Half-hourly meters

A: A half hourly meter (also known as HH or 00) is a business electricity meter that sends consumption data to the energy supplier every half hour via telecommunications.

Both the older AMR (also called 'advanced') and the newer smart meter technologies allow for half hourly metering.

For businesses that have a maximum demand of 100kW or higher during any half hour period of the day, half-hourly metering is compulsory.

A: DNO stands for your local Distribution Network Operator. Regulated by Ofgem, these companies are separate from your energy supplier.  They manage and maintain the electricity network in your area – the local connectivity of cables and wires that bring power from the National Grid to homes and businesses.

In general, the development, maintenance and upgrading of the local network by DNOs is paid out of your energy bills through Distribution Use of System (DUoS).

Larger energy users, including all businesses with half-hourly meters, must have an agreement with their DNO about the maximum power which their premises will pull from the electricity system. This enables the DNO to ensure that the local system is robust enough to supply users’ energy needs. In turn, businesses pay a charge depending on their agreed maximum power load, usually called the Maximum Import Capacity or Available Supply Capacity.

A: Maximum Demand (MD) is a business’s highest demand of electricity at any half-hour period and is measured in either kW or kVA.

Maximum Import Capacity (MIC) is also known as Available Supply Capacity (ASC), Availability and Agreed Capacity. This is a connection agreement between your business and the local Distribution Network Operator (DNO). The agreement specifies the upper threshold of energy that the consumer expects to draw from the distribution system.

If the Maximum Demand exceeds the agreed-upon Maximum Import Capacity, an Excess Capacity Charge is levied by the DNO.

A: An organisation responsible for installing and maintaining your electricity meter. With a half-hourly meter, you'll need to appoint a Meter Operator.  It's worth making an informed choice as prices and services vary and metering contracts can last up to 5 years. If you're unsure about your current metering arrangements, we can help.

A: It's a legal requirement for you to have a contract with your MOP covering the supply and maintenance of your meter, as well as the necessary telecommunications for sending your consumption data to your energy supplier.

A: A Data Collector collects your half-hourly consumption data through a remote communications link. A Data Aggregator takes this data and validates it so it can be used for billing and settlement purposes, in line with industry requirements. Usually it's the same company, but this is not essential. If you need help appointing an accredited company, we can help.

A: Capacity Charge (also known as the Availability Charge) is the monthly per-unit charge that an energy user pays the local Distribution Network Operator (DNO).

The charge is based on the agreed-upon Maximum Import Capacity (MIC) of the business and it covers the maintenance of the electricity network.

A: The kVA (kilo-Volt-ampere) charge is a monthly amount paid to the local Distribution Network Operator (DNO) for the available power capacity provided to your business. This is paid indirectly to the DNO, via your energy bill. Your kVA charge is based on your Maximum Import Capacity (MIC).

A: Your MIC and KVA charge are usually shown on your energy bill. Maximum Import Capacity (MIC) may be listed as Agreed Supply Capacity (ASC), Agreed Capacity or Availability. For your kVA charge, look for Capacity Charge or Availability Charge. Another simple way to find this key information is to call your local Distribution Network Operator (DNO).

A: Time-of-use (also called time-of-day) tariffs offer lower rates of energy for business consumers who can shift their demand to off-peak hours. This helps suppliers and the entire UK energy network balance demand more efficiently. Plus, it helps business customers save on their energy bill.

Smart meters are crucial for the implementation of time-of-use tariffs. Businesses with smart meters can more easily understand their own patterns of energy use and can pinpoint opportunities to shift their demand.

A: P272 is a regulation which requires that energy suppliers measure the electricity consumption of business customers in in half-hourly intervals. This meant upgrading meters with Profiles 05, 06, 07 & 08 to Profile 00. You can tell if you have a half-hourly (00) meter quite simply: next to the large S, your bill will show the number 00.

The reason for the change is to make the energy market more efficient. Due to changes in demand during the day, energy is more expensive at certain ‘peak’ periods. To price accurately, your energy supplier needs to compare how much energy your business uses at different times of the day with how much energy they need to buy from the generator.

In order to make this comparison process (known as ‘settlement’) more accurate, Ofgem introduced the P272 regulation.

A: Reactive power is energy that's produced to power equipment such as motors and transformers. It's wasted energy as it doesn't get used by the equipment to create an output. Reactive power is chargeable if it exceeds the limits set out by your DNO.

If your site has a poor power factor (ratio of active power to reactive power), you can install Power Factor Correction equipment to mitigate the costs. Your DNO will be happy to discuss this with you.

The charge price and value is determined by the distributor. The charge is passed through onto your invoice. It can be found under the Pass through reconciliation section on your bill.

Details of these charges are available on the annual rate schedules published by DNO on their websites.