Glossary

A

AGU

Autonomous Gas Units, storage systems (tanks) associated with isolated distribution networks or dedicated to large industrial clients, located in areas of the country where there is no natural gas transmission network and where the supply for the AGUs is carried out by tanker trucks.

B

Biomass

Vegetable or animal organic matter that can be used as a source of energy

BV

Block valve station

C

Caves

Facilities for underground storage of natural gas

Consumption

Energy consumption in a given period of time

Consumption in Pumping

Energy consumed pumping water from one reservoir to another in a given period of time

CTWD

Corrected for the effects of Temperature and number of Working Days

CTS

Custody transfer station

Conventional Market

Household and industrial consumers, excluding combined-cycle power plants

D

DNO

Distribution Network Operator

E

Electricity market

Combined-cycle power plants that use natural gas as fuel for electricity generation

G

Gas day

Period between 5 a.m. of a given day and 5 a.m. of the following day.

Gas pipelines

Pipeline system for natural gas transmission

GRMS

Gas Reduction and Measurement Stations are infrastructures belonging to the National Natural Gas Transmission Network (RNTGN) that ensure the physical interconnection between it and the distribution networks or final clients connected directly to the High Pressure Network

H

HP

High Pressure (relative to atmospheric pressure, higher than 20 bar)

HV

High Voltage (between 45 kV and 110 kV)

HP Clients

Clients supplied at High Pressure

Hydro Capability Factor

Ratio between the inflows to hydroelectric dams in a given period and the historical average inflows in the same period

I

ICJCT

Junction station with a single branch

Injection

Entry of natural gas into the underground storage

Interconnection

Transmission Network Element which crosses a border between neighbouring states to interconnect their respective networks

Importing Trade Balance

Difference between Imports and Exports, positive when importer and negative when exporter

J

JCT

Junction station

L

LNG

Liquefied Natural Gas – natural gas kept at a sufficiently low temperature to be liquid

Linepack

Amount of natural gas in the pipeline at a given moment

Losses

Difference between energy input and energy output for a given period

LNGT

LNG Terminal - Liquefied natural gas

M

MV

Medium Voltage (between 1 kV and 45 kV)

N

Natural Gas

A stable mixture of gases (hydrocarbons and inert gases) of fossil origin, of which methane is the main constituent (83% to 99%)

O

Own Consumption

Energy consumed in the transmission system’s auxiliary services

P

Pumping

Transfer of water from one reservoir to another at a higher level

Peak

Maximum power observed in a given period

Pumped Storage Generation

Generation from water previously pumped into reservoirs

R

Reservoir

Hydroelectric dam with storage capacity

Run-of-the-river

Hydroelectric dam with reduced storage capacity

Renewable

Generation from natural resources (water, wind, sun, waves, biomass, urban waste)

RNDGN

National Natural Gas Distribution Network

RNT

National Transmission Network

RNTGN

National Gas Transmission Network

RNTIAT

National LNG Transmission, Storage Infrastructure and Terminals Network

S

Storage

Quantity of gas stored in a given facility

Solar Capability Factor

Ratio between solar energy generation in a given period and the average historical generation in the same period

SNGN

National Natural Gas System

Solar

Generation of electricity from the Sun

T

Tanker

Cryogenic trucks used to supply Autonomous Gas Units

TSO

Transmission System Operator

U

Underground storage

A set of caves that enable storing natural gas in gaseous form

V

VHV Clients

Clients supplied at Very High Voltage

VHV

Very High Voltage (over 110 kV)

W

Wind power

Electricity produced from wind;

Withdrawal

Withdrawal of natural gas from the underground storage

Wind Capability Factor

Ratio between wind energy generation in a given period and the average historical generation in the same period