Energy buzzwords

Inertia. Synchronous generator. Dispatchable power. Frequency response. Get to know your energy buzzwords with our useful guide, which will help you talk about the complexities of the energy debate, including the role of renewable energy and storage in Australia’s energy mix, with ease. Collated by the Climate Council’s own energy experts.


All electricity grids need to balance electricity demand and supply, and cope with variability (to respond to demand changes during the day, week, and seasons). Power stations, like coal and nuclear (sometimes referred to as "baseload"), run continuously, producing a constant output of electricity. These power stations are very inflexible, and slow to respond to changes in electricity demand. These power stations are poorly suited to the needs of a modern, more flexible electricity grid. 

In a modern electricity grid, electricity demand and supply can be balanced through a mix of variable renewables (wind and solar PV), on-demand renewables (such as solar thermal, biomass or established hydro), energy storage (such as pumped hydro or batteries), energy efficiency and demand response.

Black System Event

When a region loses power due to a major power supply disruption, affecting a significant number of customers (a widespread blackout).


Measured in kW or MW, capacity is a measure of the maximum amount of power able to be generated by a given power generation plant.

Demand Response Management

Demand response management involves reducing consumer demand for energy by paying consumers to reduce their usage. Demand response management is useful for responding to short periods of very high electricity consumption to avoid electricity shortages.

Dispatchable Power

Dispatchable power refers to power stations (and other technologies) which are able to be turned on and off, or ramped up and down quickly to balance electricity supply and demand.

There is a wide range of technologies capable of providing dispatchable power including pumped hydro, solar thermal, batteries, certain types of gas power stations as well as demand response management.

Frequency Response

Frequency is a measure that enables operators to know if electricity supply and demand is in balance. Frequency response is a service which can be provided to re-balance electricity supply and demand. This service can be provided by a range of technologies including battery storage systems, and modern wind turbine and solar technology.


Generators convert one form of energy into another. Solar plants convert solar radiation from the sun into electricity while fossil fuel power stations burn coal and gas to convert it into electricity.


An energy company that both generates and sells electricity.

High Voltage

Any voltage higher than 1 kilovolt.


Inertia provides an initial, immediate response to keep the electricity system working when supply and demand are out of balance.

Power stations that generate electricity via large rotating steam or water turbines are sometimes called synchronous generators. These rotating steam and water turbines provide what is known as ‘physical inertia’.

Solar thermal, hydropower, and biomass power plants are synchronous generators capable of providing physical inertia. Renewable power plants (like wind and solar PV) and battery systems can be configured with appropriate software controls to provide similar grid stability services to physical inertia.


A high voltage transmission line, or group of power lines connecting different regions. Interconnectors transport electricity very long distances, connecting up the electricity grids of Australia’s eastern states. Interconnectors can increase the flexibility of the grid.


Demand for electricity by an individual, business or broader region.

Load shedding

Load shedding is when users of power are deliberately disconnected from the power system, or the amount of electricity they can use is reduced for a short period of time. This is usually experienced as localised, short-term power interruptions. Load shedding is designed to protect the overall electricity system when there is not enough power supply to meet demand.

National Electricity Market

The National Electricity Market, NEM, is not actually a “national” grid. The NEM refers to the interconnected power grids and operating systems connecting the eastern states of Australia (Queensland, New South Wales, Victoria and Tasmania) as well as South Australia and the Australian Capital Territory.

The Northern Territory and Western Australia are not part of the NEM. There are two separate interconnected systems in Western Australia (the South West Interconnected System (SWIS) and the North West Interconnected System (NWIS)) and 35 other smaller grids. The Northern Territory has three smaller separate electricity systems.

Image source: ElectraNet

National Electricity Objective

The National Electricity Objective (NEO) guides the operation of the NEM. The current NEO aims to: to promote efficient investment in, and efficient operation and use of, electricity services for the long term interests of consumers of electricity with respect to – price, quality, safety, reliability, and security of supply of electricity; and the reliability, safety and security of the national electricity system.

Operating Reserve

Operating reserve is planned spare electricity generation capacity that can be called upon when there are unexpected variations in electricity demand, or generation or transmission faults.


Reclassification ensures that the electricity system is operated more carefully during periods where extremes are likely to occur, such as severe weather conditions, lightning storms and bushfires.

Spot Price

The price for electricity within a given time period, usually a 30 minute period.

Synchronous Generator

Power plants, which generate electricity via large rotating steam or water turbines, are sometimes called synchronous generators. Coal and gas power stations are synchronous generators, but so too are solar thermal, hydropower, and biomass power plants.