Grid resilience

Designing innovative systems to sustain critical functions during a disaster

Solar panels

With engineering expertise in renewable energy systems, power engineering, and risk and resilience analysis, Sandia can help cities determine resilience-enhancing energy system options, based on available resources. Sandia can design innovative systems that, in the event of a disaster, can prioritize which critical functions receive power as it becomes available.

For example, Sandia's Energy Surety Microgrid™ increases city resilience by allowing it to generate and control electrical power in self-contained, localized areas. This ensures that if the main power grid is disrupted, essential infrastructure, such as buildings, transportation, and medical facilities, has the power necessary to maintain life-saving ability.

Energy systems are critical to the basic functions of a city. They enable communities to rebound after disruptive events and provide the necessary foundation for long-term growth. Resilient energy systems can both withstand disasters and provide sustainable, affordable power.

Many cities experience frequent, small-scale power disruptions due to weather events, such as ice and wind storms, and because of this, they are often capable of keeping critical functions operational for one or two days only. Cities must decide how long and at what scale power resilience is necessary beyond what is required for these more frequent events. There are different ways to design systems to withstand specific abnormal events, such as an earthquake or a hurricane, but truly resilient systems must be designed for all possible scenarios.

Cities may prepare for both far-future disasters and disasters that might happen in the near-term (in the coming weeks or months). When planning for near-term events, cities may be heavily constrained by their existing power infrastructure. Back-up systems must be designed to work with existing systems, and there may be severe constraints on the types and potential locations of fuel generators or renewable energy sources. Short-term resilience often focuses primarily on the prioritization of critical facilities and on having a comprehensive emergency response plan. However, for long-term resilience, cities should assess what infrastructure changes are required to create an energy system that is operable during and after a wide array of hazards and provides long-term, accessible power for citizens.

Common energy challenges facing a city include:

Prioritization: Large cities may find it difficult to prioritize a myriad of critical functions and facilities. For example, a city of 8 million people may have 100 hospitals with disrupted power while a city of 100,000 may only have 10.

Coordination between power stakeholders: A city's energy system often has significant interdependencies with other cities' energy systems, and coordination across both government- and privately-owned power utilities is often necessary.

Ability to maintain backup fuel infrastructure: Storing diesel fuel for use in back-up generators is one common method used to improve energy resilience in a city. However, storing massive quantities of fuel near or in a city presents additional challenges. Further, energy is required to distribute backup fuel. In one assessment Sandia conducted, the local jurisdiction had built backup fuel systems, but had not determined how the fuel would be accessed in the event of a power outage.

Reliability of renewables: Renewable energy such as photovoltaic systems or wind turbines cannot be relied on solely as backup energy sources simply because there is no guarantee that the sun will be shining or the wind blowing when the power grid goes down.

Energy resilience-enhancing opportunities for cities include:

Localization of electrical power generation: Increasing city and surrounding-region power generation and control capabilities sets the stage for future grid modernization and increased energy resilience. Truly resilient energy systems lessen the need for the construction of large, distant electrical power plants.

Fast improvement for smaller cities: There is significant opportunity for smaller cities to implement resilient power grids within a short amount of time (1-3 years) due to decreased complexity and costs.

Enhancing other infrastructure: Having a resilient energy system is a cornerstone of a comprehensive emergency response plan. Resilient energy systems can help prevent further damage during disruptive events, such as fires following earthquakes from downed power lines or broken gas pipes.

Economic gains: Investing in new infrastructure and energy production technology can help boost local economies not only with the creation of jobs, but also by decreasing reliance on imported resources.

Improved quality of life: Increased use of renewable energy provides opportunities for cities to lessen the environmental impact of traditional power generation, and over time, with reduced need for oil, the likelihood of catastrophic oil spills is likewise lessened.

Sandia has extensive expertise in designing energy systems for near- and long-term energy resilience. Sandia can help cities assess what infrastructure changes are required so that a basic level of critical functions remain operable during and after a disaster for the required amount of time.

For example, Sandia can work with a city to develop multiple energy-resilient designs, based on the city's budget and desired level of resilience. Sandia can evaluate a city's existing power grid performance levels for its defined risks, and then determine what resilience-enhancing improvements can be made based on the city's budget. Specific examples include:

Critical function prioritization: Sandia works directly with cities to understand their specific needs and risks with regard to critical functions, and helps them correctly prioritize these functions to ensure there are no critical-path interdependencies. Sandia uses power systems models and algorithms to develop an energy-system design so that during a disruption, critical functions can be allocated available power on a priority basis. Critical functions are prioritized based on the risks posed if they do not receive power.

Energy Surety Microgrid™ (ESM): Working with the city of Hoboken, New Jersey and the New Jersey Transit System as they rebuild from Super-storm Sandy, Sandia has helped design proprietary ESMs that improve New Jersey's energy system and transportation resilience to future storms. The ESM design was first used with military installations, and allows the microgrid to be either grid-tied (operated in conjunction with, and even augmenting, the main grid with microgrid-generated power), or islanded (operated completely independent of the main power grid). Sandia's computer modeling is being used to determine the safest, most efficient, cost-effective, and secure combination of distributed energy resources within the microgrid. Sandia utilizes the same risk assessment approach to identify critical needs and functions within a microgrid.