We would like to provide additional information and context as to what occurred during the multiple outages last week and what we are doing to help improve the reliability of our system over the next four years. In order to better explain the circumstances, we need to provide a few details regarding how electric service is provided.
South Central Indiana REMC is a distribution cooperative, which means that we own and operate the “last mile” of electric lines that provide electric service directly to our membership. These lines are called distribution lines, and are a mixture of overhead and underground lines operating from 7,200V down to 120V. These distribution lines originate at various substations located throughout our service territory. Distribution lines can only serve a relatively short distance, which means that many substations are needed to provide service in a territory the size of ours. SCI REMC currently has 21 substation locations and operates over 3,800 miles of distribution lines. Each of these substations can serve thousands of members located in that geographical region.
The power to these substations is provided through higher voltage power lines (69,000 volts or 34,500 volts) called transmission lines. Due to their critical nature, transmission lines are usually constructed with taller poles and have a larger right of way cleared for added reliability. Since they are operated at a higher voltage, they can serve more load from further distances and are almost always constructed overhead vs underground. The transmission lines providing power to our substation locations are not owned or operated by SCI REMC, but by our power suppliers (namely Hoosier Energy and Duke). While SCI REMC has little direct control over these lines, they are absolutely critical because if they go out—the power to the substation and all of the distribution lines/members fed from that substation go out. As such, we work very closely with our power suppliers to try and ensure we have a reliable transmission system. This is strategy #3 in our reliability improvement initiatives, and more information will be provided on this strategy in the near future.
Unfortunately, on October 30th our power suppliers experienced significant equipment issues twice, resulting in a loss of power to one of our substations serving over 2,000 members multiple times. The first outage was at 5:23AM and lasted approximately 42 minutes before the issue was resolved. The second power supply outage occurred at 2:34PM. Due to the type of problem experienced and the expected duration, SCI REMC made the decision to dispatch crews into the field to transfer members without power to other substations. Currently, this is a manual process that can take a lot of time, as there are multiple locations that our linecrews must travel to in order to operate the equipment. While we were successful in transferring everyone to other substations, many members still experienced an outage of over an hour due to drive times. Later that evening, our power suppliers resolved the problem at the substation which allowed us to transfer members back to their normal substation. Unfortunately, another short outage was required to make this transfer.
As your Electric Cooperative, SCI REMC takes full responsibility for ensuring that you have reliable electric service. In order to combat power supplier reliability issues—we are in constant communication with our providers on needed reliability improvements. Both Duke and Hoosier Energy are taking our requests seriously, and we hope to have significant investments made in the coming years to dramatically improve our power supply reliability. In addition, we are in the process of installing a fiber network to many of the devices connecting our distributions/substations together. When we have this completed, we will be able to transfer between substations remotely when we have a power supply failure vs. sending out linecrews. This will often reduce outage times of well over an hour to just a few minutes.