Tucson Electric Power has me confused on their rate schedules. Looking at Schedule GS-2 for secondary service versus Schedule GP-1 for primary. The demand charge difference is only $0.65/kW but there's some language about "delivery voltage adjustments" that I can't decipher. Anyone familiar with TEP's tariffs?
TEP secondary vs primary - rate schedule confusion
Omar - I don't know TEP specifically but most utilities have voltage adjustment factors built into their rate schedules. Higher delivery voltage usually means lower distribution losses, so they pass some of that savings to the customer. Check if there's a separate tariff rider or if it's built into the base rates.
I dealt with TEP back in 2015 on a similar issue. The voltage adjustment is in their Schedule 1 - Standard Contract Terms. Primary service gets about 2.5% discount on energy charges plus the demand charge reduction. For our 500kW load, it saved us about $4,200 annually.
Kim - thanks, found the Schedule 1 reference. The voltage adjustment shows 97.5% multiplier for secondary service and 95.0% for primary service on energy charges. So primary service gets both lower demand charges and lower energy rates. That's a significant difference for our 750kW facility.
Omar - Eugene Water & Electric has similar voltage adjustments. We save about 3% on energy charges plus $0.95/kW on demand charges with primary service. Just remember to factor in transformer maintenance costs - budget about $2,000-3,000 annually for testing and upkeep on a 1000kVA unit.