Home EV charging cost is the electricity drawn from your meter multiplied by your tariff. For an illustrative EV using 16 kWh of battery energy per 100 km at an assumed 90% charging efficiency, a 10c/kWh rate costs about €1.78 per 100 km; a 30c/kWh rate costs about €5.33. Your consumption, charging times and electricity contract determine the actual result.
This guide uses clearly labelled examples rather than treating an old supplier offer as today's price. For live plan research, use our EV electricity-plan comparison and the supplier links there. Use the charging cost calculator to explore your own driving and rate assumptions.
Cost per 100 km and per year
For this table, assume 16 kWh of battery energy per 100 km and 90% charging efficiency. The meter supplies about 17.78 kWh per 100 km: 16 ÷ 0.90. Over 16,000 km of annual driving, all charged at home, that means about 2,844 kWh per year. These are worked assumptions, not a claim about every EV or an advertised supplier tariff.
| Illustrative electricity rate | Cost per 100 km | Cost over 16,000 km |
|---|---|---|
| 10c/kWh | €1.78 | €284.44 |
| 20c/kWh | €3.56 | €568.89 |
| 30c/kWh | €5.33 | €853.33 |
| 40c/kWh | €7.11 | €1,137.78 |
The calculation covers charging electricity only. It excludes the charger installation, public-network fees, insurance, servicing, finance, depreciation and changes to the rest of your household's electricity bill.
How much does a full charge cost?
First decide whether you mean a complete empty-to-full charge or the top-up you normally need. A battery's usable capacity and starting percentage matter more than the model name alone.
For a hypothetical 60 kWh usable battery going from 20% to 80%, the battery needs 36 kWh. Assuming 90% charging efficiency purely for this example, the meter supplies 40 kWh: 36 ÷ 0.90 = 40.
| Illustrative rate | 20% to 80% top-up: 40 kWh from meter | 0% to 100%: 66.7 kWh from meter |
|---|---|---|
| 10c/kWh | €4.00 | €6.67 |
| 20c/kWh | €8.00 | €13.33 |
| 30c/kWh | €12.00 | €20.00 |
| 40c/kWh | €16.00 | €26.67 |
Efficiency varies with the car and charging conditions. Do not add a separate loss allowance if your consumption figure already measures electricity drawn from the supply. Dashboard driving consumption and billed charging electricity are not necessarily the same measurement.
What if charging crosses the cheap window?
Split the session by tariff band. If 25 kWh is billed at an illustrative 10c/kWh and another 15 kWh at 30c/kWh, the total is €2.50 + €4.50 = €7, not €4.
At a constant 7.4 kW, 40 kWh takes about 5.4 hours, before any further reduction in charging power. A shorter boost window cannot contain that whole session. The night-rate charging guide explains window lengths, charge targets and scheduling.
Check the full electricity plan before switching. A cheaper EV rate can come with different day and peak rates or a higher standing charge. The CRU's accredited comparison services provide a route to comparing whole-house offers.
Home charging versus public charging
Use the public network's price for the connector and payment method you intend to use. Include any subscription, session, parking or overstay charge that applies. There is no single public-charging rate that accurately describes every Irish network or charging speed.
For a mixed example, suppose 80% of your charging electricity costs 10c/kWh at home and 20% costs 60c/kWh away from home. The blended energy rate is (0.80 × 10c) + (0.20 × 60c) = 20c/kWh. At 16 kWh of battery energy per 100 km and 90% efficiency, that is about €3.56 per 100 km, before any extra public-network charges. Both rates are illustrative.
For an actual trip, consult the operator's live price information, such as ESB ecars, rather than applying the home tariff to every kilometre.
EV electricity versus petrol: compare like with like
A petrol car using an illustrative 6.5 litres per 100 km at an assumed €1.85 per litre costs about €12.03 per 100 km. Over 16,000 km that is €1,924 in petrol. The EV example at 20c/kWh costs about €569 in charging electricity over the same distance.
That approximate €1,355 difference is a fuel-only calculation using stated assumptions. It is not a forecast of your total ownership saving, a current Irish pump-price claim or a promise that a charger pays for itself within a year. Substitute your own fuel receipts, mileage and electricity figures before making a purchase decision.
Keep installation cost separate from running cost
Charging electricity is a continuing expense. The charger and installation are a separate purchase. Compare the available charger models, current installed prices and what standard installation includes.
The SEAI grant overview explains the grant route and refund process. Do not subtract a grant from every annual charging bill or assume that eligibility has already been confirmed.
Frequently asked questions
Does a 7.4 kW charger cost 7.4 kWh every hour?
Only if it draws 7.4 kW continuously for the whole hour. Actual power can be lower because of the car's charging limit, load management or the charging session's state.
Where should I get my actual consumption figure?
Use charger or supplier records where available, and note whether they measure energy from the supply or energy added to the battery. Calculate over several comparable journeys or sessions instead of assuming one session represents the whole year.
How can I reduce the cost without changing my car?
Check your tariff, match the charging schedule to the cheap window and avoid unnecessary charging outside it. Compare the whole-house bill before switching plans. If you need a charger, start a property assessment to establish the installation scope.