Network design
Technical losses
As electricity transfers from generator to customer it passes through different voltage levels. Typically, electricity enters our networks at 132,000V and then reduces to 33,000V and 11,000V before it’s reduced to 230V, termed Low Voltage, and supplied to the domestic consumer.
High voltages help to distribute electricity over long distances and keep losses to a minimum. But the cost of equipment used to distribute electricity increases disproportionately with voltage. So, to manage the network in a cost efficient manner, voltage is reduced the closer we are to the end user, Unfortunately, reducing voltage means increasing current and losses.
It’s possible to redesign the network so that more of the network operates at higher voltages, such as 132,000V. By doing this, one level of transformation can be removed and the network can step from 132,000V to 11,000V rather than using an interim 33,000V stage. The losses benefit are twofold:
- Removing a transformation stage reduces the fixed losses that are always present whenever a transformer is switched on.
- Reducing the length of the lower voltage circuits and increasing the length of the higher voltage circuits reduces the variable losses within the circuits.
The cost of building a network structured in this way is higher but can sometimes be justified where the value of the losses saved outweighs the increased cost of assets.
We continue to investigate where opportunities exist to remove transformation stages and reduce the length of lower voltage circuits.
