By PUCO Office of Public Affairs
There are several reasons most Ohioans stayed warm and their lights stayed on last month while Texans endured a days-long period without electricity. It’s more than the fact that Texas temperatures dipped as low as -4 degrees on February 16 while Ohio’s coldest moment that day was 12 degrees, according to the National Oceanic and Atmospheric Administration.
Ohio’s electric system is fundamentally different from the one in Texas, and Ohio has learned from prior experience, notably the polar vortex of 2014.
Ohio’s four electric utilities, American Electric Power, AES Ohio (formerly Dayton Power & Light), Duke Energy and FirstEnergy are members of PJM Interconnection, the nation’s largest regional transmission organization. PJM includes all or parts of 13 states and the District of Columbia, a region that is comprised of more than 65 million electricity customers.
PJM is an independent operator of the wholesale electric transmission market and manages the high-voltage electricity grid, under the oversight of the Federal Energy Regulatory Commission (FERC). PJM is responsible for regional grid reliability, ensuring that electricity is delivered where needed at a reasonable price. It also oversees power imports from outside the PJM territory when required and power exports to neighbors when generators produce more electricity than is needed within PJM’s borders. The PUCO actively monitors PJM’s operations and regularly participates in FERC and other federal agencies’ proceedings to ensure reliability at least cost.
Within PJM, generators and renewable resources are paid for providing the power they produce every day. Separately, many also are paid for standby power. Called capacity, it is defined as the amount of electricity a generator can produce when it's running at its maximum output. This maximum amount of power is typically measured in megawatts (MW) or kilowatts (kW) and helps utilities and PJM project how much of an electricity load a generator can handle. While generating capacity is available at all times, capacity allow generator to provide extra power when called upon on rare occasions like extreme temperatures or when portions of the electric grid are unavailable. It works much like insurance as customers pay for the standby capacity year-round even if the extra power is used rarely. Power generators must respond quickly when called upon, ready to deliver amounts of energy previously promised though the PJM process.
It is not a flawless process. When Ohio faced its first polar vortex in January 2014, PJM resources were put to the test. Extreme cold weather knocked 22% of PJM’s power supply offline as generators faced frozen equipment, downed power lines and limited availability of coal and natural gas. Generators of both everyday power and standby capacity power were disabled, some for as long as three days. Afterward, with FERC oversight, PJM instituted new rules for weatherization of grid equipment and penalties to generators that didn’t meet their obligations. PJM also raised reserve power requirements, now at 31% more megawatts than they deem necessary under normal conditions. Although Ohio endured a second polar vortex in 2015, and during extreme weather conditions on several occasions since then in both the winter and summer, operations were unhampered.
In Texas, the electric system operates differently. Its wholesale market of 26 million customers is managed by the Electric Reliability Council of Texas (ERCOT) and covers most but not all of Texas. It was designed to stay within state borders so that it could retain local control of its operations. It doesn’t answer to FERC. Oversight is by the Public Utility Commission of Texas and the Texas state legislature.
ERCOT doesn’t have a standby capacity market. Nor does it require power generators to winterize their equipment, although it is recommended. And ERCOT has limited connections with its neighbors so Texans can’t rely on them for extra power; especially when those neighboring systems were also experiencing outages from the cold temperatures.
When the polar vortex hit Texas on Valentine’s Day, it brought the coldest weather since the 1940s or longer. At its peak on February 16, more than 48% of power supplies was unavailable. Natural gas-fired resources were hardest hit as equipment froze from wellheads to pipelines. Also disabled were coal and nuclear power plants as well as wind and solar resources. ERCOT had underestimated the amount of electricity needed and customers pushed demand to an all-time high. ERCOT ordered four days of rolling blackouts to keep the overburdened system from collapsing long-term. Changes to ERCOT practices are expected as investigations are under way by both state and federal authorities.