Grid Reliability and Resiliency

For many decades, the United States has enjoyed an electricity grid that is 99 percent reliable, delivering electricity effectively and consistently to millions of households and businesses across the country. But under the frequency of more extreme weather, growing demand, and underinvestment in transmission infrastructure, the grid is showing signs of weakness.

There are two concepts that are interrelated – reliability and resiliency. To meet the end goal of “keeping the lights on”, the electric grid must be resilient enough to bounce back from disruptive events quickly.

Grid reliability is the ability of the power system to deliver electricity in the quantity and with the quality demanded by users. The nation’s largest grid operator, PJM Interconnection, defines reliability as “designing, running, and maintaining electricity supply to provide an adequate, safe, and stable flow of electricity.” This is accomplished by having enough generation resources to meet all power demands and having enough built-in redundancy to minimize the effects of single point failures. Reliability is the supreme measurement of grid performance. Even with successful investments in grid modernization, utilities still measure their customer and regulatory performance on their ability to reliably deliver electricity.

On the other hand, resiliency has become a hot topic over the past few years due to more frequent extreme weather events and increased grid sabotage. In fact, attacks against the electrical grid nationwide are at an all-time high. According to Department of Energy statistics, human attacks were responsible for 171 “electric disturbance incidents” around the country in 2022, compared with 99 in 2021. (Department of Energy labeled this as the result of vandalism, sabotage, actual physical attack, cyber event, and suspicious activity.) The grid’s ability to recover from adversity is at the root of resiliency. Disruptive events can and do occur and the grid should be designed to bounce back quicker.

Our reality – the current state

Our electric infrastructure is aging, and it is being pushed to do more than it was originally designed to do. To date, power transmission infrastructure has been built with fossil fuel and nuclear plants in mind. Although the Federal Energy Regulatory Commission has launched proceedings within the last year to address barriers to strengthening and expanding the nation’s transmission system within existing grid regions, the U.S. currently lacks a plan for ensuring power transfers between those regions. The federal regulator should require that neighboring regions plan for a minimum amount of interregional transfer capability to ensure storm-affected areas can access a reliable power supply even when local generators come offline.

This will pose a challenge for renewable energy sources located outside of the existing transmission infrastructure. If renewable energy is to play a major role in bridging the gap from fossil fuel generation, the need for transmission line capacity is estimated to triple. Large urban areas with the highest electricity needs are typically long distances from abundant renewable energy sources like wind, biomass, location sunlight, and hydropower. There are also challenges with permitting and building additional power transmission lines, including the construction of interconnection upgrades to connect generation sources to the grid.

The influence of the Inflation Reduction Act on the grid will require a huge shift in how much renewable energy flows into the grid to meet the established goals of the IRA.  If the grid is not expanded on, it will restrict the success of renewable development in many states. This requires alignment with state and federal policies so that interconnection applications are processed efficiently. A possible bright spot is FERC’s proposed reforms aimed at improving the transmission planning process.

The current state of our national grid is best exemplified by Georgia Power’s delay in shuttering some coal-fired units because the state’s transmission system can’t handle their exit from the grid or the renewable energy additions that would be needed to replace the power plants. Situations like this are prevalent across the country.

What else can be done to improve grid reliability?

Modernizing the grid is of the utmost importance. The grid needs to become “smarter” and more resilient with cutting-edge technologies, equipment, and controls that communicate and work together to deliver electricity more reliably and efficiently. The result will be reduced frequency and duration of power outages, reduced storm impacts, and faster service restoration when outages occur. Additionally, consumers can better manage their own energy consumption and costs because they have easier access to their own data. Utilities also benefit from a modernized grid, including improved security, reduced peak loads, increased integration of renewables, and lower operational costs.

The need for transformation of the nation’s electric grid creates both challenges and opportunities to advance the capabilities of today’s electricity delivery system.  A critical component of grid modernization is a coordinated, strategic research, development and demonstration effort that involves both the public and private sectors.

Many contend that renewables like wind and solar, as well as the emerging capabilities of battery storage and other advanced technologies will stabilize the grid’s reliability. Grid operators in California are successfully using batteries to store solar power during the day and provide valuable energy as the sun sets but temperatures remain high, avoiding blackouts even as demand soars.

Battery storage is a tool in the quest for a more reliable electric grid, with the potential to move from a just-in-time delivery system for low-cost energy to a system that can flexibly store and release power when needed. Batteries are most beneficial for energy storage when the wind isn’t blowing and the sun isn’t shining.

Another solution is unlocking more local resources and “virtual power plants” made up of small-scale resources like home batteries, EVs, thermostats, and water heaters. These systems improve system reliability by using software to better integrate electricity assets we’ve already paid for with the grid.

Key Findings from the Department of Energy “Draft Report”

The United States will likely need 47,300 GW-miles of new transmission by 2035, a 57% increase compared to today’s transmission system under a moderate load growth-high clean energy growth scenario, according to a Department of Energy Draft Report.

The Draft Report found the transmission needs in the U.S. are “pressing,” that inter-regional transmission offers the biggest benefits, and that the needs will shift over time, according to Adria Brooks, a transmission planning engineer in the Department of Energy’s Grid Deployment Office. “Significant transmission deployment is needed as soon as 2030 in the Plains, Midwest and Texas regions, but by 2040, large deployments will also be needed in the Mountain and Mid-Atlantic and Southeast,” Brooks said.

“Large amounts of low-cost generation potential exist in the middle of the country and accessing this generation through increased transmission is cost effective for neighboring regions,” DOE said.

Based on differences in market prices, the most value is found by connecting the Electricity Reliability Council of Texas to the Southwest region of the Western Interconnection, followed by connecting ERCOT with the Eastern Interconnection, DOE said.

There is also “significant value” in connecting the Southwest Power Pool with the Mountain region of the Western Interconnection and with the Midcontinent Independent System Operator to the east, the department said.

Note: Department of Energy aims to issue a Final Report this summer, according to Brooks.

Written by: Jason Bear, Energy & Utilities Practice, CG Infinity Inc.

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