Electrifying: New cement makes concrete generate electricity


electric cement

Protective Relay Training - Basic

Our customized live online or in‑person group training can be delivered to your staff at your location.

  • Live Online
  • 12 hours Instructor-led
  • Group Training Available
Regular Price:
$699
Coupon Price:
$599
Reserve Your Seat Today

Cement-Based Conductive Composite transforms concrete into power by energy harvesting via triboelectric nanogenerator action, carbon fibers, and built-in capacitors, enabling net-zero buildings and self-sensing structural health monitoring from footsteps, wind, rain, and waves.

 

Key Points

A carbon fiber cement that harvests and stores energy as electricity, enabling net-zero, self-sensing concrete.

✅ Uses carbon fibers to create a conductive concrete matrix

✅ Acts as a triboelectric nanogenerator and capacitor

✅ Enables net-zero, self-sensing structural health monitoring

 

Engineers from South Korea have invented a cement-based composite that can be used in concrete to make structures that generate and store electricity through exposure to external mechanical energy sources like footsteps, wind, rain and waves, and even self-powering roads concepts.

By turning structures into power sources, the cement will crack the problem of the built environment consuming 40% of the world’s energy, complementing vehicle-to-building energy strategies across the sector, they believe.

Building users need not worry about getting electrocuted. Tests showed that a 1% volume of conductive carbon fibres in a cement mixture was enough to give the cement the desired electrical properties without compromising structural performance, complementing grid-scale vanadium flow batteries in the broader storage landscape, and the current generated was far lower than the maximum allowable level for the human body.

Researchers in mechanical and civil engineering from from Incheon National University, Kyung Hee University and Korea University developed a cement-based conductive composite (CBC) with carbon fibres that can also act as a triboelectric nanogenerator (TENG), a type of mechanical energy harvester.

They designed a lab-scale structure and a CBC-based capacitor using the developed material to test its energy harvesting and storage capabilities, similar in ambition to gravity storage approaches being scaled.

“We wanted to develop a structural energy material that could be used to build net-zero energy structures that use and produce their own electricity,” said Seung-Jung Lee, a professor in Incheon National University’s Department of Civil and Environmental Engineering, noting parallels with low-income housing microgrids in urban settings.

“Since cement is an indispensable construction material, we decided to use it with conductive fillers as the core conductive element for our CBC-TENG system,” he added.

The results of their research were published this month in the journal Nano Energy.

Apart from energy storage and harvesting, the material could also be used to design self-sensing systems that monitor the structural health and predict the remaining service life of concrete structures without any external power, which is valuable in industrial settings where hydrogen-powered port equipment is being deployed.

“Our ultimate goal was to develop materials that made the lives of people better and did not need any extra energy to save the planet. And we expect that the findings from this study can be used to expand the applicability of CBC as an all-in-one energy material for net-zero energy structures,” said Prof. Lee, pointing to emerging circular battery recycling pathways for net-zero supply chains.

Publicising the research, Incheon National University quipped: “Seems like a jolting start to a brighter and greener tomorrow!”

 

Related News

Related News

Southern California Edison Faces Lawsuits Over Role in California Wildfires

SCE Wildfire Lawsuits allege utility equipment and power lines sparked deadly Los Angeles blazes; investigations, inverse condemnation, and stricter utility regulations focus on liability, vegetation management, and wildfire safety amid Santa Ana winds.

 

Key Points

Residents sue SCE, alleging power lines ignited LA wildfires; seeking compensation under inverse condemnation.

✅ Videos cited show sparking lines near alleged ignition points.

✅ SCE denies wrongdoing; probes and inspections ongoing.

✅ Inverse condemnation may apply regardless of negligence.

 

In the aftermath of devastating wildfires in Los Angeles, residents have initiated legal action, similar to other mega-fire lawsuits underway in California, against Southern California Edison (SCE), alleging that the utility's equipment was responsible for sparking one of the most destructive fires. The fires have resulted in significant loss of life and property, prompting investigations into the causes and accountability of the involved parties.

The Fires and Their Impact

In early January 2025, Los Angeles experienced severe wildfires that ravaged neighborhoods, leading to the loss of at least 29 lives and the destruction of approximately 155 square kilometers of land. Areas such as Pacific Palisades and Altadena were among the hardest hit. The fires were exacerbated by arid conditions and strong Santa Ana winds, which contributed to their rapid spread and intensity.

Allegations Against Southern California Edison

Residents have filed lawsuits against SCE, asserting that the utility's equipment, particularly power lines, ignited the fires. Some plaintiffs have presented videos they claim show sparking power lines in the vicinity of the fire's origin. These legal actions seek to hold SCE accountable for the damages incurred, including property loss, personal injury, and emotional distress.

SCE's Response and Legal Context

Southern California Edison has denied any wrongdoing, stating that it has not detected any anomalies in its equipment that could have led to the fires. The utility has pledged to cooperate fully with investigations to determine the causes of the fires. California's legal framework, particularly the doctrine of "inverse condemnation," allows property owners to seek compensation from utilities for damages caused by public services, even without proof of negligence. This legal principle has been central in previous cases involving utility companies and wildfire damages, and similar allegations have arisen in other jurisdictions, such as an alleged faulty transformer case, highlighting shared risks.

Historical Context and Precedents

This situation is not unprecedented. In 2018, Pacific Gas and Electric (PG&E) faced similar allegations when its equipment was implicated in the Camp Fire, the deadliest wildfire in California's history. PG&E's equipment was found to have ignited the fire, and the company later pleaded guilty in the Camp Fire, leading to extensive litigation and financial repercussions for the company, while its bankruptcy plan won support from wildfire victims during restructuring. The case highlighted the significant risks utilities face regarding wildfire safety and the importance of maintaining infrastructure to prevent such disasters.

Implications for California's Utility Regulations

The current lawsuits against SCE underscore the ongoing challenges California faces in balancing utility operations with wildfire prevention, as regulators face calls for action amid rising electricity bills. The state has implemented stricter regulations and oversight, and lawmakers have moved to crack down on utility spending to mitigate wildfire risks associated with utility infrastructure. Utilities are now required to invest in enhanced safety measures, including equipment inspections, vegetation management, and the implementation of advanced technologies to detect and prevent potential fire hazards. These regulatory changes aim to reduce the incidence of utility-related wildfires and protect communities from future disasters.

The legal actions against Southern California Edison reflect the complex interplay between utility operations, public safety, and environmental stewardship. As investigations continue, the outcomes of these lawsuits may influence future policies and practices concerning utility infrastructure and wildfire prevention in California. The state remains committed to enhancing safety measures to protect its residents and natural resources from the devastating effects of wildfires.

 

Related News

View more

Does Providing Electricity To The Poor Reduce Poverty? Maybe Not

Rural Electrification Poverty Impact examines energy access, grid connections, and reliability, testing economic development claims via randomized trials; findings show minimal gains without appliances, reliable supply, and complementary services like education and job creation initiatives.

 

Key Points

Study of household grid connections showing modest poverty impact without reliable power and appliances.

✅ Randomized grid connections showed no short-term income gains.

✅ Low reliability and few appliances limited electricity use.

✅ Complementary investments in jobs, education, health may be needed.

 

The head of Swedfund, the development finance group, recently summarized a widely-held belief: “Access to reliable electricity drives development and is essential for job creation, women’s empowerment and combating poverty.” This view has been the driving force behind a number of efforts to provide electricity to the 1.1 billion people around the world living in energy poverty, such as India's village electrification initiatives in recent years.

But does electricity really help lift households out of poverty? My co-authors and I set out to answer this question. We designed an experiment in which we first identified a sample of “under grid” households in Western Kenya—structures that were located close to but not connected to a grid. These households were then randomly divided into treatment and control groups. In the treatment group, we worked closely with the rural electrification agency to connect the households to the grid for free or at various discounts. In the control group, we made no changes. After eighteen months, we surveyed people from both groups and collected data on an assortment of outcomes, including whether they were employed outside of subsistence agriculture (the most common type of work in the region) and how many assets they owned. We even gave children basic tests, as a frequent assertion is that electricity helps children perform better in school since they are able to study at night.

When we analyzed the data, we found no differences between the treatment and control groups. The rural electrification agency had spent more than $1,000 to connect each household. Yet eighteen months later, the households we connected seemed to be no better off. Even the children’s test scores were more or less the same. The results of our experiment were discouraging, and at odds with the popular view that supplying households with access to electricity will drive economic development. Lifting people out of poverty may require a more comprehensive approach to ensure that electricity is not only affordable (with some evidence that EV growth can benefit all customers in mature markets), but is also reliable, useable, and available to the whole community, paired with other important investments.

For instance, in many low-income countries, the grid has frequent blackouts and maintenance problems, making electricity unreliable, as seen in Nigeria's electricity crisis in recent years. Even if the grid were reliable, poor households may not be able to afford the appliances that would allow for more than just lighting and cell phone charging. In our data, households barely bought any appliances and they used just 3 kilowatt-hours per month. Compare that to the U.S. average of 900 kilowatt-hours per month, a figure that could rise as EV adoption increases electricity demand over time.

There are also other factors to consider. After all, correlation does not equal causation. There is no doubt that the 1.1 billion people without power are the world’s poorest citizens. But this is not the only challenge they face. The poor may also lack running water, basic sanitation, consistent food supplies, quality education, sufficient health care, political influence, and a host of other factors that may be harder to measure but are no less important to well-being. Prioritizing investments in some of these other factors may lead to higher immediate returns. Previous work by one of my co-authors, for example, shows substantial economic gains from government spending on treatment for intestinal worms in children.

It’s possible that our results don’t generalize. They certainly don’t apply to enhancing electricity services for non-residential customers, like factories, hospitals, and schools, and electric utilities adapting to new load patterns. Perhaps the households we studied in Western Kenya are particularly poor (although measures of well-being suggest they are comparable to rural households across Sub-Saharan Africa) or politically disenfranchised. Perhaps if we had waited longer, or if we had electrified an entire region, the household impacts we measured would have been much greater. But others who have studied this question have found similar results. One study, also conducted in Western Kenya, found that subsidizing solar lamps helped families save on kerosene, but did not lead children to study more. Another study found that installing solar-powered microgrids in Indian villages resulted in no socioeconomic benefits.

 

Related News

View more

Energy minister unveils Ontario's plan to address growing energy needs

Powering Ontario's Growth accelerates clean electricity, pairing solar, wind, and hydro with energy storage, efficiency investments, and new nuclear, including SMRs, to meet rising demand and net-zero goals while addressing supply planning across the province.

 

Key Points

Ontario's clean energy plan adds renewables, storage, efficiency, and nuclear to meet rising electricity demand.

✅ Over $1B for energy-efficiency programs through 2030+

✅ Largest clean power procurement in Canadian history

✅ Mix of solar, wind, hydro, storage, nuclear, and SMRs

 

Energy Minister Todd Smith has announced a new plan that outlines the actions the government is taking to address the province's growing demand for electricity.

The government is investing over a billion dollars in "energy-efficiency programs" through 2030 and beyond, Smith said in Windsor.

Experts at Ontario's Independent Electricity System recommended the planning start early to meet demand they predict will require the province to be able to generate 88,000 megawatts (MW) in 20 years.

"That means all of our current supply ... would need to double to meet the anticipated demand by 2050," he said during the announcement.

"While we may not need to start building today, government and those in the energy sector need to start planning immediately, so we have new clean, zero emissions projects ready to go when we need them."

The project is called Powering Ontario's Growth and will advance new clean energy generation from a number of sources, including solar, hydroelectric and wind.

He said this would be the biggest acquisition of clean energy in Canada's history.

Smith made the announcement at Hydro One's Keith Transmission Station.

He said the new planned procurement of green power will pair well with recent energy storage procurements, so that power generated by solar panels, for example, can be stored and injected into the system when needed.

NDP Opposition Leader Marit Stiles said Monday's announcement lacks specifics.

"It's light on details, including key questions of cost, climate impact, waste management and financial risk," said Stiles.

"Ford's Conservatives should be playing catch-up after undermining clean energy in their first term. Instead, they're offering generalities and a vague sense of what they might do."

The Green Party criticized the move Monday afternoon, noting that clean, affordable electricity remains a key Ontario election issue today.

"Ontario is facing an energy crunch – and the Ford government is making it worse by choosing more expensive, dirtier options," said MPP for Guelph Mike Schreiner in the statement.

He said Premier Doug Ford has "grossly" mismanaged the province's energy supply by cancelling 750 renewable energy projects and slashing efficiency programs.

"Now, faced with an opportunity to become a leader in a world that's rapidly embracing renewable energy, this government has chosen to funnel taxpayer dollars into polluting fossil gas plants and expensive new nuclear that will take decades to come online," said Schreiner.

Smith announced last week the plan for three more small modular reactors at the site of the Darlington nuclear power plant. The province also shared its intention to add a third nuclear generating station to Bruce Power near Kincardine. 

"With this backwards approach, the Ford government is squandering a once-in-a-generation opportunity to make Ontario a global leader in attracting investment dollars and creating better jobs in the trillion-dollar clean energy sector," said Schreiner.

 

Related News

View more

Iran eyes transmitting electricity to Europe as region’s power hub

Iran Electricity Grid Synchronization enables regional interconnection, cross-border transmission, and Caspian-Europe energy corridors, linking Iraq, Azerbaijan, Russia, and Qatar to West Asia and European markets with reliable, flexible power exchange.

 

Key Points

Iran's initiative to link West Asian and European power grids for trade, transit, reliability, and regional influence.

✅ Synchronizes grids with Iraq, Azerbaijan, Russia, and potential Qatar link

✅ Enables east-to-Europe electricity transit via Caspian energy corridors

✅ Backed by gas-fueled and combined-cycle generation capacity

 

Following a plan for becoming West Asia’s electricity hub, Iran has been taking serious steps for joining its electricity network with neighbors in the past few years.

The Iranian Energy Ministry has been negotiating with the neighboring countries including Iraq for the connection of their power networks with Iran, discussing Iran-Iraq energy cooperation as well as ties with Russia, Afghanistan, Azerbaijan, and Qatar to make them enable to import or transmit their electricity to new destination markets through Iran.

The synchronization of power grids with the neighboring countries, not only enhances Iran’s electricity exchanges with them, but it will also increase the political stance of the country in the region.

So far, Iran’s electricity network has been synchronized with Iraq, where Iran is supplying 40% of Iraq's power today, and back in September, the Energy Minister Reza Ardakanian announced that the electricity networks of Russia and Azerbaijan are the next in line for becoming linked with the Iranian grid in the coming months.

“Within the next few months, the study project of synchronization of the electricity networks of Iran, Azerbaijan, and Russia will be completed and then the executive operations will begin,” the minister said.

Meanwhile, Ardakanian and Qatari Minister of State for Energy Affairs Saad Sherida Al-Kaabi held an online meeting in late September to discuss joining the two countries' electricity networks via sea.

During the online meeting, Al-Kaabi said: "Electricity transfer between the two countries is possible and this proposal should be worked on.”

Now, taking a new step toward becoming the region’s power hub, Iran has suggested becoming a bridge between East and Europe for transmitting electricity.

In a virtual conference dubbed 1st Caspian Europe Forum hosted by Berlin on Thursday, the Iranian energy minister has expressed the country’s readiness for joining its electricity network with Europe.

"We are ready to connect Iran's electricity network, as the largest power generation power in West Asia, with the European countries and to provide the ground for the exchange of electricity with Europe," Ardakanian said addressing the online event.

Iran's energy infrastructure in the oil, gas, and electricity sectors can be used as good platforms for the transfer of energy from east to Europe, he noted.

In the event, which was aimed to study issues related to the development of economic cooperation, especially energy, between the countries of the Caspian Sea region, the official added that Iran, with its huge energy resources and having skilled manpower and advanced facilities in the field of energy, can pave the ground for the prosperity of international transport and energy corridors.

"In order to help promote communication between our landlocked neighbors with international markets, as Uzbekistan aims to export power to Afghanistan across the region, we have created a huge transit infrastructure in our country and have demonstrated in practice our commitment to regional development and peace and stability," Ardakanian said.

He pointed out that having a major percentage of proven oil and gas resources in the world, regional states need to strengthen relations in a bid to regulate production and export policies of these huge resources and potentially play a role in determining the price and supply of these resources worldwide.

“EU countries can join our regional cooperation in the framework of bilateral or multilateral mechanisms such as ECO,” he said.

Given the growing regional and global energy needs and the insufficient investment in the field, with parts of Central Asia facing severe electricity shortages today, as well as Europe's increasing needs, this area can become a sustainable area of cooperation, he noted.

Ardakanian also said that by investing in energy production in Iran, Europe can meet part of its future energy needs on a sustainable basis.

In Iraq, plans for nuclear power plants are being pursued to tackle chronic electricity shortages, reflecting parallel efforts to diversify generation.

Iran currently has electricity exchange with Armenia, Azerbaijan, Iraq, where grid rehabilitation deals have been finalized, Turkmenistan, and Afghanistan.

The country’s total electricity exports vary depending on the hot and cold seasons of the year, since during the hot season which is the peak consumption period, the country’s electricity exports decreases, however electrical communication with neighboring countries continues.

Enjoying abundant gas resources, which is the main fuel for the majority of the country’s power plants, Iran has the capacity to produce about 85,500 megawatts [85.5 gigawatts (GW)] of electricity.

Currently, combined cycle power plants account for the biggest share in the country’s total power generation capacity as Iran is turning thermal plants to combined cycle to save energy, followed by gas power plants.

 

Related News

View more

This kite could harness more of the world's wind energy

Autonomous Energy Kites harness offshore wind on floating platforms, using carbon fiber wings, tethers, and rotors to generate grid electricity; an airborne wind energy solution backed by Alphabet's Makani to cut turbine costs.

 

Key Points

Autonomous Energy Kites are tethered craft that capture winds with rotors, generating grid power from floating platforms.

✅ Flies circles on tethers; rotors drive generators to feed the grid.

✅ Operates over deep-sea winds where fixed turbines are impractical.

✅ Lighter, less visual impact, and lower installation costs offshore.

 

One company's self-flying energy kite may be the answer to increasing wind power around the world, alongside emerging wave power solutions as well.

California-based Makani -- which is owned by Google's parent company, Alphabet -- is using power from the strongest winds found out in the middle of the ocean, where the offshore wind sector has huge potential, typically in spots where it's a challenge to install traditional wind turbines. Makani hopes to create electricity to power communities across the world.

Despite a growing number of wind farms in the United States and the potential of this energy source, lessons from the U.K. underscore how to scale, yet only 6% of the world's electricity comes from wind due to the the difficulty of setting up and maintaining turbines, according to the World Wind Energy Association.

When the company's co-founders, who were fond of kiteboarding, realized deep-sea winds were largely untapped, they sought to make that energy more accessible. So they built an autonomous kite, which looks like an airplane tethered to a base, to install on a floating platform in water, as part of broader efforts to harness oceans and rivers for power across regions. Tests are currently underway off the coast of Norway.

"There are many areas around the world that really don't have a good resource for renewable power but do have offshore wind resources," Makani CEO Fort Felker told Rachel Crane, CNN's innovation correspondent. "Our lightweight kites create the possibility that we could tap that resource very economically and bring renewable power to hundreds of millions of people."

This technology is more cost-efficient than a traditional wind turbine, which is a lot more labor intensive and would require lots of machinery and installation.

The lightweight kite, which is made of carbon fiber, has an 85-foot wingspan. The kite launches from a base station and is constrained by a 1,400-foot tether as it flies autonomously in circles with guidance from computers. Crosswinds spin the kite's eight rotors to move a generator that produces electricity that's sent back to the grid through the tether.

The kites are still in the prototype phase and aren't flown constantly right now as researchers continue to develop the technology. But Makani hopes the kites will one day fly 24/7 all year round. When the wind is down, the kite will return to the platform and automatically pick back up when it resumes.

Chief engineer Dr. Paula Echeverri said the computer system is key for understanding the state of the kite in real time, from collecting data about how fast it's moving to charting its trajectory.

Echeverri said tests have been helpful in establishing what some of the challenges of the system are, and the team has made adjustments to get it ready for commercial use. Earlier this year, the team successfully completed a first round of autonomous flights.

Working in deeper water provides an additional benefit over traditional wind turbines, according to Felker. By being farther offshore, the technology is less visible from land, and the growth of offshore wind in the U.K. shows how coastal communities can adapt. Wind turbines can be obtrusive and impact natural life in the surrounding area. These kites may be more attractive to areas that wish to preserve their scenic coastlines and views.

It's also desirable for regions that face constraints related to installing conventional turbines -- such as island nations, where World Bank support is helping developing countries accelerate wind adoption, which have extremely high prices for electricity because they have to import expensive fossil fuels that they then burn to generate electricity.

Makani isn't alone in trying to bring novelty to wind energy. Several others companies such as Altaeros Energies and Vortex Bladeless are experimenting with kites of their own or other types of wind-capture methods, such as underwater kites that generate electricity, a huge oscillating pole that generates energy and a blimp tethered to the ground that gathers winds at higher altitudes.

 

Related News

View more

Renewable growth drives common goals for electricity networks across the globe

Energy Transition Grid Reforms address transmission capacity, interconnection, congestion management, and flexibility markets, enabling renewable integration and grid stability while optimizing network charges and access in Australia, Ireland, and Great Britain.

 

Key Points

Measures to expand transmission, boost flexibility, and manage congestion for reliable, low-carbon electricity systems.

✅ Transmission upgrades and interconnectors ease congestion

✅ Flexible markets, DER, and storage bolster grid stability

✅ Evolving network charges and access incentivize siting

 

Electricity networks globally are experiencing significant increases in the volume of renewable capacity as countries seek to decarbonise their power sectors, even as clean energy's 'dirty secret' highlights integration trade-offs, without impacting the security of supply. The scale of this change is creating new challenges for power networks and those responsible for keeping the lights on.

The latest insight paper from Cornwall Insight – Market design amidst global energy transition – looks into this issue. It examines the outlook for transmission networks, and how legacy design and policies are supporting decarbonisation, aligning with IRENA findings on renewables and shaping the system. The paper focuses on three key markets; Australia, Ireland and Great Britain (GB).

Australia's main priority is to enhance transmission capacity and network efficiency; as concerns over excess solar risking blackouts grow in distribution networks, without this, the transmission system will be a barrier to growth for decentralised flexibility and renewables. In contrast, GB and Ireland benefit from interconnection with other national markets. This provides them with additional levers that can be pulled to manage system security and supply. However, they are still trying to hone and optimise network flexibility in light of steepening decarbonisation objectives.

Unsurprisingly, renewable energy resources have been growing in all three markets, with Ireland regarded as a leader in grid integration, with this expected to continue for the foreseeable future. Many of these projects are often located in places where network infrastructure is not as well developed, creating pressure on system operation as a result.

In all three markets, unit charges are rising, driven by a reduced charging base as decentralised energy grows quickly. This combination of changes is leading to network congestion, a challenge mirrored by the US grid overhaul for renewables underway, as transmission network development struggles to keep up, and flexibility markets are being optimised and changed.

In summary, reforms are on-going in each jurisdiction to accommodate the rapid physical transformation of the generation mix. Each has its objectives and tensions which are reflective of wider global reform programmes being undertaken in most developed, liberalised and decarbonising energy markets.

Gareth Miller, CEO of Cornwall Insight, said: “Despite differences in market design and characteristics, all three markets are grappling with similar issues, that comes from committing to deep decarbonisation. This includes the most appropriate methods for charging for networks, managing access to them and dealing with issues such as network congestion and constraint.

“In all three countries, renewable projects are often placed in isolated locations, as seen in Scotland where more pylons are needed to keep the lights on, away from the traditional infrastructure that is closer to demand. However, as renewable growth is set to continue, the networks will need to transition from being demand-centric to more supply orientated.

“Both system operators and stakeholders will need to continually evaluate their market structures and designs to alleviate issues surrounding locational congestion and grid stability. Each market is at very different stages in the process in trying to improve any problems implementing solutions to allow for higher efficiencies in renewable energy integration.

“It is uncertain whether any of the proposed changes will fundamentally resolve the issues that come with increased renewables on the system. However, despite marked differences, they certainly could all learn from each other and elements of their network arrangements, as well as from US decarbonisation strategies research.”

 

Related News

View more

Sign Up for Electricity Forum’s Newsletter

Stay informed with our FREE Newsletter — get the latest news, breakthrough technologies, and expert insights, delivered straight to your inbox.

Electricity Today T&D Magazine Subscribe for FREE

Stay informed with the latest T&D policies and technologies.
  • Timely insights from industry experts
  • Practical solutions T&D engineers
  • Free access to every issue

Live Online & In-person Group Training

Advantages To Instructor-Led Training – Instructor-Led Course, Customized Training, Multiple Locations, Economical, CEU Credits, Course Discounts.

Request For Quotation

Whether you would prefer Live Online or In-Person instruction, our electrical training courses can be tailored to meet your company's specific requirements and delivered to your employees in one location or at various locations.