Capacity: The real problem with NC's power grid
Published January 5, 2023
By Mick Rankin
Going into Christmas 2022, there were a series of rolling blackouts in North Carolina. Frustration for the rolling blackouts resulted in social media posts and media reporting to assign blame and call for government oversight. What is missing is a practical discussion on how and why the blackouts occurred. Fixing the problem starts with understanding the problem. Our problem is one of capacity.
Grid capacity can be understood by comparing it to electrical code in residential building. These codes require normal lighting and outlet wiring to be a minimum 15 amperage current capacity, even though the electrical supply at 110 volts can provide much higher current. If a homeowner plugs in multiple devices that exceed that 15-ampere limit, and if the breaker does not trip, then the wiring overheats and can cause the house to burn. The same concept applies to our electrical grid transmission facilities, where if the demand is greater than the capacity the facility may be damaged, or in best case tripped offline. As witnessed in the recent vandalism of Duke Energy substations the cost to repair/replace is much greater, and takes longer, than a temporary shutdown or rolling blackout.
We are in a capacity crisis in the electrical grid. When faced with rolling blackouts, it is often cited as problem with generation capacity. There are issues with power generation capacity. Wind and solar are not always available, plants must be started up to produce power and that takes time depending on type of fuel, or the availability of fuel. For example, natural gas is prioritized in cold weather for individual customers over power plants. What is missing is the transmission capacity figures showing that even if we were able to meet the demand in generating power, we could still lose power as the transmission facilities were either shut down or damaged by overuse.
Duke and other energy companies are businesses that must balance costs. Building a power grid based on anticipated use requires careful planning. The cost of the grid must be reasonable so that customers can afford the service. As a business, Duke Energy has a responsibility to shareholders to provide return on their investment. If there is little to no investment return, then investors will take their money elsewhere. This is not to blindly defend Duke Energy, but as a public utility they are a single source of service. To be fair, Duke Energy operates a variety of power plants that use coal, natural gas, nuclear, wind, and solar so they offer power sources that can adapt to changing conditions. That said, as a single source of service they are also a single point of failure.
All energy companies, when building service in a location, plan for growth. That growth drives the decisions for two major power components — generation and distribution. The population and business density represent the third major component of power — the load. Unfortunately, community growth data often falls short of reality as communities strive for faster economic development. More development means more people and power required to support that development. The result can be an electric grid closer to capacity than originally planned.
If the growth is faster than services can accommodate, then the grid becomes stressed and rolling blackouts are necessary to prevent total power outages. This is not just a danger in North Carolina, but across the country, where regular blackouts occur. The problem is not just the capacity to generate, but the stress on the transmission systems as load (users) increases. Rolling blackouts are a way to prevent the transmission facilities damage from too high load demand.
The 2022 multi-trillion infrastructure package has not produced improvements in the electrical grid, although it promises planned “free” EV charging stations. Free is not free, first the stations and the power they provide are at taxpayer expense. Second, adding more load to the grid without adding capacity will cost in more blackouts. A failure to plan is a plan for failure.
Finally, we are an electric society. No matter the source, it is the single point of failure. We need to harden our electric grid by increasing capacity and guarding against external interruptions, whether they are rolling blackouts, cyber-attacks, physical damage/terrorism, solar flare events, or EMP weapons.