Client runs a chemical plant in Akron on Ohio Edison with 2 MW of backup diesel generators. They've never looked into an interruptible rate because they assumed it required actually shutting down production. But the tariff says interruptible service customers just need the ability to curtail load to a specified level within a certain timeframe. With 2 MW of backup generation, the plant can curtail grid demand by switching to generators. Does this qualify?
Interruptible rate for a plant with backup generators
It should qualify. Ohio Edison's interruptible rate requires the customer to reduce grid demand to an agreed-upon firm service level within 30 minutes of notification. If your client can start the backup generators and transfer load within 30 minutes, they meet the requirement. The discount on the interruptible rate can be 10-20% on demand charges. On a 2 MW facility, that could be $8,000-$15,000/month in savings. The trade-off is that the plant has to actually curtail when called upon — typically 5-10 times per year during system emergencies.
Jim W. is right on the mechanics. A few important considerations: the plant needs to have enough generator capacity and fuel supply to sustain curtailment for the required duration — typically 4-8 hours per event. The generators need to be tested and operational. And the plant needs to actually respond when called — missing a curtailment event can result in significant penalties, sometimes exceeding the annual discount. Make sure the client understands the obligation before enrolling. That said, for a plant that already has 2 MW of backup generation that sits idle 99% of the time, the interruptible rate turns an idle asset into a revenue generator.
We have a chemical plant on an interruptible rate and they've been called 6 times in 3 years. Each event lasted about 4 hours. The annual savings are about $130,000. The diesel fuel cost for the curtailment events is maybe $8,000 total. No-brainer for anyone with backup generation.
The numbers work. Going to present the interruptible rate option with the cost-benefit analysis. $130K in savings against maybe $10K in fuel is compelling. The plant manager already tests the generators monthly so he knows they work. Filing the application with Ohio Edison.