Use time-of-use scheduling to reduce the price paid for flexible electricity. Use efficiency and runtime changes to reduce the amount of electricity used. Moving a load to midnight can lower cost without saving a single kWh, so do not describe load shifting as energy reduction.
| Goal | Best tactic | Metric |
|---|---|---|
| Lower total electricity use | Reduce unnecessary runtime or improve efficiency | kWh |
| Lower cost on a time-varying tariff | Shift flexible loads off peak | Cost by rate period |
| Reduce demand overlap | Stagger large loads | Peak kW and demand charges, if applicable |
| Support grid events | Utility-approved program | Event participation and bill credit |
A worked example: cheaper can still mean more electricity
Assume an eligible load uses 4 kWh, with an illustrative peak variable rate of $0.35/kWh and off-peak rate of $0.12/kWh. These are example rates, not a current utility offer.
| Operating pattern | Energy | Variable cost |
|---|---|---|
| Original peak operation | 4 kWh | $1.40 |
| Same service moved off peak | 4 kWh | $0.48 |
| Off-peak operation with 10% extra energy | 4.4 kWh | $0.528 |
The unchanged load saves $0.92 per occurrence in variable cost and zero kWh. The third case still costs about $0.87 less than the first, but consumes 10% more energy. Reporting only the bill difference would conceal that tradeoff.
Use the marginal charges that actually vary with the shifted consumption. An unchanged daily service charge is not a saving. Demand charges, solar self-consumption, export credits and battery losses require additional calculations; do not apply this simple table to them without adjustment.
Finally, require the same useful result: charged vehicle ready when needed, completed appliance cycle, or acceptable comfort. A missed task is not a successful low-cost schedule.
Start with the tariff, not the app
Read the utility rate sheet and bill. Record peak, mid-peak, and off-peak windows, seasonal changes, weekends, holidays, delivery charges, and any demand component. A smart-plug calculator using one flat cents-per-kWh figure cannot model a complex tariff accurately.
Then identify flexible loads. EV charging, dishwasher cycles, laundry, and some water-heating schedules may be movable when the equipment, household needs, noise rules, and safety constraints allow it. Heating and cooling usually have narrower comfort limits.
What automation can do
Use the appliance’s approved scheduler first. An EV charger, thermostat, water-heater controller, or dishwasher understands its own operating constraints better than a generic smart plug. A home platform can coordinate schedules, but it should not bypass equipment protections or switch loads beyond the controller’s rating.
A Tapo P110M (Amazon search) can schedule a supported 120V plug load and estimate costs with periodic rates. It is not a controller for an EV charger, electric water heater, dryer, or central HVAC.
What actual energy reduction looks like
Reducing kWh may involve a thermostat setback, fixing excessive HVAC runtime, reducing unnecessary standby, changing a dehumidifier setting, air sealing, or replacing inefficient equipment at end of life. Compare total kWh across similar weather and occupancy.
An off-peak schedule can occasionally increase energy use if it causes longer preheating, extra cycles, or rebound. Watch both energy and cost.
Avoid peak stacking
Moving every flexible appliance to the first off-peak minute can create a new household peak. Stagger EV charging, laundry, dishwashing, and water heating where practical. This matters especially on tariffs with demand charges or service-capacity constraints.
Do not compromise ventilation, freeze protection, food safety, medical needs, or sleep merely to chase a cheaper interval.
Measure the result correctly
Track three numbers:
- total kWh for a comparable period;
- kWh in each rate period;
- the resulting supply and delivery cost.
A lower bill with unchanged kWh is successful load shifting. Lower kWh is lower consumption; call it improved efficiency only when comparable useful service is delivered. Report them honestly as different outcomes.
Separate Lower Usage From Lower Cost
Shift first when the tariff rewards flexibility and the load has an approved scheduler. Reduce runtime when the goal is energy savings. The strongest plan does both without pretending that a cheaper kilowatt-hour disappeared.
The monitoring versus automation guide helps decide whether an unknown load needs measurement before any schedule is added.
Tapo scheduling and cost-estimation features were checked against the Tapo P110M US page .