Like many industries, the energy industry has developed an language all of it's own. Brokers and suppliers talk about Duos Charges and Triads and avialabiity, but what to they actually mean?

We've put together what we think is the most complete glossary of energy terms on the net, if you can't find what you're looking for here give us a call and we'll see if we can help you.



In a buyer’s contract, take-or-pay is the obligation to pay for a specified amount of gas, whether this amount is taken or not. Depending on the contract terms. Under-takes or over-takes may be taken as make-up or carry-forward into the next contract period.  When it is credited into another contract period, this is called make-up gas.


The imperial unit of measurement for a quantity of gas, equivalent to 100,000 British thermal units.


Trade and Industry Committee.


The minimum price movement of a financial contract, expressed in fractions of a point.

Time value:

Part of the option premium that reflects the excess over the option’s intrinsic value, or the entire premium, if there is no intrinsic value. At given price levels, the option’s time value will decline until expiration.

Transmission network:

Electricity transmission system operating at voltages above 132kV (but including 132kV in Scotland).


Transmission Operator of an electricity transmission network. The TO is NGET in England and Wales. There are two TOs in Scotland, Scottish and Southern Energy and Scottish Power.

Tolling Agreement:

An agreement between a power buyer and a power generator, under which the buyer supplies the fuel and receives an amount of power generated based on an assumed heat rate at an agreed cost.


Third Party access. Where the owner of a pipeline or electricity network is obliged to transport gas, crude or electricity in a non-discriminatory way – ie, for any third party at the same rate as all other users. Third-party access can either be regulated by a separate agency or law, or negotiated between the incumbent and the new entrant. Also called open access and common carriage.


The gas system operator, part of NGET.


Terawatts – one million megawatts.


Terawatt hours.