The Storm and How Our System Works
The Storm and How Our System Works
The following is from a boxholder put out by the W.I. Electric Co-op right after the wind storm of September 29th which caused a power outage on the Island.
The Washington Island Electric Cooperative would first like to thank all the members for their patience and understanding during the severe storm of September 29 and 30. We would also like to thank the Town Crew, Officers McGrane and Schultz and members of the Washington Island Fire Department for their assistance. The amount of damage done to our system was unprecedented at least in the last 10 years (it was significantly worse than last year’s storm and the storm in 2002) and likely significantly longer. When you are working during a storm and there are trees and branches coming down around you as you work, these folks deserve extra thanks. We would also like to thank all those members who offered help, brought in food and gave us encouraging comments during the storm. It is greatly appreciated.
Wisconsin Public Service would echo these comments as more than 65% of their meters were impacted and over 165 employees, both from WPS and mutual aid were brought in for storm restoration. In addition to WPS crews from all over their territory, there were crews from Alliant, Pieper, Madison Gas and Electric, Hooper, Michaels, Marshfield Electric, and 10 Asplundh Tree Service Crews. As of the time of this writing (7 days later) many were still without power because repairs to their service require the work of an electrician. They had 75 poles broken in the County and had serious storm damage in their northern Wisconsin territory as well as at UPPCO (Upper Peninsula Power Company). In discussion with Dale Swanson who is the manager of the Door and Kewaunee County Territory for WPS, this storm caused the most extensive, wide ranging damage that they have seen and resulted in one of their largest calls for mutual aid.
Second, from the number of disparaging, inaccurate and sometimes malicious remarks that have been made both directly and in the community, it is apparent that an explanation of the series of events and how our electrical system works is necessary.
Between 2010 and 2011, our engines have run for nearly 60 hours during service interruptions from WPS. Most people were not even aware that power had been lost or that we were on engines and then subsequently transferred back to shore power. Our engines and switchgear system functioned exactly as it should during these times and in spite of commentary in the public, they functioned exactly as they should during this storm.
It is important to note that, even had the engines been running, if there are trees down on the lines, there is no way for that power to get to you. Electricity cannot be magically transmitted when wires are on the ground and reclosers are open. Reclosers are safety devices that open during a fault to isolate the fault from the system. An open recloser can affect many customers. That said, and without getting into too detailed technical explanation, three phase generators such as ours are wired in one of two configurations: Delta or Wye. In order to be compatible with WPS distribution, our engines are wired in Wye. Delta engines, such as our old engines, were seen as a fault on the WPS system and caused safety equipment to open as far back as the Sister Bay Substation when they were in line. This fact, in addition to age and reliability issues, as well as the availability of an interruptible rate, is the reason why the new engines are Wye configured. The engines require a balanced load where there are less than 39 amps of return current on the neutral in order for the switch gear to allow them to stay running in order to protect the windings of the generator. Damage to the windings of the generator would result in large replacement costs and would make the engines completely inoperable until replaced or repaired.
When the storm hit, at approximately 8PM Thursday evening, we began to suffer individual outage calls all over the Island, and began to respond to them. At approximately 9PM we lost power from the mainland as the storm’s severity increased. At that time we had approximately 6-8 outage calls backed up (it would later become 6 pages +). After opening those OCRs where we knew there would be issues (when a fault occurs and there is no electricity, safety equipment does not automatically open), an attempt was made to start the engines. There were over 100 Amps of return current at this time and they shut down. The way the engines responded while they were running indicated that many more places had suffered outages in the short span it took to get from the field to the plant to attempt to start them. One additional attempt to start the engines was made and failed and a single engine was left on to provide power for the station. This was necessary to allow continued radio and telephone communications, keep switch gear batteries and engine batteries charged and to provide power for the boilers which keep the engines close to operating temperature. Without this power, as repairs were made it would not be possible to make additional attempts to start the engines.
At this point, additional calls began coming in from our local Officers, Town crew and others regarding trees across lines, lines in the road, secondary services pulled off houses, etc. and it became very apparent that no amount of trying was going to get the engines back on line until repairs were made. Wisconsin Public Service had been called and informed of our situation and said they would do the best that they could, but they had their hands full as well and were calling for mutual aid.
As noted earlier, our own list would extend to 6+ pages very shortly and in the case of Foss Road, Green Bay Road as well as others, we would clear all the faults, remove taps, make repairs and move on to the next incident only to receive a call that additional trees had gone down since we left. We were at Green Bay Road a minimum of 6 times during the storm, and had to return to other roads numerous times as well. In many cases, it was necessary to clear trees from the road before we could even get to the area requiring repair.
Damage ranging from broken poles, smashed transformers and downed lines to secondary services pulled off houses lying on the ground all had to be responded to. In one location on Jackson Harbor Road a number of large locust trees uprooted and went across all three phases, ensuring that no one on the North end of the Island would have power until they were repaired even if we got the engines running. The lines in this area were a tangled mess that extended back two spans and we will need to return to this area for further work at a later date. This went on through the night and into the day on Friday. By 7:30PM Friday night (almost 24 hours from the first call) we had made enough repairs and opened enough breakers where we knew there were issues that we felt we could attempt starting the engines again. We tried starting the engines, but not only did we have a high differential current, but the load showed as over 3000KW with the engine’s capacity being 3200KW. After two attempts, since it was obvious there was no way to balance the load or to easily decrease it in order to keep the engines running, the decision was made to send the crew home. Remember, at this point, in addition to the regular day on Thursday, all 4 of us had been working for 24 hours straight repairing storm damage in the worst of conditions. Mary, Don, Randy, and Lee Engstrom (who had been working with me all day Friday) went home and I stayed to maintain contact with WPS by phone and radio and also to do some additional line patrol and fault clearing where one person could safely do the work.
Wisconsin Public Service had said that they hoped to have the power on within hours at this point, but every estimate they gave ended up getting moved out as they found more and more damage. During the day, they had dedicated two WPS crews and three Asplundh crews to restoring three phase power to North Port. Almost every tap fuse and cut-out from South of Ellison Bay was tripped and they were bypassing each of these issues in order to get the main three phase back on. The primary WPS crew that I was in contact with was from Chilton, Wisconsin and you could hear the frustration in their voices as they would tell me that they kept coming on more damage or upon trees that were sure to go across the lines as soon as the repair was made and that Asplundh was working on cutting them. During this time I also was cutting trees and opening breakers hoping not to have missed any (I did) when the power was restored. Finally, at about 3:00AM I got the call that the crews were closing the reclosers south of Isle View Road to energize the 100 Amp fuses serving Northport and that the breaker at Northport was closed and the submarine cable was energized and I returned to the plant. The extra effort these crews made is to be complimented as well.
At this point, the Island had been without power for approximately 31 hours and in order to protect the cable and the main substation transformer, load needed to be put on incrementally. I waited approximately 15 minutes before I put only the load of the substation transformer on the cable. I then waited another 15 minutes before adding only the load of the station on the transformer. After an additional 15 minutes I began bringing up the South phases one at a time in approximately 5 to 10 minute intervals all the time listening to the system as you could hear breakers opening where faults had not been cleared yet or where additional faults had occurred since we had cleared the initial faults. By 4 AM I had the entire Island up except the B phase going North (and also excepting those spots where breakers were still open due to trees, etc). Everything appeared stable so I got in the truck and spent the next hour and a half patrolling the line between the plant and the reclosers East of the fire department and the reclosers on Jackson Harbor Road at the end of Range Line Road. I cleared two additional faults (luckily no broken lines) and returned to the plant to try again and had the B phase back up at approximately 6AM.
Don, Randy and Mary returned to the plant at around 6:30 AM and once again began the job of cutting trees, clearing faults, repairing lines and restoring power to areas and individuals. At this point I went home to get a few hours of sleep (and no, the power had not yet been restored to my home). Including the Thursday regular day, I had been without sleep for over 50 hours. I returned to work around 1PM and rejoined the crew.
All through the storm, we had to prioritize our repairs based on safety, number of people out, whether a home was occupied and expediency of the repair. In some cases, we needed to just remove a tap, make note and return later to finalize the repairs. We worked until l0:30pm on Saturday night and broke for some sleep returning to work at 6:30AM Sunday Morning. When we quit at 5PM on Sunday, we had two occupied homes without power and approximately 6 unoccupied homes without power. As of Thursday AM all homes on the Island had power. However, we still have several primary neutral repairs to make, numerous temporary repairs to finalize and lots of secondary services on the ground and temporaried where the homeowner had power. As of this writing, I expect it will take us a couple weeks to clean up those issues that we know about and expect to hear about more as we patrol and as folks discover issues on their own.
We hope that reading this at least gives you a basic understanding of what went into restoring power to the Island and might give you a little pause before you make a negative comment to or about the crew you have working for you. We understand and share your frustration when the power is not on, especially considering we are doing our best to restore it usually under difficult conditions and considering that the power is out to our own homes too.
Don, Randy and Mary deserve a big thanks for their efforts and the hours they put in to get your power restored. Lee Engstrom and the town employees mentioned earlier also deserve your thanks. Crews at other locations have mandatory rest periods after so many hours (usually 18 on and 8 off). Your crew voluntarily significantly exceeded the standards set by other crews.
by Robert Cornell, Washington Island Electric Cooperative Manager
