Natural gas
A fossil fuel consisting of, among other things,
hydrocarbons (C and H), carbon dioxide (CO2) and nitrogen (N2).
APX - Amsterdam Power Exchange
The Amsterdam Power Exchange (APX) is a virtual electricity market. Electricity consumers, distributors, producers and traders carry out deals on the APX spot market. The APX plays an important role in solving the problem of limited import capacity for electricity at the Dutch border. The APX is mainly used for reciprocal trade in power between energy companies and for supplying a control current to compensate for imbalances. The APX index is a standard index for the electricity spot market.
Calorific value
The calorific value indicates how much heat is released during complete combustion of gas and is important for the smooth functioning of gas-powered appliances. In the Netherlands, standard m³ G-gas is used with a calorific value of 35.17 MJ / m³.
Conversion factors
- 1 MMBTU = 1 million British Thermal Units
- 1 MMBTU = 292.7 kWh = 1.055 GJ = 30.0 m³ gas (n; 35.17)
- 1 kWh = 0.0036 GJ = 0.0034 MMBTU = 0.103 m³ natural gas (n; 35.17)
Commercial flexibility
The demand for flexibility, which applies to shippers and arises when individual shippers have to balance their individual portfolios.
Daily flexibility
The extent to which the permitted difference between input and offtake can be increased for a network user for a maximum duration of one day, by contracting daily flexibility.
Entry point
A point where transmission capacity can be contracted or traded in order to input natural gas into the national network. Entry points can be divided into domestic production points (43), border points (17), underground storage points (7) and TTF points (4).
Exit point
The point where transmission capacity can be contracted or traded in order to withdraw natural gas from the national network. Exit points can be divided into industrial points (420), local distribution points, pseudo-GOSs, (682), border points (22), underground storage points (7) and TTF points (4).
Flexibility service
The service that enables a network user (shipper) to balance his input and offtake of gas, if there should be a discrepancy between the volumes of gas introduced and withdrawn from the system.
G-gas / Groningen gas
Natural gas from the Groningen Slochteren field consists of 81% methane,
3.6% of higher gaseous hydrocarbons and 0.4% of H2S
(hydrogen sulphide) and the remainder is nitrogen and carbon dioxide. Groningen natural gas
supplies an average amount of energy of 35.17 MJ / m³ when it burns. This is the equivalent of 9.8
kWh of energy.
GOS
Gas receiving station. These are local stations where the gas is
transferred from the main network or regional network to town or factory networks.
A town has several 'GOSs'.
Degree day
Every degree that the average daily temperature lies below 18 ° C less the average daily temperature measured at de Bilt.
H-gas / High-calorific gas
Gas that consists almost exclusively of hydrocarbons.
L-gas / Low-calorific gas
Gas containing considerable volumes (up to 25%) of nitrogen and/or carbon dioxide in addition to hydrocarbons. The natural gas from the Slochteren field is L-gas.
LNG / Liquified Natural Gas
Liquefied natural gas. At normal pressure, natural gas is liquid at temperatures of around -162 ° C. LNG is widely used when transporting natural gas by sea in LNG tankers. The volume of LNG is approximately 600 times smaller than the gas at normal temperature and pressure. This volume reduction makes it cheaper to transport the gas if there is no pipeline available, generally where transport is by LNG carriers.
NBP - National Balancing Point
The virtual market place in the UK on Gas Transport Services' gas transmission network where the position of a network user is determined and gas can be
traded. The National Balancing Point is achieved by the input of gas at an entry point and the off-take of gas at an exit point.
Nomination
Notification given by a producer or supplier of the volume of gas to which he is committing himself for a period applicable in the future.
Shipper
A natural or legal person who uses the transport services of the national network operator for transporting natural gas. Gas Transport Services (GTS), in Groningen, is the Transmission System Operator in the Netherlands.
Swing in production
The capacity of a producer to vary the volume of natural gas in the interests of a constant level of production.
TTF - Title Transfer Facility
A Dutch trading hub where both Dutch and foreign parties can buy and sell natural gas. Gas may be transferred to another network user prior to the start of the shipment. The seller of the gas creates a virtual exit point, the buyer of gas creates a virtual entry point. This is why the TTF is known as a virtual trading hub.
Transport capacity
The volume of gas that can be transported per unit of time, at an entry point or an exit point,
or between a combination of entry points and exit points, measured in normal cubic meters per hour.
Volume balance
The sum of the balances to one hour in a given contract year
(in m³). The volume balance is determined for each hour during the contract year.
The volume balance can be positive or negative.
Working volume
The difference between the highest value of the volume balance and the lowest value of the volume balance in any hour during the relevant contract year (in m³). The working volume is determined on expiry of the contract year.
CHP
CHP stands for combined heat and power. This is the cogeneration of electricity (power) and heat. The heat generated by CHP is generally of a high temperature (steam, hot water) and consequently can be used for other purposes (process heat in industry, space heating, district heating). A high level of efficiency is achieved through combined generation in CHP plants.
Wobbe index
A measure for the combustion behaviour of gas in an appliance, taking the following Wobbe bands as a guideline:
- H-gas: 48 to 56 MJ / m³
- G-Gas: 43.5 to 44.4 MJ / m³
- L-gas: 42.5 to 47 MJ / m³