What is Time-of-Use Tariff?
An electricity pricing plan where the rate per kWh varies depending on the time of day.
Quick Answer
Several Irish electricity suppliers offer smart tariffs with time-of-use rates, requiring a smart meter. Typical structures include day rates of 40–50c/kWh, night rates of 20–25c/kWh, and sometimes a free electricity window. Solar PV homeowners on ToU tariffs benefit by using solar power during expensive peak hours and running appliances like washing machines and dishwashers during free or cheap periods.
Fact-checked by John Rooney, Solar Energy Editor. Editorial policy
Time-of-Use Tariff Explained
A time-of-use (ToU) tariff is an electricity pricing structure where the cost per kWh changes based on when electricity is consumed. Rates are typically divided into peak (most expensive, usually evenings), off-peak (cheapest, usually overnight), and sometimes mid-peak or day-rate periods. ToU tariffs reward users who shift energy-intensive activities to cheaper periods. For solar homeowners, ToU tariffs can increase savings by using free solar electricity during expensive daytime peak rates and importing cheap electricity overnight.
How Does Time-of-Use Tariff Work in Ireland?
Several Irish electricity suppliers offer smart tariffs with time-of-use rates, requiring a smart meter. Typical structures include day rates of 40–50c/kWh, night rates of 20–25c/kWh, and sometimes a free electricity window. Solar PV homeowners on ToU tariffs benefit by using solar power during expensive peak hours and running appliances like washing machines and dishwashers during free or cheap periods.
Frequently Asked Questions
Is a time-of-use tariff worth it with solar panels?
Usually yes. Solar panels generate during peak/day-rate hours when electricity is most expensive, so you offset the highest-cost electricity. A battery adds further value by storing cheap overnight electricity.
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John Rooney is the founder of Solar Info and has been covering the Irish solar energy market since 2023. He fact-checks all content against official SEAI data and maintains relationships with SEAI-registered installers across Ireland.