US researchers develop methodology for quantifying the value of resilience to energy systems

By Will Bugler

Researchers at the National Renewable Energy Laboratory (NREL) in US have developed a framework for valuing the benefits of applying resilience approaches to the country’s energy systems. Their work could be a major breakthrough in helping to demonstrate the importance of building resilience into critical infrastructure systems. To date, utilities have been able to calculate with reasonable accuracy the cost of applying resilience measures but have not been able to reliably quantify their benefits. This has been a major barrier to the widespread implementation of resilience in practice.

“We’ve heard from federal agencies, states, local governments, tribes, other countries, and industry professionals that there is a need for more secure and resilient power systems,” said Eliza Hotchkiss, co-principal investigator of the resilience research project and co-author for two forthcoming publications on quantifying resilience metrics. “Understanding the nuances of power system vulnerabilities and how to finance resilience solutions has been a large barrier for implementing resilient systems. Our research is trying to overcome those barriers through robust resilience science and energy modelling to further knowledge in this space.”

Today, large-scale systemic threats are receiving unprecedented attention due to the COVID-19 pandemic, and infrastructure managers are looking for ways to manage complex systems in times of uncertainty. Beyond the current pandemic crisis, climate change will make the operating conditions for human systems less certain on a permanent basis. Governments are therefore exploring resilience approaches to ensuring that critical infrastructure systems can continue to provide their primary services during times of shocks and stress. Global peace, security and prosperity depends on critical infrastructure systems more than any other time in its history. With more people living in cities than ever, well-functioning food, energy, water, transport and sanitation systems are the things seperate functioning societies from chaotic breakdown. Organisations such as Resilience Shift are driving the resilience agenda in critical infrastructure, helping to move the concept from theoretical discussion into widespread applied practice.

Modelling resilience benefits to energy systems

For utilities, the costs of implementing resilience measures to energy systems (for example the price of replacing a power line after a storm or installing more grid capacity) are reasonably easy to calculate. However, assessing the benefits of resilience are more challenging to reliably quantify. Many of the benefits accrue some time into the future (which means they are subject to discount rates), may only be as savings from avoided damages or interruptions to the system, and may only be realised when shocks or stresses occur that test the system.

NREL researchers have therefore developed a framework that models and values resilience metrics when applied to different energy systems. They have published the framework in a technical report that show how the framework can be applied to five different energy system types.

The NREL framework runs simulations of shocks and stresses to energy systems, such as power interruptions, and includes resilience metrics in these systems at varying scales. Examples of resilience metrics include the number of hours that customers are without power, the number of hospitals or fire stations without power, the loss of business and community economic revenue, and the loss of utility revenue. The output of the modelling is designed to help utilities inform their resilience investments and planning.

“In the face of increasing long-duration outages with broad economic and social impacts, strengthening the resilience of the power system is more important than ever,” said Kate Anderson, co-principal investigator of the project alongside Hotchkiss. “For system owners and operators tasked with weighing the cost of a resilience investment against the benefit it provides, understanding the value of resilience is important for informing public and private investment decisions in power systems resilience.”

The NREL researchers have since further refined the analysis framework applying it to two case studies. The first case study examines the framework for a grid-level operator, while the second considers a campus, base, or building-level operator. Their finds have been published  IEEE Systems Journal article, “Integrating the Value of Electricity Resilience in Energy Planning and Operations Decisions”. In the study, the authors analyse how the quantified value of lost load during a disruption and its impact on customers can help officials better forecast their resilience needs.