Distribution Use of System (DUoS)

What are DUoS charges?

Distribution Use of System (DUoS) charges are fees levied by Distribution Network Operators (DNOs) for the use of their distribution networks. These charges are incurred for the delivery of electricity from the transmission grid to end users.

Who is impacted by DUoS?

DUoS charges affect all users who are connected to a distribution network, both generators and demand. The amount of DUoS charges paid will depend on:

• The location of the site. Each DNO has different charges - see our Locations page to determine your DNO.
• The voltage of the site. Lower voltages typically have higher costs, because they use more of the distribution network. For example sites connected at 7kV typically have higher costs than those at 33kV: low voltage (LV) rates are higher than high voltage (HV) rates which are higher than Extremely High Voltage (EHV) rates.
• The behaviour of the site. For example, sites consuming lots of power during the evening peak (which falls in the DUoS 'red band' around 16:00 - 19:00) will typically have higher costs than those consuming power outside of that time band. That's because some elements of the DUoS tariffs are time-of-use.

DUoS and batteries

More information on DUoS charges and batteries can be found here.

Essentially, DUoS charges can result in batteries either paying, or being paid for connection to the grid in different regions, similar to other network charges. When connected at a low voltage in regions close to demand centres, revenues from optimising a battery around time-of-use DUoS tariffs can be significant.

However, for EHV sites - covering the majority of utility-scale distribution-connected storage - time-of-use DUoS rates are usually negligible. They are also site-specific. Hence they are ignored for the generic sites within our forecast run library.

DUoS charges consist of fixed and variable tariffs

• Fixed Charges: Incurred regardless of the amount of electricity consumed or generated.
• Capacity Charges: Based on the maximum capacity provided to the site.
• Unit Charges: These vary depending on the amount of electricity passed through the network and are influenced by whether the facility is consuming energy or exporting it back to the grid.
• Time-of-Use Tariffs: LV and HV sites have green, amber and red pricing bands, which depend on the time of use. The red band is typically between 16:00 and 19:00 on weekdays, and the green band is typically overnight. Batteries on HV and LV sites should consider these DUoS rates in their optimization strategy, as they can help to minimize these time-of-use costs. EHV sites have a site specific super red band between 16:00 and 19:00 which is often 0.

DUoS charges within the Modo Forecast

You can model the DUoS charges your site will face by running a bespoke forecast, and inputting the relevant data into the forecast builder. You will need to provide us with some data on the DUoS rates specific to your site. The required data is listed below.

If you need assistance with determining these inputs for your asset, reach out to your account manager or [email protected].

Please note, both import and export prices should be positive values.