage, and delayed power restoration.

✅ 16 floors in Tin Ping Estate lost power after meter room blast.

✅ Contractor faces HK$100,000 daily fines for late restoration.

✅ Kat O and Ap Chau families remain off-grid in humid heat.

Nearly 600 Hong Kong families are still sweltering under the summer heat and facing dark nights without electricity after Typhoon Mangkhut cut off power supply to areas, echoing mass power outages seen elsewhere.

At Sheung Shui’s Tin Ping Estate in the New Territories, 384 families were still without power, a situation similar to the LA-area blackout that left many without service. They were told on Tuesday that a contractor would rectify the situation by Friday, or be fined HK$100,000 for each day of delay.

In remote areas such as outlying islets Kat O and Ap Chau, there were some 200 families still without electricity, similar to Tennessee storm outages affecting rural communities.

The power outage at Tin Ping Estate affected 16 floors – from the 11th to 26th – in Tin Cheung House after a blast from the meter room on the 15th floor was heard at about 5pm on Sunday, and authorities urged residents to follow storm electrical safety tips during repairs.

“I was sitting on the sofa when I heard a loud bang,” said Lee Sau-king, 61, whose flat was next to the meter room. “I was so scared that my hands kept trembling.”

While the block’s common areas and lifts were not affected, flats on the 16 floors encountered blackouts.

As her fridge was out of power, Lee had to throw away all the food she had stocked up for the typhoon. With the freezer not functioning, her stored dried seafood became soaked and she had to dry them outside the window when the storm passed.

Daily maximum temperatures rose back to 30 degrees Celsius after the typhoon, and nights became unbearably humid, as utilities worldwide pursue utility climate adaptation to maintain reliability. “It’s too hot here. I can’t sleep at all,” Lee said.

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Polycrystalline Tin Selenide Thermoelectrics enable waste heat recovery with ZT 3.1, matching single crystals while cutting costs, powering greener car engines, industrial furnaces, and thermoelectric generators via p-type and emerging n-type designs.

Key Points

Low-cost tin selenide devices that turn waste heat into power, achieving ZT 3.1 and enabling p-type and n-type modules.

✅ Oxygen removal prevents heat-leaking tin oxide grain skins.

✅ Polycrystalline ingots match single-crystal ZT 3.1 at lower cost.

✅ N-type tin selenide in development to pair with p-type.

So-called thermoelectric generators turn waste heat into electricity without producing greenhouse gas emissions, providing what seems like a free lunch. But despite helping power the Mars rovers, the high cost of these devices has prevented their widespread use. Now, researchers have found a way to make cheap thermoelectrics that work just as well as the pricey kind. The work could pave the way for a new generation of greener car engines, industrial furnaces, and other energy-generating devices.

“This looks like a very smart way to realize high performance,” says Li-Dong Zhao, a materials scientist at Beihang University who was not involved with the work. He notes there are still a few more steps to take before these materials can become high-performing thermoelectric generators. However, he says, “I think this will be used in the not too far future.”

Thermoelectrics are semiconductor devices placed on a hot surface, like a gas-powered car engine or on heat-generating electronics using thin-film converters to capture waste heat. That gives them a hot side and a cool side, away from the hot surface. They work by using the heat to push electrical charges from one to the other, a process of turning thermal energy into electricity that depends on the temperature gradient. If a device allows the hot side to warm up the cool side, the electricity stops flowing. A device’s success at preventing this, as well as its ability to conduct electrons, feeds into a score known as the figure of merit, or ZT.

 Over the past 2 decades, researchers have produced thermoelectric materials with increasing ZTs, while related advances such as nighttime solar cells have broadened thermal-to-electric concepts. The record came in 2014 when Mercouri Kanatzidis, a materials scientist at Northwestern University, and his colleagues came up with a single crystal of tin selenide with a ZT of 3.1. Yet the material was difficult to make and too fragile to work with. “For practical applications, it’s a non-starter,” Kanatzidis says.

So, his team decided to make its thermoelectrics from readily available tin and selenium powders, an approach that, once processed, makes grains of polycrystalline tin selenide instead of the single crystals. The polycrystalline grains are cheap and can be heated and compressed into ingots that are 3 to 5 centimeters long, which can be made into devices. The polycrystalline ingots are also more robust, and Kanatzidis expected the boundaries between the individual grains to slow the passage of heat. But when his team tested the polycrystalline materials, the thermal conductivity shot up, dropping their ZT scores as low as 1.2.

In 2016, the Northwestern team discovered the source of the problem: an ultrathin skin of tin oxide was forming around individual grains of polycrystalline tin selenide before they were pressed into ingots. And that skin acted as an express lane for the heat to travel from grain to grain through the material. So, in their current study, Kanatzidis and his colleagues came up with a way to use heat to drive any oxygen away from the powdery precursors, leaving pristine polycrystalline tin selenide, whereas other devices can generate electricity from thin air using ambient moisture.

The result, which they report today in Nature Materials, was not only a thermal conductivity below that of single-crystal tin selenide but also a ZT of 3.1, a development that echoes nighttime renewable devices showing electricity from cold conditions. “This opens the door for new devices to be built from polycrystalline tin selenide pellets and their applications to be explored,” Kanatzidis says.

Getting through that door will still take some time. The polycrystalline tin selenide the team makes is spiked with sodium atoms, creating what is known as a “p-type” material that conducts positive charges. To make working devices, researchers also need an “n-type” version to conduct negative charges.

Zhao’s team recently reported making an n-type single-crystal tin selenide by spiking it with bromine atoms. And Kanatzidis says his team is now working on making an n-type polycrystalline version. Once n-type and p-type tin selenide devices are paired, researchers should have a clear path to making a new generation of ultra-efficient thermoelectric generators. Those could be installed everywhere from automobile exhaust pipes to water heaters and industrial furnaces to scavenge energy from some of the 65% of fossil fuel energy that winds up as waste heat. 

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Nova Scotia Power Rate Increase Settlement faces UARB scrutiny as regulators weigh electricity rates, fuel costs, storm rider provisions, Bill 212 limits, and Muskrat Falls impacts on ratepayers and affordability for residential and industrial customers.

Key Points

A deal proposing 13.8% electricity hikes for 2023-2024, before the UARB, covering fuel costs, a storm rider, and Bill 212.

✅ UARB review may set different rates than the settlement

✅ Fuel cost prepayment and hedging incentives questioned

✅ Storm rider shifts climate risk onto ratepayers

Nova Scotia Premier Tim Houston is calling on provincial regulators to reject a settlement agreement between Nova Scotia Power and customer groups that would see electricity rates rise by nearly 14% electricity rate hike over the next two years.

"It is our shared responsibility to protect ratepayers and I can't state strongly enough how concerned I am that the agreement before you does not do that," Houston wrote in a letter to the Nova Scotia Utility and Review Board late Monday.

Houston urged the three-member panel to "set the agreement aside and reach its own conclusion on the aforementioned application."

"I do not believe, based on what I know, that the proposed agreement is in the best interest of ratepayers," he said.

The letter does not spell out what his Progressive Conservative government would do if the board accepts the settlement reached last week between Nova Scotia Power and lawyers representing residential, small business and large industrial customer classes.

Other groups also endorsed the deal, although Nova Scotia Power's biggest customer — Port Hawkesbury Paper — did not sign on.

'We're protecting the ratepayers'
Natural Resources Minister Tory Rushton said the province was not part of the negotiations leading up to the settlement.

"As a government or department we had no intel on those conversations that were taking place," he said Tuesday. "So, we saw the information the same as the public did late last week, and right now we're protecting the ratepayers of Nova Scotia, even though the province cannot order Nova Scotia Power to lower rates under current law. We want to make sure that that voice is still heard at the UARB level."

Rushton said he didn't want to presuppose what the UARB will say.

"But I think the premier's been very loud and clear and I believe I have been, too. The ratepayers are at the top of our mind. We have different tools at our [disposal] and we'll certainly do what we can and need to [do] to protect those ratepayers."

The settlement agreement
If approved by regulators, rates would rise by 6.9 per cent in 2023 and 6.9 per cent in 2024 — almost the same amount on the table when hearings before the review board ended in September.

The Houston government later intervened with legislation, known as Bill 212, that capped rates to cover non-fuel costs by 1.8 per cent. It did not cap rates to cover fuel costs or energy efficiency programs.

In a statement announcing the agreement, Nova Scotia Power president Peter Gregg claimed the settlement adhered "to the direction provided by the provincial government through Bill 212."

Consumer advocate Bill Mahody, representing residential customers, told CBC News the proposed 13.8 per cent increase was "a reasonable rate increase given the revenue requirement that was testified to at the hearing."

Settlement 'remarkably' similar to NSP application
The premier disagrees, noting that the settlement and rate application that triggered the rate cap are "remarkably consistent."

He objects to the increased amount of fuel costs rolled into rates next year before the annual true up of actual fuel costs, which are automatically passed on to ratepayers.

"If Nova Scotia Power is effectively paid in advance, what motive do they have to hedge and mitigate the adjustment eventually required," Houston asked in his letter.

He also objected to the inclusion of a storm rider in rates to cover extreme weather, which he said pushed the risk of climate change on to ratepayers.

Premier second-guesses Muskrat Falls approval
Houston also second-guessed the board for approving Nova Scotia Power's participation in the Muskrat Falls hydro project in Labrador.

"The fact that Nova Scotians have paid over $500 million for this project with minimal benefit, and no one has been held accountable, is wrong," he said. "It was this board of the day that approved the contracts and entered the final project into rates."

Ratepayers are committed to paying $1.7 billion for the Maritime Link to bring the green source of electricity into the province, while rate mitigation talks in Newfoundland lack public details for their customers.

Although the Maritime Link was built on time and on budget by an affiliated company, only a fraction of Muskrat Falls hydro has been delivered because of ongoing problems in Newfoundland, including an 18% electricity rate hike deemed unacceptable by the province's consumer advocate.

"I find it remarkable that those contracts did not include different risk sharing mechanisms; they should have had provisions for issues in oversight of project management. Nevertheless, it was approved, and is causing significant harm to ratepayers in the form of increased rates."

Houston notes that because of non-delivery from Muskrat Falls, Nova Scotia Power has been forced to buy much more expensive coal to burn to generate electricity.

Opposition reaction
Opposition parties in Nova Scotia reacted to Houston's letter.

NDP Leader Claudia Chender dismissed it as bluster.

"It exposes his Bill 212 as not really helping Nova Scotians in the way that he said it would," she said. "Nothing in the settlement agreement contravenes that bill. But it seems that he's upset that he's been found out. And so here we are with another intervention in an independent regulatory body."

Liberal Leader Zach Churchill said the government should intervene to help ratepayers directly.

"We just think that it makes more sense to do that directly by supporting ratepayers through heating assistance, lump-sum electricity credits, rebate programs and expanding the eligibility for that or to provide funding directly to ratepayers instead of intervening in the energy market in this way," he said.

The premier's office said that no one was available when asked about an interview on Tuesday.

"The letter speaks for itself," the office responded.

Nova Scotia Power issued a statement Tuesday. It did not directly address Houston's claims.

"The settlement agreement is now with the NS Utility and Review Board," the utility said.

"The UARB process is designed to ensure customers are represented with strong advocates and independent oversight. The UARB will determine whether the settlement results in just and reasonable rates and is in the public interest."

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Florida Hurricane Irma Power Outages strain the grid as utilities plan rebuilds; FPL and Duke Energy deploy crews to restore transmission lines, substations, and service amid flooding, storm surge, and widespread disruptions statewide.

Key Points

Large-scale post-storm power losses in Florida requiring grid rebuilds, thousands of crews, and phased restoration.

✅ Utilities prioritize plants, transmission, substations, then critical facilities

✅ 50,000-60,000 workers mobilized; bucket trucks wait for safe winds

✅ Remote rerouting and hardening aid faster restoration amid flooding

Parts of Florida could be without electricity for more than a week, as damage from Hurricane Irma will require a complete rebuild of portions of the electricity grid, utility executives said on Monday.

Irma has knocked out power to 6.5 million Florida electricity customers, or nearly two-thirds of the state, since making landfall this weekend. In major areas such as Miami-Dade, 74 percent of the county was without power, according to Florida's division of emergency management.

Getting that power back online may require the help of 50,000 to 60,000 workers from all over the United States and Canadian power crews as well, according to Southern Company CEO and Chairman Thomas Fanning. He is also co-chair of the Electricity Subsector Coordinating Council, which coordinates the utility industry and government response to disasters and cyberthreats.

While it is not uncommon for severe storms to down power lines and damage utility poles, Irma's heavy winds and rain batted some of the state's infrastructure to the ground, Fanning said.

"'Restore' may not capture the full sense of where we are. For the very hard impacted areas, I think you're in a 'rebuild' area," he told CNBC's "Squawk Box."

"That's a big deal. People need to understand this is going to take perhaps weeks, not days, in some areas," Fanning said.

Parts of northern Florida, including Jacksonville, experienced heavy flooding, which will temporarily prevent crews from accessing some areas.

Duke Energy, which serves 1.8 million customers in parts of central and northwestern Florida, is trying to restore service to 1.2 million residences and businesses.

Florida Power & Light Company, which provides power to an estimated 4.9 million accounts across the state, had about 3.5 million customers without electricity as of Monday afternoon, said Rob Gould, vice president and chief communications officer at FPL.

The initial damage assessments suggest power can be restored to parts of the state's east coast in just days, but some of the west coast will require rebuilding that could stretch out for weeks, Gould told CNBC's "Power Lunch."

"This is not a typical restoration that you're going to see. We actually for the first time in our company history have our entire 27,000-square-mile, 35-county territory under assault by Irma," he said.

FPL said it would first repair any damage to power plants, transmission lines and substations as part of its massive response to Irma, then prioritize critical facilities such as hospitals and water treatment plants. The electricity company would then turn its attention to areas that are home to supermarkets, gas stations and other community services.

Florida utilities invested billions into their systems after devastating hurricane seasons in 2004 and 2005 in order to make them more resilient and easier to restore after a storm. Irma, which ranked among the most powerful storms in the Atlantic, has nevertheless tested those systems.

The upgrades have allowed FPL to automatically reroute power and address about 1.5 million outages, Gould said. The company strategically placed 19,500 restoration workers before the storm hit, but it cannot use bucket trucks to fix power lines until winds die down, he said.

Some parts of Florida's distribution system — the lines that deliver electricity from power plants to businesses and residences — run underground. However, the state's long coastline and the associated danger of storm surge and seawater incursion make it impractical to run lines beneath the surface in some areas.

Duke Energy has equipped 28 percent of its system with smart grid technology to reroute power remotely, according to Harry Sideris, Duke's state president for Florida. He said the company would continue to build out that capability in the future.

Duke deployed more than 9,000 linesmen and support crew members to Irma-struck areas, but cannot yet say how long some customers will be without power.

Separately, Gulf Power crews reported restoring service to more than 32,000 customers.

"At this time we do not know the exact restoration times. However, we're looking at a week or longer from the first look at the widespread damage that we had," Sideris told CNBC's "Closing Bell."

FPL said on Monday it was doing final checks before bringing back nuclear reactors that were powered down as Hurricane Irma hit Florida.

"We are in the process now of doing final checks on a few of them; we will be bringing those up," FPL President and CEO Eric Silagy told reporters.

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Texas power grid highlights ERCOT reliability strains from extreme heat, climate change, and low wind, as natural gas and renewables balance tight capacity amid EV charging growth, heat pumps, and blackout risk across the U.S.

Key Points

Texas power grid is ERCOT-run and isolated, balancing natural gas and wind amid extreme weather and electrification.

✅ Isolated from other U.S. grids, limited import support

✅ Vulnerable to extreme heat, winter storms, low wind

✅ Demand growth from EVs and heat pumps stresses capacity

Texas has a unique state-run power grid facing a Texas grid crisis that has raised concerns, but its issues with extreme weather, and balancing natural gas and wind, hold lessons for an entire U.S. at risk for power outages from climate change.

Grid operator the Electric Reliability Council of Texas, or ERCOT, which has drawn criticism from Elon Musk recently, called on consumers to voluntarily reduce power use on Monday when dangerous heat gripped America’s second-most populous state.

The action paid off as the Texas grid avoided blackouts — and a repeat of its winter crisis — despite record or near-record temperatures that depleted electric supplies amid a broader supply-chain crisis affecting utilities this summer, and risked lost power to more than 26 million customers. ERCOT later on Monday lifted the call for conservation.

For sure, it’s a unique situation, as the state-run power grid system runs outside the main U.S. grids. Still, all Americans can learn from Texas about the fragility of a national power grid that is expected to be challenged more frequently by hot and cold weather extremes brought on by climate change, including potential reliability improvements policymakers are weighing.

The grid will also be tested by increased demand to power electric vehicles (EVs) and conversions to electric heat pumps — all as part of a transition to a “greener” future.

Why is Texas different?
ERCOT, the main, but not only, Texas grid, is unique in its state-run, and not regional, format used by the rest of the country. Because it’s an energy-rich state, Texas has been able to set power prices below those seen in other parts of the country, and its independence gives it more pricing authority, while lawmakers consider market reforms to avoid blackouts. But during unusual strain on the system, such as more people blasting their air conditioners longer to combat a record heat wave, it also has no where else to turn.

A lethal winter power shortage in February 2021, during a Texas winter storm that left many without power and water, notoriously put the state and its independent utility in the spotlight when ERCOT failed to keep residents warm and pipes from bursting. Texas’s 2021 outage left more than 200 people dead and rang up $20 billion in damage. Fossil-fuel CL00, 0.80% backers pointed to the rising use of intermittent wind power, which generates 23% of Texas’s electricity. Others said natural-gas equipment was frozen under the extreme conditions.

This week, ERCOT is asking for voluntary conservation between 2 p.m. and 8 p.m. local time daily due to record high electricity demand from the projected heat wave, and also because of low wind. ERCOT said current projections show wind generation coming in at less than 10% of capacity. ERCOT stressed that no systemwide outages are expected, and Gov. Greg Abbott has touted grid readiness heading into fall, but it was acting preemptively.

A report late last year from the North American Electric Reliability Corp. (NERC) said the Texas system without upgrades could see a power shortfall of 37% in extreme winter conditions. NERC’s outlook suggested the state and ERCOT isn’t prepared for a repeat of weather extremes.

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