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GWP Heat Wave Messaging


During the last heatwave, GWP used its customer notification process to make a case for adding new gas power equipment at the Grayson Power Plant.  


GWP is running an antiquated primarily 4kv system.



Labor Day weekend 2020 brought temperatures well into the triple digits for a widespread part of Southern California. These record high temperatures simply overwhelmed electrical supply, transmission, and distribution systems statewide.  Equipment, primarily transformers, of all types and sizes are not designed to bear this type of sustained heat cycle. Extensive transformer failures and outages, and in some cases rolling blackout events, occurred in Anaheim, Riverside, LADWP, Imperial Irrigation District, Pasadena, and Burbank.

During the Labor Day weekend, GWP sent an emergency notification and asked its customers to conserve as much energy as possible to reduce the strain on the electrical grid. The message indicated, among other things, that we have an aging and unreliable power generating facility at Grayson. The plant in its current condition exacerbates the problem we face in Glendale during sustained heatwaves.  The fact that the plant is “old and unreliable” is undisputed regardless of where an individual might be in the discussion on the future of our electrical generation and supply in Glendale.  It is decades beyond the manufacturer’s recommended operational life and the units have all continued to break down in various degrees of severity over the last 10 years, creating extensive down time and expensive repairs. 

During this particular heat wave, we had zero reserves and minimal units operating at Grayson. We were once again fortunate not to have a supply shortage due in large part to the heat occurring on a weekend (Sunday is traditionally the lowest use-day of the week) and the pandemic that has kept many large commercial customers out of operation or operating at a reduced capacity.  





The letter also implied that GWP is running an antiquated primarily 4kv system. GWP has systematically converted its system from 4kv to 12kv through annual Council approved Capital Improvement Projects. The conversion is labor and time intensive, arduous and expansive, and not something accomplished overnight.  Fifty percent (50%) of GWPs system is converted to 12kv.  While we have converted 50% of the total infrastructure, the system is actually operating on 12kv at a much higher capacity.  Currently, our system is being supplied by 77% 12kv and 23% 4kv based on the length of the circuits. An all 12kv system is the goal; however, while it will help in extreme heat events, it will not prevent the kind of transformer related incidents we have had in high-sustained heat.  To clarify the claims made in the letter regarding neighboring cities, the table below displays the conversion efforts by both Pasadena and Burbank in comparison to Glendale. 




Overall, Glendale appeared to have had less heat-related impacts than many other utilities in the area and in the state during the Labor Day weekend, which is a result of excellent maintenance and upkeep of our system. Power was restored to all customers by early Monday morning of September 7, when most other utilities had outages well into the week.  We continue to be focused on providing our customers and community with the highest levels attainable in regards to clean, renewable, sustainable, climate friendly, reliable, and affordable energy alternatives. 

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