A large electricity discount does not by itself identify a cheap plan. To compare tariffs before winter, a household needs to know how much electricity it uses, when it uses it and which charges apply beyond the advertised unit price.

This guide sets out a practical comparison method using regulator and network guidance checked on 25 October 2026. All numerical tariff examples below are invented to explain the arithmetic. They are not live supplier offers, predictions of winter prices or a recommendation of a particular product.

Which figures do I need from my current account?

The Commission for Regulation of Utilities switching guide recommends checking consumption, current cost and contract end date. For a time-of-use plan, it also advises considering when electricity is used. A fixed-term contract may carry an early-exit charge if you leave before it ends.

Start with a recent bill and, where possible, a full year's consumption in kilowatt-hours. Note the plan name, unit rates, standing charge, discount expiry and payment conditions. A euro direct-debit amount alone is not a reliable measure of energy use: it may reflect budgeting, credit or an estimated bill.

Make sure the account information relates to the home being compared. A recent move, new heat pump, electric car or change in household routine can make last year's pattern a poor guide to next year. Treat those changes as assumptions to examine, not as savings already achieved.

How do unit rates and standing charges combine?

For a simple single-rate example, suppose annual use is 3,000kWh. Fictional Plan A charges 30 cent per kWh and €300 a year in standing charges. That gives €900 for consumption plus €300, or €1,200 before any other applicable item.

Fictional Plan B charges 28 cent per kWh and €400 standing charges. Consumption costs €840, making the equivalent total €1,240. The lower unit price produces a higher total in this example because the additional standing charge outweighs the energy saving.

Keep every figure on the same VAT basis and include all other applicable charges when making a real comparison. If one quote includes tax and another excludes it, the apparent difference is misleading. Check whether a standing charge is daily or annual before entering it in your calculation.

The comparison can change with consumption. At 6,000kWh, the same invented A and B figures give €2,100 and €2,080 respectively. Neither plan is universally cheaper; the break-even point here is 5,000kWh because a two-cent saving must recover a €100 standing-charge difference.

Why can a percentage discount mislead?

A percentage needs a starting price. A larger discount from one supplier's standard rate need not beat a smaller discount from a different starting rate. Compare the resulting unit prices and total cost rather than ranking the percentages.

Check what the discount covers, how long it lasts and whether it depends on direct debit, electronic billing or another condition. A credit or cashback payment may have separate qualifying terms. Put each benefit into the period in which it actually applies.

For an illustrative twelve-month comparison, a €100 one-off credit reduces that first year's qualifying cost by €100. It does not reduce every future year's bill by the same amount. Record the normal price after the offer ends so the renewal decision does not come as a surprise.

Does having a smart meter mean I must choose a smart tariff?

A meter and a tariff are different things. The CRU's smart-meter guidance explains how smart services and time-of-use pricing work and directs customers to their consumption data. Check the conditions and future options before agreeing to change plan type.

A time-of-use tariff charges different rates at different times. Its value depends on how your actual usage falls into those periods. A low overnight rate is less useful if most electricity is consumed during a more expensive evening band and little can reasonably move.

Ask the supplier to identify the exact hours, rates and meter requirements of the proposed product. Do not assume every plan uses the same bands, and do not assume that a free period means the whole day or weekend is free of all charges.

How do I test a time-of-use offer?

Use a weighted calculation. Imagine 3,000kWh split into 1,800 daytime units at 30 cent, 600 peak units at 40 cent and 600 night units at 15 cent. The invented energy cost is €540 plus €240 plus €90: €870, before standing and other charges.

If 200kWh could realistically move from the 40-cent band to the 15-cent band, the energy saving would be €50. That is 200 multiplied by the 25-cent difference. It is not a promise that a household can move that amount, or that every appliance should be operated unattended.

Compare the full plan before and after the proposed shift. Consider convenience, safe appliance use and whether the habit is sustainable through the year. A plan that depends on changes nobody in the household can maintain may be cheaper only on paper.

Where can I find my actual smart-meter data?

ESB Networks explains its consumption downloads through the customer's online account. Available files include half-hourly data and daily summaries. Access depends on being the registered customer for the relevant meter, and data can have gaps or timing differences from supplier billing.

Pay attention to units. Kilowatts describe power; kilowatt-hours describe energy. A half-hour power figure cannot simply be treated as the same number of energy units. Use the file and interpretation appropriate to the comparison tool or calculation.

Keep the raw file and the period covered. A few mild weeks do not represent a full heating season. Where data are missing, identify the gap instead of presenting an incomplete comparison as an exact annual result. There is no need to share your meter number, account details or usage file with this publication.

What is different about a dynamic tariff?

The CRU's dynamic-price guidance describes half-hourly electricity prices linked to wholesale market rates, alongside standing charges. It says next-day prices are published in advance and advises customers to review usage and discuss suitability with their supplier.

That is different from a time-of-use plan with recurring fixed day, peak and night prices. Someone comparing dynamic offers needs to understand the pricing formula, applicable caps, other charges and how frequently they would need to respond to changing prices.

Do not compare a single cheap half-hour with a full year on another plan. A useful assessment must consider expensive periods too. If managing day-to-day changes would be impractical, include that constraint in the decision rather than treating flexibility as free.

What should I confirm before switching?

Ask for the full tariff schedule, contract term, discount expiry, early-exit fee, payment conditions and cancellation arrangements in writing. CRU guidance describes a cooling-off period and notes that some distance or off-premises contracts have an extended period; confirm which applies to the way you sign up.

Use the regulator's route to price-comparison information and compare against your own consumption. Ask your current supplier about alternatives as well. Check any vulnerable-customer arrangements through the official supplier process if relevant to your household.

Save the agreed terms and the opening and closing account records. After the switch, check the final old bill and first new bill for the correct plan and readings. The useful outcome is a plan whose total cost and conditions you understand, with a reminder to review it when the offer ends.