Paul N. in San Jose but dealing with a ComEd account in Illinois. Client operates a data center that's been bouncing around the 100 kW demand threshold between small general Schedule SGS and large general Schedule LGS. Some months they hit 105-115 kW, others drop to 85-95 kW. ComEd keeps switching them back and forth which creates billing confusion and rate volatility. What's the standard practice for threshold crossings? Is there a grace period or minimum duration requirement?
ComEd demand threshold confusion - crossing from small to large general service
Carl B. from Springfield IL - ComEd typically requires three consecutive months above 100 kW to move to LGS, but once you're there you need three consecutive months below 100 kW to drop back down. The problem is LGS has a minimum demand charge that might actually cost more if you're barely over the threshold. Have you run the numbers comparing both rate schedules at their actual usage levels?
Dale O. from Columbus - similar issue with AEP Ohio. The key is understanding the ratchet provisions and minimum charges on the higher tier. Sometimes it's better to implement demand management to stay consistently below the threshold rather than bouncing back and forth. What type of loads are causing the demand spikes?
Carl, the math is tricky because LGS has better energy rates but higher demand charges. Dale, the spikes come from HVAC load during server room cooling in summer months. Winter usage is consistently under 100 kW but July-September pushes 110-120 kW. I'm thinking demand control or thermal storage might be the answer rather than fighting the rate classification.
Randy Dawson here - Paul, you're dealing with a common issue in deregulated markets. ComEd's tariff Schedule LGS actually has a threshold provision in section 3.2 that allows customers to elect to remain on LGS once they qualify, even if demand drops below 100 kW for several months. This eliminates the ping-pong effect and provides rate stability. The LGS rates are often better for consistent loads above 80 kW even with higher demand charges. I'd recommend running a 12-month analysis comparing both schedules and consider the election option if LGS proves more cost-effective. Also look into their Real-Time Pricing program if the client can handle rate volatility.
Randy's right about the election option - I forgot about that provision. Paul, also check if they qualify for ComEd's Energy Efficiency programs. Data centers often qualify for custom rebates on cooling system upgrades that could help manage those summer demand spikes while improving overall efficiency.
Excellent point about the election option Randy - that would solve the volatility issue. Running the numbers now on both schedules with their actual 24-month usage history. The client is also interested in exploring battery storage to shave peak demand which could keep them in the lower tier permanently. Thanks for the guidance everyone!
Glenda G. from Idaho - slightly off topic but Paul, make sure you're also checking for any available time-of-use variants. Some utilities offer TOU options on both small and large general service that can provide significant savings for data centers with 24/7 operations. The energy arbitrage opportunities can be substantial.
Update for anyone following this thread - elected to stay on ComEd Schedule LGS and the client is saving about $340/month compared to the constant switching. Also implementing a 250 kWh battery system to shave summer peaks. Randy's advice about the election option was spot on. Thanks again everyone!