Active Power

Measured in watts (as kW or MW), this is the rate at which electrical energy is produced, transmitted and used.


Average daily consumption (m3)

ADC (Average Daily Consumption)

The average amount of energy your home or business uses on a daily basis, measured in kWh.

Agreed Capacity

This is the agreed amount of electricity supply or load that’s sent to a premises. It’s an essential consideration for larger enterprises.

AMR (Automated Meter Reading)

This is where electricity and gas meter readings are taken automatically, and sent across to your provider. There’s often a charge associated with this.

Annual Bill

The amount a customer pays on gas, electricity, water over a full year.

Annual Contract

A year-long contract with your energy supplier.

Annual Quantity (AQ or AAQ)

Is the annual amount of gas you used measured in kilowatt-hours (kWh).

APR (Annual Percentage Rate)

A yearly rate added on to any loans you’ve taken out, or investments you’ve made. This can appear on your energy bills.

ASHP (Air Source Heat Pump)

An air source heat pump absorbs outdoor heat from the air, and distributes this indoors. It’s often touted as a good solution for more rural areas, and for those looking to heat their premises cheaply.

Assessed Charges

When a company fines a charging value inappropriate.


Automatic contract rollover- a supplier has the ability to extend the duration of an existing term tariff or apply a new fixed term tariff without the consumers say.


Addressing affordability and vulnerability of clients/customers.

Back Billing

Bills sent to your premises when you’ve not been properly charged for the energy you consumed.


How much you owe to the energy company.

Barrier To Entry

A cost or reason that may prevent a business from entering the market.

Base Load

The minimum expected level of demand across the electricity grid over a set amount of time (such as weekly, monthly, biannually, or annually).

Base Rate

The Base Rate, also known as the Bank of England’s Base Rate, is the 5.25% interest added to any purchase, loan or contract.


The Department for Business, Energy and Industrial Strategy. It was split down in 2023 into several other departments, including the Department for Energy Security and Net Zero (DESNZ).

Billing Period

A period of time that’s used to calculate how much you need to pay.


Biogas is a renewable energy made up of a mixture of methane, carbon dioxide and hydrogen sulphide.


BioResources refers to the wastewater sludge transport, disposal, and recycling.


The amount of natural gas that can be produced in a period under network design conditions.

Capped Pricing

An electricity or gas tariff that guarantees the price per kWh will not increase above a certain price for a fixed period.

Capped Tariffs

The cost of energy per unit is capped at a specified level and cannot rise above that price.

Carbon Credits

A certificate which allows a country or business to produce a certain amount of carbon emissions and which can be traded if the full allowance is not used.

Carbon Debt

The amount of carbon emissions that exceed sustainable carbon sinks. A carbon debt could be assigned to any entity to which carbon emissions can be attributed, such as an individual, a firm, a group, a country, or an industry. Attribution of emissions and estimation of sustainable carbon sinks are complications to calculating this metric.

Carbon Neutral

The state of making no net release of carbon dioxide to the atmosphere, achieved through offsetting emissions, typically by planting trees.

Carbon Offsetting

The process of compensating for carbon dioxide emissions arising from human activity, by removing the equivalent amount of carbon dioxide from the atmosphere, typically through carbon credits or offsetting projects.

Carbon Price

The value applied to each unit or carbon emissions.

Carbon Tax

An approach to limiting emissions of carbon dioxide, a major contributor to human-induced climate change, by establishing a tax on goods and services that is commensurate with the amount of CO2 released in their creation and delivery.


Carbon Capture & Storage. This involves capturing the carbon emission produced through industrial and manufacturing processes, and storing it in special containers underground. It’s often viewed as an innovation in carbon offsetting, and a good step forward towards carbon neutrality.


Contracts For Difference. A government initiative designed to provide significant levels of support and funding to renewable energy generation.

Climate Change Levy (CCL)

A government tax aimed at reducing gas emissions and encouraging greater energy efficiency across businesses or non-domestic organisations.

Commodity Charge

The common name given to the costs associated with the generation and distribution of the electricity and gas you use.


Total energy units used within a specific period, measured in kilowatt-hours (kWh).

Contract End Date

The date your current energy tariff contract ends, and the date by which you’ll need to have arranged your next contract in order to avoid costly deemed rates.

Cooling Off Period

The time you’re given after choosing an energy provider to cancel your contract with no penalty. These are common in domestic contracts, but less so in business energy.


Charging value of a product or service.


The Department of Energy and Climate Change. Formerly its own branch of government, it was absorbed by the Department for Business, Energy and Industrial Strategy in 2016.

Deemed Rate Contract

This is the contract you’ll be placed on if you move into a new premises without first agreeing a contract with a provider, and proceed to use any energy. These are often much more expensive than an agreed-upon contract.

Department for Business, Energy & Industrial Strategy (BEIS)

The Department for Business, Energy & Industrial Strategy (BEIS) replaced the Department of Energy and Climate Change (DECC) in 2016.


The Department for Energy Security and Net Zero. This split from the Department for Business, Energy and Industrial Strategy in 2023, and seeks to better illuminate the future of renewable energy.

Discharge Points

The point trade effluent service is provided to premises.

Distribution Network

Delivers lower voltage electricity to homes, businesses and industries across the UK.


Distribution Network Operator, a company that’s licensed to distribute electricity.

Dual Fuel bill (DF)

An energy contract where customers use the same supplier for both gas and electricity.


The Distribution Use of System. A charge applied to cover the cost of receiving your power from the regional distributor. Closely relates to TNUoS (Transmission Network Use of System).  

Electrical Installation Certificate (EIC)

A safety certificate issued by an electrician after new electrical work is carried out, ensuring it conforms to the UK national standard BS 7671.

Electricity Bill

The monthly or annual bill you’ll receive for the electricity you’ve used.

Energy Efficiency

The practice of using less energy to provide the same amount of useful output.

Energy Ombudsman

A independent party used to resolve disputes between a supplier and consumer. Free to use and its decisions are binding.

Energy Supplier

The company that provides your electricity, gas or water. For instance, British Gas (owned by Centrica plc.) are one of the more popular energy suppliers UK-wide.

Estimated Annual Consumption (EAC)

The estimated annual consumption is a measurement in kWh of the estimated usage for the upcoming year.

Estimated Meter Reading

Estimation of your average energy usage to calculate your bill.

Estimated Rate/Rate

This is your energy supplier’s best estimate at your current meter reading. It can mean that your actual bill increases or decreases when an accurate meter reading is received.

Evergreen contract

An energy tariff that is contracted for an indefinite length and does not contain a fixed term period.

Fittings Regulations

The water fixture regulations act 1999.

Fixed Term Contract

A contract that lasts for a specified length of time. This is usually annual, but businesses can have contracts that last up to 5 years.

Fixed-rate tariffs

Can guarantee the price of energy for a fixed time period e.g. 12 months, offering a fixed price for each unit of power.


Fuel Mix Disclosure. A requirement for all electricity suppliers to disclose openly where they source their electricity from.

Fossil Fuel Power

Electricity generated by coal, oil, and natural gas.

Fossil Fuels

Fuels such as oil, gas and coal which are formed in the earth from plant and animal remains. Typically burnt to release the energy which also produced greenhouse gas emissions.

Fuel Poverty

The term applied to any household or business that uses 10% or more of their annual income to cover energy bills.

Gas Bill

The bill you’ll receive from your gas supplier. Usually issued on a monthly or annual basis, but certain contracts may use a different timescale.

Gas Distribution Networks (GDN)

There are four Gas Distribution Network companies which cover different geographical regions across the UK.

Gas Substation

A small facility located on-site that reduces that stabilises pressurised gas for use in domestic or business properties.

Giggawatt (GW)

A gigawatt is equivalent to 1 billion watts. This would power more then 10 million light bulbs.

Green Gas Support Scheme (GGSS)

The Green Gas Support Scheme is a government scheme that provides financial aid or incentives for new biomethane plants to increase green gas in the gas grid. This scheme is open to applicants within England, Scotland, and Wales.

Green Tariff

Tariffs that use green or carbon offset energy to power homes and businesses.

Greenhouse Gas (GHGs)

Greenhouse gasses are in the earth’s atmosphere that trap heat.

Grid Supply Point (GSP)

The point in which the energy supply is taken from the National Grid transmission systems into a local distribution system.

Heat Rate

The rate at which energy is produced at power plants. More technically, it’s the amount of input (or heat) needed to produce one unit of output.

HH Meters

Half Hourly Meters. These send reliable data across to the energy provider on a half-hourly basis through AMR, ensuring accurate monthly bills.


Half Hourly Data. The data and information that HH Meters send across to the energy supplier.

High User

A particularly large consumer of energy. Ofgem states that this is a user who expends more than 5,100 kWh of electricity, and/or 23,000 kWh of gas.


This is any electricity generated through hydropower. These are usually dams or underwater turbines that turn the flow of water into energy.


Independent Distribution Network Operator, also licensed to distribute electricity but often on a smaller, local level within a larger DNO.


Independent Gas Transporter. A gas transportation network that operates outside of the main regional gas distribution networks, and can provide power outside of the main grid.

Indirect Costs

Costs that aren’t a direct result of the energy you consume. This includes your supplier’s operating costs like the CCL and VAT.


Large cables that transport electricity across country borders and longer distances.


Integrated Pollution Prevention & Control. A scheme designed to help manage and mitigate the pollution from industrial-sized businesses.

Kilowatt (kW)

Unit of electric power, equal to 1000 Watts.

Kilowatt-hours (kWh)

Unit of measurement for energy consumption.

Large Business

Defined as a business with more than 100 staff, and that uses between 25,000 and 50,000 kWh per year.

Large Energy Suppliers

Also known as The Big Six. This is the collective name given to the 6 largest energy providers in the UK – British Gas, EDF Energy, E.ON, npower, Scottish Power and SEFE.


The Low Carbon Building Programme. A former government initiative designed to better promote renewable and forward-thinking energy solutions. It ended in 2010, to be replaced by the RHI in 2011.


Liquefied Natural Gas. Natural gas that has been cooled to a liquid state so that it can be transported more easily and safely.


Letter of Authority- A legal document that allows a third party to deal with suppliers on your behalf.

Load Management

Load management is the controlling of energy and electrical consumption, specifically to ensure fiscal security.


Any lost electricity or gas during the transmission stage.

Low User

A customer that uses a much lower amount of electricity. Ofgem defines this as a company that uses less than 2,100 kWh of electricity, and/or 11,000 kWh of gas.

Loyalty Discount

A discount or additional incentive applied to an energy deal for opting to remain with a company for an extended period of time.


If your business is on a meter, then your water will be measured in cubic metres. A cubic metre is equivalent to 1000 litres of water.

Market Share

The amount of customers, or the share of the market, an energy company has. Larger companies will have a greater share of the market, for example.

Medium Sized Business

Defined as a business that has between 50 and 100 employees, and that uses in the range of 15,000 and 25,000 kWh per year.

Megawatt hour (MWh)

A unit of measurement of electricity used in one particular area. A megawatt hour is equal to 1000 kWh of electricity.


A device measuring the quantity of water used on a business premise.

Meter Point Reference (MPR)

Is the unique reference number for all gas meters in the UK.

Meter Readings

Used to measure your energy consumption and calculate a bill.


Defined as a business that has less than 9 employees, and uses less than 5,000 kWh per year.

Million-cubit meters (MCM)

A unit used to measure energy, 1 MCM is approximately 360,000 therms.


Meter Operator. The company that’s responsible for installing and maintaining your meter, as well as any necessary adjustments or readings.


Also known as a supply number, a meter point administration number is a 13-digit code unique to every electric meter.

National Balancing Point (NBP)

Is the point where wholesale gas is traded within the UK.

National Grid

The infrastructure that transports all electricity and gas across the UK. The national grid feeds into the distribution networks.

National Transmission System (NTS)

It is the National Grid’s high-pressure gas network that supplies gas to end consumers, including large end users such as industrial consumers and power stations, who receive gas directly from the NTS.


A target of completely negating the amount of greenhouse gases produced by human activity to net-zero levels.  Achieved by reducing emissions and increasing absorbing carbon dioxide from the atmosphere.

Network Costs

The costs needed to maintain, repair and run the energy network. Suppliers are charged this, which they then collect from their customers.

Network Operators

These are the companies responsible for maintaining and repairing the pipes and cabling that directs energy to our homes and businesses.

NHH Data

Non-Half Hourly Data. This is data that’s not sent to the energy provider on a half-hour basis, and is instead reported on a daily, weekly or monthly basis.

Non Time of Use Tariff (non-ToU)

A tariff that is not a time of use tariff.

Non-portable Water

Non-portable water has not been treated to the required standard to enter the public distribution network.

Non-Renewable Energy

Energy that’s sourced from non-renewable or green sources, such as coal, oil and natural gas.


Any times outside of the peak hours of energy usage. Off-peak times are usually after 9pm until 6am, with peak times being during normal business hours, and into the evening when most are at home.


The Office of Gas and Electricity Markets, a regulatory body for the electricity and gas markets in the UK, is responsible for protecting consumer rights and helping to establish a fairer and greener energy system.


Office of Water Services, is the body responsible for regulating the privatised water and sewerage industry in England and Wale.

Online Account Management

The online functionality of any electricity and gas providers. Most providers will allow you to pay bills, check meter readings, and ask questions through an online portal.


Office for Zero Emission Vehicles is a team working across the government to support the transition to zero emission vehicles (ZEVs).

Paperless Billing

This is where you’ll receive all of your energy bills online via an email or online portal, rather than through the post.

Peak Demand

This is when the National Grid experiences its greatest amount of demand. It’s usually between the hours of 6am and 9pm.


These are the transportation channels for gas and oil. They’re usually deep underground or on the seabed.

Pre-Payment Tariff

This is where you can pay in advance for the energy you use. It’s most common in domestic properties, where you can top up a prepayment meter at a shop or post office.

Pre-Payment Tariffs

A pay-as-you-go option for houses with a pre-payment meter, you pay for energy before you use it via a key, card, or token.

Principal Terms

These are the primary or main terms of the contract you’ll receive when you first sign up. They’re usually related to payment terms, any limitations, and legal information.


Stands for photovoltaic. This means products (usually panels) that use solar energy to provide power.


This means the gradual increase of prices, specific to the energy sector. It’s a regular occurrence, and may be a term as energy prices have gone up over the last few years.

Raw Water

Raw water is water that has not been passed through water treatment facilities.

Reactive Power (KVAR)

The difference between the electricity that is supplied and the electricity that is converted into power, which indicates electricity wastage.


A person or organisation whose job it is to ensure the fair and stable running of the market. For example, Ofgem is the regulator of the gas and electricity markets.

Renewable Energy

Energy produced from sources that do not run out and are naturally replenished such as the sun, wind, and water.

Renewable Resources

Electricity generated by sustainable sources. For example, solar panels, wind, geothermal, biomass, wave, or tidal power.


Renewables Obligation Scheme. This initiative was designed to improve uptake of renewable energies, and closed in 2017.


Smart Export Guarantee. A government-supported initiative that’s designed to reward small-scale renewable energy generators by paying them for the electricity they produce and ship.

Serial Number

A unique identification number given to products and items. In energy, it’s also called an MPAN or MPRN.

Sewerage Licence

A holder of a sewerage licence is allowed entry into the wastewater and sludge service market.


Service Industry Code. A specific code that’s assigned to the industry or sector your business operates in. It can be part of any business energy contract application.

Small Business

Defined as a business that has between 10 and 50 employees, and that uses between 5,000 and 15,000 kWh per year.

Smart Meter

A meter that allows you to see your energy consumption in real-time and that communicates directly with your energy supplier.

Solar Panels

Solar (or photovoltaic) panels capture solar energy (from the Sun) to generate electricity. They’re one of the UK’s main sources of renewable energy, alongside wind turbines.

Standing Charge

A daily charge you incur even if you don’t use any energy.


The company that provides your gas, electricity and/or water. For example, your gas supplier could be British Gas, and your electricity supplier could be Octopus Energy.


An additional charge applied to your bill. This can apply to a variety of factors, from administration costs to standing charges.


The term given to swapping from one supplier to another. This is usually done towards or at the end of your contract.

Switching Costs

Any costs that are associated with the switching process. This could be exit costs (such as leaving a contract early), metering and equipment charges, or less quantifiable costs like time or effort.

Switching Window

The window at the end of your current contract (usually around a month) where you can switch to a new provider without penalty or termination fees being applied.


A documented list of utility rates, and terms and conditions, that have been approved by the Government.

Termination Fees

The costs associated with terminating (or ending) your energy contract early. This is to prevent any constant or disruptive switching.


A unit of energy measurement. To calculate the equivalent value in kWh, multiply by 29.3071.

ToU Tariff

A Time of Use tariff. This means you pay less for energy that you use at off-peak times.

Trade Effluent

Trade effluent is untreated sewage from commercial properties.


A component in a circuit that allows electricity to be transferred across. It’s an essential part of the National Grid, and diverting power from cables into homes and businesses.

Transmission Network

A network that carries high voltage electricity from power stations to where it’s needed in the country.

Transportation Charge

A hidden cost on your gas and electricity bills. It’s the cost associated with the creation, maintenance and upkeep of the network, and any associated costs with transporting the power.


Transmission Use of Service. Any charges associated with the transmission of moving of large quantities of energy across the power grid.

Unit Rate/Cost

The cost you’ll pay per unit of electricity or gas, measured in kWh.

Unlimited Energy Tariff

A tariff that allows you to pay a set amount per month, for a set fee per month. They’re rarely offered due to the volatility of the market.

Unlimited Energy Tariffs

Offer unlimited energy for a year at a specified cost, which is determined by examining old bills. You’ll never be charged additional fees for using more energy.


A premise that is not on a water meter.

Variable Tariffs

The price will vary with the market, fluctuating up and down depending on conditions.


The difference between different tariffs and energy charges.

Volume Based Charges

A charge that is calculated based on the amount of water received from a meter.

Water Bill

The bill you’ll receive for the water you’ve used at your property. This is usually issued on a monthly basis, but can be done on an annual, biannual, or quarterly basis.

Water Industry Act 1991 (WIA)

The primary legislation that concerns the regulation of the water industry, including sewage services.


A unit of measure for power, or how fast energy is used.


Warm Home Discount. Opening on 23rd October 2023 for ‘23/’24 applications, it provides a £150 discount to lower-income households in England and Wales.

Wholesale Costs

The cost of purchasing the electricity and gas you use. It’s normally included as part of your unit cost, and isn’t usually visible on the average utility bill.

Wind Turbine

A large turbine that generates electricity through its spinning blades. It’s one of the UK’s largest forms of renewable energy generation.


Water Industry (Vulnerable Groups) Regulations 1999.

Woodland Credits

One of the more common forms of carbon crediting, these are assigned to businesses that have been involved with or invested in woodland initiatives, such as planting trees or foliage.