Losses

National Grid Electricity Distribution (NGED) is committed to driving down customer costs and carbon emissions. Hence the company are doing as much as possible to reduce losses, although a certain economic level of losses are required in the normal running of the network.

The long-established electricity network of the United Kingdom is shown below: 

A Traditional Electricity Network

Over the past circa eight years large amounts of distributed generation have been added to the existing NGED electricity network which adds to the issues faced by DNO’s. The typical arrangement exists with the distributed generation is shown below:




The total quantity of electricity supplied in the United Kingdom during 2015 was 338TWh, but only 311TWh was consumed by customers. The difference between these two values is known as the electrical loss. Ofgem quote a societal cost of £42.48/MWh for losses. 

Distribution network losses can be broadly defined as the difference between the electrical energy entering the distribution network, from base generation or embedded generators either upstream / same level / downstream networks, and the electrical energy exiting the distribution network, for consumption purposes and properly accounted for it, in percentage terms for a particular period.



Raw levels of losses in kWh are of significance for any DNO, but a direct comparison with other DNO losses levels is more difficult: indeed, DNO losses depend not only on the network structure, but also on network energy flows.

Losses rates make a comparison between loss and energy flow levels. Consequently, they provide reference values that may be rather comparable between networks, even if they are detailed by voltage level for relevant benchmarks.
This page provides an introduction to the concept of losses; an explanation of what can be done to reduce them and a comprehensive list of what National Grid are doing to limit them. More detail on all of these topics can be found in our most recent losses strategy.