Distribution Use of System (DUoS) charges reflect the cost of installing and maintaining the local distribution networks, paid by users to Distribution Network Operators (DNOs). On the Leaderboard, two columns exist. These reflect the two different components of DUoS charges paid by distribution network users: 'DUoS' and 'Fixed DUoS'. This charge is levied at distribution-connected battery energy storage system (BESS) assets.

The first stage of calculating DUoS charges is determining which distribution system each asset is connected to. This is determined by their Grid Supply Point (GSP) group. For each GSP group, we use scraping algorithms to get data from the Schedule of Charges spreadsheets for each DNO.

Table 1 (below) highlights the tariffs we use for imports and exports for all assets on the Leaderboard. DUoS charges change annually, and DUoS rates, bands and periods vary between DNOs and connection types. (The Modo team are currently expanding upon our asset database to include MPAN numbers for each asset, which will improve the accuracy of our DUoS charge estimations.)

* HV = high-voltage; HH = half-hourly.

The 'DUoS' column on the Leaderboard represents the energy-based DNO costs assets are liable to pay. This is calculated by multiplying our estimated net energy throughput by the respective green, amber, and red tariffs applicable for each settlement period. The green, amber, and red tariffs represent times in the day when charges differ as outlined by each DNO in the Schedule of Charges spreadsheets.

The 'Fixed DUoS' column represents the fixed costs associated with using the distribution system. This is calculated using the ‘Fixed p/MPAN/day’ & ‘Capacity charge p/kVA/day’ charges, assuming two MPANs (one import and one export) and and a unity power factor. A schedule is then created using these fixed charges for each settlement period across each day in each GSP group. These schedules are then mapped to BESS assets by GSP. Monthly costs are aggregated to estimate the Fixed DUoS cost.

Although Fixed DUoS is project-specific and not impacted by operational performance, the cost is included in the Leaderboard to provide greater visibility of charges for BESS assets in GB.

To find out more about how DUoS works, watch our Energy Academy video here.