Working on a 180 kW retail client in Phoenix and trying to understand APS's E-32 TOU schedule versus the E-34. The tariff book shows E-32 for general service 21-299 kW but E-34 seems targeted at retail with different demand windows. The on-peak hours are 3-8 PM weekdays May through October but I'm seeing conflicting information on winter periods. Has anyone worked through these APS schedules recently?
Arizona Public Service TOU schedules - E-32 vs E-34 for large retail
Michelle T., I've done several APS comparisons this year. E-32 is the standard general service TOU but E-34 has that retail-specific demand structure with separate billing for on-peak vs off-peak kW. Winter on-peak drops to just 5-9 AM and 5-9 PM weekdays November through April. The key difference is E-34's ratchet provision - 50% of peak demand from May-September carries through winter months.
Both of you are in Arizona so this is perfect timing. Sarah M. hit the key point about the ratchet clause in E-34 - that summer peak demand billing can really hurt clients with seasonal variations. The other gotcha is the power factor adjustment on both schedules. APS charges extra for power factor below 90% lagging, which retail clients often struggle with due to lighting and HVAC loads. Michelle, what's your client's typical power factor running?
Randy D., the power factor has been running around 85-87% which definitely triggers the penalty. Looking at 2% increase in demand charges when below 90%. Sarah M., thanks for clarifying the winter on-peak hours - that makes E-32 look much better since they're open 6 AM to 11 PM most days.
Different state but similar issues with power factor penalties in Florida. Has your client considered capacitor banks? For a 180 kW load the payback is usually under 2 years just from avoiding the penalty, plus you get some demand reduction from improved efficiency.
Kevin O. brings up a good point about power factor correction. In Arizona with APS the penalty can be substantial. Michelle, also check the monthly minimum demand on both schedules - E-34 has a 30 kW minimum billing demand that might impact slower months.
Great insights everyone. Running the numbers with the power factor penalty included, E-32 comes out about $400 monthly cheaper even with the broader on-peak hours. The demand minimum isn't an issue since this client rarely drops below 120 kW. Going to recommend E-32 with power factor correction equipment.
Michelle T., which power factor correction vendor are you considering? We've had good luck with automatic capacitor banks from ABB for similar applications in California. Worth getting quotes from multiple suppliers since pricing varies widely.