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Monday, September 11, 2017

Reducing Vulnerability of Electric Power Grid to Extreme Weather Events

Hurricane Harvey

The threat to our electric power system continues to be on many people’s agendas.

Written by Gavin Dillingham,Program Director, Clean Energy Policy

The primary story line for Hurricane Harvey is the amount of rain that it dropped on southeast Texas. Some estimates have the total amount at about 27 trillion gallons of water, approximately 86,000 Astrodomes. Much of the region saw significant flooding and recovery will take some time. Fortunately, Hurricane Harvey did not cause significant, long-term power outages. There were a large number, estimates range up to 800,000 customers, but my no means the power outages that were seen during Hurricane Ike, where 2.1 million customers in CenterPoint’s territory alone lost power1. Many of these customers were without power for several weeks. Hurricane Irma looks to put millions of utility of customers in the dark, as well.

Hurricanes and tropical storms are just one of the increasing number of natural disaster events that are threatening our electric power system. Ice storms, tornadoes and wildfires in 2017 have also resulted in significant power outages for the state. To see the national extent of this disaster potential check out the DOE report titled “US Energy Sector Vulnerabilities to Climate Change and Extreme Weather.”2

Fortunately, the threat to our electric power system continues to be on many people’s agendas. The National Academies Press has just published a report titled “Enhancing the Resilience of the Nation’s Electric System3.” This report considers a multi-pronged threat to our system including cyber, physical and natural disaster threats. I will be in Washington DC this week discussing the natural disaster risk findings of this report with the House Committee on Science, Space and Technology.

For all of the risks, there are a variety of technology and data solutions that are actively being deployed that can minimize them.

Deploy Resilient Technologies
First, in light of our current situation, microgrids should be further deployed to reduce risk of hurricanes, tropical storms and flooding. Microgrids are mini-power systems for a building, campus, neighborhood, that typically have a variety of generation resources working together including a combined heat and power system, solar panels, and/or batteries. Microgrids and particularly microgrids with CHP are being considered more often to increase the resilience of critical infrastructure, including hospitals, wastewater and water treatment plants, police and fire stations, data centers, emergency centers, etc. It is estimated that approximately 3.7 GW of microgrid systems will be deployed by 2020.4 Small in comparison to other resources, but a very important resource as we look for systems that are resilient and have demonstrated their efficacy through a wide number of natural disaster events. To be resilient, these systems must be placed above predicted flood levels, have black start capability; must be able to operate independent from the grid, have appropriate switch gear controls and ample carrying capacity. An emerging funding mechanism to pay for these these systems may be resilience bonds. These bonds are to be issued to mitigate risk to critical infrastructure. This bond type has yet to be issued but has received a recent push by the insurance industry because of a desire reduce risk exposure to natural disasters. Technical resources also exist to help deploy CHP and microgrids. This includes DOE’s CHP Deployment program. Under this program, HARC has partnered with the DOE to operate the Southwest CHP Technical Assistance Partnership.

The second risk that is not so apparent now, but was a real problem a few years ago, is extreme drought and heat. Approximately 85% of power generation in the United States requires water for cooling. Due to drought risk, there should be greater emphasis on deploying systems that do not require water to operate5 . Water supply is a problem for states such as Texas that have been known to experience long-term droughts. The 2011 and 2012 Texas droughts resulted in the curtailment of power generation across the state. Besides drought, many western states see significant water risk due to growing demand for water by communities, agriculture and industry. Two generation systems that require no water to operate are PV solar6 and wind7 systems. These systems have been deployed at a growing rate, but will need financial resources and regulatory certainty to scale more quickly. A potential financial solution could be the master limited partnerships. This would put renewables on a more even playing field with fossil fuel assets that already use this funding mechanism. Green bonds are another possible solution that should receive further consideration.

Build to a Certain Standard
No matter what weather event is being prepared for, it is highly recommended that utilities and power system developers begin to design their power generation systems and transmission and distribution infrastructure to meet resilience standards like PEER (Performance Excellence in Electricity Renewal). PEER is a rating process designed to measure and improve sustainable power system performance. PEER is a voluntary program that utilities and power providers can work toward. A PEER rated power system meets strict criteria for reliability and resilience, operational effectiveness and environmental standards.

Improve Decision Making
It is difficult to determine the timing, the location and intensity of extreme weather events. With this level of uncertainty and when financial resources are limited, it is challenging to make the appropriate investment decisions. When decisions are not made, infrastructure is not built and our systems are not prepared. The result is significant damage and loss. However, recently there has been some progress in better understanding future climate patterns. Progress is being made with climate models that are greatly improving our understanding of the likelihood and intensity of future storms. Down-scaled regional climate models, developed by organizations like Texas Tech University’s Climate Science Center, are helping planners and decision makers to make more informed decisions. As our understanding improves better decisions can be made that will result in more resilient power infrastructure.

Solutions exists and new solutions are coming online to reduce the risk to our electric power systems. I discuss only a couple of options and their role in mitigating the risk of certain natural disaster events. For a resilient power systems, there is not just one or two solutions, there are a number of solutions and combination of solutions that must be deployed. For example, utility scale wind is great for drought scenarios, but may be vulnerable to high wind events, tornadoes and ice storms.
To scale these solutions quickly will require political will and considerable funding. The funding is there, but due to the political environment, it is largely sitting on the sideline. The political will has been a bit slow catching up. Regulations and policies must catch up with the reality that power systems are facing. The way is clear, the political will is less certain.