TNUoS

Key takeaways

TNUoS is the charge linked to the national electricity transmission system.

It helps recover the cost of installing and maintaining the transmission network.

It may be bundled into your unit rate or shown separately under network / non-commodity charges.

What does TNUoS stand for?

TNUoS stands for Transmission Network Use of System.

NESO explains that TNUoS charges recover the cost of installing and maintaining the transmission system in Great Britain.

Why businesses see it

Power has to move from generation sources to demand centres.

The transmission system is the high-voltage network that does the heavy lifting, and TNUoS is one of the mechanisms used to recover its allowed costs.

How it appears on quotes

1. included in a bundled unit rate (all-inclusive), or
2. shown as a separate network charge (pass-through / itemised)

If you are comparing offers and one is all-inclusive and another is pass-through, you need a total-cost comparison to avoid false savings.

Sources

1. NESO, TNUoS charges definition and purpose
2. National Grid, “Electricity network charges explained” (plain-English overview of major charge types)