Severe weather, coupled with an aging and overstressed electrical infrastructure, is having a dramatic impact on the U.S. population.
In late 2012, Superstorm Sandy’s devastation left 132 people dead; more than 8 million people in 16 states lost power; subway tunnels were inundated with water; 305,000 homes in New York City and 72,000 homes and businesses in New Jersey were damaged or destroyed; sewage plants in were crippled with hundreds of millions of gallons of sewage flowing into waterways; and four New York City hospitals shut their doors.
Rebuilding after any major storm is a formidable challenge. The core principal of any major reconstruction effort should be to “rebuild smart,” ensuring that reconstruction funds maximize the deployment of technologies to mitigate future power outages, save lives, and protect property.
Resilient and reliable power is critical for first responders, communications, healthcare, transportation, financial systems, water and wastewater treatment, emergency food and shelter, and other vital services. When smart technologies are in place, power outages are avoided and lives, homes, and businesses are protected.
Good examples are the deployment of microgrids, energy storage, and cogeneration. As reported in the MIT Technology Review:
- Local power generation with microgrids showed the benefits of reliability during Superstorm Sandy.
- The Food and Drug Administration’s White Oak research facility in Maryland switched over to its onsite natural gas turbines and engines to power all the buildings on its campus for two and a half days.
- Princeton was able to switch off the grid and power part of the campus with about 11 megawatts of local generation.
- Similarly, a cogeneration plant at New York University was able to provide heat and power to part of the campus.
- A 40MW combined heat and power plant in the Bronx was able to provide electricity and heat to a large housing complex.1
The 400-plus member companies of the National Electrical Manufacturers Association (NEMA) and its staff of experienced engineers and electroindustry experts—spanning more than 50 industry sectors—stand ready to assist industry and government officials when rebuilding after a disaster.
The remaining pages of this overview section describe key technologies highlighted in this document, noting their ability to contribute to a more resilient electric grid.
Smart Grid Solutions
Rebuilding the electric power system should incorporate the use of Smart Grid solutions—information and communications technologies, such as smart meters and high-tech sensors, to isolate problems and bypass them automatically. These technologies provide resilience—quick recovery from extreme weather and other outages.
In much the same way as new information and communications technologies are reshaping how we work, learn, and stay in touch with one another, these same technologies are being applied to the electric grid, giving utilities new ways to manage the flow of power and to expedite restoration efforts.
By integrating information and communications technologies into the electric grid, utilities can not only minimize the extent of an outage, but also immediately identify customers who are impacted, shunt electricity around downed power lines to increase public safety, and enable faster restoration of services.
For example, when disturbances are detected in the power flow, modern circuit breakers can automatically open or close to help isolate a fault. Much like a motorist using his GPS to find an alternate route around an accident, this equipment can automatically re-route power around the problem area so that electricity continues to flow to other customers. Smart Grid solutions also enable utilities to protect the electric grid from cyberattack.
Smart Grid issues and options discussed in this guide:
- Smart meters have two main components: an electronic meter that measures energy information accurately and a communication module that transmits and receives data.
- The primary drivers for deployment of smart meters have been cost reduction and energy savings. Less prominent, but just as important, is the role of smart meters in disaster recovery situations because of their capabilities as smart sensors.
- Smart meter communications provide information on where outages have occurred, allow power to be cut to certain areas to minimize the risk of fire or injury, and enable demand response to manage customer consumption of electricity in response to a stressed distribution system.
- Another benefit of smart meters is verification of power restoration, which is accomplished when a meter reports in after being reenergized. This provides automated and positive verification that all customers have been restored, there are no nested (isolated) outages, and associated trouble orders are closed before restoration crews leave the areas.
- Distribution automation systems can reduce outage times by automatically detecting a fault, isolating the faulted section from the grid, and restoring service to the unfaulted sections. Integrated distribution management systems, together with smart meters, provide control room operators with real-time information on outages rather than waiting for customers to call.
- If most of a grid is still functional, a fault location, isolation, and service restoration (FSLIR) system, integrated into an outage management system can restore power to unfaulted portions line in seconds.
- FLISR systems in tandem with advanced distribution automation enable efficient restoration of the grid.
- Modern reclosers have shortened dead time during auto reclosing, include voltage and current sensors, and can be equipped with intelligent controllers.
- Another component of Smart Grid is flood resistant fiber optics, which can be used to measure current.
Microgrids, Energy Storage, and Other Distributed Generation systems
When power interruptions occur, microgrids, energy storage, and other distributed (i.e., decentralized) generation systems can ensure continued operation of critical facilities.
A microgrid, sometimes referred to as an electrical island, is a localized grouping of electricity generation, energy storage, and electrical loads. Where a microgrid exists, loads are typically also connected to a traditional centralized grid. When the microgrid senses an outage, it disconnects from the central grid and uses its own generation and storage capabilities to serve the local electrical load.
In critical situations microgrids can direct power to high priorities such as first responders, critical care facilities, and hospitals.
Microgrid generation resources can include natural gas, wind, solar panels, diesel or other energy sources. A microgrid’s multiple generation sources and ability to isolate itself from the larger network during an outage on the central grid ensures highly reliable power.
The effectiveness of microgrids is further enhanced through energy storage. Storage systems not only provide backup power while the microgrid’s generation sources are coming online, they can also be used to regulate the quality of the power and protect sensitive systems like hospital equipment that may be vulnerable to power surges during restoration efforts.
Microgrids offer additional advantages. Surplus power from microgrids can be sold to the central grid or stored for later use. In combination with energy storage and energy management systems, microgrids can also provide ancillary services to the broader electric grid such as voltage and frequency regulation. Microgrids also reduce dependence on long distance transmission lines—reducing transmission energy losses.
Also of increasing importance, microgrids can mitigate the effects of cyberattacks by segmenting the grid.
Microgrid, energy storage, and distributed/decentralized energy systems discussed in this guide:
- Microgrids are essentially miniature versions of the electric grid that include localized generation and storage. Localized and increasingly clean generation allows microgrids to provide power to campuses and small communities independent of a macrogrid. These stability islands can keep whole communities of rate payers warm, fed, and safe and allow first responders to start their work sooner.
- A microgrid can coordinate a network of backup generators ensuring the optimum use of fuel.
- Microgrids can tie in alternative energy sources such as wind and solar, gas turbines providing combined heat and power (CHP); energy storage systems. They also have the ability to automatically decouple from the grid and go into island mode.
- A successful microgrid must have intelligent methods to manage and control customers’ electrical loads.
- University campuses, military bases and other federal facilities, hospitals, large research and data centers, industrial parks, and waste water treatment plants are good candidates for microgrids because they typically have a common mission and are managed by the same organization.
- Microgrids are also appropriate for a densely populated urban area, such as Manhattan, where concentration of energy use is high and significant scale justifies connecting multiple buildings as part of a microgrid network.
- New energy storage system designs offer safer and longer operational lifespans, as well as allow customers to install large battery systems that provide emergency power to critical functions when the grid fails. Equally important is their capacity to produce revenue and reduce costs during normal operation.
- Advanced technology battery systems have already proven their ability to nearly double the efficiency of the diesel generators they support.
- Energy storage systems can also reduce thermal strain on the grid during peak load periods and provide a reliable backup power supply in the event of a major storm, other natural disaster, or cyberattack.
- Emergency relief centers can be sustained during outages by incorporated advanced energy storage systems.
- A fleet of large-capacity energy storage units distributed throughout the grid can support hundreds of homes, small businesses, and critical infrastructure during an outage. When combined with a community’s renewable generation resources, the resultant microgrid is capable of operating for many hours or even days.
- For most facilities with the need to maintain power throughout every type of grid disruption, combined heat and power (CHP), also commonly referred to as cogeneration, should be considered. CHP captures waste heat from the generation of electricity—typically by natural gas turbines—to provide heat and hot water, steam for an industrial process, or cooling for a data center. CHP is more energy efficient than producing electricity and heat separately.
- The integration of advanced battery storage systems with CHP has the potential to create a safe, resilient, and efficient energy campus microgrid.
Onsite backup power provides a reliable and cost-effective way to mitigate the risks to lives, property and businesses from power outages. For many facilities, such as assisted living facilities and nursing homes, there is a life safety aspect to consider. Other facilities, such as cell tower sites, emergency call centers, and gas stations, have far-reaching social impact and availability is critical. For businesses with highly sensitive loads such as data centers and financial institutions, the risk of economic losses from downtime is high. One way to mitigate these various risks is onsite backup power equipment.
Traditionally, diesel and natural gas generators are used to provide long-term backup generation. When combined with energy storage, continuous power can be provided without disrupting even the most sensitive medical and electronic equipment.
Backup generation issues and options discussed in this guide:
Wiring, Cabling, and Components
For critical equipment, cabling should be used that is resistant to long-term submersion in water, as well as oil and other pollutants potentially present in flood waters that may have an effect on less robust insulation materials.
In addition, there are classes of transformers, switches, and enclosures that are designed to be submersible. Initial equipment installation can be more expensive than non-submersible equipment, but can pay for itself in subway systems and substation environments that are susceptible to flooding.
Water resistant wiring, cabling, and components issues and options discussed in this guide:
- For cities where much of the power infrastructure is below street level, install submersible transformers and switches.
- Deploy switchgear specially designed for subsurface application in vaults resistant to flood waters containing contaminants.
- Medium-voltage (MV) switchgear, especially for electrical substations, is available in gas-insulated form, which means that all electrical conductors and vacuum interrupters are protected from the environment. This type of containment makes MV switchgear conductors resistant to water contamination.
- In the rebuilding effort following a major storm, the question of how to rebuild existing circuits and which wiring and cables to install are key considerations, arguably the most important considerations from a cost perspective.
- Installing wire and cable that have specific performance characteristics (e.g. water resistant or ruggedized) as well as utilizing installation methods that reduce exposure to the elements (e.g. relocation, undergrounding, and redundancy) can improve an electrical system’s protection from storm damage.
- Damage to cables occurs because the flooded wiring is not designed to withstand submersion in water. The answer is to use robust wet-rated cables indoors in any areas that can be exposed to flood waters.
- When upgrading line capacity, storm-hardening existing lines, or installing new lines, installers can benefit from the use of underground high voltage cable systems that have a history of high reliability and are largely immune to high winds and flooding.
- Covered aerial medium-voltage systems can greatly improve the reliability and reduce the vulnerability of overhead distribution during major weather events.
- Self-healing cables ensure that minor insulation damage to underground 600V cables is limited. Channels between insulation layers hold a sealant that flows into insulation breaks and seals them permanently, preventing the corrosion failures that typically occur with exposure to moisture.
- Using wet-rated products in industrial and commercial applications, especially in critical circuits, can reduce the time and cost of restoring operations after flooding.
- Residential wiring in basements and other vulnerable areas can be made more flood-resistant by substituting a wet-rated product for the commonly used dry-rated one. This may allow power to be restored to residences more quickly without extensive wiring replacement.
Relocation or Repositioning of Equipment
Another smart use of rebuilding funds is relocating or repositioning of equipment or power lines. In light of the devastation caused by recent floods and storms, it is time to evaluate the location of critical infrastructure and identify situations where investing money today will protect vital equipment from future storms.
Relocation and repositioning issues and options discussed in this guide:
Disaster Recovery Planning
After a disaster, power should be restored to the most critical services first. In addition, planning efforts should carefully consider safety issues that can emerge when recovering from flooding.
Disaster recovery planning issues and options discussed in this guide:
Advanced Metering Infrastructure (AMI) Evaluation Final Report Completed for Commonwealth Edison Company (ComEd), Black & Veatch, July 2011