There are many words and expressions in the energy sector. Here, Skagerak Energi will provide you with an explanation of some the most common expressions.
ExpressionExplanationAbbreviation
Ampere (electrical power)Unit of measurement for electrical power. Electrical power is measured in ampere (A, often shortened to ‘amps’), which is a measure of the amount of electricity that flows through the cables. (This can be compared to the amount of water flowing through the garden hose)A
Generating unitA device used to produce electrical energy comprising an electric generator and a turbine.
Wave power plantA power plant operated by wave energy.
DamA structure that dams up water in a reservoir and makes it possible to regulate the water flow in a watercourse. The root is the base of a dam and the crest is the top.
Operating centreCentre for monitoring and control of transmission facilities and for monitoring, control and coordination of power plants.
Distribution networkCommon term for local distribution network and main distribution network.
Run-of-the-river (ROR) power plantPower plant developed in a river where the water flow cannot be regulated to any degree by means of a reservoir connected to the plant.
Distribution transformerAn electrical transformer that provides the final voltage transformation to bring energy to the consumer (230 volts or 400 volts).
Gas Power PlantHeat power plant using gas as fuel.
GeneratorRotating machine that transforms mechanical energy into electrical energy.
GigawattGW= gigawatt (1,000,000 kW)GW
Gigawatt-hourGWh = gigawatt-hour (1 mill. kWh - one million kilowatt-hour)GWh
HorsepowerA unit of power (hp). One horsepower is equivalent to 0.736 kW.HP
Main distribution networkElectrical cable network with voltage level 66-132 kV, which connects the local distribution network (see this) and acts as a main network (see this) within each particular part of the country. The main distribution network is the connector between the nationwide main network and the local distribution networks.
HydrologyThe science of the occurrence, cycles and distribution of water on earth. In a broader sense, hydrology also includes the physical and chemical properties of water.
High voltageElectrical energy with a voltage higher than 1,000 V alternating current and 1,500 V direct current (in Norway).
Intake reservoirThe reservoir from which water is conveyed down to the power plant.
JouleJoule 1 J = 1 watt-second, i.e. 1kWh is equivalent to 3.6 million J. Internationally recommended and adopted as Norwegian Standard (NS 1024). Common unit for energy in the form of thermal energy, mechanical energy and electrical energy. kWH, MWH etc. are still used for electrical energy.J
Underground cableElectrical power cable for burying underground.
Earth currentElectrical power that flows in the ground.
Power lineElectrical power lines above ground including foundations, masts, lines, isolators, earth lines etc. The terms power line and overhead power line are also used interchangeably.
Power companyA company that produces electrical energy and/or carries out wholesale distribution.
Power stationBuildings and installations for the production of electrical power.
Co-generation plantCo-generation plant producing both electrical energy and heat (in the form of steam or hot water) for instance for heating of houses. A co-generation plant is usually the same thing as a combined heat and power (CHP) plant.
Power plantFacility for production of electrical energy. A power plant may consist of several power stations, reservoirs and tunnel systems
KilowattKilowatt (1,000 watt) (output).KW
Kilowatt-hourA kilowatt-hour is the amount of energy a 1,000-watt heater uses when it is switched on for one hour.kWh
Low voltageElectrical voltage of up to 1,000 volts for alternating current or 1,500 volts for direct current (in Norway). May vary from country to country. See also high voltage and medium voltage.
Direct currentElectricity in which the current flows continuously in a single direction, as opposed to alternating current.
Local distribution networkElectrical cable network that transfers energy from the distribution network (see this) to each subscriber. The voltage level in this network varies from 230 V at the lowest setting to 22 kV at the highest. Most subscribers are connected to the network at the 230 V level, while large consumers are supplied at a higher voltage level.
ReservoirNatural or artificial lake, in which water is collected during periods of high inflow and low consumption. When consumption is high, the reservoir water is utilised.
MegawattMegawatt (1,000 kW). One megawatt is 1,000 kilowatts.MW
Megawatt-hourMegawatt-hour (1,000 kWh)MWh
OhmUnit of measurement for electrical resistance
TransformerA machine that transforms electrical energy of one nature into electrical energy of another nature, e.g. alternating current at 50 Hz to 162/3 Hz (railway transformer) or alternating current into direct current.
Pumped storage power plantPower plants used either for power production or to pump water up into the intake reservoir for later use.
Regional gridSe main distribution network.
Central gridNationwide transmission network with a voltage equal to or higher than 220kV.
Sea cableA power line in or on the seabed.
Solar cellA device that produces power from the sun’s rays.
Waste heatHeat energy that has not been used and which is emitted to the surroundings e.g. in industry, heat power plants etc.
Supply cableCable from distribution network to homes.
Live electric lineThe part of the power line conducting electrical power. Usually an aluminium line with a steel core or a copper line.
TransformerA device that transforms electrical alternating current of one voltage to alternating current of a different voltage.
Transformer kioskA network station where all electrical equipment is placed enclosed in a weather-proof and protective construction.
Transmission networkSee central grid
TurbineThe turbine is part of the generating unit. It is a circular disc with spoon-shaped buckets mounted on it, and is fastened to a rotating shaft. Water turbines cause magnets inside a generator to rotate and create electricity. Turbines installed in heat power plants run on the same principle, but use steam rather than water to spin the turbine.
TerrawattTW = terrawatt (1,000,000,000 kW)TW
Terrawatt-hourOne terrawatt-hour is one billion kilowatt-hours.TWh
Drought yearA year with less precipitation than normal.
VoltVoltage between two points in a power circuit. Can be described as electrical ‘pressure’ (This can be compared to water pressure in a garden hose).V
Hydroelectric power plantA power plant that transforms the potential energy of water into electrical energy. In the broadest sense, this also includes tidal power stations.
Energy conversion efficiencyThe ratio between the amount of energy output from a power plant in the form of electrical power and the amount of energy that is produced e.g. in the form of heat in a heat power plant. In a gas power plant, this ratio can reach around 50 per cent. In other words, of the heat that is generated, half is transformed to electricity while the other half is transferred out of the power plant along with the cooling water. The energy conversion efficiency in a hydroelectric power plant can be over 90 per cent, meaning that more than 90 per cent of the water’s potential energy is converted to electrical energy.
Wind turbineA device used to produce electrical power from wind energy.
WattUnit of measurement for electrical output. A watt is the output produced in a conductor conducting electrical power equal to 1 ampere, in which the voltage drop over the conductor is 1 volt.
Watt peakIndicates the maximum output of a solar cellwp