Composite Technology inks turbine deal in Canada

Raindrop Triboelectric Energy Harvesting converts falling water into electricity using Teflon (PTFE) on indium tin oxide and an aluminum electrode, forming a transient water bridge; a low frequency nanogenerator for renewable, static electricity harvesting.

Key Points

A method using PTFE, ITO, and an aluminum electrode to turn raindrop impacts into low frequency electrical power.

✅ PTFE on ITO boosts charge transfer efficiency.

✅ Water bridge links electrodes for rapid discharge.

✅ Low frequency output suits continuous energy harvesting.

Scientists at the City University of Hong Kong have used a Teflon-coated surface and a phenomenon called triboelectricity to generate a charge from raindrops. “Here we develop a device to harvest energy from impinging water droplets by using an architecture that comprises a polytetrafluoroethylene [Teflon] film on an indium tin oxide substrate plus an aluminium electrode,” they explain in their new paper in Nature as a step toward cheap, abundant electricity in the long term.

Triboelectricity itself is an old concept. The word means “friction electricity”—from the Greek tribo, to rub or wear down, which is why a diatribe tires you out—and dates back a long, long time. Static electricity is the most famous kind of triboelectric, and related work has shown electricity from the night sky can be harvested as well in niche setups. In most naturally occurring kinds, scientists have studied triboelectric in order to avoid its effects, like explosions inside of grain silos or hospital workers touching off pure oxygen. (Blowing sand causes an electric field, and NASA even worries about static when astronauts eventually land on Mars.)

One of the most studied forms of intentional and useful triboelectric is in systems such as ocean wave generators where the natural friction of waves meets nanogenerators of triboelectric energy. These even already use Teflon, which has natural conductivity that makes it ideal for this job. But triboelectricity is chaotic, and harnessing it generally involves a bunch of complicated, intersecting variables that can vary with the hourly weather. Promises of static electricity charging devices have often been, well, so much hot, sandy wind.

The scientists at City University of Hong Kong used triboelectric ideas to turn falling raindrops into energy. They say previous versions of the same idea were not very efficient, with materials that didn’t allow for high-fidelity transfer of electrical charge. (Many sources of renewable energy aren’t yet as efficient to turn into power, both because of developing technology and because their renewability means even less efficient use could be better than, for example, fossil fuels, and advances in renewable energy storage could help.)

“[A]chieving a high density of electrical power generation is challenging,” the team explains in its paper. “Traditional hydraulic power generation mainly uses electromagnetic generators that are heavy, bulky, and become inefficient with low water supply.” Diversifying how power is generated by water sources such as oceans and rivers is good for the existing infrastructure as well as new installations.

The research team found that as simulated raindrops fell on their device, the way the water accumulated and spread created a link between their two electrodes, one Teflon-coated and the other aluminum. This watery de facto wire link closes the loop and allows accumulated energy to move through the system. Because it’s a mechanical setup, it’s not limited to salty seawater, and because the medium is already water, its potential isn’t affected by ambient humidity either.

Raindrop energy is very low frequency, which means this tech joins many other existing pushes to harvest continuously available, low frequency natural energy, including underwater 'kites' that exploit steady currents. To make an interface that increases “instantaneous power density by several orders of magnitude over equivalent devices,” as the researchers say they’ve done here, could represent a major step toward feasibility in triboelectric generation.

Related News

• Electricity Forum News

• Renewable Energy News

ABO Wind Tunisia 10MW Solar Project will build a photovoltaic park in Gabes with a STEG PPA, fixed tariff, 2,500 m grid connection, producing 18 million kWh annually, targeted for 2020 commissioning with local partners.

Key Points

A 10MW photovoltaic park in Gabes with a 20-year STEG PPA and fixed tariff, slated for 2020 commissioning.

✅ 18 million kWh/year; 2,500 m grid tie, 20-year fixed tariff

✅ Electricity supplied to STEG under PPA; 2020 commissioning

✅ Located in Gabes; built with local partners, 10MW capacity

ABO Wind has received a permit and a tariff for a 10MW photovoltaic project in Tunisia, amid global activity such as Spain's 90MW wind project now underway, which it plans to build and commission in 2020.

The solar park, in the governorate of Gabes, is 400km south of the country’s capital Tunis and aligns with renewable funding initiatives seen across developing markets.

The developer said it plans to build the project next year in close cooperation with local partners, as regional markets from North Africa to the Gulf expand, with Saudi Arabia boosting wind capacity as well.

ABO Wind department head Nicolas Konig said: “The solar park will produce more than 18 million kilowatt hours of electricity per year and will feed it into the grid at a distance of 2500 metres.”

The developer will conclude an electricity supply contract with the state-owned energy supplier (Societe tunisienne de l’electricite et du gaz (STEG), which will provide a fixed remuneration over 20 years, a model echoed by Germany's wind-solar tender for the electricity fed into the grid.

Earlier this year, ABO Wind had already secured a tariff for a wind farm with a capacity of 30MW in a tender, 35km south-east of Tunis, underscoring Tunisia's wind investments under its long-term plan.

The company is working on half a dozen Tunisian wind and solar projects, as institutions like the World Bank support wind growth in developing countries.

“We are making good progress on our way to assemble a portfolio of several ready-to-build wind and solar projects attractive to investors, as Saudi clean energy targets continue to expand globally,” said ABO Wind general manager responsible for international business development Patrik Fischer.

Related News

• Electricity Forum News

• Renewable Energy News

Wildfire Resilient Power Grid Act proposes DOE grants for utility companies to fund wildfire mitigation, grid resilience upgrades, undergrounding power lines, fast-tripping protection, weather monitoring, and vegetation management, prioritizing rural electric cooperatives.

Key Points

A federal bill funding utility wildfire mitigation and grid hardening via DOE grants, prioritizing rural utilities.

✅ $1B DOE matching grants for grid upgrades and wildfire mitigation.

✅ Prioritizes rural utilities; supports undergrounding and hardening.

✅ Funds fast-tripping protection, weather stations, vegetation management.

U.S. Sens. Ron Wyden and Jeff Merkley today introduced new legislation, amid transmission barriers that persist, to incentivize utility companies to do more to reduce wildfire risks as aging power infrastructure ignite wildfires in Oregon and across the West.

Wyden and Merkley's Wildfire Resilient Power Grid Act of 2020 would ensure power companies do their part to reduce the risk of wildfires through power system upgrades, even as California utility spending crackdown seeks accountability, such as the undergrounding of power lines, fire safety equipment installation and proper vegetation management.

"First and foremost, this is a public safety issue. Fire after fire ignited this summer because the aging power grid could not withstand a major windstorm during the season's hottest and driest days," Wyden said. "Many utility companies are already working to improve the resiliency of their power grid, but the sheer costs of these investments must not come at the expense of equitable regulation for rural utility customers. Congress must do all that it can to stop the catastrophic wildfires decimating the West, and that means improving rural infrastructure. By partnering with utilities around the country, we can increase wildfire mitigation efforts at a modest cost -- a fire prevention investment that will pay dividends by saving lives, homes and businesses."

"When this year's unprecedented wildfire event hit, I drove hundreds of miles across our state to see the damage firsthand and to hear directly from impacted communities, so that I could go back to D.C. and work for the solutions they need," said Merkley. "What I saw was apocalyptic--and we have to do everything we can to reduce the risk of this happening again. That means we have to work with our power companies to get critical upgrades and safety investments into place as quickly as possible."

The Wildfire Resilient Power Grid Act of 2020:

* Establishes a $1 billion-per-year matching grant program for power companies through the Department of Energy, even as ACORE opposed DOE subsidy proposals, to reduce the risk of power lines and grid infrastructure causing wildfires.

* Gives special priority to smaller, rural electric companies to ensure mitigation efforts are targeted to forested rural areas.

* Promotes proven methods for reducing wildfire risks, including undergrounding of lines, installing fast-tripping protection systems, and constructing weather monitoring stations to respond to electrical system fire risks.

* Provides for hardening of overhead power lines and installation of fault location equipment where undergrounding of power lines is not a favorable option.

* Ensures fuels management activities of power companies are carried out in accordance with Federal, State, and local laws and regulations.

* Requires power companies to have "skin in the game" by making the program a 1-to-1 matching grant, with an exception for smaller utilities where the matching requirement is one third of the grant.

* Delivers accountability on the part of utilities and the Department of Energy by generating a report every two years on efforts conducted under the grant program.

Portland General Electric President and CEO Maria Pope: "We appreciate Senator Wyden's and Senator Merkley's leadership in proposing legislation to provide federal funding that will help protect Oregon from devastating wildfires. When passed, this will help make Oregon's electric system safer, faster, without increasing customer prices. That is especially important given the economy and hotter, drier summers and longer wildfire seasons that Oregon will continue to face."

Lane County Commission Chair Heather Butch: " In a matter of hours, the entire Lane County community of Blue River was reduced to ashes by the Holiday Farm Fire. Since the moment I first toured that devastation I've been committed to building it back better. I applaud Senators Wyden and Merkley for drafting the Wildfire Resilient Power Grid Act, as it could well provide the path towards meeting this important goal. Moreover, the resultant programs will better protect rural communities from the increasing dangers of wildfires through a number of preventative measures that would otherwise be difficult to implement."

Linn County Commissioner Roger Nyquist: "This legislation is a smart strategic investment for the future safety of our residents as well as the economic vitality of our community."

Marion County Commissioner Kevin Cameron: "After experiencing a traumatic evacuation during the Beachie Creek and Lion's Head wild fires, I understand the need to strengthen the utility Infrastructure. The improvements resulting from Senator Wyden and Merkley's bill will reduce disasters in the future, but improve everyday reliability for our citizens who live, work and protect the environment in potential wildfire areas."

Edison Electric Institute President Tom Kuhn: "EEI thanks Senator Wyden and Senator Merkley for their leadership in introducing the Wildfire Resilient Power Grid Act. This bill will help support and accelerate projects already planned and underway to enhance energy grid resiliency and mitigate the risk of wildfire damage to power lines. Electric companies across the country are committed to working with our government partners and other stakeholders on preparation and mitigation efforts that combat the wildfire threat and on the rapid deployment of technology solutions, including aggregated DERs at FERC, that address wildfire risks, while still maintaining the safe, reliable, and affordable energy we all need."

Oregon Rural Electric Cooperative Association Executive Director Ted Case: "Oregon's electric cooperatives support the Wildfire Resilient Power Grid Act and appreciate Senator Wyden's and Senator Merkley's leadership and innovative approach to wildfire mitigation, particularly for small, rural utilities. This legislation includes targeted assistance that will help us to continue to provide affordable, reliable and safe electricity to over 500,000 Oregonians."

Sustainable Northwest Director of Government Affairs & Program Strategy Dylan Kruse: "In recent years, the West has seen too many wildfires originate due to poorly maintained or damaged electric utility transmission and distribution infrastructure. This legislation plays an important role to ensure that power lines do not contribute to wildfire starts, while providing safe and reliable power to communities during wildfire events. Utilities must, even as Wyoming clean energy bill proposals emerge, live up to their legal requirements to maintain their infrastructure, but this bill provides welcome resources to expedite and prioritize risk reduction, while preventing cost increases for ratepayers."

Oregon Wild Wilderness Program Manager Erik Fernandez: "2020 taught Oregon the lesson that California learned in the Paradise Fire, and SCE wildfire lawsuits that followed underscore the stakes. Addressing the risk of unnaturally caused powerline fires is an increasingly important critical task. I appreciate Senator Ron Wyden's efforts to protect our homes and communities from powerline fires."

Related News

• Electricity Forum News

• Energy Policy News

France Nuclear Heatwave Output Restrictions signal reduced reactor capacity along the Rhone River, as EDF curbs output to meet cooling-water rules, balance the grid, integrate solar peaks, and limit impacts on power prices.

Key Points

EDF limits reactor output during heat to protect rivers and keep the grid stable under cooling-water rules.

✅ Cuts likely at midday/weekends when solar peaks

✅ Bugey, Saint Alban maintain minimum grid output

✅ France net exporter; price impact expected small

The high temperature warning has come early this year but will affect fewer nuclear power plants, amid a broader France-Germany nuclear dispute over atomic power policy that shapes regional energy flows.

High temperatures could halve nuclear power production at plants along France's Rhone River this week, as European power hits records during extreme heat. 

Output restrictions are expected at two nuclear plants in eastern France due to high temperature forecasts, nuclear operator EDF said, which may limit energy output during heatwaves. It comes several days ahead of a similar warning that was made last year but will affect fewer plants.

The hot weather is likely to halve the available power supply from the 3.6 GW Bugey plant from 13 July and the 2.6 GW Saint Alban plant from 16 July, the operator said.

However, production will be at least 1.8 GW at Bugey and 1.3 GW at Saint Alban to meet grid requirements, and may change according to grid needs, the operator said.

Kpler analyst Emeric de Vigan said the restrictions were likely to have little effect on output in practice. Cuts are likely only at the weekend or midday when solar output was at its peak so the impact on power prices would be slim.

During recent lockdowns, power demand held firm in Europe, offering context for current price dynamics.

He said the situation would need monitoring in the coming weeks, however, noting it was unusually early in the summer for such restrictions to be imposed.

Water temperatures at the Bugey plant already eclipsed the initial threshold for restrictions on 9 July, underscoring France's outage risks under heat-driven constraints. They are currently forecast to peak next week and then drop again, Refinitiv data showed.

"France is currently net exporting large amounts of power – single nuclear units' supply restrictions will not have the same effect as last year," Refinitiv analyst Nathalie Gerl said.

The Garonne River in southern France has the highest potential for critical levels of warming, but its Golfech plant is currently offline for maintenance until mid-August, the data showed, highlighting how Europe is losing nuclear power during critical periods.

"(The restrictions were) to be expected and it will probably occur more often," Greenpeace campaigner Roger Spautz said.

"The authorities must stick to existing regulations for water discharges. Otherwise, the ecosystems will be even more affected," he added.

Related News

• Electricity Forum News

• Power Generation News

Hydropower Covid-19 Resilience highlights clean, reliable energy and flexible grid services, with pumped storage, automation, and affordability supporting climate action, decarbonization, and recovery through sustainable infrastructure, policy incentives, and capacity upgrades.

Key Points

Hydropower Covid-19 Resilience is the sector's ability to ensure clean, reliable, flexible power during crises.

✅ Record 4,306 TWh in 2019, avoiding 80-100 Mt CO2e emissions.

✅ 1,308 GW installed; 15.6 GW added; flexibility and storage in demand.

✅ Policy, tax incentives, and fast-track approvals to spur projects.

The Covid-19 pandemic has underlined hydropower's resilience and critical role in delivering clean, reliable and affordable energy, especially in times of crisis, as highlighted by IAEA lessons for low-carbon electricity. This is the conclusion of two new reports published by the International Hydropower Association (IHA).

The 2020 Hydropower Status Report presents latest worldwide installed capacity and generation data, showcasing the sector's contribution to global carbon reduction efforts, with low-emissions sources projected to cover almost all demand increases in the next three years. It is published alongside a Covid-19 policy paper featuring recommendations for governments, financial institutions and industry to respond to the current health and economic crisis.

"Preventing an emergency is far better than responding to one," says Roger Gill, President of IHA, highlighting the need to incentivise investments in renewable infrastructure, a view echoed by Fatih Birol during the crisis. "The events of the past few months must be a catalyst for stronger climate action, including greater development of sustainable hydropower."

Now in its seventh edition, the Hydropower Status Report shows electricity generation hit a record 4,306 terawatt hours (TWh) in 2019, the single greatest contribution from a renewable energy source in history, aligning with the outlook that renewables to surpass coal by 2025.

The annual rise of 2.5 per cent (106 TWh) in hydroelectric generation - equivalent to the entire electricity consumption of Pakistan - helped to avoid an estimated additional 80-100 million metric tonnes of greenhouse gases being emitted last year.

The report also highlights:

* Global hydropower installed capacity reached 1,308 gigawatts (GW) in 2019, as 50 countries completed greenfield and upgrade projects, including pumped storage and repowering old dams in some regions.

* A total of 15.6 GW in installed capacity was added in 2019, down on the 21.8 GW recorded in 2018. This represents a rise of 1.2 per cent, which is below the estimated 2.0 per cent growth rate required for the world to meet Paris Agreement carbon reduction targets.

* India has overtaken Japan as the fifth largest world hydropower producer with its total installed capacity now standing at over 50 GW. The countries with the highest increases in were Brazil (4.92 GW), China (4.17 GW) and Laos (1.89 GW).

* Hydropower's flexibility services have been in high demand during the Covid-19 crisis, even as global demand dipped 15% globally, while plant operations have been less affected due to the degree of automation in modern facilities.

* Hydropower developments have not been immune to economic impacts however, with the industry facing widespread uncertainty and liquidity shortages which have put financing and refinancing of some projects at risk.

In a companion policy paper, IHA sets out the immediate impacts of the crisis on the sector, noting how European responses to Covid-19 have accelerated the electricity system transition, as well as recommendations to assist governments and financial institutions and enhance hydropower's contribution to the recovery.

The recommendations include:

• Increasing the ambition of renewable energy and climate change targets which incorporate the role of sustainable hydropower development.
• Supporting sustainable hydropower through introducing appropriate financial measures such as tax incentives to ensure viable and shovel-ready projects can commence.
• Fast-tracking planning approvals to ensure the development and modernisation of hydropower projects can commence as soon as possible, in line with internationally recognised sustainability guidelines.
• Safeguarding investment by extending deadlines for concession agreements and other awarded projects.
• Given the increasing need for long-duration energy storage such as pumped storage, working with regulators and system operators to develop appropriate compensation mechanisms for hydropower's flexibility services.

Related News

• Electricity Forum News

• Power Generation News

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."

Related News

• Electricity Forum News

• EV Infrastructure News