Before you begin
What decides whether a smart tariff pays you
Your own two figures come off a recent bill; the smart plan's four come off that plan's price list. Verdanyx keeps no tariff list, so the comparison is exactly as current as what you read.
Put every rate on the same basis — including VAT, after any discount you actually receive. A VAT-inclusive rate against a VAT-exclusive one is the one mistake that reliably reverses the answer.
If a smart meter has been in the house a few months, take the three yearly totals from myaccount.esbnetworks.ie. They are printed in kWh, which is what this asks for, and they replace every assumption below them.
Tick a flexible load only if it would genuinely move, and only if it does not already run overnight.
Reading the answer
Reading the day, night and peak split
The bands are set by ESB Networks, not by suppliers, so the windows are the same on every smart plan. Only the prices in them differ.
Without your own figures the comparison starts from the CRU's Standard Smart Tariff load profile — 52% day, 39% night, 9% peak — which is the profile a supplier's own Estimated Annual Bill is calculated on. It is a national average, and it includes homes with storage heating running overnight, so a house with busy evenings sits below 39% and the smart plan does worse than the estimate suggests.
The night share is the whole decision, and the break-even is the figure to argue with: if you cannot say whether the profile fits your house, you can usually still say whether you are above or below a stated percentage.
Boundaries
Assumptions and limitations
Working assumptions
- Without your own figures, the year starts split the way the CRU's reference profile splits it rather than the way Verdanyx would guess.
- A flexible load runs today across the bands in the same proportion as the rest of the house, so only the share of it not already at night can move, and only as far as the day and peak bands reach.
- Each flexible load carries the annual energy the Verdanyx appliance calculator maintains for the same appliance.
- Both plans are compared on unit rates and standing charges only, over one year.
Where to be careful
- It does not know any supplier's prices, and it compares one smart plan with one standard plan rather than ranking the market.
- Two homes on the same annual total can sit either side of the verdict, which is why the recorded-year route exists and the break-even is published.
- Introductory discounts, cashback, contract length and exit fees are not modelled, and any of them can outweigh a unit-rate result.
- Storage heating is not offered as a flexible load, and solar export, microgeneration and battery arbitrage are not included; the battery and solar tools cover those.
Worked example
The same question, answered end to end
A household that read its three yearly band totals off its ESB Networks account, then asked what would change if the dishwasher and dryer ran overnight.
What was entered
- Recorded year: 1,200 kWh night, 2,400 kWh day, 600 kWh peak.
- The dishwasher and tumble dryer would move; nothing else.
- Standard rate 38c/kWh; smart plan 41c day, 19c night, 48c peak, all including VAT.
- The same €251 standing charge on both plans.
How it is worked out
The three totals are the year: 4,200 kWh, of which 29% is already at night. No profile is applied on top of them.
Dishwasher 286 + tumble dryer 390 = 676 kWh a year between them.
Only the part not already at night can move. Day and peak are 3,000 kWh of the 4,200, so 676 × (3,000 ÷ 4,200) = 483 kWh moves.
That 483 kWh leaves day and peak in proportion — 386 kWh and 97 kWh — and joins the night band.
The year becomes 1,683 kWh night, 2,014 kWh day, 503 kWh peak: 40% at night.
Smart units: (1,683 × 19 + 2,014 × 41 + 503 × 48) ÷ 100 = €1,387, plus €251 standing = €1,638.
Standard: 4,200 × 38 ÷ 100 = €1,596, plus €251 standing = €1,847.
The smart plan is €209 a year cheaper. Without moving anything it was €96, which is the difference the two appliances make.
What the tool returns
- Cost on your standard rate
- €1,847/year
- Cost on the smart plan
- €1,638/year
- Smart plan versus your standard rate
- €209/year cheaper
- Share of your use in the night band
- 40%
Common questions
Questions about this tool
Are the time bands the same on every supplier's smart plan?
Yes. ESB Networks configures the meter, so night is 11pm to 8am, peak is 5pm to 7pm and day is everything else, whoever you buy from. What differs between plans is the price in each band and the standing charge.
Where does the night share come from if I have not given my own?
From the CRU's Standard Smart Tariff load profile: 52% day, 39% night, 9% peak. It is an average, and the CRU says a bill built on it does not reflect a household changing its behaviour, so a house with busy evenings and quiet nights uses less than 39% at night and a smart plan pays it less well. That is why the tool asks first whether you have your own figures.
Where do I find my real day, night and peak totals?
Register at myaccount.esbnetworks.ie with the MPRN from your bill and a mobile number. The account shows the breakdown your meter has already recorded, in kWh, with up to two years of history to download. You do not need to be on a smart plan for the meter to have recorded it.
How is this different from the Estimated Annual Bill a supplier shows me?
It starts from the same CRU profile, so the two agree when you change nothing. The difference is that this one lets you depart from that profile — by entering the totals your own meter recorded, or by saying which loads you would move after 11pm — which is the assumption the CRU itself names as the limit of the Estimated Annual Bill.
Why does the tool not just tell me the cheapest plan?
That would mean Verdanyx maintaining every Irish supplier's tariff card, and a stale rate would quietly decide your answer. You enter the plan in front of you instead, so the comparison is exactly as current as the price list you read it from.
Is a higher night share always better?
Only against the plan you entered. A large night share on a plan whose day and peak rates are far above your standard rate can still lose, which is what the break-even night share in the result is for.