Vibrations good for harvesting power

By EE Times


Electrical Testing & Commissioning of Power Systems

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By converting vibrations into usable power, researchers are enabling the battery-free operation of ultra-low-power wireless devices for everything from medical implants to that black-box under the seat of new automobiles. If a sensor is needed but it is inconvenient to supply power - from the inside of a jet engine to the heart's aorta valve, for example - energy harvesters are being designed to convert environmental gradients into usable electrical power.

The latest batch of energy harvesters for vibrations use piezoelectric actuators sized to match the energy required by the application, from centimeter-sized fibers ruggedized to supply milliwatts in harsh environments, all the way down to micron-sized actuators fabricated using micro-electromechanical systems (MEMS) to supply microwatts to wireless sensors.

"We have shown that it is possible to harvest vibrations using a weighted MEMS beam and an on-chip piezoelectric actuator to generate as much as 40 microwatts - enough to power a wireless sensor node," said Jo De Boeck, director of IMEC's Holst Centre, in the Netherlands.

IMEC is a European research center dedicated to anticipating the needs of the electronics industry by three to 10 years, and the Holst Centre houses its most forward-looking outpost. Previously, IMECs' Holst Centre demonstrated a batteryless pulse-oxymeter powered by a thermal scavenger, designed to measure the oxygen level in blood. That project, slated to be commercialized within five years, stimulated development of its MEMS vibration harvester for applications in which thermal gradients were not present.

The IMEC vibration harvester uses a micron-sized cantilever with a carefully calculated mass on its free-end that oscillates in the presence of vibrations. The cantilever's fixed end is embedded in a piezoelectric capacitor formed from two metal electrodes separated by the piezoelectric dielectric called PZT (Lead Zirconate Titanate). As the cantilever oscillates, the tiny mass on its end causes the piezoelectric layer to be alternatively stretched and compressed by about 180 nanometers. Each cycle causes an alternating current (AC) to be generated in the circuit it powers, producing a maximum of 40 microwatts at the cantilever's resonance frequency of 1.8 kHz.

"Our output power is in microwatts, but this is within the range of power needed by wireless-sensor applications," said De Boeck. "We believe our harvesters will begin to be commercialized within five years and will become commonplace by the end of the next decade."

The IMEC researchers are currently working on a new type of vibrating capacitor that outperforms even the most exotic piezoelectric formulations. This capacitor will have permanently charged plates with the cantilever's vibrations changing the distance between them. The result will be an AC output similar to the piezoelectric capacitor, but with the charge carried by this device freed from the constraints of piezoelectric materials.

The biggest obstacle to vibration harvesters today is their extreme sensitivity to resonant frequency. A vibration harvester can output as much as 200-times the energy when operating exactly on its resonant frequency, compared with being just a few cycles off resonance. As a result, companies crafting vibration harvesters today are working with their customers to precisely match their application's vibes, as well as manufacturing their own piezoelectric materials that mitigate the effect of resonance.

For instance, in July, Advanced Cerametrics Inc. (Lambertville, N.J.) will announce a vibration harvester using its proprietary piezoelectric fibers that can generate milliwatts of power for remote sensors, wireless transmitters and industrial monitors.

"The key to how it works, is that, even while in sleep mode, it is harvesting vibrations to build up charge on a capacitor," said Farhad Mohammadi, director of research at Advanced Cerametrics. "When the capacitor's voltage gets up to 3.5 (volts), it comes out of sleep mode and turns the application's circuits on - for instance, to wirelessly transmit telemetry data then go back to sleep."

Advanced Cerametrics Inc. was already supplying the Department of Defense with a custom version of its harvester to mine the vibrational energy at the precise resonant frequency of specific pieces of military equipment. But its new line of commercial harvesters is less sensitive to resonant frequency, the company claims, giving it the latitude to serve a variety of applications, from powering industrial wireless sensors to consumer devices, such as pedometers.

To make its piezoelectric fibers less sensitive to resonant frequency, and more ruggedized for a wider variety of applications, Advanced Cerametrics manufactures its own piezoelectric elements, called Bimorphs. Bimorphs are made by spinning 10-micron piezoelectric fibers together with rayon, then embedding them into epoxy. Three Bimorphs power the first harvester model in Advanced Cerametrics new commercial line.

Other companies manufacturing their own piezoelectric materials include Mide Technology Corp, (Medford, Mass.), which earlier this year announced its line of commercial vibration harvesters that are currently being evaluated by several customers, including a railroad that intends to wirelessly transmit data to the operator about the force being applied by brakes on its trains.

"We use a piezoelectric beam with a tip mass, but have encapsulated the fibers in Kapton (a DuPont polymer), making our harvester much more rugged and less sensitive to resonant frequency," said Mide Technology's CEO, Marthinus van Schoor.

As much as 80 percent of an energy harvester's output can be wasted in parasitic losses due to the turn-on voltage requirements for conventional transistors, according to Advanced Linear Devices Inc. To the rescue is the company's invention of a zero-threshold MOSFET, which reduces parasitic losses to as little as five percent.

All normal transistors have a fixed turn-on voltage of 0.7 volts, but ALD's zero-threshold MOSFETs turn on with as little as 10 millivolts, thereby harvesting more energy. The zero-threshold transistor is fabricated by embedding a permanent negative charge on a floating-gate that biases the MOSFET's input to start storing energy immediately, rather than requiring at least 0.7 volts just to turn on and initiate a charge cycle.

"Our zero-threshold MOSFET can work with as little as nanowatts of power, which makes it perfect for harvesting environmental energy," said Bob Chai, ALD founder and CEO.

The zero-threshold circuitry is biased internally at the factory to set the turn-on voltage of each transistor to zero, enabling its circuits to operate at voltage and power levels far below conventional circuitry. ALD claims that its floating-gates will not leak charge for 100 years.

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Duke Energy Florida to build its largest battery storage projects yet

Duke Energy Florida battery storage will add 22 MW across Trenton, Cape San Blas and Jennings, improving grid reliability, outage resilience, enabling peak shaving and deferring distribution upgrades to increase efficiency and customer value.

 

Key Points

Three lithium battery projects totaling 22 MW to improve Florida grid reliability, outage resilience and efficiency.

✅ 22 MW across Trenton, Cape San Blas and Jennings sites

✅ Enhances outage resilience and grid reliability

✅ Defers costly distribution upgrades and improves efficiency

 

Duke Energy Florida (DEF) has announced three battery energy storage projects, totaling 22 megawatts, that will improve overall reliability and support critical services during power outages.

Duke Energy, the nation's largest electric utility, unveils its new logo. (PRNewsFoto/Duke Energy) (PRNewsfoto/Duke Energy)

Collectively, the storage facilities will enhance grid operations, increase efficiencies and improve overall reliability for surrounding communities, with virtual power plant programs offering a model for coordinating distributed resources.

They will also provide important backup generation during power outages, a service that is becoming increasingly important with the number and intensity of storms that have recently impacted the state.

As the grid manager and operator, DEF can maximize the versatility of battery energy storage systems (BESS) to include multiple customer and electric system benefits such as balancing energy demand, managing intermittent resources, increasing energy security and deferring traditional power grid upgrades.

These benefits help reduce costs for customers and increase operational efficiencies.

The 11-megawatt (MW) Trenton lithium-based battery facility will be located 30 miles west of Gainesville in Gilchrist County. The energy storage project will continue to improve power reliability using newer technologies.

The 5.5-MW Cape San Blas lithium-based battery facility will be located approximately 40 miles southeast of Panama City in Gulf County. The project will provide additional power capacity to meet our customers' rising energy demand in the area. This project is an economical alternative to replacing distribution equipment necessary to accommodate local load growth.

The 5.5-MW Jennings lithium-based battery facility will be located 1.5 miles south of the Florida-Georgia border in Hamilton County. The project will continue to improve power reliability through energy storage as an alternative solution to installing new and more costly distribution equipment.

Currently the company plans to complete all three projects by the end of 2020.

"These battery projects provide electric system benefits that will help improve local reliability for our customers and provide significant energy services to the power grid," said Catherine Stempien, Duke Energy Florida state president. "Duke Energy Florida will continue to identify opportunities in battery storage technology which will deliver efficiency improvements to our customers."

 

Additional renewables projects

As part of DEF's commitment to renewables, the company is investing an estimated $1 billion to construct or acquire a total of 700 MW of cost-effective solar power facilities and 50 MW of battery storage through 2022.

Duke Energy is leading the industry deployment of battery technology, with SDG&E's Emerald Storage project underscoring broader adoption across the sector today. Last fall, the company and University of South Florida St. Petersburg unveiled a Tesla battery storage system that is connected to a 100-kilowatt (kW) solar array – the first of its kind in Florida.

This solar-battery microgrid system manages the energy captured by the solar array, situated on top of the university's parking garage, and similar low-income housing microgrid financing efforts are expanding access. The solar array was constructed three years ago through a $1 million grant from Duke Energy. The microgrid provides a backup power source during a power outage for the parking garage elevator, lights and electric vehicle charging stations. Click here to learn more.

In addition to expanding its battery storage technology and solar investments, DEF is investing in transportation electrification to support the growing U.S. adoption of electric vehicles (EV), including EV charging infrastructure, 530 EV charging stations and a modernized power grid to deliver the diverse and reliable energy solutions customers want and need.

 

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It's CHEAP but not necessarily easy: Crosbie introduces PCs' Newfoundland electricity rate reduction strategy

Crosbie Hydro Energy Action Plan outlines rate mitigation for Muskrat Falls, leveraging Nalcor oil revenues, export sales, Holyrood savings, and potential Hydro-Quebec taxation to keep Newfoundland and Labrador electricity rates near 14.67 cents/kWh.

 

Key Points

PC plan to cap post-Muskrat rates by using Nalcor revenues, exports, and savings, with optional Accord funds.

✅ $575.4M yearly to hold rates near 14.67 cents/kWh

✅ Sources: Nalcor oil $231M, Holyrood $150M, rates/dividends $123.4M

✅ Options: export sales, restructuring, Atlantic Accord, HQ tax

 

Newfoundland and Labrador PC Leader Ches Crosbie says Muskrat Falls won't drive up electricity rates, a goal consistent with an agreement to shield ratepayers from cost overruns, if he's elected premier.

According to Crosbie, who presented the party's Crosbie Hydro Energy Action Plan — acronym CHEAP — at a press conference Monday, $575.4 million is needed per year in order to keep rates from ballooning past 14.67 cents per kilowatt hour.

Here's where he thinks the money could come from:

  • Hydro rates and dividends — $123.4 million
  • Export sales — $40.1 million
  • Nalcor restructuring — $30 million
  • Holyrood savings — $150  million
  • Nalcor oil revenue — $231 million

The oil money, Crosbie said, isn't going into government coffers but being invested into the offshore which, he said, is a good place for it.

"But the plan from the beginning around Muskrat Falls was that if there was need for it — for mitigation for rates — that those revenues and operating cash flows from Nalcor oil and gas would be available to be recycled into rate mitigation, as reflected in a recent financial update on the pandemic's impact. and that's what we're going to have to do," he said.

According to Crosbie, his numbers come from the preliminary stage of the Public Utilities Board process, even as rate mitigation talks have lacked public details.

This is a recent aerial view of the Muskrat Falls project in central Labrador. The project is more than 90 per cent complete, with first power forecast for late 2019, alongside Ottawa's $5.2B support for the project. (Nalcor)

"I'm telling you this is the best information available to anyone outside of government," he said. "We're working on what we can."

The PUB estimated Nalcor restructuring could save between $10 million and $15 million, according to Crosbie, but he figures there's "enough duplication and overpayment involved in the way things are now set up that we can find $30 million there."

Currently, provincial ratepayers pay about 12 cents per kilowatt hour as electricity users have started paying for Muskrat Falls costs.

Crosbie's $575.4-million figure would put rates at 14.67 cents per kilowatt-hour in 2021, where his plan pledges to keep them.

A recent Public Utilities Board Report says there's a potential $10 million to $15 million in savings from Nalcor, but Crosbie says he can find $30 million. (CBC)

"The promise is that Muskrat Falls, when it comes online — comes in service — will not increase your rates. Between now and when that happens there are rate increases already in the pipeline up to that level of [14.67 cents per kilowatt-hour] … so that is the baseline target rate at which rates will be kept.

"In other words, Muskrat will not drive up prices for electricity to consumers beyond that point."

In addition to those savings, Crosbie's plan outlined two further steps.

"We think it could be done out of the resources that I've just identified now, but if there's a problem with that, and as a temporary measure, we can use a modest amount of the Atlantic Accord review, fiscal review, revenues," he said.

 

Plan 'nothing new'

Premier Dwight Ball slammed the plan at the House of Assembly on Monday, saying it lacked insight.

"It was a copy and paste exercise," he told reporters. "There's nothing new in that plan. Not at all."

"We're not leaving any stone unturned of where the opportunity would be to actually generate revenue," he said.  "We are genuinely concerned about rate mitigation and we've got to get a plan in place."

 

Potential to tax Hydro-Québec

Crosbie also said there's potential to tax Hydro-Québec.

According to Crosbie, tax exemptions that expired in 2016 allow the province to tax exports from the Upper Churchill, which, he said, could result in "hundreds of millions or billions" in revenue.

"It's not my philosophy to immediately go and do that because that would generate litigation — who needs more of that? — but we do need to let Quebec know that we're very aware of that, and aware of that opportunity, and invite them to come talk about a whole host of issues," Crosbie said.

Crosbie said the tax would also have to be applied to domestic consumption.

"But so massive is the potential revenue from the Upper Churchill export that there would be ways to mitigate that and negate the effect of that on consumers in the province."

Crosbie said with the Atlantic Accord revenue, he could still present a balanced budget by 2022.

 

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US Approves Rule to Boost Renewable Transmission

FERC Transmission Rule accelerates grid modernization and interregional high-voltage lines, enabling renewable energy integration, load balancing, and reliability to advance net-zero goals while strengthening resilience, capacity expansion, and decarbonization across U.S. regional transmission organizations.

 

Key Points

A federal policy mandating interregional grid planning and cost sharing to expand high-voltage lines for renewables.

✅ Expands interregional high-voltage transmission capacity

✅ Improves reliability, resilience, and load balancing

✅ Aligns cost allocation and long-term planning for renewables

 

On May 13th, 2024, the US took a monumental step towards its clean energy goals. The Federal Energy Regulatory Commission (FERC) approved a long-awaited rule designed to significantly expand the transmission of renewable energy across the nation's power grid, a US grid overhaul that many advocates say was overdue. This decision aligns with President Biden's ambitious plan to achieve net-zero carbon emissions by 2050, with renewable energy playing a central role.

The new rule tackles a critical bottleneck hindering the widespread adoption of renewables – transmission infrastructure. Unlike traditional power plants like coal or natural gas that run constantly, solar and wind power generation fluctuates with weather conditions. This variability poses a challenge for the existing grid, which is not designed to efficiently handle large-scale integration of these intermittent sources, helping explain why the grid isn't 100% renewable today.

The FERC rule aims to address this by promoting the construction of new, high-voltage transmission lines, particularly those connecting different regions, where grid limitations in the Pacific Northwest have highlighted the need for better interregional transfers. This improved connectivity would allow for a more strategic distribution of renewable energy. Imagine solar energy harnessed in the sun-drenched Southwest being transmitted eastward to meet peak demand during hot summer days on the Atlantic Coast.

The benefits of this expanded transmission network are multifaceted. First, it unlocks the full potential of renewable resources by allowing for their efficient utilization across the country, a trend consistent with wind and solar surpassing coal in U.S. generation. Abundant wind power in the Midwest could be utilized on the West Coast, while surplus solar energy from the South could supplement demand in the Northeast.

Second, a more robust grid with a higher capacity for renewables reduces reliance on fossil fuel-based power plants and complements other ways to meet decarbonization goals across sectors. This translates to cleaner air and a significant reduction in greenhouse gas emissions, contributing to the fight against climate change.

Third, a modernized grid with improved long-distance transmission bolsters the nation's energy security. Extreme weather events, a growing concern due to climate change, can disrupt energy production in specific regions. This interconnected grid would provide a buffer, ensuring a more reliable and resilient power supply and helping put regions on the road to 100% renewables even during adverse weather conditions.

The FERC's decision is a win for environmental groups and the renewable energy industry. They see it as a critical step towards a cleaner energy future and a significant driver of job creation in the construction and maintenance of new transmission lines. However, concerns have been raised by some stakeholders, particularly investor-owned utilities. They worry about the potential cost burden associated with building these expansive new lines, and recent reports of stalled grid spending underscore those concerns and the need for efficient cost allocation mechanisms. Striking a balance between efficiency, affordability, and environmental responsibility will be crucial for the successful implementation of this policy.

 

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Ontario takes constitutional challenge of its global adjustment electricity fee to Supreme Court

Ontario Global Adjustment Supreme Court Appeal spotlights a constitutional challenge to Ontario's electricity charge, pitting National Steel Car against the IESO over regulatory charge vs tax, procurement policy, and renewable energy feed-in tariff contracts.

 

Key Points

An SCC leave bid on whether Ontario's global adjustment is a valid regulatory charge or an unconstitutional tax.

✅ Appeals Court revived case for full record review

✅ Dispute centers on regulatory charge vs tax classification

✅ FIT renewables contracts and procurement policies at issue

 

The Ontario government wants the Supreme Court of Canada to weigh in on a constitutional challenge being brought against a large provincial electricity charge, a case the province claims raises issues of national importance.

Ontario’s attorney general and its Independent Electricity System Operator applied for permission to appeal to the Supreme Court in January, according to the court’s website.

The province is trying to appeal a Court of Appeal decision reinstating the challenge from November that said a legal challenge by Hamilton, Ont.-based National Steel Car Ltd. should be sent back to a lower-court for a full hearing.

Court reinstates constitutional challenge to Ontario's hefty ‘global adjustment’ electricity charge
National Steel Car appealing decision in legal challenge of Ontario electricity fee it calls an unconstitutional tax
Doug Ford’s cancellation of green energy deals costs Ontario taxpayers $231 million
National Steel Car launched its legal challenge in 2017, with the maker of steel rail cars claiming the province’s global adjustment electricity charge was a tax intended to fund certain post-financial-crisis policy goals. Since it is allegedly a tax, and one not imposed by the provincial legislature, the company’s argument is the global adjustment is unconstitutional, and also in breach of a provincial law requiring a referendum for new taxes.

The global adjustment mostly bridges the gap between the province’s hourly electricity price and the price guaranteed under contracts and regulated rates with power generators. It also helps cover the cost of building new electricity infrastructure and providing conservation programs, but the fee now makes up most of the commodity portion of a household power bill in the province.

Ontario argued the global adjustment is a valid regulatory charge, and moved to have National Steel Car’s challenge thrown out. An Ontario Superior Court judge agreed, and dismissed the challenge in 2018, saying it was “plain, obvious and beyond doubt” it could not succeed. However, an appeals court judge disagreed, writing in a decision last November that the “merits should not have been determined on a pleadings motion and without the development of a full record.”

In filings made to the Supreme Court, both the IESO and Ontario’s Ministry of the Attorney General argued their proposed appeals raise “issues of national and public importance,” such as whether incorporating environmental and social policy goals in procurement could turn attempts by a public body to recover costs into an unconstitutional tax.

Most applications for leave to appeal to the Supreme Court are dismissed, but the Ontario government claims the court’s guidance is required in this case, as it could lead to questions being raised about other fees or charges, such as money raised from fishing licences.

“A failure to dispose of this claim at the pleadings stage may well result in such uncertainty that public authorities across Canada decline to incorporate the kind of environmental and social policy goals objected to in this case into the decisions they make about how to spend funds raised from regulatory charges,” the filing from the attorney general states. “Alternatively, it may induce governments not to engage in cost recovery in connection with publicly supplied goods and services, which can otherwise be sound public policy.”

The government has so far had to pay National Steel Car $250,000 in legal costs “to avoid responding to the credible claim that the Global Adjustment is an unconstitutional tax,” said David Trafford of Morse Shannon LLP, one of National Steel Car’s lawyers.

“The application for leave to appeal is the next step in this effort to avoid having to respond to the case on the merits,” Trafford added in an email.

The application for leave to appeal is the next step in this effort to avoid having to respond to the case on the merits

David Trafford of Morse Shannon, one of National Steel Car’s lawyers
 
National Steel Car has particularly taken issue with the part of the global adjustment that funded contracts for renewable energy under a “feed-in tariff” program, or FIT, which the company called “the main culprit behind the dramatic price increases for electricity.”

The FIT program has been ended, but contracts awarded under it remain in place and form part of the global adjustment. Ontario’s auditor general estimated in 2015 that electricity consumers would pay $9.2 billion more for renewable energy under the government’s guaranteed-price program, a figure that later featured in a dispute between the auditor and the electricity regulator that drew political attention.

National Steel Car said its global adjustment costs grew from $207,260 in 2008 to almost $3.4 million in 2016, reflecting how high electricity rates have pressured manufacturers, to almost $3.4 million in 2016. For 2018, there was approximately $11.2 billion in global adjustment collected, according to the IESO’s reporting.

A spokesperson for the IESO said it “is not in a position to comment” because the case is still before the courts.

Electricity prices have been an ongoing problem for both Ontario consumers and politicians, which the previous Liberal government tried to address in 2017 by, among other things, refinancing global-adjustment costs through the Fair Hydro Plan and other measures.

Since National Steel Car filed its lawsuits, though, the Liberals lost power in the province and were succeeded in 2018 by Premier Doug Ford and the Progressive Conservatives, who made changes to the previous government’s power policies, including legislation to lower electricity rates introduced early in their mandate.

The province has also pursued interprovincial power arrangements, including building on an electricity deal with Quebec as part of its broader energy strategy.

“The present government of Ontario does not agree with the former government’s electricity procurement program, which ceased awarding new contracts in 2016,” Ontario’s attorney general said in a filing. “However, Ontario submits that (the lower-court judge) was correct in holding that it does not give rise to a claim susceptible to being remedied by the courts.”

 

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FERC needs to review capacity market performance, GAO recommends

FERC Capacity Markets face scrutiny as GAO flags inconsistent data on resource adequacy and costs, urging performance goals, risk assessment, and better metrics across PJM, ISO-NE, NYISO, and MISO amid cost-recovery proposals.

 

Key Points

FERC capacity markets aim for resource adequacy, but GAO finds weak data and urges goals and performance reviews.

✅ GAO cites inconsistent data on resource adequacy and costs

✅ Calls for performance goals, metrics, and risk assessment

✅ Applies to PJM, ISO-NE, NYISO; MISO market is voluntary

 

Capacity markets may or may not be functioning properly, but FERC can't adequately make that determination, according to the GAO report.

"Available information on the level of resource adequacy ... and related costs in regions with and without capacity markets is not comprehensive or consistent," the report found. "Moreover, consistent data on historical trends in resource adequacy and related costs are not available for regions without capacity markets."

The review concluded that FERC collects some useful information in regions with and without capacity markets, but GAO said it "identified problems with data quality, such as inconsistent data."

GAO included three recommendations, including calling for FERC to take steps to improve the quality of data collected, and regularly assess the overall performance of capacity markets by developing goals for those assessments.

"FERC should develop and document an approach to regularly identify, assess, and respond to risks that capacity markets face," the report also recommended. The commission "has not established performance goals for capacity markets, measured progress against those goals, or used performance information to make changes to capacity markets as needed."

The recommendation comes as the agency is grappling with a controversial proposal to assure cost-recovery for struggling coal and nuclear plants in the power markets. So far, the proposal would only apply to power markets with capacity markets, including PJM Interconnection, the New England ISO, the New York ISO and possibly MISO. However MISO only has a voluntary capacity market, making it unclear how the proposed rule would be applied there. 

 

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From smart meters to big batteries, co-ops emerge as clean grid laboratories

Minnesota Electric Cooperatives are driving grid innovation with smart meters, time-of-use pricing, demand response, and energy storage, including iron-air batteries, to manage peak loads, integrate wind and solar, and cut costs for rural members.

 

Key Points

Member-owned utilities piloting load management, meters, and storage to integrate wind and solar, cutting peak demand.

✅ Time-of-use pricing pilots lower bills and shift peak load.

✅ Iron-air battery tests add multi-day, low-cost energy storage.

✅ Smart meters enable demand response across rural co-ops.

 

Minnesota electric cooperatives have quietly emerged as laboratories for clean grid innovation, outpacing investor-owned utilities on smart meter installations, time-based pricing pilots, and experimental battery storage solutions.

“Co-ops have innovation in their DNA,” said David Ranallo, a spokesperson for Great River Energy, a generation and distribution cooperative that supplies power to 28 member utilities — making it one of the state’s largest co-op players.

Minnesota farmers helped pioneer the electric co-op model more than a century ago, similar to modern community-generated green electricity initiatives, pooling resources to build power lines, transformers and other equipment to deliver power to rural parts of the state. Today, 44 member-owned electric co-ops serve about 1.7 million rural and suburban customers and supply almost a quarter of the state’s electricity.

Co-op utilities have by many measures lagged on clean energy. Many still rely on electricity from coal-fired power plants. They’ve used political clout with rural lawmakers to oppose new pollution regulations and climate legislation, and some have tried to levy steep fees on customers who install solar panels.

Where they are emerging as innovators is with new models and technology for managing electric grid loads — from load-shifting water heaters to a giant experimental battery made of iron. The programs are saving customers money by delaying the need for expensive new infrastructure, and also showing ways to unlock more value from cheap but variable wind and solar power.

Unlike investor-owned utilities, “we have no incentive to invest in new generation,” said Darrick Moe, executive director of the Minnesota Rural Electric Association. Curbing peak energy demand has a direct financial benefit for members.

Minnesota electric cooperatives have launched dozens of programs, such as the South Metro solar project, in recent years aimed at reducing energy use and peak loads, in particular. They include:

Cost calculations are the primary driver for electric cooperatives’ recent experimentation, and a lighter regulatory structure and evolving electricity market reforms have allowed them to act more quickly than for-profit utilities.

“Co-ops and [municipal utilities] can act a lot more nimbly compared to investor-owned utilities … which have to go through years of proceedings and discussions about cost-recovery,” said Gabe Chan, a University of Minnesota associate professor who has researched electric co-ops extensively. Often, approval from a local board is all that’s required to launch a venture.

Great River Energy’s programs, which are rebranded and sold through member co-ops, yielded more than 101 million kilowatt-hours of savings last year — enough to power 9,500 homes for a year.

Beyond lowering costs for participants and customers at large, the energy-saving and behavior-changing programs sometimes end up being cited as case studies by larger utilities considering similar offerings. Advocates supporting a proposal by the city of Minneapolis and CenterPoint Energy to allow residents to pay for energy efficiency improvements on their utility bills through distributed energy rebates used several examples from cooperatives.

Despite the pace of innovation on load management, electric cooperatives have been relatively slow to transition from coal-fired power. More than half of Great River Energy’s electricity came from coal last year, and Dairyland Power, another major power wholesaler for Minnesota co-ops, generated 70% of its energy from coal. Meanwhile, Xcel Energy, the state’s largest investor-owned utility, has already reduced coal to about 20% of its energy mix.

The transition to cleaner power for some co-ops has been slowed by long-term contracts with power suppliers that have locked them into dirty power. Others have also been stalled by management or boards that have been resistant to change. John Farrell, director of the Institute for Local Self-Reliance’s Energy Democracy program, said generalizing co-ops is difficult. 

“We’ve seen some co-ops that have got 75-year contracts for coal, that are invested in coal mines and using their newsletter to deny climate change,” he said. “Then you see a lot of them doing really amazing things like creating energy storage systems … and load balancing [programs], because they are unique and locally managed and can have that freedom to experiment without having to go through a regulatory process.”

Great River Energy, for its part, says it intends to reach 54% renewable generation by 2025, while some communities, like Frisco, Colorado, are targeting 100% clean electricity by specific dates. Its members recently voted to sell North Dakota’s largest coal plant, but the arrangement involves members continuing to buy power from the new owners for another decade.

The cooperative’s path to clean power could become clearer if its experimental iron-air battery project is successful. The project, the first of its kind in the country, is expected to be completed by 2023.

 

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