IMPROVING RELIABILITY THROUGH INVESTMENT IN THE GREATER GRID
Electricity is something people often don’t think about until they don’t have it: that’s why we think about it every minute of every day. Since our inception in 2003, ITC has been working to build and maintain the infrastructure that delivers power from where it’s generated at the power plant to where it’s needed locally to the distribution systems that carry electricity into homes and buildings.
To make sure that happens, ITC invests in the transmission system – by building new high-voltage power lines and improving existing systems – to make sure that communities, businesses and families have the reliable power they need, whenever they need it. By building a greater – more resilient – grid, power flows more reliably and efficiently through the system, often reducing electricity costs and benefitting local economies.
Sustained Improvements in System Performance
After more than 15 years as an independent transmission operator, we are proud that our systems routinely perform in the top 25% of utilities nationwide. In fact, as of 2018, we have reduced the average number of outages by 60% at ITC Midwest, 48% at ITCTransmission, and 24% at METC.
These system reliability improvements track with ITC’s sustained investments in targeted capital and maintenance programs over the years. Below we take a closer look at the improvements in each system.
ITC Michigan has two systems in the state: ITCTransmission serving Southeast Michigan, and Michigan Electric Transmission Company (METC) serving most of the remaining Lower Peninsula.
- ITCTransmission has reduced the average number of outages on its system by 48% since ITC acquired the system in 2003, based on a rolling three-year average. Following 15 years of intensive capital investment to raise its reliability performance, ITCTransmission has reduced the number of outages from an average 65 in the first three years of ownership to an average now holding under 40 per year. ITC continues its targeted capital investments and maintenance program to sustain the system’s reliability performance, strengthen resilience, and support interconnections of new generation. ITCTransmission has 3,100 circuit miles of line serving southeast Michigan at voltages ranging from 120kV to 345kV.
- METC has reduced the average number of outages on its system by 24% since ITC acquired the system in 2006, based on a rolling three-year average. Now in our 13th year of sustained investment to raise its reliability performance, METC has reduced the number of outages from an average 90 in the first three years of ownership to an average under 70 per year. ITC continues its targeted capital investments and maintenance program to sustain the system’s reliability performance, strengthen resilience, and support interconnections of new generation. METC has 5,600 circuit miles of line serving most of Michigan’s Lower Peninsula at voltages ranging from 120kV to 345kV.
The ITC Midwest system serves a large portion of Iowa, southern Minnesota, and parts of Illinois and Missouri. ITC Midwest has reduced the average number of outages on its system by 60% since ITC acquired the assets in 2007, based on a rolling three-year average. This performance comes as a result of sustained, targeted capital investments over the years and ITC’s ongoing operations and maintenance program. ITC Midwest has 6,600 circuit miles of line at voltages ranging from 34.5kV to 345kV.
- At voltages of 100kV and above, ITC Midwest has reduced the number of outages from an average 58 in the first three years of ownership to an average 30 in the most recent three years – representing a 53% decrease in the rolling average.
- At voltages below 100kV – which comprises most of the system – ITC Midwest has reduced the number of outages from an average 1,122 in the first three years of ownership to an average 493 in the most recent three years – representing a 60%* decrease in the rolling average. Approximately 61% of the circuit miles in ITC Midwest are below 100kV. Since acquiring the transmission system, ITC Midwest has been following through on its commitment to improve electric reliability in Iowa by upgrading about 640 circuit miles of the 34.5kV system to 69kV. ITC is on schedule to complete the rebuilds, by 2021.
*Note: The 60% overall outage reduction percentage for ITC Midwest is tabulated by combining the outage numbers of each voltage class (below 100kV and 100kV and above, treating ITC Midwest as one system), versus averaging the percentage decreases of the two systems.
Definition of Outages: Two types of automatic outages comprise ITC’s reliability data: momentary and sustained outages. A momentary, or transient outage, is generally under 60 seconds in duration and automatically restored with no human intervention. Reclosing schemes reenergize the affected circuit, usually after a fault clearing period and in an established order. A sustained circuit outage is one having a duration greater than 60 seconds and usually requiring human intervention to resolve.
Generally, transmission circuit outages do not equate to end-use customer outages.
Outages outside the control of ITC equipment and resources can be caused by other utilities, customer equipment, generation, instability or under-frequency, and distribution through-faults. These causes are excluded from the statistics.
After an Outage: ITC tracks all momentary and sustained outages as well as customer restoration time after an outage, if applicable. Tracking and determining a cause for each event and any prudent follow up actions helps to reduce the occurrence of future outages. Restoring power quickly after an outage is one of ITC’s core competencies and strategic advantages. A prudently designed and maintained transmission system is not impervious to severe weather conditions.
Outage Calculation Methodology: ITC compares the most recent three-year rolling average number of all system outages with the first three-year average number of outages under ITC ownership as data points. Fluctuation in outages from year-to-year is expected. ITC’s methodology removes potentially misleading single-year distortions, such as those marked by severe weather events. ITC believes this approach is the most meaningful way to illustrate outage reductions.