DUoS charges: the latest rates for high-voltage battery energy storage

Want to find all the latest DUoS charges relevant to battery energy storage? Click here to download the data!

Charlie explains DUoS costs for battery energy storage.

What are DUoS charges?

Distribution Use of System (DUoS) charges are paid by users of the distribution system. They cover the costs of installing and maintaining local electricity distribution networks - and each of Great Britain’s 14 license areas (also called “Grid Supply Point [GSP] groups”) has its own tariffs.

Assets connected at high voltage (HV) to the distribution network pay fixed charges (pence/MPAN/day), capacity charges (p/kVA/day), and energy unit charges (p/kWh).
Battery energy storage assets pay unit charges to import electricity (DUoS), and receive unit credits (gDUoS) for exporting. These charges are time-banded, so unit import charges and export credits are higher during peak times.

While these time bands may differ depending on license area, they don’t really vary beyond that. DNOs can choose to adjust these bands each year, but none have done so at any time in the financial years 2021-2024. (There also aren’t any red bands during weekends or bank holidays.)

So, how much DUoS are batteries paying?

Following the Targeted Charging Review, generation-only and storage-only sites are exempt from residual charges. However, there is a new charge: HV Site Specific No Residual.

This tariff has significantly lower fixed daily charges than other high-voltage tariffs. As a result, DUoS charges for battery storage assets are now made up almost entirely of capacity charges.

Batteries are able to offset these charges via energy unit charges - by importing energy during green bands, and exporting during red bands.

Breakdown of DUoS charges for a 50MW, one-hour battery performing one cycle per day, importing during green bands and exporting during red bands.

Since 2021, most batteries will have seen their total DUoS bill increase year-on-year - but there are huge differences between license areas:

In the South Western region, a 50 MW, one-hour battery performing one cycle per day (at the correct times) would pay nothing in DUoS (in 2024).
That same battery in North Scotland could be looking at a DUoS bill of over £50,000/MW!

Net DUoS charges for a 50 MW, one-hour battery performing one cycle per day, importing during green bands and exporting during red bands.

Can DUoS charges become a revenue stream?

For two-hour systems, DUoS tariffs offer an opportunity to generate revenue.

For two-hour batteries performing one cycle per day at the correct times, the additional electricity exported can offset those high capacity charges. In some regions, this can generate up to £16,000/MW (for 2024).

Net DUoS charge for a 50 MW, two-hour battery performing one cycle per day, importing during green bands and exporting during red bands.

Want the relevant DUoS rates in one handy spreadsheet?

Then you’ve come to the right place! You can find all the DUoS rates relevant to high-voltage battery assets right here. And, if you want more information, here are the links to the Schedule of DUoS Charges for each of the Distribution Network Operators:

If you find this data useful, please let us know!