Transparent by design
Methodology
Cheapest Hours reads the first energy tier assigned to every month, day type, and hour, then compares the lowest and highest published energy prices. The result is a schedule guide, not a bill forecast.
How rate schedules are classified
A rate is flat when every hour maps to the same energy price. A rate is time-of-use when a day contains at least two distinct prices. A rate is tiered when energy use crosses quantity thresholds. Rates can be both time-of-use and tiered. Residential demand charges are flagged separately.
How cheapest windows are found
For each month and day type, the pipeline calculates tier-one price as the published rate plus adjustment. Months with matching 24-hour schedules are grouped into seasons. Consecutive hours at the minimum price become cheapest windows. Consecutive hours at the maximum price become peak windows.
Published load-shift assumptions
| Load | Energy | Movable share |
|---|---|---|
| EV | 300 kWh/month | 90% |
| Heat pump water heater | 150 kWh/month | 80% |
| Dishwasher and laundry | 40 kWh/month | 100% |
| Home battery | 10 kWh/day | 90% round trip |
| Space heating and cooling | 400 kWh/month in four high-cost months | 30% |
Annual value equals movable kilowatt-hours multiplied by the seasonal price spread. Space-conditioning results are the least certain because weather and building performance vary widely.
Important limitations
URDB is reviewed roughly annually. Taxes, baseline allowances, minimum bills, credits, rate eligibility, demand charges, and changing fuel adjustments can affect a real bill. Always confirm the current tariff with the utility.
Methodology reviewed on .