Home EV charging cost and electricity tariff glossary
Plain-English definitions of the 15 electricity tariff, smart meter, kWh consumption and home charger terms that shape your EV running bill.
Free, no obligation. One registered electrician prices a charger, not five.
- 15terms defined A to Z
- 8.84cEV tariff window
- 15.42cnight rate
- €300SEAI grant
A to Z of home EV charging costs and tariff terms
9% Reduced VAT on Electricity
The Irish VAT rate applied to domestic electricity unit rates and standing charges, already included in the 8.84c EV window, 15.42c night rate, and 34.38c 24-hour benchmark figures.
AC-to-DC Charging Loss (10%)
The 8% to 12% energy overhead consumed by the car's on-board charger electronics, battery cooling pumps, and cable resistance when converting 230 V household AC into DC stored in the battery.
Cold-Weather Range Factor
During frosty Irish winter weeks (0°C to 5°C), dense cold air and cabin heating increase EV consumption per 100 km by roughly 15% to 20% compared with mild summer driving.
Cost per 100 km Equivalence
The standard Irish benchmark comparing fuel spend across drivetrains: typically €1.40 to €1.90/100 km on an EV night window, €2.50 to €3.30/100 km on a standard night rate, versus €10.50 to €12.00/100 km for diesel or petrol.
Day / Night Meter (MCC02)
An older dual-register mechanical or digital meter that gives a flat night rate across a full 9-hour window (11pm to 8am in winter, midnight to 9am in summer) without peak early-evening pricing.
EV Booster / Night Boost Window
A 2- to 4-hour ultra-low electricity rate slot (typically 2am to 5am or 2am to 6am at roughly 8.45c to 8.84c/kWh incl. VAT) offered on smart-meter EV tariffs specifically for scheduled car charging.
kWh Added per 3-Hour Window
On a 7.4 kW (32 A) home charger, a 3-hour ultra-cheap 2am–5am slot delivers roughly 22.2 kWh from the wall (around 20 kWh into the battery), enough for 110 to 135 km of daily driving.
Microgeneration Export Credit (CEG)
The tax-free Clean Export Guarantee rate (typically 18.5c to 24c/kWh) paid by Irish suppliers for rooftop solar electricity exported to the grid—often higher than the 8.84c/kWh cost of charging the car at 2am.
Payback Period on Home Charger
The time taken for fuel savings over petrol or diesel (or over public DC rapid chargers at 55c–75c/kWh) to recover the €700 to €1,200 net cost of installing a grant-aided home unit—typically 8 to 14 months at 15,000 km/year.
Pre-Conditioning on Mains Power
Warming the cabin and defrosting the windscreen via the car's app at 7:30am while still plugged into the wallbox so winter heating energy comes from night-rate mains electricity rather than reducing driving range.
Scheduled Charging Timer
A timer set either in the smart wallbox app or in the vehicle infotainment screen that keeps a plugged-in car asleep at 6pm and starts drawing power only when the cheap night or EV rate begins.
Smart Meter Tariff (MCC12 / MCC16)
A half-hourly smart meter billing profile split into Day (8am–11pm), Night (11pm–8am), Peak (5pm–7pm), and optional EV boost bands.
Standing Charge
The fixed annual daily supply charge on an Irish electricity bill (often €220 to €340/year on urban smart tariffs). Comparing standing charges is vital because a slightly higher standing charge can offset small EV window savings on low-mileage cars.
Wall-to-Wheel Consumption
The actual kilowatt-hours drawn through your home electricity meter per 100 km driven, calculated by taking WLTP battery consumption and adding roughly 10% for charging losses.
WLTP Combined Wh/km
The Worldwide Harmonised Light Vehicles Test Procedure laboratory figure for energy used per kilometre. Multiply Wh/km by 0.1 and add 10% charging loss to get real metered kWh per 100 km.
What will charging cost you?
Four quick taps. You see your yearly cost at home, the cost per 100 km and the saving against petrol and diesel. Your number is only asked for at the end, if you want a price.
A Tesla Model Y doing 15,000 km a year on a night rate: about €407 a year at home, against about €1,783 for a petrol car.
How this is worked out
The energy is your car's real-world use per km, plus a tenth for what's lost while charging. The unit rates include VAT: a standard 24-hour rate of 34.38c a kWh, a night rate of 15.42c, and an EV tariff's cheap window at 8.84c. Standing charges are left out. Petrol and diesel are at pump prices of about €1.98 and €2.15 a litre. It's a guide to plan with; your own bill has your rates.
Home Car Chargers guides & price breakdowns
Straight answers to what people ask most: itemised costs, specifications, planning or grants, and what to check before you book.
More guides & resources: All guides & calculator hub · Technical & trade glossary · Frequently asked questions · Charging times by car · 3-pin plug or charger · Installers by county · Claiming the grant · No driveway?
Questions people ask
Is it cheaper to charge my car from rooftop solar panels or on the 2am EV night window?
If your electricity supplier pays 18.5c to 24c per kWh for exported solar under the Clean Export Guarantee and charges around 8.5c to 9c per kWh during the 2am–5am EV window, it is financially smarter to export your daytime solar for credit and schedule the car to charge overnight at the 8.84c rate.
Can I fully charge a large 77 kWh battery inside a 3-hour 2am–5am EV tariff window?
A 7.4 kW home charger delivers about 22 kWh in a 3-hour window (roughly 120 km of driving range). That covers almost any daily commute in a single night; if you return home near empty after a long weekend trip, you either top up across two consecutive nights or let the charge run into the surrounding 15.42c/kWh night rate.
Why does my electricity bill show 10% more kWh than the car's dashboard trip computer?
Your car's dashboard displays energy drawn from the battery to turn the wheels, whereas your ESB meter bills the AC electricity entering the charger. Roughly 10% is used by the car's on-board AC-to-DC converter, cooling fans, and battery management electronics during charging.
Home Car Chargers across all 26 counties
Requests from all 26 counties go to one vetted local specialist who covers your county — from Dublin, Cork, Galway and Limerick to Kildare, Meath, Wicklow, Waterford and Donegal. Pick your county below for local prices, specifications and advice.
What will yours cost?
Four taps to your yearly cost at home and the saving on petrol. Then, if you want, one registered electrician who fits home chargers in your county rings with a price for a charger.