Evolve Energy Glossary

The portion of electrical power that performs actual work in a circuit, such as running motors, lighting, or heating equipment, also known as real power or true power. Measured in watts (W) or kilowatts (kW), active power represents the energy that is genuinely consumed and converted into useful output, as opposed to reactive power.

Additionality refers to the extent to which an activity or investment results in outcomes that would not have occurred without it, often used in energy and carbon markets.

The maximum electrical capacity (measured in kVA) that a site is permitted to draw from the electricity network at any time, as set by the local Distribution Network Operator (DNO). Customers pay a capacity charge based on this agreed limit, which covers investment and maintenance of the distribution network. Maximum demand should not exceed the agreed capacity to avoid additional charges or penalties.

An Allocation Agent (AA) is responsible for calculating and distributing energy volumes between market participants in accordance with agreed rules.

An Allocation Terminal is a system or interface used to submit, receive, and manage energy allocation data between market participants. It supports the accurate exchange of metered volumes and adjustments in line with market rules, helping ensure settlement processes reflect actual consumption and generation.

A biological process in which microorganisms break down organic matter in the absence of oxygen, producing biogas primarily composed of methane (CH4) and carbon dioxide (CO2). For I&C energy users, AD facilities can convert organic waste streams such as food processing waste and commercial food waste into renewable energy and heat. Large I&C consumers may operate on-site AD plants to qualify for ROCs or CfDs.

It is the sum of the annual consumption of all meters on a site. This comes from National Grid, and is based on historical usage from previous years. Measured in kWh (electricity) or Therms (gas). Supply Point AQ is the total annual consumption of all meters on a site. Meter Point AQ is the AQ for a particular Meter Point.

The total power in an AC electrical system, calculated as the product of voltage (volts) and current (amps), and measured in kilovolt-amperes (kVA) or megavolt-amperes (MVA). Apparent power comprises both active power and reactive power.

is a scheme implemented as part of the Energy Act 2004 and designed to reduce the cost of electricity distribution in ‘Specified Areas’, which is currently the North of Scotland.

A metering technology that enables automatic collection and transmission of meter data remotely to suppliers and network operators, eliminating the need for manual meter readings. AMR systems transfer consumption data directly into billing and settlement systems, improving accuracy and enabling more frequent reads.

The system by which National Grid ESO balances electricity supply and demand in real-time to maintain grid stability. Large I&C consumers and generators can participate by submitting offers and bids to increase or decrease output or consumption. The BM operates continuously with participants receiving instructions and payments based on accepted offers to manage system imbalances.

Balancing risk refers to the financial exposure faced by energy suppliers or generators when actual electricity demand or generation differs from forecast positions. These imbalances must be corrected through the balancing mechanism, often at volatile prices, which can significantly impact costs.

Charges levied by National Grid ESO to recover the costs of balancing electricity supply and demand across the GB transmission system in real-time. These charges cover frequency response, reserve services, constraints management, and other balancing mechanisms. BSUoS charges are typically expressed as GBP/MWh and are volatile, making them a significant non-commodity cost for HH metered I&C customers.

The minimum level of electrical demand that occurs continuously over a 24-hour period, representing the constant underlying consumption that never ceases. In I&C energy procurement, understanding baseload consumption is critical for optimising supply contracts, as it represents the consistent demand that can be served by constant generation sources.

Power generation facilities that provide steady, continuous electricity supply to the grid, typically operating at consistent output levels 24 hours a day, 7 days a week. These generators, traditionally including nuclear and large coal or gas plants, ensure grid stability by meeting minimum constant demand regardless of time or season.

Direct contractual agreements between two parties, typically a generator and a supplier, to deliver electricity at a specified future date and agreed terms. This type of trading occurs outside centralised markets and allows parties to negotiate prices, volumes, and delivery schedules independently.

A renewable fuel generated through anaerobic digestion, where bacteria break down biological material in the absence of oxygen. The resulting gas is a mixture of methane and carbon dioxide, making it suitable for electricity generation and heat production.

Organic matter used as fuel for energy generation, obtained directly from plants or indirectly from industrial, commercial, domestic, or agricultural by-products. In I&C energy contexts, biomass is used in CHP plants, boilers, and renewable energy systems, and is classified as carbon neutral because CO2 released during combustion is balanced by that absorbed during plant growth. Commercial users may procure biomass-generated electricity through RECs or PPAs.

Carbon dioxide is a greenhouse gas that contributes to climate change by trapping heat in the Earth’s atmosphere.

Certificates representing a specific amount of carbon dioxide emissions. These are often used in emissions trading schemes or for voluntary carbon offsetting.

When new renewable energy projects are added to the system, they can sometimes reduce the revenue earned by existing renewable generators. This occurs when high levels of renewable generation push overall electricity prices down. The risk of this happening is known as cannibalisation.

Also known as emissions trading and regulated by the government, cap-and-trade limits or caps the amount of emissions that can be resulted from industrial activities. Elements capped are specific chemicals, particularly CO2.

A fee levied by the Distribution Network Operator (DNO) based on the agreed capacity (kVA) of a premises. This charge covers the investment in and maintenance of the local electricity distribution network. It is calculated per unit of agreed capacity and forms part of the Distribution Use of System (DUoS) charges for commercial and industrial sites.

A government scheme designed to ensure security of electricity supply by providing payments to reliable capacity providers to maintain sufficient generation and demand-side response capability to meet peak demand.

This is the average price per unit of energy that a generator receives for its output over a given period. The price is calculated taking the wider market and subsidies into account.

This is the set budget for how much greenhouse gases can be emitted over a set period of time.

A suite of technologies designed to capture carbon dioxide (CO2) emissions from industrial processes and power generation facilities and transport it for long-term geological storage underground. CCS prevents CO2 from entering the atmosphere and is considered critical for decarbonising hard-to-abate industrial sectors.

In relation to carbon emissions, CO2 is measured in tonnes. A typical household has around 10.9 tonnes of CO2 emissions per year. Carbon Emissions Reduction Target (CERT) The CERT, previously the energy efficiency commitment (EEC2) is the governments main policy instrument for reducing carbon emissions from existing households. CERT is due to run from 2008-2011, Defra will be responsible for setting the CER target for suppliers and OFGEM is responsible for administrating the programme.

A carbon footprint is the total amount of greenhouse gas emissions produced as a result of activities carried out by an individual, organisation, or product. These emissions are mainly carbon dioxide and can come from sources such as travel, energy consumption, and the use of resources. For example, travelling to meetings, operating equipment, or running buildings can all add to a carbon footprint.

A measure of the amount of carbon dioxide (CO2) emissions produced per unit of electricity generated, typically expressed in grams of CO2 per kilowatt-hour (gCO2/kWh). Carbon intensity enables I&C customers to compare the environmental impact of different electricity sources, with coal at approximately 890 gCO2/kWh having significantly higher intensity than gas at approximately 370 gCO2/kWh or renewable sources.

Describes an activity, process, organisation, or product that achieves net zero carbon dioxide emissions by balancing greenhouse gas emissions produced with an equivalent amount removed from the atmosphere or offset through verified carbon reduction projects. In the I&C energy context, businesses achieve carbon neutrality through energy efficiency measures, renewable energy procurement, and certified carbon offsets.

A mechanism whereby commercial and industrial organisations compensate for their greenhouse gas emissions by funding projects that reduce or remove an equivalent amount of CO2 from the atmosphere. Common activities include reforestation, renewable energy projects, methane capture, and carbon sequestration.

Carbon Reduction Commitment (CRC) The CRC is a UK government emissions trading scheme for large organisations which are not eligible for EU Emissions Trading. This includes banks, large offices, universities, large hospitals, large local authorities and central government departments. The scheme is mandatory. The CRC is expected to deliver emissions reductions totalling 0.5m tonnes of carbon (Mtc) per year by 2015.

An independent non profit company set up by the Government with support from businesses to encourage and promote the development of low carbon technologies. Key to this aim is its support for UK businesses in reducing carbon emissions through funding, supporting technological innovation and by encouraging more efficient working practices.

The sun warms the Earth, and gases in the air (called greenhouse gases) trap that heat. The more gases released, the more heat is trapped, and the warmer Earth gets. This warming is called climate change, and it can cause problems for the Earth and all the living things on it. Burning fossil fuels coal, oil and gas are the most significant contributor to global climate change.

An agreement between the Government and a business user, whereby a reduced rate of Climate Change Levy is payable in return for a commitment by the user to achieve certain pre-determined targets for energy usage or carbon emissions.

CCL is a government-imposed tax to encourage reduction in gas emissions and greater efficiency of energy used for business or non domestic purposes. CCL is chargeable only on units/kWh used and not on any other component of the bill, e.g. standing charge. The rate of CCL is now index-linked and therefore likely to increase on 1 April each year. Under current legislation: where VAT is charged at the standard rate, CCL (plus VAT on CCL) will usually be added to the bill where VAT is charged at the reduced rate, the supply is automatically excluded from CCL Where VAT is charged at the standard rate but sites are entitled to full or.

Published in 2000, sets out the Government and Devolved Administration strategic approach to tackling Climate Change and meeting the UK's Kyoto target of a 12.5% reduction in greenhouse gas emissions from 1990 levels by 2008-2012 and the domestic goal of reducing CO2 emissions by 20% by 2010.

Also known as Combined Heat and Power (CHP), cogeneration is the simultaneous generation of electricity and useful thermal energy from a single fuel source at the point of use. This technology enables commercial and industrial sites to generate power onsite, improving energy security and efficiency, and can utilise low-carbon primary fuels such as biogas to reduce environmental impact.

Commodity charges refer to the charges you pay for the actual energy you use, which is based on your level of consumption.

The cost of the actual energy (electricity or gas) you use.

Certificates that demonstrate compliance with legal or regulatory requirements, such as renewable energy mandates or emissions reduction targets.

In 1992, some United Nations member countries signed a landmark treaty to tackle climate change. The leaders of these countries (and others who have signed the treaty since) meet every year to discuss and negotiate efforts to address climate change. COP stands for Conference of the Parties. The number after it stands for the session number. So, COP29 means the 29th time these leaders have met.

A legally binding contract between an I&C customer (or generator) and either a Distribution Network Operator (DNO) or National Grid ESO that establishes the technical and commercial terms for connecting electrical installations to the distribution or transmission network. The agreement specifies connection capacity, technical requirements, charging arrangements, and ongoing obligations.

Price of a unit of gas or electricity which the supplier charges the customer.

This indicates a supply offer, which has all delivery charges (DUoS & TUoS) built into the unit rates for the supply of electricity.

The UK government's primary mechanism for supporting low-carbon electricity generation, established in 2013. Under the CfD scheme, generators receive a guaranteed strike price for the electricity they produce, providing revenue certainty to incentivise investment in renewable and low-carbon technologies.

A Corporate Power Purchase Agreement is a contract between a corporate energy buyer and a renewable energy generator. It enables the corporation to buy electricity at a pre-agreed price for a pre-agreed time period.

For sites using large amounts of gas it is often deemed necessary to measure the temperature and pressure variations more accurately rather than just applying a fixed conversion factor. In these cases an additional corrector meter is attached to the meter.

A device used to record meter readings and automatically transmit them to the meter reading agency.

A default supply agreement that automatically comes into effect when a business begins consuming electricity or gas at a premises without having signed a formal supply contract. These contracts apply standard, often less competitive rates until the customer arranges a negotiated fixed-term agreement. Deemed rates are typically higher than contracted rates and serve as a safeguard mechanism to ensure continuous energy supply.

The deliberate adjustment of electricity consumption by commercial and industrial users in response to price signals, grid conditions, or requests from network operators or National Grid ESO. DSR programmes enable businesses to reduce or shift their energy demand during peak periods, helping to balance supply and demand, reduce system stress, and support grid stability. Participants may receive financial incentives or reduced energy costs in exchange for their flexibility.

Electricity generation usually on a relatively small scale that is connected to the distribution networks rather than directly to the national transmission systems.

Electrical energy losses that occur as electricity is transmitted through distribution network infrastructure from the Grid Supply Point (GSP) to customer metering points. D-loss charges are calculated using Line Loss Factors (LLF) applied as multipliers to metered consumption, and are recovered through DUoS charges for I&C customers.

A licensed company responsible for owning, operating, and maintaining the regional electricity distribution network that delivers power from the transmission system to end-user sites. There are 14 DNO licence areas in Great Britain, each managing local infrastructure including substations, transformers, and cables.

Charges levied by Distribution Network Operators (DNOs) for the use of the local electricity distribution network to transport power from the transmission grid to a customer's meter. These charges consist of multiple components including daily standing charges, capacity charges (p/kVA/day), and unit rates (p/kWh), with time-of-use bands (red, amber, green) affecting unit rates for Half Hourly metered sites.

A set of criteria used to evaluate a company's performance in areas such as environmental sustainability, social responsibility and corporate governance.

The rate at which electricity flows through an electrical conductor, usually measured in amperes (amps).

A device that measures the amount of electricity used.

The industry administrator helping ensure the energy system runs as it should.

A market mechanism that allows emitters (countries, companies or facilities) to buy emissions from or sell emissions to other emitters. Emissions trading is expected to bring down the costs of meeting emission targets by allowing those who can achieve reductions less expensively to sell excess reductions (e.g. reductions in excess of those required under some regulation) to those for whom achieving reductions is more costly.

A market-based mechanism designed to reduce greenhouse gas emissions by establishing a cap on total allowable emissions within a defined sector or economy. Participants, typically large industrial and commercial energy users, must hold emissions allowances covering their carbon output and can trade these allowances in a regulated market. By assigning a cost to carbon emissions, an ETS incentivises businesses to invest in cleaner technologies, supporting UK ETS and EU ETS decarbonisation targets.

Certificates that represent the environmental and social attributes of a megawatt of energy, such as its carbon intensity or the renewable nature of its source.

The optimisation of energy consumption to achieve required operational outputs such as lighting, heating, cooling, or production processes while minimising waste and reducing overall energy use. In commercial and industrial contexts, energy efficiency is achieved through technology upgrades, process optimisation, monitoring systems, and operational controls that deliver cost savings and carbon reduction without compromising performance.

The process of recovering energy from post-recycling waste residue through thermal treatment, typically incineration with energy recovery. This generates electricity and sometimes heat for district heating systems, providing an alternative to landfill disposal. For I&C customers, EfW facilities represent both a waste management solution and a source of renewable electricity supply contracts.

The physical location where gas is delivered into the National Transmission System (NTS), typically at a gas terminal or import facility.

The EU emissions trading scheme, introduced in April 2005. See the section on Carbon emissions trading scheme', above.

This enables a site to export electricity generated onsite.

A UK government scheme introduced in April 2010 to incentivise small-scale renewable electricity generation, such as solar PV and wind installations. Participants received payments for electricity generated and exported to the grid, with scheme costs recovered through levies on all energy suppliers and passed to end customers. For I&C customers, FiT costs appeared as environmental and social obligation charges on electricity bills. The scheme closed to new applicants in April 2019.

Gas supplied to a customer on a guaranteed basis, without interruption.

A daily, monthly or quarterly charge levied by the supplier and is in addition to the standing charge.

A long-term contract between a power producer (typically a renewable generator) and a power purchaser in which the producer agrees to sell electricity at a fixed price over a defined period, typically 10 to 25 years. Fixed PPAs provide price certainty for both parties, enable project financing for generators, and allow corporate purchasers to secure renewable energy supply while hedging against wholesale market volatility.

Fixed term contracts are energy supply agreements where unit rates and standing charges are fixed for a specified contract duration. These contracts provide price certainty and budget stability, protecting businesses against wholesale market volatility, though they may include break clauses, rollover provisions, and separate pass-through charges for non-commodity costs such as DUoS, TNUoS, and CCL.

An energy source formed in the Earth's crust from decayed organic material. The common fossil fuels are oil, coal, and natural gas.

In England and Wales the Fossil Fuel Levy is set at 0.3%. This levy was introduced to cover the cost of decommissioning the nuclear generating plants. The Scottish equivalent is called the S.R.O. (Scottish Renewable Order) levy which was set at 0.8%.

A regulatory requirement whereby all UK energy suppliers must annually inform their customers about the mix of fuels used to generate the electricity supplied.

These charges cover the cost of transporting gas from where it enters the UK to the end user. The cost also covers maintenance, safety and security of the network and in the development new gas connections. The transportation charge is invoiced per kWh.

The production of electricity at power stations and generating facilities that supply power to the national grid. In the I&C energy market, generation encompasses various fuel sources including gas, nuclear, coal, and increasingly renewable sources such as wind, solar, and biomass. Understanding generation mix and capacity is crucial for commercial energy buyers as it affects wholesale prices, carbon intensity, and the availability of PPAs.

A power unit equal to one billion watts; often used to measure the capacity of large power plants or electricity grids.

The long-term increase in Earth's average surface temperature primarily caused by human activities, particularly the emission of greenhouse gases from fossil fuel combustion and industrial processes. I. Global warming drives regulatory frameworks including carbon pricing mechanisms, renewable energy mandates, and corporate sustainability reporting requirements.

An electronic certificate that provides evidence that one megawatt-hour (MWh) of electricity was generated from a specific renewable or low-carbon energy source. GOs are used across European markets to track and verify the renewable attributes of electricity generation separately from the physical power itself

A term referring to low-carbon or renewable gases, such as biomethane or hydrogen, that can be used as alternatives to fossil-based natural gas.

The physical location where electricity is transferred from the National Grid high-voltage transmission system into a regional Distribution Network Operator's (DNO) local distribution network. GSPs serve as critical metering and pricing boundaries, with each GSP Group area having distinct DUoS charges and regional electricity pricing characteristics relevant to commercial energy procurement.

A Half Hourly Meter automatically captures and sends automatic readings from your electricity meter to your energy supplier every half hour.

HHD is a record of electricity consumption data taken at 30-minute intervals from the HH meter.

A risk management strategy where energy buyers purchase electricity or gas in advance of consumption to lock in prices and protect against future market volatility. This procurement approach allows businesses to secure fixed or capped rates through forward contracts, futures, or other financial instruments. Corrected: in advanced to in advance.

When we use the term High Voltage, we mean 11,000 Volts or above.

The generation of electricity by harnessing the energy of flowing or falling water to drive turbines connected to electrical generators. Hydroelectric power represents a renewable energy source available through green energy contracts and PPAs. Hydroelectric generation provides baseload renewable capacity and is commonly included in renewable energy portfolios for commercial customers.

A power producer that is not owned by a utility company and often focuses on renewable or distributed energy sources. Independent renewable generators support the growth of clean energy, help meet business demand for renewable power and reduce carbon emissions.

These relate mostly to the costs of providing the infrastructure required to deliver power. They include the cost of energy lost as heat as it travels from the power station down the transmission and distribution wires to you, and charges for using the transmission and distribution networks (which are called TUoS and DUoS).

J is the symbol for a joule the way we measure energy. One watt (W) is equivalent to electricity flowing at a rate of one joule per second.

kW or kilowatt is the universal standard for measuring electricity. One kilowatt equals 1,000 watts.

The kWh, or kilowatt hour measures how much energy you use per hour. Your electricity bill will feature the price per kWh your provider charges.

A supply point where the reference consumption actual quantity (AQ) is equal to or exceeds 732,000 kWh/25,000 therms per annum.

The risk of damaging a company's reputation or being financially penalised when an organisation doesn't adhere to policies, standards, regulations and laws.

Line Loss Factor codes are used to calculate the related DUoS charges for an MPAN. The figure gives us the voltage scale of the Mpan and reflects both the amount of transmission infrastructure used to supply the point and the amount of energy lost through heat etc.

LNG is natural gas that has been cooled to a liquid state at about -162°C, making it easier to store and transport.

The amount of electric power delivered or required at any specific point or points on an electrical system. The requirement originates at the energy-consuming equipment of the customer.

Load Factor is a comparison of the average energy usage to the peak energy usage over time. For example, a data centre working 24/7 would have a high Load Factor—steady, consistent energy consumption throughout a day or time period. The average energy usage would be close to the peak usage, and there would be fewer variations in demand. On the other hand, a factory which is open during the day and closed at night would have a low Load Factor. Its peak usage would be much higher than its average usage.

A load profile is a graph or chart showing the variation in demand for electrical load over a specific period.