Electricity Terms Explained: Gas and Electric Glossary 2024

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Having a hard time understanding your bill, or can’t quite get what your energy supplier is talking about in the latest letter you received? We’ve tracked down everything and anything gas and electricity-related for you to use as a handy reference.


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If you’re looking for advice specific to your energy bills, check out our guide to understanding utility bills.


Amp is short for ampere, which is a unit of electric current. It is used to measure electricity much like litres for water. Amp is normally used when talking about the strength of an electrical current.


Biogas is a type of gas produced by fermenting organic material. It is not yet widely available in Ireland, although it appears that Panda Power (as part of the Beauparc group) does source some biogas from a Beauparc project.


A fuel-burning device used to heat water which can then be used for heating and/or hot water purposes. Boilers can run off electricity, gas, solid fuels, or oil. Boilers typically require boiler services every year.

Carbon Tax

The carbon tax in Ireland is a tax on the use of fossil fuels. This includes coal, diesel, natural gas, oil, peat and petrol, anything that emits carbon dioxide when combusted. The carbon tax for 2023 is currently set at  €0.008080 per kWh of gas. This is reflected in a charge of about €88.88 per year, added to your gas bill by your supplier.

Collective Switch

A collective switch is where a group of people band together to negotiate and ask suppliers for tenders and through collective bargaining, perhaps obtain a better deal. In Ireland, One Big Switch normally organises collective switches. It is free to sign up for and carries no obligation to accept any offers.

Credit Meter

A credit meter is the standard meter usually used in most households. With a credit meter, you use electricity and/or gas “on credit” and are then issued a monthly or bimonthly bill to pay for the amount used.


The CRU is the Commission for Regulation of Utilities, formally known as CER, is the organisation tasked with monitoring the activities of energy providers in Ireland and setting guidelines. They also act as an ombudsman and can intervene on customers’ behalf if they are unable to resolve issues with their suppliers.

Cubic Foot

The volume of a cube where all sides measure one foot, this measurement is commonly used to show how much gas has been used by your household, before calculating the usage in kWh.


DG1 describes a type of DUoS, with DG1 indicating that a customer has been classified as being in an urban standing charge area.


DG2 then indicates that customers’ residences have been labelled rural, for standing charge purposes.

Direct Debit

A Direct Debit is an agreement made between a customer and a bank to allow a third party to transfer money from the customer’s account, usually to pay recurring items such as bills.


A discount is usually a deduction from the normal price of something. When you hear “discount” when energy suppliers refer to their tariffs, e.g. 8% discount off electricity and gas for new customers, this discount is always applied to the unit rate of gas and/or electricity. You do not receive a discount on your entire bill.

Distribution Network

A distribution network is generally a network of transmission lines or piping (depending on whether it is for electricity or gas) which transmits electricity or gas from the transmission network to people’s homes.


A DNO, or Distribution Network Operator, is the organisation tasked with the maintenance and distribution of a distribution network. In Ireland, Gas Networks Ireland is the DNO for the gas network, and ESB Networks is the DNO of the electricity network.

Dual Fuel

A term commonly used to refer to customer accounts that are signed up for both gas and electricity.

💸 Cheapest Duel Fuel Offer per Supplier


Best Offer

Price per year

Flogas Logo Contact Details

22% on Electricity and Gas


SSE Airtricity Contact Details

No Discount


Electric Ireland Contact Details

28% on Electricity and Gas


Energia Logo Contact Details

Subscribe Now for 29% off Dual Fuel

(01) 913 1771 📞


Bord Gais Logo Contact Details

24% on Electricity, 20% on Gas


Electric Ireland Contact Details

No Discount


*Figures are for illustrative purposes only. All discounts and cashback have been applied to the price. Calculations based on average consumption figures for an urban home with a 24-hour standard meter.
Last updated: July 2024


Distribution Use of System (DUoS), normally implies a charge for use of the distribution system (the grid), reflected in the standing charges that most customers pay.


EAC stands for Estimated Annual Consumption and is normally used to refer to the quantity of gas and/or electricity consumed by your household every year. It can be useful to know your EAC to calculate the savings you could make by switching energy providers.

Estimated Bill

If for some reason, ESB Networks or Gas Networks Ireland technicians cannot access your meter to read it (if you are absent, for example), they will then issue an estimated reading which will then be used to estimate your bill. You should never accept a bill based on an estimated reading and should always keep your billing current by submitting your meter readings should you receive an estimated one.

Exit Fee

This is the fee that is normally charged if you should exit your contract with an energy supplier early. Most contracts last 12 months in Ireland, and on average, the exit fee is around €50. We don’t recommend switching unless you can recover the difference, and do be sure to read the fine print regarding this fee. Note that you cannot be charged an exit fee for cancelling a contract within the first 14 days (also known as the “cooling off” period).


Before 2016, FIT or REFIT (Feed-in-Tariff or Renewable Energy Feed-In Tariff))meant that if you had solar panels or similar renewable energy devices, and surplus energy produced, then you could “feed” your electricity back into the grid and get paid for it. However, since 2016 there has been no support scheme in place, although a new one is due to be announced in 2019.

Fixed Price Plan

Rare in Ireland, currently only offered by the energy provider Just Energy (who are closing down their Irish operations), a fixed price plan means that you agree to pay a set price for your electricity and the price of your gas for an agreed term. If energy prices increase, you won’t take a hit, however, if they decrease you also won’t benefit.

Fuel Allowance

The fuel allowance, also known as the winter fuel allowance, is a government aid for citizens who might otherwise suffer disproportionately during the winter months with heating costs.

Fuel Mix

A supplier’s fuel mix refers to the ratio of fuels and energy sources the supplier uses to generate electricity. Usually, most fuel mixes are composed of different amounts of coal, gas, nuclear, renewables and “Other”. We have included information on each supplier’s fuel mix on our energy provider pages.


GPRN stands for Gas Point Reference Number. The number indicates the location of where your house connects to the gas network. As such, it is not a customer-dependent number and will change if you should move house.

Green Energy

Green energy is often used interchangeably with renewable energy. Green energy can be characterised as energy produced from natural sources such as sunlight, wind, tides and rain.


The grid is an informal term for the physical infrastructure of an energy network in Ireland. It can be used for both the electricity network and the gas one, although it’s most commonly used for electricity.

High User

A “high” energy user is classified as someone who uses over 5400 kWh of electricity per year and/or over 13700 kWh of gas. High energy users in the residential energy sector are normally large family households.


A kilowatt-hour (kWh) is the unit of measurement most often used to describe and compare electricity and gas usage in Ireland and calculate bills. If considering switching and examining tariffs, the unit rate will be charged per kWh, for example.

Low User

A low energy user is defined as a customer who uses less than 2900 kWhs and/or 6900 kWh of electricity and gas respectively per calendar year. As energy providers can not make any significant profit margin on such low volumes of energy, it can end up costing them money to supply energy to such customers.

Ergo, anyone categorised as a “low energy user” will have to pay a higher standing charge. The higher standing charge for low energy users tends to add between €5 - €6 to each bill. Note that customers who receive the free electricity allowance (part of the household benefits package) will not have the extra charge applied to them.


MCC, sometimes spelt MC, stands for Meter Configuration Code. This code indicates the type of meter you have at your premises. The codes typically run from 1 to 11 and 50 to 79 for residential premises, e.g.:

MCC01 (24-hour credit meter)

MCC02 Day and night meter

Meter reading

Meter reading can refer to two things - one, the physical act of checking the numbers on your meter (usually carried out by a technician, however, you can also do it yourself), and two, the numbers obtained by checking a meter.


A Meter Serial Number (MSN) refers to a unique number which can be used to identify a particular meter.


A Meter Point Reference Number (MPRN) refers to the point at which your property connects to the electrical distribution network.


Nightsaver is both a tariff and a meter. Having a separate Nightsaver meter installed will allow you to take advantage of cheaper nighttime electricity with a Nightsaver tariff.


PAYG stands for Pay As You Go, also known as prepaid or prepayment, and refers to a system of paying for energy up front instead of later as with credit meters. A PAYG meter must be installed if customers wish to use PAYG. Some individuals prefer PAYG as they feel better able to control their energy budget, and in other cases, PAYG meters are used to help with debt repayment.

PSO Levy

The PSO Levy, or Public Service Obligation Levy, is a charge added to all electricity bills in Ireland to subsidise the research, development, and maintenance necessary to support renewable and indigenous energy generation in Ireland. For 2023/24 it is set at €0 per year (including VAT) and is currently being added as credit to your gas and electricity bills to ease the cost of living crisis.

Smart Meter

A smart meter is a fairly new type of meter that can communicate with an IHD (In-Home Device) or display, and with suppliers directly. This means that customers with smart meters never need to submit meter readings again or receive estimated readings, and can monitor their consumption closely.

Standard Tariff

A standard tariff is an energy tariff without a discount and is the most expensive energy tariff to be on. If customers do not switch energy providers when their contract ends, usually after 12 months, or renegotiate a new contract with their supplier, then they will automatically roll on to the standard tariff.

Standing Charge

A standing charge is the amount of money customers pay to be connected to a gas or electricity distribution network. Standing charges usually cover maintenance costs and upgrading the networks. Prices for standing charges can vary from supplier to supplier.

Storage Heater

A storage heater is a special type of heater, usually filled with ceramic bricks, that can be heated up at night when electricity rates are cheaper, and release its “stored” heat during the day. Storage heaters require a separate Nightsaver meter to be cost-effective.

Unit Rate

This is the cost per unit of electricity or gas on your bill. The rest of your bill is then made up of taxes and levies.

Variable Price Plan

The majority of Irish energy providers offer this plan. A variable price plan simply means that the unit price of electricity and/or gas is subject to change, and can increase or decrease along with market fluctuations.


Most of us know that VAT stands for Value Added Tax, but did you know that VAT on energy and all other related charges is set at 13.5%?


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