Avista thanks its customers following protective outages during heat wave
No further protective outages planned into the weekend
As the extreme heat subsides, Avista thanks all of its customers that were impacted by the focused, protective outages that were implemented this week to alleviate the strain on the electric system. The company does not plan to complete additional protective outages into the weekend.
“We are incredibly grateful to all of our customers who experienced outages this week for their patience, understanding and resilience,” said Dennis Vermillion, Avista president and CEO. “Dealing with power outages during these hot days was challenging, and we recognize our part in adding to an already stressful situation. We strive to put our customers first, and we realize it didn’t feel that way for many of them this week. We commit to learning from this and improving for the future.
“We also appreciate all of our residential and commercial customers who worked hard to conserve electricity. Many of our customers used air conditioning less frequently or turned it off, and some of our business customers took great steps to reduce their usage and help their neighbors navigate outages. All of it made a big difference in reducing the need for and impact of outages, and we’re grateful for the partnership,” Vermillion said.
The unprecedented and extreme heat wave in the Pacific Northwest broke records this week, including setting a new system-wide peak electric load for Avista of approximately 2,300 megawatts. The heat also put significant strain on the electric grid. The combination of the temperatures and the increased electric usage, due in large part to air conditioning use, caused parts of the electric system focused in Spokane and Lewiston, Idaho to overload or not perform as expected.
The impacted equipment served areas in north Spokane and parts of the South Hill, Spokane Valley and Lewiston Orchards in Lewiston. This is why customers in those locations experienced outages throughout the afternoon and evening Monday, Tuesday and Wednesday. The issues in those areas on the electric distribution system are what drove the need for protective outages to prevent extensive damage and prolonged outages. Avista maintained adequate electricity supply to serve customers throughout the high temperatures.
The heat and increased usage impacted seven out of 128 substations on Avista’s system. Over the course of three days, Avista was able to minimize the protective outages and alleviate some of the strain on the system as customers conserved electricity and the company shifted electric load and modified parts of the grid. The unique number of customers who experienced protective outages was 15,307 on Monday, 6,793 on Tuesday and 602 on Wednesday. There were no protective outages initiated on Thursday or Friday. The previous outage numbers included the number of outages experienced, rather than the number of unique customers impacted.
Avista continues to monitor the system 24/7 to provide all customers with safe and reliable energy. As outages may occur as they do on any given day, customers can visit myavista.com/outage to report an outage, get information on how to prepare for outages and to check on outage status.
A heatwave that will go down in history
On Tuesday, June 29, the city of Spokane set a new record for the hottest day in recorded history when the temperature soared to 109 degrees. That same day, Avista also set a record for the highest amount of customer energy usage in the company’s 132-year history.
Typically, most of the power Avista provides is used and delivered during cold winter months. We are what is called a “winter peaking utility.” But on June 29, for the first time ever, demand for energy peaked during the summer. This historic swing was triggered by several consecutive days of unprecedented record-breaking high temperatures across our region.
Avista had plenty of power to serve our customers. This was not a power supply issue. The challenge was that the sustained hot temperatures and high energy demand stressed our electric system and pushed some of the equipment on our grid to its limits as we strained to deliver the record amount of energy that our customers were using.
Here are some Questions and Answers that help explain what happened:
Record-breaking high temperatures across our region have resulted in the highest energy usage in Avista’s history. This record-high usage strained parts of our electrical system and caused some of the equipment that runs our electric grid to over-heat. When substation transformers and related equipment are sending too much energy through them, they can overheat and trip off to prevent them from being damaged. It’s similar to when a circuit breaker in your home trips when it detects a problem.
Avista was monitoring all our equipment, trying to prevent over-heating and tripping. When it reached a certain point, we intentionally shut it off to let it cool down. Otherwise, it could have caused permanent and costly damage, and led to a prolonged outage to fix or replace the damaged equipment.
To prevent the equipment from overloading and allow it to cool down, we implemented protective planned outages for customers served by that substation transformer and equipment. The planned outages were expected to last about an hour. We were hoping that sequenced one-hour cool-down periods would help avoid longer outages and prevent damage to equipment.
Avista contacted customers by phone and/or email to let them know if and when their location was scheduled for a planned outage.
A map that identified areas where the outages were planned, as well as areas that Avista was actively monitoring for potential outages was posted on this page. The areas labeled “planned” were those where customers could expect to be notified of an outage. The areas labeled “monitoring” were on a “watch list” in case action needed to be taken that would have required planned outages to protect equipment.
These protective planned outages took place between noon and 8pm and were expected to last approximately one hour, while some actual times may have varied from this. Some customers may have experienced more than one outage with no less than one hour in between outages. Read how to prepare for outages.
During this historic heatwave, some customers may have experienced multiple outages because parts of the electric system that serve them directly were at risk of failing.
Avista tried to impact the fewest number of customers by implementing planned outages in targeted areas where the electric equipment was most impacted by the heat. This is why some customers in certain areas experienced the protective outages and others did not.
We monitored the entire system and had identified the parts of the electric system where the equipment had been prone to overheating. The planned outages were intended to protect the system and prevent extensive damage that could have resulted in prolonged, unplanned outages and costly repairs.
We typically see the highest energy usage from customers during the afternoon and evening hours. The combination of high temperatures and high electrical demand can stress parts of our electrical system and cause some of the equipment that runs our electric grid to over-heat. These protective planned outages were a proactive effort to reduce the risk of longer outages that could result if equipment gets overheated and damaged. Planned outages were targeted in areas where the electric equipment was most impacted by the heat and at risk of overheating.
Yes, under a reasonable range of temperature conditions. We continually invest in our system to ensure reliability. Substations are the “heart” of the electric grid. They keep the energy flowing to the neighborhoods in the communities we serve. That’s why we took proactive measures to protect this critical equipment.
Avista’s electric system includes 130 substations that house more than 200 transformers. During this unprecedented heat and demand on our system, we experienced issues on four transformers, which serve specific areas. That’s why only areas served by these four transformers experienced planned outages.
Circuits and feeders are the “arteries” that flow from the “heart.” These circuits “feed” electricity from the substation to the streets and homes in your neighborhood. Avista has 360 circuits on our electric system. And we identified 9 circuits that may have issues, so they were on our watch list. If we had needed to take protective measures, areas served by these 9 circuits or feeders may also have experience planned outages.
Avista works constantly to upgrade the electrical system. Every year, we invest more than $400 million in capital to maintain and upgrade the equipment and systems that are used to generate and deliver energy to our customers. A large portion of our capital budget goes directly toward the type of distribution equipment that is being strained during this heat wave.
Knowing that extremely hot weather was in the forecast, we planned ahead based on how much energy we expected customers to use, and the capacity of our equipment based on its rating. We expected to be able to meet our forecasted energy needs.
However, customers used more energy than we forecasted and some equipment did not perform as we expected. Some equipment started to overheat, which required us to shut off power to avoid prolonged outages and damaging equipment.
Avista has always had sufficient power supply to meet demand. Instead, the extreme heat conditions put stress on some equipment and caused it to over-heat. To avoid over-heating and the damage it can cause, we proactively turned off specific equipment for about an hour so it can cool down. This resulted in protective planned outages for customers in the area, while the equipment cooled off. By sequencing these targeted planned outages, we hoped to avoid damaging equipment, which might take several hours or a full day to repair.
The record-breaking high temperatures did not last as long in Seattle and Portland. Also, most homes in these cities do not have air conditioners, which use a lot of energy to operate.
When we have record high temperatures outside, our air conditioners must work harder and run longer to keep us comfortable inside. Normally, air conditioners cycle on and off at different times to help even out energy demand. But when everyone had their AC on all the time, that’s what caused the unprecedented strain on our system.
Federal and state regulators expect Avista to preserve the stability of the entire power system to ensure that we can provide this essential service to all of our customers. Sometimes that requires us to take preventive steps in targeted locations to reduce the risk of causing damage to the system at large.
In this case, some of the equipment that is used to deliver energy to our customers was at risk of overheating, so we needed to take measures to avoid costly damage to the equipment, which would have resulted in more prolonged outages that would have impacted a large number of customers.
We appreciate your conservation efforts during the extreme heat we experienced. We still have plenty of hot summer weather ahead of us. You can view additional information and tips on how to conserve energy and keep your home cool when the weather heats up below.