Biggest annual savings find of my career: a large manufacturing plant in Toledo on FirstEnergy. The plant owns its own transformers and takes service at primary voltage (13.2 kV). The tariff offers a 5% discount on energy charges for primary voltage service because the utility doesn't have to provide and maintain a transformer. The plant has been on the standard secondary voltage rate for at least 10 years. Nobody ever applied for the primary voltage discount. Savings: $67,000 per year. Refund going back 4 years: $268,000.
Primary voltage discount saved client $67K/year
That is enormous. The primary voltage discount is one of the most missed items in industrial auditing because it requires knowing the physical service configuration, not just reading the bill. The bill doesn't tell you whether the customer owns the transformer or the utility does. You have to ask or do a site visit. Every manufacturing plant, large warehouse, and data center should be checked for primary voltage eligibility.
Outstanding find. The primary/secondary voltage discount is worth checking on every account with demand over 200-300 kW. The discount varies by utility — some offer 2-3%, others up to 8%. On a large industrial account, even 2% of annual charges can be tens of thousands of dollars. The key verification step is confirming transformer ownership. If the customer owns the transformer (usually visible as a pad-mount or pole-mount transformer on the customer's property), they should be receiving the primary voltage discount. If the utility owns the transformer, the customer is correctly on secondary service.
$268K recovery — that's a career-defining find. Congrats Derek. Adding transformer ownership to my site visit checklist immediately.