Polluting power plants seek to expand output

SM-1A Nuclear Plant Decommissioning details the US Army Corps of Engineers' removal of the Fort Greely reactor, Cold War facility dismantling, environmental monitoring, remote-site power history, and timeline to 2026 under a deactivated nuclear program.

Key Points

Army Corps plan to dismantle Fort Greely's SM-1A reactor and complete decommissioning of remaining systems by 2026.

✅ Built for remote Arctic radar support during the Cold War

✅ High costs beat diesel; program later deemed impractical

✅ Reactor parts removed; residuals monitored; removal by 2026

The US Army Corps of Engineers has begun decommissioning Alaska’s only nuclear power plant, SM-1A, which is located at Fort Greely, even as new US reactors continue to take shape nationwide. The $17m plant closed in 1972 after ten years of sporadic operation. It was out of commission from 1967 to 1969 for extensive repairs. Much of has already been dismantled and sent for disposal, and the rest, which is encased in concrete, is now to be removed.

The plant was built as part of an experimental programme to determine whether nuclear facilities, akin to next-generation nuclear concepts, could be built and operated at remote sites more cheaply than diesel-fuelled plants.

"The main approach was to reduce significant fuel-transportation costs by having a nuclear reactor that could operate for long terms, a concept echoed in the NuScale SMR safety evaluation process, with just one nuclear core," Brian Hearty said. Hearty manages the Army Corps of Engineers’ Deactivated Nuclear Power Plant Program.

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He said the Army built SM-1A in 1962 hoping to provide power reliably at remote Arctic radar sites, where in similarly isolated regions today new US coal plants may still be considered, intended to detect incoming missiles from the Soviet Union at the height of the Cold War. He added that the programme worked but not as well as Pentagon officials had hoped. While SM-1A could be built and operated in a cold and remote location, its upfront costs were much higher than anticipated, and it costs more to maintain than a diesel power plant. Moreover, the programme became irrelevant because of advances in Soviet rocket science and the development of intercontinental ballistic missiles.

Hearty said the reactor was partially dismantled soon after it was shut down. “All of the fuel in the reactor core was removed and shipped back to the Atomic Energy Commission (AEC) for them to either reprocess or dispose of,” he noted. “The highly activated control and absorber rods were also removed and shipped back to the AEC.”

The SM-1A plant produced 1.8MWe and 20MWt, including steam, which was used to heat the post. Because that part of the system was still needed, Army officials removed most of the nuclear-power system and linked the heat and steam components to a diesel-fired boiler. However, several parts of the nuclear system remained, including the reactor pressure vessel and reactor coolant pumps. “Those were either kept in place, or they were cut off and laid down in the tall vapour-containment building there,” Hearty said. “And then they were grouted and concreted in place.” The Corps of Engineers wants to remove all that remains of the plant, but it is as yet unclear whether that will be feasible.

Meanwhile, monitoring for radioactivity around the facility shows that it remains at acceptable levels. “It would be safe to say there’s no threat to human health in the environment,” said Brenda Barber, project manager for the decommissioning. Work is still in its early stages and is due to be completed in 2026 at the earliest. Barber said the Corps awarded the $4.6m contract in December to a Virginia-based firm to develop a long-range plan for the project, similar in scope to large reactor refurbishment efforts elsewhere. Among other things, this will help officials determine how much of the SM-1A will remain after it’s decommissioned. “There will still be buildings there,” she said. “There will still be components of some of the old structure there that may likely remain.”

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Peterborough Distribution Inc. Sale to Hydro One delivers a $105 million deal pending Ontario Energy Board approval, a 1% distribution rate cut, five-year rate freeze, job protections, and a new operations centre and fleet facility.

Key Points

A $105M acquisition of PDI by Hydro One, with OEB review, rate freeze, job protections, and a new operations centre.

✅ $105 million purchase; Ontario Energy Board approval required

✅ 1% distribution rate cut and a five-year rate freeze

✅ New operations centre; PDI employees offered roles at Hydro One

The City of Peterborough said Wednesday it has agreed to sell Peterborough Distribution Inc. to Hydro One for $105 million, amid a period when Hydro One shares fell after leadership changes.

The deal requires approval from the Ontario Energy Board before it can proceed.

According to the city, the deal includes a one per cent distribution rate reduction and a five-year freeze in distribution rates for customers, plus:

• A second five-year period with distribution rate increases limited to inflation and an earnings sharing mechanism to offset rates in year 11 and onward
• Protections for PDI employees with employees receiving employment offers to move to Hydro One
• A sale price of $105 million
• An agreement to develop a regional operations centre and new fleet maintenance facility in Peterborough

“Hydro One was unique in its ability to offer new investment and job creation in our community through the addition of a new operations centre to serve customers throughout the broader region,” Mayor Daryl Bennett said.

“We’re surrounded by Hydro One territory — in fact, we already have Hydro One customers within the City of Peterborough and new subdivisions will be in Hydro One territory. Hydro One will be able to create efficiencies by better utilizing its existing infrastructure, benefiting customers and supporting growth.”

The sale comes after months of negotiations amid investor concerns about Hydro One’s uncertainties. At one point, it looked like the sale wouldn’t go through, after it was announced that Hydro One had walked away from the bargaining table.

City council approved the sale of PDI in December 2016, despite a strong public opposition and debate over proposals to make hydro public again among some parties.

Elsewhere in Canada, political decisions around utilities have also sparked debate, as seen when Manitoba Hydro faced controversy over policy shifts.

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BC Hydro pandemic electricity trends reveal weekend-like energy consumption patterns: later morning demand, earlier evenings, more cooking, streaming on smart TVs, and work-from-home routines, with tips to conserve using laptops and small appliances.

Key Points

Weekend-like shifts in power demand from work-from-home routines: later mornings, earlier evenings, and more streaming.

✅ Later morning electricity demand; earlier evening peaks

✅ More cooking and baking; increased streaming after dinner

✅ Conservation tips: laptops, small appliances, smart TVs

The latest report on electricity usage in British Columbia reveals the COVID-19 pandemic has created an atmosphere where every day feels like a Saturday, a pattern also reflected in BC electricity demand during peak seasons.

BC Hydro says overall power usage hasn't changed much, but similar Ontario electricity demand shifts suggest regional differences, while Manitoba demand fell more noticeably, and a survey of 500 people shows daily routines have shifted dramatically since mid-March when pandemic-related closures began.

The hydro report says, with nearly 40 per cent of B.C. residents working from home, trends in residential electricity use confirm almost half are sleeping in and eating breakfast later, while about a quarter say they are showering less.

Those patterns more closely resemble what hydro says is typical weekend power consumption, and could influence time-of-use rates as electricity demand occurs later in the morning and earlier in the evening.

The report also finds many people are cooking and baking more than before the pandemic, preparing the evening meal earlier, streaming or viewing more television after dinner even as Ottawa's electricity consumption dipped earlier in the pandemic, and 80 per cent are going to bed later.

Although electricity use is normal for this time of year, hydro says homebound residents can conserve by using laptops instead of desktops, small appliances such as Instant Pots instead of ovens, and streaming movies or TV shows on a smart televisions instead of game consoles, even as Hydro One peak rates continue to shape consumption patterns elsewhere.

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Nighttime Thermoelectric Generator converts radiative cooling into renewable energy, leveraging outer space cold; a Stanford-UCLA prototype complements solar, serving off-grid loads with low-power output during peak evening demand, using simple materials on a rooftop.

Key Points

A device converting nighttime radiative cooling into electricity, complementing solar for low-power evening needs.

✅ Uses thermocouples to convert temperature gradients to voltage.

✅ Exploits radiative cooling to outer space for night power.

✅ Complements solar; low-cost parts suit off-grid applications.

Two years ago, one freezing December night on a California rooftop, a tiny light shone weakly with a little help from the freezing night air. It wasn't a very bright glow. But it was enough to demonstrate the possibility of generating renewable power after the Sun goes down.

Working with Stanford University engineers Wei Li and Shanhui Fan, University of California Los Angeles materials scientist Aaswath Raman put together a device that produces a voltage by channelling the day's residual warmth into cooling air, effectively generating electricity from thin air with passive heat exchange.

"Our work highlights the many remaining opportunities for energy by taking advantage of the cold of outer space as a renewable energy resource," says Raman.

"We think this forms the basis of a complementary technology to solar. While the power output will always be substantially lower, it can operate at hours when solar cells cannot."

For all the merits of solar energy, it's just not a 24-7 source of power, although research into nighttime solar cells suggests new possibilities for after-dark generation. Sure, we can store it in a giant battery or use it to pump water up into a reservoir for later, but until we have more economical solutions, nighttime is going to be a quiet time for renewable solar power. 

Most of us return home from work as the Sun is setting, and that's when energy demands spike to meet our needs for heating, cooking, entertaining, and lighting.

Unfortunately, we often turn to fossil fuels to make up the shortfall. For those living off the grid, it could require limiting options and going without a few luxuries.

Shanhui Fan understands the need for a night time renewable power source well. He's worked on a number of similar devices, including carbon nanotube generators that scavenge ambient energy, and a recent piece of technology that flipped photovoltaics on its head by squeezing electricity from the glow of heat radiating out of the planet's Sun-warmed surface.

While that clever item relied on the optical qualities of a warm object, this alternative device makes use of the good old thermoelectric effect, similar to thin-film waste-heat harvesting approaches now explored.

Using a material called a thermocouple, engineers can convert a change in temperature into a difference in voltage, effectively turning thermal energy into electricity with a measurable voltage. This demands something relatively toasty on one side and a place for that heat energy to escape to on the other.

The theory is the easy part – the real challenge is in arranging the right thermoelectric materials in such a way that they'll generate a voltage from our cooling surrounds that makes it worthwhile.

To keep costs down, the team used simple, off-the-shelf items that pretty much any of us could easily get our hands on.

They put together a cheap thermoelectric generator and linked it with a black aluminium disk to shed heat in the night air as it faced the sky. The generator was placed inside a polystyrene enclosure sealed with a window transparent to infrared light, and linked to a single tiny LED.

For six hours one evening, the box was left to cool on a roof-top in Stanford as the temperature fell just below freezing. As the heat flowed from the ground into the sky, the small generator produced just enough current to make the light flicker to life.

At its best, the device generated around 0.8 milliwatts of power, corresponding to 25 milliwatts of power per square metre.

That might just be enough to keep a hearing aid working. String several together and you might just be able to keep your cat amused with a simple laser pointer. So we're not talking massive amounts of power.

But as far as prototypes go, it's a fantastic starting point. The team suggests that with the right tweaks and the right conditions, 500 milliwatts per square metre isn't out of the question.

"Beyond lighting, we believe this could be a broadly enabling approach to power generation suitable for remote locations, and anywhere where power generation at night is needed," says Raman.

While we search for big, bright ideas to drive the revolution for renewables, it's important to make sure we don't let the smaller, simpler solutions like these slip away quietly into the night.

This research was published in Joule.

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Smart EV Charging orchestrates vehicle-to-grid (V2G), demand response, and fast charging to balance the power grid, integrating renewables, electrolyzers for hydrogen, and megawatt chargers for fleets with advanced control and co-optimization.

Key Points

Smart EV charging coordinates EV load to stabilize the grid, cut peaks, and integrate renewable energy efficiently.

✅ Reduces peak demand via coordinated, flexible load control

✅ Enables V2G services with renewables and battery storage

✅ Supports megawatt fast charging for heavy-duty fleets

As electric vehicle (EV) sales continue to rev up in the United States, the power grid is in parallel contending with the greatest transformation in its 100-year history: the large-scale integration of renewable energy and power electronic devices. The expected expansion of EVs will shift those challenges into high gear, causing cities to face gigawatt-growth in electricity demand, as analyses of EV grid impacts indicate, and higher amounts of variable energy.

Coordinating large numbers of EVs with the power system presents a highly complex challenge. EVs introduce variable electrical loads that are highly dependent on customer behavior. Electrified transportation involves co-optimization with other energy systems, like natural gas and bulk battery storage, including mobile energy storage flexibility for new operational options. It could involve fleets of automated ride-hailing EVs and lead to hybrid-energy truck stops that provide hydrogen and fast-charging to heavy-duty vehicles.

Those changes will all test the limits of grid integration, but the National Renewable Energy Laboratory (NREL) sees opportunity at the intersection of energy systems and transportation. With powerful resources for simulating and evaluating complex systems, several NREL projects are determining the coordination required for fast charging, balancing electrical supply and demand, and efficient use of all energy assets.

Smart and Not-So-Smart Control
To appreciate the value of coordinated EV charging, it is helpful to imagine the opposite scenario.

"Our first question is how much benefit or burden the super simple, uncoordinated approach to electric vehicle charging offers the grid," said Andrew Meintz, the researcher leading NREL's Electric Vehicle Grid Integration team, as well as the RECHARGE project for smart EV charging. "Then we compare that to the 'whiz-bang,' everything-is-connected approach. We want to know the difference in value."

In the "super simple" approach, Meintz explained that battery-powered electric vehicles grow in market share, exemplified by mass-market EVs, without any evolution in vehicle charging coordination. Picture every employee at your workplace driving home at 5 p.m. and charging their vehicle. That is the grid's equivalent of going 0 to 100 mph, and if it does not wreck the system, it is at least very expensive. According to NREL's Electrification Futures Study, a comprehensive analysis of the impacts of widespread electrification across all U.S. economic sectors, in 2050 EVs could contribute to a 33% increase in energy use during peak electrical demand, underscoring state grid challenges that make these intervals costly when energy reserves are procured. In duck curve parlance, EVs will further strain the duck's neck.

The Optimization and Control Lab's Electric Vehicle Grid Integration bays allow researchers to determine how advanced high power chargers can be added safely and effectively to the grid, with the potential to explore how to combine buildings and EV charging. Credit: Dennis Schroeder, NREL
Meintz's "whiz-bang" approach instead imagines EV control strategies that are deliberate and serve to smooth, rather than intensify, the upcoming demand for electricity. It means managing both when and where vehicles charge to create flexible load on the grid.

At NREL, smart strategies to dispatch vehicles for optimal charging are being developed for both the grid edge, where consumers and energy users connect to the grid, as in RECHARGEPDF, and the entire distribution system, as in the GEMINI-XFC projectPDF. Both projects, funded by the U.S. Department of Energy's (DOE's) Vehicle Technologies Office, lean on advanced capabilities at NREL's Energy Systems Integration Facility to simulate future energy systems.

At the grid edge, EVs can be co-optimized with distributed energy resources—small-scale generation or storage technologies—the subject of a partnership with Eaton that brought industry perspectives to bear on coordinated management of EV fleets.

At the larger-system level, the GEMINI-XFC project has extended EV optimization scenarios to the city scale—the San Francisco Bay Area, to be specific.

"GEMINI-XFC involves the highest-ever-fidelity modeling of transportation and the grid," said NREL Research Manager of Grid-Connected Energy Systems Bryan Palmintier.

"We're combining future transportation scenarios with a large metro area co-simulationPDF—millions of simulated customers and a realistic distribution system model—to find the best approaches to vehicles helping the grid."

GEMINI-XFC and RECHARGE can foresee future electrification scenarios and then insert controls that reduce grid congestion or offset peak demand, for example. Charging EVs involves a sort of shell game, where loads are continually moved among charging stations to accommodate grid demand.

But for heavy-duty vehicles, the load is harder to hide. Electrified truck fleets will hit the road soon, creating power needs for electric truck fleets that translate to megawatts of localized demand. No amount of rerouting can avoid the requirements of charging heavy-duty vehicles or other instances of extreme fast-charging (XFC). To address this challenge, NREL is working with industry and other national laboratories to study and demonstrate the technological buildout necessary to achieve 1+ MW charging stationsPDF that are capable of fast charging at very high energy levels for medium- and heavy-duty vehicles.

To reach such a scale, NREL is also considering new power conversion hardware based on advanced materials like wide-bandgap semiconductors, as well as new controllers and algorithms that are uniquely suited for fleets of charge-hungry vehicles. The challenge to integrate 1+ MW charging is also pushing NREL research to higher power: Upcoming capabilities will look at many-megawatt systems that tie in the support of other energy sectors.

Renewable In-Roads for Hydrogen

At NREL, the drive toward larger charging demands is being met with larger research capabilities. The announcement of ARIES opens the door to energy systems integration research at a scale 10-times greater than current capabilities: 20 MW, up from 2 MW. Critically, it presents an opportunity to understand how mobility with high energy demands can be co-optimized with other utility-scale assets to benefit grid stability.

"If you've got a grid humming along with a steady load, then a truck requires 500 kW or more of power, it could create a large disruption for the grid," said Keith Wipke, the laboratory program manager for fuel cells and hydrogen technologies at NREL.

Such a high power demand could be partially served by battery storage systems. Or it could be hidden entirely with hydrogen production. Wipke's program, with support from the DOE's Hydrogen and Fuel Cell Technologies Office, has been performing studies into how electrolyzers—devices that use electricity to break water into hydrogen and oxygen—could offset the grid impacts of XFC. These efforts are also closely aligned with DOE's H2@Scale vision for affordable and effective hydrogen use across multiple sectors, including heavy-duty transportation, power generation, and metals manufacturing, among others.

"We're simulating electrolyzers that can match the charging load of heavy-duty battery electric vehicles. When fast charging begins, the electrolyzers are ramped down. When fast charging ends, the electrolyzers are ramped back up," Wipke said. "If done smoothly, the utility doesn't even know it's happening."

NREL Researchers Rishabh Jain, Kazunori Nagasawa, and Jen Kurtz are working on how grid integration of electrolyzers—devices that use electricity to break water into hydrogen and oxygen—could offset the grid impacts of extreme fast-charging. Credit: National Renewable Energy Laboratory
As electrolyzers harness the cheap electrons from off-demand periods, a significant amount of hydrogen can be produced on site. That creates a natural energy pathway from discount electricity into a fuel. It is no wonder, then, that several well-known transportation and fuel companies have recently initiated a multimillion-dollar partnership with NREL to advance heavy-duty hydrogen vehicle technologies.

"The logistics of expanding electric charging infrastructure from 50 kW for a single demonstration battery electric truck to 5,000 kW for a fleet of 100 could present challenges," Wipke said. "Hydrogen scales very nicely; you're basically bringing hydrogen to a fueling station or producing it on site, but either way the hydrogen fueling events are decoupled in time from hydrogen production, providing benefits to the grid."

The long driving range and fast refuel times—including a DOE target of achieving 10-minutes refuel for a truck—have already made hydrogen the standout solution for applications in warehouse forklifts. Further, NREL is finding that distributed electrolyzers can simultaneously produce hydrogen and improve voltage conditions, which can add much-needed stability to a grid that is accommodating more energy from variable resources.

Those examples that co-optimize mobility with the grid, using diverse technologies, are encouraging NREL and its partners to pursue a new scale of systems integration. Several forward-thinking projects are reimagining urban mobility as a mix of energy solutions that integrate the relative strengths of transportation technologies, which complement each other to fill important gaps in grid reliability.

The Future of Urban Mobility
What will electrified transportation look like at high penetrations? A few NREL projects offer some perspective. Among the most experimental, NREL is helping the city of Denver develop a smart community, integrated with electrified mobility and featuring automated charging and vehicle dispatch.

On another path to advanced mobility, Los Angeles has embarked on a plan to modernize its electricity system infrastructure, reflecting California EV grid stability goals—aiming for a 100% renewable energy supply by 2045, along with aggressive electrification targets for buildings and vehicles. Through the Los Angeles 100% Renewable Energy Study, the city is currently working with NREL to assess the full-scale impacts of the transition in a detailed analysis that integrates diverse capabilities across the laboratory.

The transition would include the Port of Long Beach, the busiest container port in the United States.

At the port, NREL is applying the same sort of scenario forecasting and controls evaluation as other projects, in order to find the optimal mix of technologies that can be integrated for both grid stability and a reliable quality of service: a mix of hydrogen fuel-cell and battery EVs, battery storage systems, on-site renewable generation, and extreme coordination among everything.

"Hydrogen at ports makes sense for the same reason as trucks: Marine applications have big power and energy demands," Wipke said. "But it's really the synergies between diverse technologies—the existing infrastructure for EVs and the flexibility of bulk battery systems—that will truly make the transition to high renewable energy possible."

Like the Port of Long Beach, transportation hubs across the nation are adapting to a complex environment of new mobility solutions. Airports and public transit stations involve the movement of passengers, goods, and services at a volume exceeding anywhere else. With the transition to digitally connected electric mobility changing how airports plan for the future, NREL projects such as Athena are using the power of high-performance computing to demonstrate how these hubs can maximize the value of passenger and freight mobility per unit of energy, time, and/or cost.

The growth in complexity for transportation hubs has just begun, however. Looking ahead, fleets of ride-sharing EVs, automated vehicles, and automated ride-sharing EV fleets could present the largest effort to manage mobility yet.

A Self-Driving Power Grid
To understand the full impact of future mobility-service providers, NREL developed the HIVE (Highly Integrated Vehicle Ecosystem) simulation framework. HIVE combines factors related to serving mobility needs and grid operations—such as a customer's willingness to carpool or delay travel, and potentially time-variable costs of recharging—and simulates the outcome in an integrated environment.

"Our question is, how do you optimize the management of a fleet whose primary purpose is to provide rides and improve that fleet's dispatch and charging?" said Eric Wood, an NREL vehicle systems engineer.

HIVE was developed as part of NREL's Autonomous Energy Systems research to optimize the control of automated vehicle fleets. That is, optimized routing and dispatch of automated electric vehicles.

The project imagines how price signals could influence dispatch algorithms. Consider one customer booking a commute through a ride-hailing app. Out of the fleet of vehicles nearby—variously charged and continually changing locations—which one should pick up the customer?

Now consider the movements of thousands of passengers in a city and thousands of vehicles providing transportation services. Among the number of agents, the moment-to-moment change in energy supply and demand, and the broad diversity in vendor technologies, "we're playing with a lot of parameters," Wood said.

But cutting through all the complexity, and in the midst of massive simulations, the end goal for vehicle-to-grid integration is consistent:

"The motivation for our work is that there are forecasts for significant load on the grid from the electrification of transportation," Wood said. "We want to ensure that this load is safely and effectively integrated, while meeting the expectations and needs of passengers."

The Port of Long Beach uses a mix of hydrogen fuel-cell and battery EVs, battery storage systems, on-site renewable generation, and extreme coordination among everything. Credit: National Renewable Energy Laboratory
True Replacement without Caveats

Electric vehicles are not necessarily helpful to the grid, but they can be. As EVs become established in the transportation sector, NREL is studying how to even out any bumps that electrified mobility could cause on the grid and advance any benefits to commuters or industry.

"It all comes down to load flexibility," Meintz said. "We're trying to decide how to optimally dispatch vehicle charging to meet quality-of-service considerations, while also minimizing charging costs."

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Texas Heat Pump Electrification replaces natural gas furnaces with electric heating across ERCOT, cutting carbon emissions, lowering utility bills, shifting summer peaks to winter, and aligning higher loads with strong seasonal wind power generation.

Key Points

Statewide shift from gas furnaces to heat pumps in Texas, reducing emissions and bills while moving grid peak to winter.

✅ Up to $452 annual utility savings per household

✅ CO2 cuts up to 13.8 million metric tons in scenarios

✅ Winter peak rises, summer peak falls; wind aligns with load

What would happen if you converted all the single-family homes in Texas from natural gas to electric heating?

According to a paper from Pecan Street, an Austin-based energy research organization, the transition would reduce climate-warming pollution, save Texas households up to $452 annually on their utility bills, and flip the state from a summer-peaking to a winter-peaking system. And that winter peak would be “nothing the grid couldn’t evolve to handle,” according to co-author Joshua Rhodes, a view echoed by analyses outlining Texas grid reliability improvements statewide today.

The report stems from the reality that buildings must be part of any comprehensive climate action plan.

“If we do want to decarbonize, eventually we do have to move into that space. It may not be the lowest-hanging fruit, but eventually we will have to get there,” said Rhodes.

Rhodes is a founding partner of the consultancy IdeaSmiths and an analyst at Vibrant Clean Energy. Pecan Street commissioned the study, which is distilled from a larger original analysis by IdeaSmiths, at the request of the nonprofit Environmental Defense Fund.

In an interview, Rhodes said, “The goal and motivation were to put bounding on some of the claims that have been made about electrification: that if we electrify a lot of different end uses or sectors of the economy...power demand of the grid would double.”

Rhodes and co-author Philip R. White used an analysis tool from the National Renewable Energy Laboratory called ResStock to determine the impact of replacing natural-gas furnaces with electric heat pumps in homes across the ERCOT service territory, which encompasses 90 percent of Texas’ electricity load.

Rhodes and White ran 80,000 simulations in order to determine how heat pumps would perform in Texas homes and how the pumps would impact the ERCOT grid.

The researchers modeled the use of “standard efficiency” (ducted, SEER 14, 8.2 HSPF air-source heat pump) and “superior efficiency” (ductless, SEER 29.3, 14 HSPF mini-split heat pump) heat pump models against two weather data sets — a typical meteorological year, and 2011, which had extreme weather in both the winter and summer and highlighted blackout risks during severe heat for many regions.

Emissions were calculated using Texas’ power sector data from 2017. For energy cost calculations, IdeaSmiths used 10.93 cents per kilowatt-hour for electricity and 8.4 cents per therm for natural gas.

Nothing the grid can't handle
Rhodes and White modeled six scenarios. All the scenarios resulted in annual household utility bill savings — including the two in which annual electricity demand increased — ranging from $57.82 for the standard efficiency heat pump and typical meteorological year to $451.90 for the high-efficiency heat pump and 2011 extreme weather year.

“For the average home, it was cheaper to switch. It made economic sense today to switch to a relatively high-efficiency heat pump,” said Rhodes. “Electricity bills would go up, but gas bills can go down.”

All the scenarios found carbon savings too, with CO2 reductions ranging from 2.6 million metric tons with a standard efficiency heat pump and typical meteorological year to 13.8 million metric tons with the high-efficiency heat pump in 2011-year weather.

Peak electricity demand in Texas would shift from summer to winter. Because heat pumps provide both high-efficiency space heating and cooling, in the scenario with “superior efficiency” heat pumps, the summer peak drops by nearly 24 percent to 54 gigawatts compared to ERCOT’s 71-gigawatt 2016 summer peak, even as recurring strains on the Texas power grid during extreme conditions persist.

The winter peak would increase compared to ERCOT’s 66-gigawatt 2018 winter peak, up by 22.73 percent to 81 gigawatts with standard efficiency heat pumps and up by 10.6 percent to 73 gigawatts with high-efficiency heat pumps.

“The grid could evolve to handle this. This is not a wholesale rethinking of how the grid would have to operate,” said Rhodes.

He added, “There would be some operational changes if we went to a winter-peaking grid. There would be implications for when power plants and transmission lines schedule their downtime for maintenance. But this is not beyond the realm of reality.”

And because Texas’ wind power generation is higher in winter, a winter peak would better match the expected higher load from all-electric heating to the availability of zero-carbon electricity.

A conservative estimate
The study presented what are likely conservative estimates of the potential for heat pumps to reduce carbon pollution and lower peak electricity demand, especially when paired with efficiency and demand response strategies that can flatten demand.

Electric heat pumps will become cleaner as more zero-carbon wind and solar power are added to the ERCOT grid, as utilities such as Tucson Electric Power phase out coal. By the end of 2018, 30 percent of the energy used on the ERCOT grid was from carbon-free sources.

According to the U.S. Energy Information Administration, three in five Texas households already use electricity as their primary source of heat, much of it electric-resistance heating. Rhodes and White did not model the energy use and peak demand impacts of replacing that electric-resistance heating with much more energy efficient heat pumps.

“Most of the electric-resistance heating in Texas is located in the very far south, where they don’t have much heating at all,” Rhodes said. “You would see savings in terms of the bills there because these heat pumps definitely operate more efficiently than electric-resistance heating for most of the time.”

Rhodes and White also highlighted areas for future research. For one, their study did not factor in the upfront cost to homeowners of installing heat pumps.

“More study is needed,” they write in the Pecan Street paper, “to determine the feasibility of various ‘replacement’ scenarios and how and to what degree the upgrade costs would be shared by others.”

Research from the Rocky Mountain Institute has found that electrification of both space and water heating is cheaper for homeowners over the life of the appliances in most new construction, when transitioning from propane or heating oil, when a gas furnace and air conditioner are replaced at the same time, and when rooftop solar is coupled with electrification, aligning with broader utility trends toward electrification.

More work is also needed to assess the best way to jump-start the market for high-efficiency all-electric heating. Rhodes believes getting installers on board is key.

“Whenever a homeowner’s making a decision, if their system goes out, they lean heavily on what the HVAC company suggests or tells them because the average homeowner doesn’t know much about their systems,” he said.

More work is also needed to assess the best way to jump-start the market for high-efficiency all-electric heating, and how utility strategies such as smart home network programs affect adoption too. Rhodes believes getting installers on board is key.

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