Glossary of Terms
AC: Alternating Current. With AC the movement (or flow) of electric charge periodically reverses its direction. It is the normal way that electricity is delivered within the electricity grid. In our homes we refer to 220 volts AC.
AMR: Automated or advanced meter reading. AMR uses one-way communications technology to collect data from the meter via PLC, radio or other networking technology. It does not support communication of utility information (for example pricing) to the meter.
AMI: Automated or advanced metering infrastructure. AMI is a utility infrastructure with two-way communications for metering and associated systems allowing delivery of a wide variety of services and applications for both the generators, transmission and distribution system operators and the customer.
Appliance: a device that operates by electricity. Examples are lights, electric heaters, immersion heaters, washing machines and toasters.
Autoproduction: A customer generating electricity for their own use. This is sometimes called autogeneration. Normally autoproduction includes all consumer-generating equipment, regardless of size. This would include microgeneration.
Bps: Bits per second. This is a measurement of data transmission speed - for example, the speed of a particular internet connection. Bit stands for "binary digit," the "0" and "1" that are the basic building blocks of computer data.
Broadband: General term for internet connections faster than dial-up. A generally accepted definition would mean data rates of more than 100,000 bps (100 kbps).
Carbon: A Molecule present in all living things and fossil fuels.
Carbon dioxide: A colourless odourless incombustible gas present in the atmosphere and formed during respiration, decomposition and combustion of organic compounds. It is used in carbonated drinks, fire extinguishers, and as dry ice for refrigeration. Its chemical formula is CO2. It is one of the greenhouse gases.
Carbon footprint: A carbon footprint is a measure of the impact our activities have on the environment, and in particular climate change. It relates to the amount of greenhouse gases produced in our day-to-day lives through burning fossil fuels for electricity, heating, transportation etc.
CER: Commission for Energy Regulation.
CHP: Combined Heat and Power: CHP is the simultaneous production of utilizable heat and electricity from an integrated thermo-dynamic process.
DC: Direct Current. The movement (or flow) of an electric charge, flowing in one direction only. This is the normal type of flow from batteries. It is not used in the electricity grid within Ireland.
Demand: The total amount of electricity required by users at any one time.
DR: Demand Response. DR refers to actions taken by electricity customers to reduce their demand. This term refers to a type of arrangement between the utilities and their customers that can take various forms but always refers to the agreement by customers to cut their use of electricity when the utility asks them to, or in some cases customers give the utility permission to remotely change the use of power within the customer's premises. Many DR arrangements are with large industrial consumers that agree to shut down some or all of their power use when the utility alerts them -- often via a phone call -- to a peak demand condition, and often with a financial consideration to mitigate the impact on the business of the customer. Programs for residential customers often use remote controls of thermostats, water heaters, swimming pool pumps and other appliances. Some DR programs offer financial incentives to the customer to have their power use reduced temporarily and others use variable power rates, boosting the cost of power to create an incentive for the customer to reduce power use at peak use times.
Distribution System: The system which consists of electric lines, electric plant, transformers and switchgear and which is dedicated to delivering electric energy to an end-user. We recognize the distribution system in our everyday lives from the poles and wires close to our homes.
DA: Distribution Automation. DA is the integration of smart sensors with integrated communications technologies to provide real time reconfiguration of distribution equipment to prevent customer outages and minimize time of disruption.
DSM: Demand Side Management. DSM is a type of utility program designed to cut power demand on the grid by 1) using technology or 2) changing the power use behaviour within the customer's premises. See Demand Response.
Eirgrid: EirGrid is the Transmission System Operator (TSO) and Market Operator (MO) in the wholesale electricity trading system in Ireland, and is the owner of the System Operator Northern Ireland (SONI Ltd), the licenced TSO and market operator in Northern Ireland.
Electric current: A flow of electrons moving along a wire or conductor.
Electrical energy: The ability of the electric current to do work. It is measured in kilowatt hours (kWh).
Embedded Storage: Because electricity cannot be practically stored, the electrical energy needs to be converted to another form for practical storage for later use. Embedded storage involves consumers converting the electrical energy into other forms (such as heat) for later use. This allows consumers purchase electricity when it is cheapest, and storing it in that form until they need it.
Energy Management System: Sometimes known as either Home Energy Management Systems (HEMS) or Building Energy Management Systems (BEMS). This is where consumers use computer and communications technology to help them manage their energy management.
ESB: The Electricity Supply Board Act was passed in 1927 to set up the Electricity Supply Board, a corporate body to control and develop Ireland's electricity network. The organization used to have sole responsibility for electricity in Ireland, but as a result of deregulation, there are now competitors. ESB Networks retains exclusive responsibility for the distribution system. It is the Distribution System Operator.
EV: Electric Vehicle. EVs are vehicles which use one or more battery powered electric motors for propulsion.
EPRI: Electric Power Research Institute. This is a leading and highly respected research body in the US that is one of the leaders in smart grid research.
Export: The term given to the provision of electricity to the grid. Consumers with their own microgeneration expect to make enough electricity to meet their own needs, and possibly have a surplus that they can sell or export to the grid for others to use. Traditionally consumers did not make their own electricity and they “imported” their electricity requirements from the grid.
Fossil fuels: Energy resources that are dug, drilled or pumped out of the ground having being created by nature’s actions over millions of years on the remains of dead plants and animals. These include coal, natural gas, peat and oil.
Frequency: The number of alternating current cycles per second, expressed in Hertz at which the electricity system normally operates. In Ireland this is 50 Hertz.
Frequency Load Control: This is a circuit fitted to electrical appliances that senses grid conditions by monitoring the frequency of the system and provides an automatic demand response when needed. It relies on the fact that a disturbance of the 50-Hz frequency is a universal indicator of serious imbalance between supply and demand that, if not tackled, leads to a blackout. The controller computer chip can be installed in household appliances and turns them off for a few minutes or even a few seconds to allow the grid to stabilize.
Generator: A machine that produces electricity.
GHG: Greenhouse gases. These are gases such as carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons and sulphur hexafluoride, that allow solar (short-wave) radiation to pass but block long-wave (infrared) radiation, thus preventing long-wave radiant energy from leaving Earth’s atmosphere. The net effect is a trapping of absorbed radiation and a tendency to warm the planet’s surface.
Grid: This is the term given to the interconnected electricity system. It involves electricity generators, the transmission infrastructure, the distribution infrastructure and electrical equipment in each of the consumer's premises. Simply – “from the wind turbine to the toaster”.
HAN: Home Area Network. This is a network in the home used for communication between digital devices typically deployed in the home, usually a small number of personal computers and accessories, such as printers and mobile computing devices. With the advent of the Smart Grid, and with DR and AMR, it can help consumers minimize their energy costs.
Hydro Power: Running water provides the power to drive turbines which generate energy. This power results in electricity being produced.
Import: The term given to the consumption, by consumers, of electricity from the grid. In effect, the electricity is “imported” from the grid. For consumers with their own microgeneration they expect to make enough electricity to meet their own needs, and maybe have a surplus that they can sell or export to the grid for others to use.
In-Home Display: An in-home display or energy monitor provides prompt, convenient feedback on electrical or other energy use. Devices may also display cost of energy used and estimates of greenhouse gas emissions. Various studies have shown a reduction in home energy use of 4-15% resulting from the greater awareness created through use of these in-home energy displays.
IP: Internet Protocol. This is the universal computer language that made the internet possible by breaking all content into packets to transmit it, carrying those packets to their intended destination and re-assembling them into text, documents, graphics, computer code and video at the other end. The real genius was realizing all that content could be mixed together along the networks and then sorted back out as needed for delivery and reassembly.
IPv4, IPv6: IP (above) version 4 is the protocol that was used to create the internet we've all come to know since the mid 1990's and includes an addressing protocol that never imagined billions of devices would one day be connected to the internet and thus need unique addresses. IPv6 is being deployed now bit-by-bit and has a new addressing standard that allows for a much larger universe of addressable devices.
Kbps: Kilobits or thousand bits per second, a measure of data transmission speed.
KW: Kilowatt or 1000 watts (see Watts)
LAN: Local Area Network. This is a network that usually connects computers and related devices in a single office, building or home.
Load: Electric utility term for the infrastructure that uses the power the utility distributes -- such as homes, businesses, industry, and in-the-field equipment -- thus, locating a power generation or storage device near the load, which means putting it close to where the power will be used.
Market Operator: SEMO is the market operator responsible for the administration of the Single Electricity Market in Ireland and Northern Ireland.
Mbps: Megabits per second, a measurement of the speed data travels in a network -- such as through a home or business internet connection.
Microgeneration: is the small scale generation of zero or low-carbon heat and power by electricity consumers to meet at least some of their own needs. This generally means that the scale of generation is of the order of 6-10kW maximum.
Mhz: Megahertz, a million hertz, is a measure of radio wave frequency.
Motor: A machine that converts electrical energy into mechanical energy.
MPRN: Meter Point Reference Number. Your MPRN is the unique identifying number for the meter at your property.
MW Megawatt (1,000,000 watts). One megawatt would be needed to light 10,000 one-hundred-watt light bulbs. If those bulbs were powered for 1 hour, 1MWh of electrical power would be used.
NCC: National Control Centre. This is a control centre that ensures that there is a balance between the amount of electricity that is generated and delivered to the grid, and the demand that all the customers are placing on the grid.
On Peak: If our electricity use is charted out, our everyday use/demand has a curve shape to it. This curve is known in the utility industry as the load curve. The peak of this curve will occur when the most electricity is demanded, usually midday to early evening. During this time the demand is highest and some of it is provided by “peaking” generators that are more expensive to operate – and so the price of electricity is highest at these times.
Off Peak: This refers to when our electric use/demand is at a minimum, usually late at night. This is the valley of the load curve.
Outage: A power outage (also known as a power cut, power failure, power loss, or blackout) is a short- or long-term loss of the electric power to an area.
PHEV: Plug-in hybrid electric vehicle. This is an electric vehicle with an internal combustion petrol or diesel engine (ICE), a generator and one or more electric motors to power the wheels. It also has a battery which can be charged from the on-board generator or it can be charged (Plugged in) from the grid in the same way as a battery powered EV.
PLC: Power Line Carrier Communications: Power line communication or power line carrier (PLC), also known as Power line Digital Subscriber Line (PDSL), mains communication, power line telecom (PLT), power line networking (PLN), or Broadband over Power Lines (BPL) are systems for carrying data on a wire also used for electric power transmission.
PV: Photovoltaic panels. This is solar power technology that turns sunlight directly into electricity. Most people will be familiar with the small PV panels that appear on some “solar powered” calculators.
Renewable energy resources: Renewable energy resources are nergy resources that are naturally replenishing. Renewable energy resources include biomass, hydro, geothermal, solar, wind, ocean thermal, wave action, and tidal action.
SCADA: Supervisory control and data acquisition. This is a system used by power utilities to send and collect supervisory controls and monitor data through power lines.
Smart Grid: The title given to an electricity grid enabled with computer technology and two-way digital communications networking. The term encompasses the ever widening range of utility applications that enhance and automate the monitoring and control of electrical distribution networks for added reliability, efficiency and cost effective operations.
Smart meter: An advanced utility meter for electricity, natural gas or water, that includes two-way communications technology. In an electricity smart meter, it has the ability to identify consumption in more detail than a conventional meter and communicates that information, via some network, back to the utility companies for monitoring and billing purposes
Tariff: The pricing scheme used to bill customers for electricity use.
TOU: Time of use. TOU refers to the dynamic pricing of electricity. This approach to electricity pricing lets time of day and other conditions move the price of power used by customers at established intervals.
Transmission System: The system of high voltage lines, large pylons, large transformer stations etc. used for conveying electricity from a generating station to the distribution system (and to some large customers).
TSO: Transmission System Operator. Eirgrid is the sole licensed operator of the Transmission System in Ireland.
Turbine: Rotors or blades that spin when driven by steam, gas, water or wind.
Unit: Consumption of electricity is measured in units. A unit of electricity is a kilo-Watt-hour kWh. So 1kWh is one unit.
Utility: An electric utility company is a company engaged in the generation, transmission and distribution of electricity.
WAN: Wide Area Network. This is a computer network connecting all the buildings in a building complex to each other or all the homes and businesses in a neighbourhood, town or city to the internet.
Watt (W): A Watt is the standard unit of electrical power. 1,000 Watts is called a kilowatt (kW). A traditional incandescent light bulb might be rated at 40 Watts.
Watt hour (Wh): 1 watt hour is the amount of electrical energy consumed by a 1-watt load over a period of one hour. For example, a 100 watt light bulb (a 100-watt load) uses 100 watt-hours of energy every hour. Rather confusingly, watt-hours are sometimes used to describe "power." This is incorrect. Watt hours are a measure of energy transferred, i.e., the product of power (kW) x time (hours).
WiFi: Wireless fidelity. This is an international standard for sending and receiving data, such as in a home or small office network.
Zigbee: ZigBee is a low-cost, low-power, wireless mesh networking proprietary standard. The low cost allows the technology to be widely deployed in wireless control and monitoring applications, the low power-usage allows longer life with smaller batteries, and the mesh networking provides high reliability and larger range.