Energy Jargon Buster

Energy Jargon Buster

Do you know your kWh from your kWp and can you explain the difference between ISO 5001 and ESOS? If the answer is no then our Energy Jargon Buster will help!


  • kWh (Kilowatt Hour) – the electricity consumed or generated every hour. A kilowatt comprises of 1000 watts
  • kWp (Kilowatt Peak) – the maximum possible electricity generation from a system
  • MWh (Megawatt Hour) – the electricity consumed or generated every hour, measured in megawatts (1000 kilowatts)
  • kWth (Kilwatt Thermal) and KWh(th) – kWth is the unit of heat supply capacity measuring the potential output from a heating plant. It is not to be confused with the units of heat produced which is measured in kWh(th)
  • HH (Half Hourly) – the meters with a ‘00’ profile number used by energy-intensive organisations
  • KVA (Kilovoltampere) – unit of power related to running industrial machinery. Kilovolt-amp (kVA). kVA is kilo-volt-ampere. kVA is a unit of apparent power, which is electrical power unit. 1 kilo-volt-ampere is equal to 1000 volt-ampere
  • DC (Direct Current) – the current / electrons flow in a single direction. DC is produced by fuel cells, batteries and generators. It is not easily converted to higher or lower voltages
  • AC (Alternating Current) – the current / electrons flow in forward and backward direction. Our electricity is predominantly powered by AC, which can be transported easier
  • CEGB (Central Electricity Generating Board) – UK electricity generators and suppliers that operated from 1957 to 1990s, when it was privatised and transferred to four companies
  • Big Six – the term referring to the major energy suppliers in the UK today with over 90% share of domestic customers. These are British Gas, EDF Energy, nPower, Scottish Power, SSE and E.ON UK
    Non-Big Six – the term used for alternative energy suppliers to the Big Six
  • DNO (Distribution Network Operator) – companies licensed to distribute electricity in the UK. These are divided into 14 geographically defined areas, based on former area electricity board boundaries. DNOs are responsible for allocating MPANs and the ECOES database of electricity supply points
  • MPAN (Meter Point Administration Number) – unique reference number for your electricity supply
  • MPRN (Meter Point Reference Number) – unique reference number for your gas supply
  • Single phase – AC 230 volt electricity supplied to our homes. It has two wires, live and neutral. Single-phase power will have period with zero power but in most situations this does not matter because the load has enough energy storage
  • Three phase – a further two electrical circuits. In a three-phase service the individual voltages peak one after the other in sequence so the power is more constant at AC 415 volt phase to phase. A 3-phase system is much more efficient for high-capacity installations, but is more costly to install. This is why 3-phase utility power is typically only available in industrial and commercial areas.
  • Standing charge – daily charge that covers the cost of maintaining your supply
  • M&V (Measurement & Verification) – the process for quantifying savings delivered by an Energy Management Program. This demonstrates the energy savings rather than cost savings and therefore enables a fair evaluation by removing external factors like energy prices
  • IPMVP (International Performance Measurement & Verification Protocol) – a non-profit organisation that provides best practice techniques for verifying the energy performance of new construction projects
  • CSR (Corporate Social Responsibility) – a process of self-regulation whereby an organisation ensures environmental, social and ethical practices. CSR encourages a positive impact on all stakeholders, including consumers, employees, investors and communities
  • Energy Performance Contract – a contract between businesses under which energy efficiency measures are provided and monitored and paid for by reference to an agreed level of energy efficiency improvement or financial savings