Smart meters and time-of-use tariffs

ESB Networks has been replacing Ireland’s electricity meters since 2019, and the great majority of homes now have a smart meter or are on the list for one. The meter is installed free, it stays the property of ESB Networks, and having one does not change your tariff by itself. What it changes is what you are allowed to buy: with a smart meter you can move to a time-of-use tariff, where the price per unit depends on when you use it.

Whether that is a good idea is entirely a question about your household, and the honest answer for a large number of homes is no.

What the meter actually does

A traditional 24-hour meter records one number: total kilowatt hours since installation. A smart meter records consumption in half-hour intervals and reports them to ESB Networks over the mobile network. That does three things.

First, it removes estimated bills — no more meter readers, no more catch-up bills after a run of estimates. Second, it makes your own consumption data available to you, through your supplier’s app or on request from ESB Networks. Third, it makes time-of-use pricing possible, because the supplier can now see when you used electricity and not just how much.

You can have a smart meter and stay on a flat 24-hour rate. Plenty of households should. Ireland does not force a tariff change on installation, and if your consumption is spread across the evening you may be better off on a single rate — see our 24-hour rates page for the flat-rate market.

The three bands

Irish suppliers generally split the day into three price bands, and the hours are set by the supplier rather than by the meter, so they differ between plans:

• Night — roughly 11pm to 8am. The cheapest band, sometimes dramatically so.
• Peak — usually 5pm to 7pm on weekdays. The dearest band, and the reason time-of-use tariffs go wrong for some households.
• Day — everything else, priced somewhere between the two.

Some suppliers add a fourth “free” or heavily discounted window at weekends, or an EV-specific overnight rate. Check the exact hours on the specific plan you are considering; assuming the standard 11pm–8am window and finding it is midnight–7am changes the arithmetic materially.

Will it save you money?

The single number that decides it is the share of your annual consumption you can move into the night band. Every cost estimate we publish for a smart tariff assumes a split of 63% day, 28% night and 9% peak, which is a reasonable national profile but is emphatically not your household.

The households that win on a time-of-use tariff have a large, shiftable block of consumption:

• An electric car charged overnight. This is the strongest case by a distance. A car charging at 7kW for a few hours a night can push your night share past 50%, and a night rate is often less than half the day rate.
• A heat pump on a timer, or storage heating, running the bulk of its cycle overnight.
• A hot water cylinder heated by immersion on a timer at 2am rather than at 6pm.
• Dishwasher, washing machine and tumble dryer run on delay timers overnight — worth having, but on their own this is a few hundred kWh a year, not a transformation.

The households that lose are the ones with no shiftable load and a busy early evening: everyone home from five, oven on, kettle on, dryer running, television on. That is exactly the peak window, at the dearest rate on the plan, and the day rate on a time-of-use tariff is normally higher than the flat rate you would otherwise have paid.

Check your own profile before you commit

Do not guess at this. Your smart meter data is yours, and it is the whole answer.

Most suppliers publish half-hourly or daily consumption in their app. ESB Networks will also provide your historic data on request through their smart meter data portal. Download it, sum the kWh falling in each band for a full year — a year matters, because winter evenings look nothing like July — and you have your real day/night/peak split.

Then take those percentages to the smart meter tariffs comparison and enter them instead of the default profile. That re-ranks every plan on your consumption rather than on a national average, and it will frequently reverse the ordering.

Shifting usage is worth more than switching plan

If your night share is currently low, the useful move is not necessarily a different tariff — it is changing when things run, then switching. Practical, low-effort changes:

• Set the dishwasher and washing machine on delay start so they run after 11pm rather than at 8pm.
• Put the immersion on a timer. Water heated at 3am is still hot at 8am in an insulated cylinder.
• Avoid running the tumble dryer, the oven and the dishwasher simultaneously between 5pm and 7pm. Moving one of them out of the peak window is worth more than most tariff changes.
• If an old dishwasher or dryer has no delay timer and is due for replacement anyway, buy one that does, and compare the total cost of a new appliance in Ireland before you order: delivery, installation and collection of the old one can matter as much as the shelf price.
• If you drive an EV, never charge it at teatime. Schedule it in the car or the charger, not by remembering.

A household that moves a third of its consumption overnight is a genuinely different customer, and the tariff that suits it is a different tariff.

Privacy, and the things people worry about

The meter reports consumption totals, not what you are running. It does not identify appliances. Your supplier receives interval data for billing, and the granularity of what they receive depends on the tariff you are on — households on a flat rate can generally opt for less frequent reporting. If that matters to you, ask your supplier what reporting level your plan requires before switching to time-of-use.

Installation itself takes under an hour, involves a short power outage, and costs nothing. You can decline the smart functionality and have the meter operate in a non-communicating mode, but you then cannot access time-of-use tariffs.

The short version

A smart meter is worth having for the accurate billing alone. A time-of-use tariff is worth having only if you can point at the block of electricity you are going to move overnight. If you cannot, price a flat rate on the electricity comparison and stay there — and if you have an older two-rate meter instead, our NightSaver page covers that market, which works on the same logic with fewer bands and far fewer plans.