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Electricity Tariff Calculator for Solar Battery Homes

Get A Battery Quote
1 · About your home
2 · Your usage
3 · Results

A few questions first

Five answers, then we price every published domestic plan against your actual usage. Nothing here is stored or sent anywhere.

Export earnings vary from 15.2c to 20c per kWh across suppliers, and on a solar home that credit can be worth more than the standing charge. It changes which plan wins.
A battery changes the shape of what you buy from the grid, which can change the cheapest plan entirely. No comparison site models this.
Usable, not nameplate — it's usually 90–95% of the headline figure.
Smart plans need one, and it's also what lets you download the half-hourly file that makes this accurate.
EV plans give you a cheap window in the small hours, paid for with dearer rates the rest of the day. Only worth it if you use the window.
Unit rates are identical. Only the standing charge differs, by anything up to €88 a year. It's printed on your bill, top right under the MPRN — DG1 is urban, DG2 rural.

Your usage

Upload your smart meter data

This is the accurate route. It prices your real half hours rather than an assumed load shape, and it's the only way to size a battery honestly.

Drop your HDF file here, or click to choose
The CSV from the ESB Networks customer portal, usually named HDF_….csv
Read in your browser. Never uploaded, never stored.
How do I get that file?
  1. Register at the ESB Networks customer portal with your MPRN — it's on your bill.
  2. Turn on half-hourly data collection if it isn't already on. Readings only start accumulating from that point, so it's worth doing well before you need them.
  3. Under your meter data, download the HDF as CSV.
  4. Drop it above. A full year gives the best answer; anything less than six months and the comparison isn't fair.

Enter your figures

We'll apply a load shape measured from a real Irish meter. Good for comparing plans; see the note at the bottom before trusting it for battery sizing.

This is what you paid for, not what your house consumed. If you have solar, the panels already covered part of your usage and you were never billed for it — so use the figure from your bill, not an estimate of everything you used. Most suppliers send an annual statement; otherwise add up twelve months. Getting this wrong scales every number on the results page in proportion, so it is the one figure worth digging out properly.
On your annual statement, or add up twelve months of bills.
An EV is usually the biggest single load in a house, and it moves the answer more than anything else because it is the one load you can deliberately shift into cheap hours. Annual kilometres divided by 5 is close enough for most cars — 15,000 km lands around 3,000 kWh. If you only charge at work or on public chargers, put 0.
Annual kilometres ÷ 5 is close enough for most EVs — 15,000 km is about 3,000 kWh.
Does it charge overnight on a timer?i
This decides whether an EV tariff can pay for itself. Those plans give you a very cheap two-to-four hour window in the small hours and charge more for everything else, all day, every day. If the car reliably charges inside that window the maths works. If it plugs in at six in the evening and starts immediately, you pay the premium and never collect the discount — the most common way people lose money on an EV tariff.
The most important input after the total. Two houses using identical amounts can pay hundreds apart depending purely on when. Night units cost roughly half day units on a day/night plan, and smart plans charge a premium between 17:00 and 19:00 in exchange for discounting the rest. If most of your electricity goes in during the evening peak, a flat 24-hour rate often beats a clever-looking smart tariff.
This decides whether a day/night or smart plan can beat a flat rate, so it's the number worth getting right.
Only day/night and smart meters split this out. Look for two lines on your bill with different unit rates, often labelled Day and Night or Standard and NightSaver, and copy the annual kWh from each. This is measured rather than assumed, so it beats every estimate on this page. A single figure on your bill means a 24-hour meter — use the typical pattern instead.
The night figure from the same two lines. Worth knowing: on a day/night meter the night window runs 23:00–08:00 in winter and midnight–09:00 in summer, shifting with the clocks. We treat it as 23:00–08:00 all year, which is what the smart plans use, so a day/night bill maps across closely but not exactly.
Straight off a day/night bill. Exact beats estimated. Night on those meters runs 23:00–08:00 in winter and 00:00–09:00 in summer; we treat it as 23:00–08:00.
The share of your total landing between 23:00 and 08:00. A house with nothing running overnight is around 20%. Storage heating, a heat pump on a night cycle, or an EV on a timer pushes it to 40–55%. This decides whether a day/night plan beats a flat one, so if you are guessing, guess low — overstating it makes night plans look better than they will turn out to be.
Two hours a day, but smart plans charge a heavy premium across them, often 20–40% above the day rate. Two hours in twenty-four is 8.3%, so perfectly flat usage sits there; most homes land between 9% and 15% because dinner, kettle and immersion cluster in that window. Above 15% and smart plans start losing to plain 24-hour rates.
Solar you generated but did not use, sold back to your supplier. It shows on your bill as CEG or microgeneration, usually as a credit. Suppliers pay between 15.2c and 20c per kWh and the gap between them is worth real money — on a big exporter the credit can exceed the standing charge. It is also why a battery changes which plan wins: storing solar means selling less of it, so the plans paying most for export have the most to lose from one.
Shown on your bill as CEG or microgeneration. If you don't have a figure yet, leave it at 0 — the comparison will simply ignore export earnings.

Send me the full breakdown

Every plan you qualify for, what each would cost you, and the battery figures — emailed to you and shown here.

Your half-hourly meter file stays in this browser and is never uploaded. Only the summary figures — annual import and export, band splits, and the plan comparison — are sent with your enquiry.

Adjust

Usable capacity, not the number on the box — manufacturers quote nominal and hold back 5–10% to protect cell life, so a 10 kWh battery is typically 9–9.5 kWh usable. The datasheet will say. Set it to 0 to see what you would pay with no battery; the difference between the two is the honest saving.
How fast the battery can take energy in or push it out, set by the inverter's battery-side rating rather than the cells. It becomes the binding constraint when the cheap window is short: three hours at 3.6 kW can only ever put in about 10.8 kWh, so a battery bigger than that cannot be filled from the grid overnight however large it is.
What survives a full charge and discharge cycle after inverter and cell losses. 88–92% is realistic for a modern hybrid system. It matters more than it looks: at 90%, grid charging only pays if the expensive rate is more than about 11% above the cheap one — which is why a battery earns nothing from arbitrage on a flat 24-hour tariff, no matter how big it is.
The PSO levy is a fixed government charge of about €19 a year that everyone pays regardless of supplier, so including it makes the bill honest but never changes the ranking. Welcome credits are one-off sweeteners for new customers, worth up to €200 — include them for your first-year cost, leave them out to see what you pay from year two. Most comparison tools quietly exclude both.

How this is worked out

Every half hour of your import is placed in the band the plan says it falls in, including plans that treat weekdays differently and plans whose peak window carves out of the day rate. Cost is rate × kWh per band. The supplier's discount comes off unit cost only, never the standing charge. Export is credited at the plan's own rate. Standing charge is pro-rated over the days your data covers.

Not included: exit fees, usage-band overage on some plans, the separate standing charge for night storage heating, and the fact that most discounts are introductory and revert after 12 months — a plan that wins year one may not win over three. Export credit is modelled uncapped; real arrangements can carry caps and conditions, and the first €400 of export income a year is exempt from income tax.

Known faults carried through from the published rate data: two Ecopower rural plans are tagged urban; Electric Ireland reuses plan Ids across different plans; Pinergy's prepay standing charges quietly include a €163.12 prepayment service charge, so they don't compare like-for-like.

Rates last checked: —. Confirm on the supplier's own page before switching.