Network charging · Transmission Network Use of System

TNUoS & the locational charging debate

The charges generators and suppliers pay to use the GB transmission grid — and the most contested question in network charging: should where you plug in change what you pay, and by how much? We trace the signal, the zonal north–south gradient, and the reform.

01 Context

Paying for the wires, by location

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What the charge covers

Why location matters

02 Why it exists

The point of a locational signal

TNUoS is meant to make users face the network cost they impose — so generation and demand site themselves efficiently, not just wherever land is cheapest.

03 How the charge is built

Locational + residual, zone by zone

The charge has a forward-looking locational part (what your location costs the network) and a residual part (recovering the rest of the network's allowed revenue). Generators and demand are charged on different bases.

Estimate a generator's locational chargei

Pick a zone and a project size to see the annual TNUoS bill (or credit).

Annual TNUoS for this zone & size

Wider locational

Local

Residual

The maths behind the locational tariff

Who pays

    04 Zonal data

    The north–south gradient

    The single clearest picture of the locational signal: what a generator pays per kW of capacity, zone by zone, from the far north of Scotland down to the south coast.

    Zonal TNUoS tariffs (£/kW/year)

    Northern zones pay the most; southern zones can be paid (negative charge).

    Charged party

    Why volatility is a reform driver

    Generation tariffs for selected zones across charging years — large year-on-year swings make investment hard to plan.

    Zonal tariff table

    Every zone used in the charts above, with the charging year stated.

    05 The reform

    From the TCR to REMA — a moving target

    TNUoS has been reformed and re-reviewed repeatedly. Here's the timeline, and the core argument: stronger locational signals are more efficient, but more volatile and harder to invest against.

    The case for stronger locational charging

      The case against (or for caution)

        Sources & notes

        Where these figures come from

        Primary & authoritative sources

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