Glossary
A
Air-source heat pump (ASHP)
The most common type of heat pump in UK homes. It uses heat drawn from the air to heat buildings.
App (application)
A small piece of software that a user can download onto a device like a smartphone. Each app carries out a specific job: for example, a calculator.
B
Bundle
A combination of a smart product and/or service and/or time of use tariff (e.g. an EV charger with an EV charging tariff and a charging optimisation service).
D
Distribution network operator (DNO)
Companies that manage the infrastructure that get electricity from the grid to homes and buildings across the UK. Unlike your energy supplier, you cannot choose who your DNO is – they own and operate the equipment that makes up the electricity network in your area.
Domestic battery storage
This stores electricity generated by rooftop solar panels in the daytime and stores it to use later, such as in the evening. With most electrical batteries you can also buy or sell electricity from the grid. This means that you can use the battery to store electricity generated when the sun is shining and get paid to feed it into the National Grid in the evening when there is high demand for electricity.
Dual fuel tariff
A tariff where the customer pays the same supplier for both their electricity and gas. See also: single fuel tariff.
Dynamic TOUT (also sometimes smart time-of-use tariff)
A time-of-use tariff that offers different energy prices that fluctuate throughout the day in response to external factors, like the amount of wind being generated by wind turbines at a particular time.
E
Economy 7 meter
A type of electricity meter that operates with an economy 7 tariff. It tracks the amount of electricity used during seven off-peak hours, and the remaining 17 peak hours of the day.
Economy 7 tariff
A type of static TOUT that charges two different prices for electricity at two different times of day. During seven off-peak hours at night electricity is cheaper. For the rest of the day, electricity is more expensive. Economy 7 tariffs come with a special Economy 7 meter.
Energy meter
A device that measures the amount of energy (usually electricity or gas) consumed by a user.
Energy supplier
The company that someone pays for the energy they use. The price of the energy is agreed in a kind of contract called an energy tariff.
Energy tariff
A type of contract which sets the price at which an energy user buys (or sometimes sells) energy from/to the grid. There are several types of energy tariffs.
EV
Electric vehicle. A car or van that is fully or partially powered by electricity instead of petrol. Pure or 100% electric EVs are powered only by an electric battery. Hybrid models work through some combination of a battery and a normal car engine. Electric batteries in EVs are recharged by the user, typically using a dedicated EV charger.
EV charger
Although EVs can be charged via a standard 3-plug socket, it is more efficient to use a powerful dedicated EV charger. EV users can install a charger at their home (usually only if they have off-street parking), or use a public charger – for instance, at a supermarket, or their workplace.
Export energy tariff
An export tariff is a contract in which a customer is paid for renewable energy they have generated that they export to the grid. See also: import energy tariff.
F
Fixed energy tariffs
In a fixed tariff, the unit price paid for energy doesn’t change over the course of a plan. Fixed tariffs offer security, and often some of the cheapest deals, but users are normally tied in for at least a year and may incur exit fees if they exit early. See also: variable energy tariffs.
G
Gas distribution network company
Companies that manage the infrastructure that get gas from the grid to homes and buildings across the UK. Unlike your energy supplier, you cannot choose who your gas distribution network company is – they own and operate the equipment that makes up the gas network in your area.
Ground-source heat pump (GSHP)
A type of heat pump that uses heat drawn from the ground to heat buildings.
H
Heat batteries (sometimes thermal stores)
A technology similar to domestic battery storage that stores energy as heat. These can be used to maximise the efficiency of renewable heating systems or to make different heating systems work together better.
Heat pump
A heating system that captures heat from outside and uses it to heat a building. This process uses electricity. Distinct types of heat pump draw their heat from different sources. See also: air-source heat pump and ground-source heat pump.
Heat-as-a-Service (HAAS or Energy-as-a-Service)
A new model for buying heating in which customers purchase an outcome – a certain amount of ‘warm hours’ – from their energy supplier, rather than kilowatt-hours of energy. The model can also be applied to electricity.
I
Import energy tariff
An import tariff refers to any energy contract in which a customer buys or ‘imports’ gas or electricity from the grid. Most domestic energy tariffs are import tariffs. See also: export energy tariff.
In-home display (IHD)
A small device with a screen that comes with a smart meter. The IHD receives and displays information from the smart meter. This helps users to track how many energy they are using (in kilowatts) and how much they are spending (in pounds and pence). An IHD can show current usage, daily, weekly, monthly, and annual usage.
N
National Grid
The company that owns and operates the grid in the UK.
O
Off-peak energy hours
Off-peak hours are periods of time when energy demand is at its daily lowest: typically, between 10pm and 8am. See also: peak energy hours.
Ofgem
The organisation that regulates the gas and electricity markets in the UK. They make rules that energy suppliers have to follow.
P
Peak energy hours
Peak energy refers to the times of day when energy demand is highest: when a lot of people are using electricity and gas. This is typically around breakfast and dinner time, as people use energy to wash, cook and heat their homes before leaving for or returning from work. See also: off-peak energy hours.
S
Single fuel tariff
A tariff where the customer pays one supplier for either electricity or gas. See also: dual fuel tariff.
Smart appliances
A household appliance, like a dishwasher or fridge, that, through connection to the internet or another network, can change how it operates in response to external signals. When paired with a smart meter, this technology can help users to save energy. For example, a smart dishwasher can communicate with a smart meter to only turn itself on when electricity is cheapest.
Smart EV charger
A type of EV charger that, when paired with a time-of-use tariff, works by charging an EV when the cost of electricity is lowest.
Smart Export Guarantee (SEG)
A kind of export tariff designed to ensure small-scale generators are paid for the renewable electricity they export to the grid. It is open to residents across the UK (except Northern Ireland) with domestic renewable technologies like solar PV panels, wind turbines or hydro. All energy companies with more than 150,000 customers must provide at least one SEG tariff.
Smart heating controls
Heating controls that (similar to smart appliances) work in response to external signals transmitted via the internet. Smart heating controls include smart programmers, smart thermostats, and smart radiator valves. These controls can automatically change heating settings across a building or room based on factors like a user’s personal routine: for example, heating the hot water at the time they usually take a shower or bath. Controls can also be operated via a smartphone when users are not at home. Some smart heating controls can also be connected to a smart meter to help use energy when it is cheapest.
Smart meter
A type of energy meter that automatically sends electricity or gas usage information to energy suppliers. The information is sent at least once a month. It can be sent as frequently as every half-an-hour to give a more accurate reflection of energy usage. Smart meters are usually paired with an in-home display.
Smartphone
A mobile phone that has internet access and an operating system capable of running downloadable apps. Some smart energy technologies will require users to run an app on a smartphone to manage and make best use of the technology.
Solar PV (solar photo-voltaic)
Technology that uses the sun to generate electricity. Usually comes in the form of panels that can be installed on roofs.
Solar thermal
Technology that uses the sun to heat up water for direct use or heating. Usually installed in a comparable way to solar PV panels. It is also possible to find combined solar PV and thermal systems, although they are quite rare.
Static TOUT
A time-of-use tariff that offers two or more different prices of energy at fixed peak and off-peak times of the day: for example, cheaper in the day and overnight, more expensive in the evenings. Economy 7 is a common example of a static TOUTs (time of use tariff).
T
The grid
The network of powerlines, pylons, gas lines and interconnectors that transport electricity and gas to meet the demand for energy across a country. In the UK, the grid is managed by a company called the National Grid.
Time-of-use tariff (TOU or TOUT)
A type of tariff which offers different prices for energy at separate times of the day. There are two main types: static and dynamic. Each type of tariff comes with an associated meter (typically an Economy 7 meter for static or a smart meter for dynamic) that speaks to the energy grid.
V
Variable energy tariffs
In a variable tariff, the unit price paid for electricity and gas can vary at the discretion of a supplier. Variable rate deals tend to be more flexible, and users can normally get out of a variable rate contract without incurring any fees. See also: fixed energy tariffs.
Vehicle-to-Grid (V2G)
A type of technology that, as well as the benefits of smart EV charging, uses the electricity stored in EV batteries to export energy to the grid. Users can receive savings on their bills or other benefits. V2G is normally paired with its own energy tariff.