Get an explanation of the most commonly used words and terms in the electricity and energy fields.
Air-to air heat pump
See heat pump.
A-rated circulator pump
An energy saving circulator pump is a central heating pump which is energy A-rated. The pump has good efficiency and increases and decreases its output in response to the radiators as they are turned up or down. This saves electricity used by the pump.
The energy label for pumps is the result of a partnership between European pump producers; the label is based on the EU Energy Labelling Directive.
A-rated energy saving bulb
An A-rated bulb is an energy saving bulb shaped like a mini fluorescent tube. A-rated energy saving bulbs recommended by the Trust are energy efficient and comply with a number of other quality requirements; colour rendering, for instance, and quality of light. A-rated bulbs use only about a quarter as much power as an incandescent bulb. They last 6,000-15,000 hours.
AutoPowerOff plug bank
When you switch off the computer or TV, an AutoPowerOff plug bank automatically switches off any connected devices, such as a monitor, printer, modem, loudspeakers, scanners, DVD, VCR, set-top box, etc.
Biofuel/biomass is a general term for organic material, such as straw, wood chips and wood pellets, which can be used as fuel. Biofuel is classified as CO2-neutral because, while growing, it absorbs as much CO2 from the atmosphere as is released when combusted.
See A-rated circulator pump.
The primary greenhouse gas which plays a key role in both the natural and man-made creation of the greenhouse effect. Plants absorb carbon dioxide as they metabolise, whereas humans and animals give off CO2. Moreover, man-made CO2 is produced by burning fossil fuels.
CO2-neutral means that no more CO2 is emitted during combustion than the same organic material absorbed during its formation. In other words, the same amount of CO2 is emitted during combustion as would be in the natural decomposition of the material.
If your electricity supply company offers you ‘CO2-neutral power’ this does not automatically mean that there will be no CO2 emissions in connection with the power production. If you want to be CO2-neutral you must ensure that the supply company destroys CO2 quotas equivalent to the amount of power you use, and that they continually increase the proportion of power produced by renewable energy sources.
The individual electricity producers are granted annual permits to discharge a certain amount of CO2. If their quotas run out, or if they have an excess capacity, they can buy and sell these quotas.
Older monitors with CRT (Cathode Ray Tube) technology.
Direct current (DC)
Current where the electrons always flow in the same direction (as opposed to alternating current where the electrons constantly change direction). Batteries produce DC which is an abbreviation for direct current.
District heating substation
District heating substations transfer the heat from the district heating supply pipe to the central heating system in the house – with or without the help of a circulator pump. These substations are most commonly installed in the utility room.
There are 3 types of substation:
- Direct connection without mixing loop: The central heating system is connected directly to the district heating supply pipe. The district heating company’s own pumps circulate the water through the central heating system in the house. Consequently, no circulator pump is required.
- Direct connection with mixing loop: The central heating system is connected directly to the district heating supply pipe, and a circulator pump distributes the hot water round the house.
- Indirect connection through heat exchanger: The central heating system is totally separated from the district heating system. A heat exchanger transfers the heat from the district heating hot water to the central heating system.
Electricity is a vital form of energy. But electricity production in Denmark costs more than twice as much in fuel terms compared with other energy forms, and the CO2 contribution is thus also twice as large.
Energy = power multiplied by the time used (in hours)
1 kWh = 1 kilowatt hour = 1,000 watts per hour
1 MWh = 1 megawatt hour = 1,000 kWh
1 GWh = 1 gigawatt hour = 1.000.000 kWh
1 TWh = 1 terawatt hour = 1,000,000 MWh
Energy Labelling Scheme for buildings
All buildings that are for sale must allocate an energy label. The Energy Labelling Scheme for buildings replaces the previous ELO and EM energy labelling schemes. The aim is to reduce buildings’ energy consumption through heating, ventilation, cooling, lighting and hot water, etc.
All public sector and commercial buildings (not industrial) must be energy labelled when they are sold or rented. Moreover, all public sector and commercial buildings over 1,000 m2 must be energy labelled every 5 years. Read more at www.femsek.dk (only in Danish) and http://www.workindk.dk/Energimaerke.
Energy Saving Label
The Trust’s Energy Saving Label makes it easy to choose energy efficient products. Producers, suppliers and stores can mark their products with the Energy Saving Label when they conform to the Trust’s requirements for the products.
The label is typically awarded to the 20% most energy efficient products in a product category, but for some products there are also further quality requirements. The requirements are based on international energy labelling schemes or on the result of a partnership between the Trust and trade organisations.
Energy Star is a voluntary energy labelling scheme which is administered by the United Sates Environmental Protection Agency (EPA). The scheme is used throughout most of the world and on an extensive range of products. The label is used for IT and computer equipment in the EU and the EU Commission is responsible for the administration of the scheme.
The label can be used on the most energy friendly IT and computer equipment such as computers, computer monitors, printers and copiers.
Energy Star equipment has a low energy consumption whether the product is in use, on standby or when switched off.
To qualify for the Energy Star label, equipment must automatically switch to a low power state or switch off completely when it is not in use. The requirements for IT and computer equipment in the Trust’s 2011 Purchasing Guidelines are equivalent to those of the Energy Star specifications.
EU Energy Labelling Scheme (A-G)
The EU energy label from A-G shows how efficient an appliance is. A is the most energy efficient. The Danish Energy Agency is responsible for controlling the correct use and implementation of energy labels.
A labelled appliances have the lowest energy consumption within an individual product group. There is also an A+ and A++ category for fridges and freezers, where A++ is the most energy efficient. Only A-rated appliances qualify to use the Energy Saving Label, with only A+ and A++ fridges and freezers qualifying in their category.
Products which must display the EU energy label*:
Fridges and freezers
Electric light bulbs
Air conditioners for household use
*All products for household use.
Flat screen monitor
Flat screen monitors for computers are much more energy efficient than the old CRT (Cathode Ray Tube) monitors. A flat screen consists of small pixels which produce the visual image. Flat screens produce a much better image than CRT monitors, and energy consumption is around half as much as that of a CRT monitor.
Flower – The European Eco-label
The EU’s Flower Eco-label indicates that products are amongst the most environmentally friendly within their product categories. The Flower Eco-label has been in existence since 1992.
The label specifies environmental requirements which comprise all the key phases of a product’s life-cycle – from raw material production to product disposal. These requirements are revised every 3-5 years. The Flower Eco-label is administrated in Denmark by Ecolabelling Denmark.
The Flower Eco-label is a voluntary scheme and producers pay a fee for the right to use the label. 21 product groups are entitled to use the label, including clothing, paint, cleaning products and energy saving bulbs. Criteria can be viewed at www.ecolabel.dk
The underlying technology in a halogen bulb is the same as that in a normal tungsten filament bulb. The temperature of the metal strip in a halogen bulb is higher and it produces more light. This is possible because the bulb contains a halogen such as iodine or bromine.
This is why halogen bulbs can be small and produce a lot of light. Halogen bulbs come in 12-230 volts. 12 volt halogen bulbs must have a transformer to enable them to be plugged in. 230 volt halogen bulbs use more or less as much power as conventional bulbs, but low voltage halogen bulbs use slightly less power than ordinary bulbs.
The Trust’s advice is that halogen bulbs should only be used for spot and concentrated lighting and should be switched off at the mains. This avoids standby consumption when the light is switched off.
Heat pumps draw heat from their surroundings and convert the energy in this heat to heat energy at a higher temperature. This can be used immediately for heating purposes. Heat pumps supply around 3 kWh (low temperature) heat for each kWh of electricity.
- Geothermal – or air-to-water heat pumps (hot water heat pumps). These are connected to the central heating system of the house and distribute heat and hot water. They are relatively expensive.
- Air-to-air heat pumps. These distribute warm air and can cover a proportion of a building’s heating requirements. These systems are relatively cheap.
IDTV stands for Integrated Digital Television – TV with a built in digital tuner. This avoids the need for an external set-top box to receive digital signals.
KW is an abbreviation for kilowatt, which is 1,000 watts. A watt is a measurement unit for power.
1 MW = 1 megawatt = 1,000 kW
1 GW = 1 gigawatt = 1,000,000 kW
kWh (kilowatt hour) is a measurement unit for energy consumption. The average cost of 1kWh in Denmark is EUR 0.23 and in conventional electricity production is equivalent to circa 500 grams of CO2. The kWh amount is calculated by multiplying the power in watts by the length of time that an appliance is in use.
kWh= Watt x hours x days
TV with standby consumption of 5 watts, which is on standby 20 hours per day all year:
5 watts x 20 hours per day x 365 days = 36.5 kWh
LCD (Liquid Crystal Display) monitors are thin flat screens which, thanks to their technology, are very efficient compared with old CRT monitors.
LED is an abbreviation for Light Emitting Diode. LEDs are small semiconductors made of materials that emit visible light when a current is applied to them. Unlike in other light sources, LEDs have no filament, glass or gasses under pressure. They are very efficient and last a long time. They come in both white and coloured types.
The unit of perceived light or luminous flux from a light source. For example, a 60 watt tungsten halogen bulb emits perceived light of circa 710 lumen, and an 11 watt A-rated energy saving bulb emits circa 600 lumen.
Natural gas is a fossil fuel. It is a cleaner fuel than coal and, because of its chemical composition, it discharges 20% less CO2 than coal when combusted. Some decentralised power stations in Denmark use natural gas as a fuel source.
The sulphur in natural gas is removed before it is distributed through the natural gas distribution network. Therefore, no sulphur dioxide (SO2) is produced during combustion. Natural gas does not create any slag or ash.
A plasma TV is a TV which has a screen constructed of a series of pixels where every pixel is made up of three separate subpixel cells. Inside these cells there is an electrically conducting ionised gas, also called a plasma. Plasma TVs are very bright and produce a high-contrast, good quality picture.
Power = Output per unit of time (second)
1 W = 1 watt
1 kW = 1 kilowatt = 1,000 watt
1 MW = 1 megawatt = 1,000 kW
1 GW = 1 gigawatt = 1,000.000 kW
1 TW = 1 terawatt = 1,000,000 MW
1 kVA = 1 kilo volt amp
1 MVA = 1 mega volt amp = 1,000 kVA
Remote controlled plug
A remote controlled plug is a plug socket which allows you to switch devices connected to it on and off with a remote controller. This can be an advantage if the plug is difficult to access – if it is hidden behind furniture for example.
Remotely read electricity meter
Everyone can have their meter read remotely. You need to install a device that transfers your meter readings (at 15 minute or hourly intervals) direct to your electricity supplier.
The advantage of this is that you can keep track of your electricity consumption without having to read the meter yourself all the time. The supply company will only charge you for the kWh that you have actually used. When you have remote metering you can generally keep track of your consumption on the supply company’s website. You can also choose My E-Home. Read more about remote metering.
Decoder for receiving digital TV transmissions. Also known as digital decoder, digital receiver and digital tuner. More
Term used in the USA to describe an AutoPowerOff plug bank.
A SparOmeter is a small, precise electricity meter which can be used to find out how much power is used by different appliances when on and in standby.
Standby consumption is the power used by appliances when they are not in use, but which you have not switched off at the mains. Newer appliances should have standby consumption of no more than 1 watt. Some of the latest computers have standby consumption of only 0.1 watt. There are some exceptions. Printers, modems, TVs and similar devices use 3-15 watts on standby, for instance.
Another term used to describe an AutoPowerOff plug bank.
Swan – The Nordic Ecolabel
Swan is the Nordic Ecolabel and was established by the Nordic Council of Ministers in 1989. Swan is used in all the Nordic countries: Denmark, Norway, Sweden, Finland, and Iceland. Swan lays down requirements for energy efficiency for all energy consuming products. Read more at www.ecolabel.dk.
Swan is a voluntary and neutral seal of approval program and producers pay a fee for the right to use the label.
Tungsten filament bulb
A tungsten filament bulb works by sending power through a thin metal strip in a glass bulb filled with a special gas. The strip heats up and emits light. This method uses 4-8 times as much power as a fluorescent tube and an A-rated energy saving bulb. A conventional bulb typically lasts for 1,000 hours. The bulb can be dimmed with a dimmer switch.
Wireless communication offers the possibility of remote metering, monitoring and remote control of appliances and systems. The principle of wireless communication is that a device (slave) supplies data to a controller (master). The slaves carry out orders sent by the master such as to turn an appliance on or off.
A master is a mini-PC that manages the dialogue with the slaves, and can simultaneously communicate with a server over the Internet. The master therefore acts as a connection between the server and the slaves. Slave devices can be sensors, an on-off switch or another type of hardware.