Electricity glossary
Plain-English definitions of terms that appear in Victorian electricity plans and on this site.
What is the AER?
The Australian Energy Regulator. The federal body that regulates energy markets in southern and eastern Australia, including Victoria. The AER publishes the Consumer Data Right (CDR) Product Reference Data that Nemity uses to retrieve plan rates.
What is the Consumer Data Right (CDR)?
A federal data-sharing framework that lets Australians access and share their own data with accredited tools. In energy, the CDR requires retailers to publish their plan rates (price, tariff structure, incentives) in a standardised format at a publicly accessible API. Nemity reads these APIs to get plan data.
What is a controlled load?
A circuit wired to a separate electricity channel (usually for a hot water system or pool pump) that the distributor can switch off during peak demand periods. Controlled load electricity is typically much cheaper than general usage. On smart meters, controlled load consumption is recorded on channel E2.
What is a demand tariff?
A tariff structure that charges based on your peak demand (the highest kilowatts drawn in a billing period), not just total energy consumed. Nemity leaves these out: no Victorian distributor assigns one to a household any more.
Who is my electricity distributor?
The company that owns the poles, wires, and meter at your address and physically delivers electricity to your home. Victoria has five distributors: CitiPower, Powercor, AusNet Services, Jemena, and United Energy. Your distributor is different from your retailer (who sends the bill). Meter data comes from your distributor's portal.
What is the ESC?
The Essential Services Commission. The Victorian state regulator for energy and other essential services. The ESC sets the Victorian Default Offer (VDO) annually.
What is a feed-in tariff?
The rate paid for electricity exported to the grid from rooftop solar panels. Feed-in tariffs are quoted in cents per kilowatt-hour. Some plans offer a flat rate regardless of time; others offer a higher rate during peak hours. Victoria had a minimum feed-in tariff set by the ESC until 30 June 2025; since then retailers set their own rate, and the only limit is that it cannot be below zero.
What is a gas network (gas distributor)?
The company that owns the gas pipes and meter at your address. Victoria has three: Australian Gas Networks, AusNet Gas, and Multinet. Like an electricity distributor, your gas network is set by your address and does not change when you switch retailer — but it does change the price, because network charges are a large part of a gas bill.
What is MDI in electricity?
A Maximum Demand Indicator is the part of a meter that records your highest sustained draw over the period — a rate of power in kilowatts (kW) or kVA, not an amount of energy in kilowatt-hours (kWh). It is an average over a short measured interval rather than an instant, so a brief surge when a motor starts does not set it, but running several large appliances together for half an hour can. Retailers bill a demand tariff on that peak, which is why it appears on a bill at all. Victoria's five distributors began closing residential demand tariffs on 1 July 2026.
What is a megajoule (MJ)?
The unit Victorian gas is sold in. It measures energy, the way a kilowatt-hour does for electricity — 1 kWh is about 3.6 MJ. Your gas bill shows the megajoules you used and a rate in cents per megajoule. A typical Victorian household uses far more gas in winter than summer, which is why Nemity asks for a summer figure and a winter figure rather than one annual number.
What is a MIRN?
The number that identifies your gas connection. It appears on your gas bill alongside the meter number, and your retailer or gas fitter uses it to identify your installation. Victoria, Queensland and South Australia use MIRNs; in New South Wales the equivalent is a DPI (Delivery Point Identifier). It is the gas counterpart of an electricity NMI. You do not need it to compare gas plans in Nemity — the summer and winter usage figures off your bill are enough.
What is a NEM12 file?
The standard Australian file format for electricity interval data. A NEM12 file contains your half-hourly usage readings, your NMI, and quality flags. Your distributor can provide a NEM12 file covering up to two years of usage. Nemity reads NEM12 files from all five Victorian distributors.
What is a NMI?
The 10-character code that identifies your electricity connection — not the meter hardware, but the point on the network where power is delivered to your address. It stays with the property when you move out or switch retailer. You will find yours on your electricity bill and in your distributor's portal, and you need it to register on that portal and download your meter data.
What is the 11th digit of a NMI (the checksum)?
A NMI is 10 characters, and some bills and portals print an 11th digit after it. That last digit is a checksum — always a number, worked out from the other ten so a mistyped NMI can be caught. AEMO's metering procedure treats it as an addition to the NMI rather than part of it, so a portal asking for "your NMI" usually wants the first 10 characters only. If a portal rejects what you typed, dropping or adding that final digit is the first thing to try.
What is off-peak electricity?
A time period with lower electricity rates on a time-of-use tariff. Off-peak periods are typically overnight and on weekends, when grid demand is lower. The exact hours vary by distributor and plan.
What is peak electricity?
A time period with higher electricity rates on a time-of-use tariff. Peak periods are typically weekday afternoons and evenings (around 3–9 pm), when grid demand is highest.
What does an electricity retailer do?
The company you have a contract with for electricity — the one that sends you a bill. Retailers buy electricity from the wholesale market and on-sell it to households. Examples include AGL, Origin, Simply Energy, and Tango Energy. Your retailer is different from your distributor (who owns the physical infrastructure).
What is shoulder electricity?
A time period with mid-range electricity rates on a time-of-use tariff, between peak and off-peak. Not all plans have a shoulder period.
What is a single-rate tariff?
An electricity tariff that charges the same rate for every kilowatt-hour, regardless of when you use it. Also called a flat-rate tariff.
What is solar export?
Electricity generated by rooftop solar panels that exceeds what your household uses and is sent back to the grid. On smart meters, solar export is recorded on channel B1. You receive a feed-in tariff credit for this energy.
What is a supply charge?
A fixed daily charge on your electricity bill, regardless of how much power you use. It covers the cost of maintaining the connection to your home. Also called a daily service charge or connection fee. Supply charges vary a lot between plans, and a plan with a low one usually charges more per kilowatt-hour to make up for it.
What is a time-of-use tariff?
An electricity tariff that charges different rates depending on when you use power — typically higher rates during peak hours and lower rates off-peak. A time-of-use plan can be cheaper than a single-rate plan if you use most of your electricity outside peak hours.
What is the Victorian Default Offer?
A regulated electricity price set by the Essential Services Commission (ESC) each year. It applies when a customer has not actively chosen a market offer and their retailer's standing offer price would otherwise apply. The VDO acts as a benchmark — if most market offers in Nemity's comparison are cheaper than the VDO for your usage pattern, that tells you something about the market.
See also: How Nemity calculates cost · About the Victorian Default Offer · Time-of-use vs single rate · Frequently asked questions