EV vs Petrol Costs Ireland 2026: Calculate Your Savings

Begin with annual kilometres and consistent units

Assume 15,000km per year. Our illustrative EV uses 17kWh per 100km at the battery, with 90% charging efficiency. Electricity purchased is therefore 15,000 ÷ 100 × 17 ÷ 0.90, or approximately 2,833kWh. Use the same measurement basis throughout: if your consumption figure already measures electricity at the charger, do not add losses again.

For the petrol comparison, assume 6.5 litres per 100km and €1.80 per litre. Annual fuel consumption is 975 litres, costing €1,755. These are chosen assumptions for the calculation, not a tested model pairing. Replace them with your own recorded consumption and a price you actually pay to make the result relevant.

Compare three EV electricity prices

At an illustrative €0.15/kWh, 2,833kWh costs €425 per year, or approximately €2.83 per 100km. At €0.30/kWh, it costs €850, or €5.67 per 100km. At €0.65/kWh, it costs approximately €1,842, or €12.28 per 100km. None of these rates is presented as an available tariff.

Against the €1,755 petrol baseline, the first scenario saves €1,330 in energy and the second €905. The third costs roughly €87 more. This is why a low home-rate example cannot describe every driver's experience. Check your expected mix of domestic, apartment, workplace and public charging, and include any extra fees charged to use those facilities.

Include a diesel or hybrid comparator honestly

For a separate diesel example, assume 5 litres per 100km and €1.75 per litre. Annual expenditure is 15,000 ÷ 100 × 5 × €1.75, or €1,312.50. Against that, the EV at €0.30/kWh saves €462.50 in energy; at €0.65/kWh, it costs about €529 more.

A hybrid should use its own real fuel consumption. A plug-in hybrid needs both its electricity use and its fuel use counted, with an explicit proportion of driving on each. Avoid comparing an optimistic EV laboratory figure with a worst-case combustion figure. Match vehicle size, route, season and driving needs as closely as the available information allows.

Calculate the mixed charging price

Suppose 70% of purchased electricity costs €0.15/kWh and 30% costs €0.65/kWh. The blended rate is €0.30/kWh, producing the €850 example. The percentages refer to energy, not visits: a long motorway trip can account for a large share of monthly electricity even if you make very few public stops.

Add operator subscriptions and parking charges where relevant. When switching home tariffs, compare daytime household use and standing charges as well. Our tariff calculator currently asks for miles and miles/kWh even when Ireland is selected. Convert kilometres by dividing by 1.609344. For this 17kWh/100km battery example, enter approximately 3.66 miles/kWh, keep charging efficiency separate and select euros.

Find your energy break-even and stress-test winter

The petrol example costs €11.70 per 100km. Dividing this by 17kWh and multiplying by 0.90 gives an electricity break-even price of approximately €0.619/kWh. Below that rate, the EV example has the lower energy cost. Against the diesel assumptions, the threshold is approximately €0.463/kWh. Fixed fees are outside these thresholds.

Now increase the EV consumption assumption to 21kWh per 100km for a deliberately more demanding scenario. Annual purchased electricity becomes 3,500kWh at the same 90% efficiency. At €0.30/kWh, the energy bill is €1,050. This is a sensitivity test, not a universal winter penalty. Use it to see how much margin your budget has before drawing conclusions from the best case.

Move from energy savings to the full decision

An illustrative €3,000 extra upfront outlay divided by the €905 petrol energy saving gives simple payback of about 3.3 years. That excludes finance, depreciation, maintenance, tyres, insurance and installation. A car kept for fewer years or sold at a different value can produce a different overall result even when the energy calculation is accurate.

Use the purchase grant guide, home charger grant guide and Irish EV tax guide to check confirmed support. The Department of Transport: benefits of switching to an EV identifies motor tax as another distinct cost. Compare purchase price minus resale value plus operating expenses, or compare the full lease payments and charges. Do not add both the entire purchase price and depreciation as separate costs in the same ownership model.

References: Department of Transport: benefits of switching to an EV