Duke Energy Florida: Navigating Commercial Time-of-Use (TOU) Rates in 2026
As peak demand surges across the peninsula, Duke Energy Florida (DEF) is heavily prioritizing the transition of its commercial and industrial customers onto Time-of-Use (TOU) or Time-of-Day (TOD) rate schedules for 2026. Under these complex tariffs, the cost of electricity during summer afternoons can reach 4x to 5x the cost of overnight baseline energy. Without sophisticated building automation to orchestrate load shifting and pre-cooling, businesses will face catastrophic budget blowouts entering the high-cooling season.
Executive Impact
- →The Summer Penalty: Operating standard loads during the designated "On-Peak" window (typically 12:00 PM to 9:00 PM) triggers punitive kW multiplier charges designed to discourage consumption.
- →The "Duck Curve" Reality: Florida is rapidly adopting utility-scale solar. When the sun sets and solar generation plummets, utilities need rapid, expensive natural gas peaker plants to manage the evening load—and they are billing commercial users for that delta.
- →The ROI of Automation: Surviving TOU in Florida simply cannot be done manually. Building Automation Systems (BAS) with predictive algorithms are now mandatory operational investments.
The Mathematics of Duke Energy TOU
Traditional commercial tariffs act broadly like a flat tax—you pay roughly the same amount for a kilowatt-hour whether you consume it at 3:00 AM on a Tuesday or 4:00 PM on the hottest day in August.
Time-of-Use (TOU) destroys that paradigm. Duke Energy defines specific "On-Peak" blocks during the day when grid capacity is strained. If your rooftop HVAC units are running at 100% duty cycle during this block to combat the Florida heat, the financial multiplier applied to those specific electrons is devastating. Conversely, "Off-Peak" (overnight and early morning) power is sold at a steep discount, often below the average wholesale cost.
Survival Strategy 1: The Pre-Cooling Shift
For retail spaces, hotels, and general commercial buildings, the primary energy hogs are chillers and RTUs (Rooftop Units). You cannot simply turn off the AC at 2:00 PM in Florida. Instead, operators must utilize thermal flywheel pre-cooling.
Between 5:00 AM and 11:00 AM, while power is exceptionally cheap, the BAS drives the facility temperature down significantly lower than standard comfort setpoints (e.g., cooling the building concrete slab to 68 degrees). As the On-Peak window hits at noon, the chillers are cycled down to minimal "coast" mode, and the building slowly warms back up to 74 degrees by 6:00 PM. You maintain inhabitant comfort while avoiding the utility peak entirely.
Survival Strategy 2: Auditing the Transition
Duke Energy often places facilities onto a new TOU rate upon smart meter deployment or major facility renovation. This is a crucial moment for intervention.
Never accept a default rate assignment without a historical interval data audit. If a facility fundamentally operates 24/7 (like a hospital or data center) and cannot shift its cooling profile, being forced onto a punishing TOU structure represents an unavoidable backdoor rate hike. The facility must petition the utility to remain on a more favorable flat-load commercial tariff, utilizing sub-meter baselines to justify the exclusion.