In my last post I looked at the 2017 Long-Term Reliability Assessment issued by NERC, the North American Electric Reliability Corporation. In that post, I focused on a grid-wide perspective. In this post, I’ll offer a few conclusions in the report that pertain to Missouri.
In the northeastern USA, the largest power outages have been caused by relatively small failures at specific locations that caused underloads or overloads, which then cascaded into region-wide outages. They have affected tens of millions of customers. Consequently, the 2017 Long-Term Reliability Report focuses on the kinds of issues involved in those blackouts: electricity demand, generating capacity, transmission capacity, and operating procedures.
In Missouri, however, the largest power outages have been caused by storms that destroyed transmission lines, most of which are in the local transmission grid. (See Electrical Outages from Storms Increase.) The 2013 Long-Term Reliability Assessment does not cover the local transmission grid, and it does not seek to evaluate the potential for damaging storms. Thus, the findings of the report deal with important planning issues for The Grid in Missouri, but they don’t address the historical reasons for our power outages. I will look at weather-related power outages in Missouri in the next post.
The resource adequacy of Missouri’s grid depends on where you are. Some western portions of the state, including Kansas City, (see Figure 1) belong to the SPP reporting region (Southwest Power Pool). The SPP 10-year compound growth rate in demand for electricity is 0.56%. The anticipated reserve margin is projected to fall from 32.43% in 2018 to 19.85% in 2027, but remain well above NERC’s 12.00% target.
The central portion of the state belongs to the SERC-N reporting region (SERC Reliability Corporation–North). The SERC-N 10-year compound growth rate in demand for electricity is projected to be 0.38%. The anticipated reserve margin is projected to fall from 21.45% to 17.18% in 2027, still above NERC’s 15.00% target.
A portion of eastern Missouri belongs to the Midwest Independent Service Organization (MISO) reporting region, including the St. Louis Metropolitan Region. The MISO 10-year compound annual growth rate is 0.28%. Though starting at 19.23% in 2018, the reserve margin level will fall below the Reference Margin Level (15.80%) in 2023, and will reach 14.56% by 2027. In fact, despite projected growth in demand, generating resources are projected to decline slightly. Figure 2 shows a graphical representation of the projection, with anticipated reserve in dark blue (anticipated reserves are based on plans announced by utilities), and prospective reserve in light blue (prospective reserves are based on potential plans discussed by utilities, but not announced).
These conclusions are more hopeful than those reached in the 2013 Long-Term Reliability Report. The primary reasons are that demand growth is projected to slow, fewer power plant retirements are projected to occur, and utilities have become better at forecasting demand and outages. That notwithstanding, we have entered a period of uncertainty with regard to our national bulk electricity grid. A few years ago legislation made it mandatory for all participants in The Grid to participate in NERC, and it gave NERC regulations the force of law. These changes hold out the potential for increased reliability and improved operations. On the other hand, many factors combine to represent threats to the long-term reliability of The Grid: aging infrastructure, environmental regulations that will force the retirement of coal-fired generating capacity, the retirement of nuclear generating capacity that has reached the end of its useful life, new generating sources that provide constantly varying amounts of power to The Grid, and uncertainty surrounding demand side management programs.
Resource adequacy in western and central Missouri is projected to be adequate through 2027. In eastern Missouri, reserves are projected to fall below the target level by 2023, and continue to edge lower through 2027. I will look at weather-related power outages in Missouri in the next post.
North American Electric Reliability Corporation. 2013. 2013 Long-Term Reliability Assessment. http://www.nerc.com/pa/RAPA/ra/Reliability%20Assessments%20DL/2013_LTRA_FINAL.pdf.
North American Electrical Reliability Corporation. 2017. 2017 Long-Term Reliability Assessment. Downloaded 4/27/2018 from https://www.nerc.com/pa/RAPA/ra/Pages/default.aspx.