Autonomous rate of energy-efficiency improvement, expressed as an annual percentage, often referring to the historical rate without special efficiency measures.

One of the three IEA sustainability criteria referring to the relative price of energy in terms of its consequent availability to users ranging from industries down to individual households.

These two terms are used interchangeably, to cover a broad range of fuels including wood waste, biogas, ethanol and plant oils.

The World Commission on Environment and Development chaired by Norwegian Prime Minister Gro Harlem Brundtland. The Commission's report, Our Common Future (1987), popularised the notion of sustainable development.

CO₂ capture and storage (strictly it includes possible ocean storage of CO₂ but otherwise synonymous with geo-sequestration or underground storage).

Carbon dioxide

Distributed generation usually refers to a combination of several small- to medium- scale generation sources feeding into the transmission grid.

Energy Efficiency and Conservation Authority

One of the three IEA sustainability criteria normally referring to minimising two types of environmental impact from energy supply and demand: localised impacts from air and water pollutants and global impacts from greenhouse gas (usually CO₂) emissions.

Gross Domestic Product (usually in the context of annual percentage growth).

Geological or underground storage of CO₂ effectively the same as CCS.

A gigajoule is a billion (1,000,000,000) joules approximately equivalent to the energy contained in a small car's full petrol tank.

Internal combustion engine.

Integrated Coal Gasification Combined Cycle.

International Energy Agency.

A kilovolt is 1000 volts.

A kilowatt-hour is the energy used by a device with a power rating of one kilowatt (kW).

This international agreement was established in 1997 as a means of setting binding emission reduction targets for greenhouse gases. It entered into force in 2005 meaning that New Zealand has agreed to return its net greenhouse gas emissions over the 2008-2012 commitment period to 1990 levels. It allows the opportunity for international initiatives to reduce emissions cost effectively through the use of its flexible mechanisms based on the trading of CO₂ equivalent emission allowances.

Liquefied natural gas.

Liquefied Petroleum Gas

Ministry of Economic Development.

A megawatt is a million watts and is the usual unit for describing the power capacity for electricity generating units. It is also used to describe the heat rating of industrial boilers.

"Not in my back yard", in reference to residents objecting to development in their locality.

Nitrogen oxides produced from combustion.

Organisation for Economic Cooperation and Development.

The issue of optionality relates to the dependence of scenarios on certain assumptions and how readily the scenario pathways can shift to meet changed circumstances.

A petajoule is 1015 (1,000,000,000,000,000) joules. The original Maui gas reserve was approximately 4000PJ.

Research, development and demonstration.

Resource Management Act.

One of the three IEA sustainability criteria referring to the relative risk of being able to supply different forms of energy. In terms of most fuels, it usually refers to the continuity of supply at a certain price. For electricity, there is the added issue of transmission management ensuring continuity of supply from hour to hour at a quality level that will not disrupt usage in industries or households.

Sulphur oxides produced from combustion.

Invested capital (or that part of invested capital) that has not been depreciated but which has no future earning potential.

THE New Zealand Business Council for Sustainable Development (The Business Council).

World Business Council for Sustainable Development.