How much does the immersion really cost to heat? What's each electric shower, tumble-dryer load and hour of the oven at Irish rates? Put in your unit rate, and every figure below updates live — in euro, honestly.
This is the price of one kilowatt-hour (kWh) on your bill, in cents, including VAT. Every cost on this page is driven by it.
Standing charges (≈€300/yr) and the PSO levy are excluded — you pay those whether the socket is on or off. This tool shows usage cost only. The number to copy in is the per-unit rate on your latest bill.
A 3 kW element heating your hot-water cylinder from cold. Incoming mains water is taken at 12°C (Irish average); the element is treated as ~100% efficient — all the electricity ends up in the water.
With a working thermostat, "leaving it on" doesn't re-boil the tank — it just tops up heat leaking through the lagging. The real waste is heating a full tank of water that nobody uses. Lag the cylinder and pipes and that daily figure roughly halves.
The night-rate trick only works with a timer — set the immersion to come on in the early hours, or you'll just heat water all day at the dear rate.
Costs are computed live from your Step 1 rate. Set how often you use each one and it feeds your weekly total below. Defaults are a rough typical household — change them to yours.
The figures here are typical values. To find your own money pits, meter the actual appliance, move the big loads to the night rate, and replace the worst offenders.
A smart plug pays for itself the first time it catches a €200/yr appliance you didn't suspect
Three things stack up: Ireland's small, island grid carries high network and connection costs per home; a large share of our power is still made by burning imported gas, so bills track the international gas price; and carbon and policy levies (like the PSO) sit on top. That combination keeps Irish household rates among the dearest in Europe — a typical urban standard unit rate is around 36c per kWh in mid-2026.
Yes — but only on a night or smart tariff, and only with a timer. At 21c a night unit versus 36c by day, a full 117 L tank heat drops from about €2.60 to roughly €1.50 — over €1 saved every heat, which is around €225 a year at four heats a week. Without a timer you'll leave it heating through the day at the dear rate and wipe out the saving.
A 9.5 kW electric shower costs about 6c a minute — roughly 46c for an 8-minute shower at 36c. Heating a full tank for a bath is €2–3 depending on cylinder size, so a shower wins easily on cost per wash. The exception is if you already heat the tank for other reasons, or you're on a night rate: then bath water heated overnight can be cheaper than a long daytime shower.
Barely. A modern TV on standby, plus a few chargers and the router, adds up to only a few euro a year each — worth switching off, but it's not your bill. The real money is in heat and motors: the immersion, electric showers, tumble dryers, ovens and electric heaters. Chase those first.
Only if you can genuinely shift big loads to the cheap night window. A smart tariff has a low night rate but a higher day and peak rate, so if your dishwasher, washing machine, immersion and EV run overnight you win — if your usage is spread through the day and the 5–7pm peak, a flat standard rate can be cheaper. Look at when you actually use power before switching.
Heat the person, not the room. An electric blanket draws about 60 watts — near 2c an hour at 36c — while a 2 kW fan heater is about 72c an hour, over thirty times more. For one person on the couch or in bed, a blanket or a heated throw is the cheapest warmth there is.