The Department for Energy Security and Net Zero (DESNZ) has published the calculation of the Renewables Obligation (RO) for 2027-2028, setting the number of Renewables Obligation Certificates (ROCs) electricity suppliers must present to Ofgem for each MWh of electricity supplied.

For Great Britain — England, Wales and Scotland —, the level has been set at 0.369 ROC/MWh, down from 0.472 ROC/MWh for 2026-2027, a reduction of around 21.8%. In Northern Ireland, the obligation will be 0.143 ROC/MWh.

Level could rise to 0.394 ROC/MWh

The UK government also published an alternative estimate linked to the future British Industrial Competitiveness Scheme (BICS).

If the necessary legislation enters into force in time for the new exemption to apply from 1 April 2027, DESNZ estimates that the obligation in Great Britain would rise to 0.394 ROC/MWh for the full 2027-2028 period.

The scheme is expected to provide eligible manufacturing companies with an exemption of up to 100% of the indirect costs of the Renewables Obligation. The government estimates that electricity consumption exempted under BICS could reach 15.7 TWh in 2027-2028, in addition to the 13.6 TWh expected under the existing exemption for energy-intensive industries.

If the legislative changes are not approved in time, the 0.369 ROC/MWh level will remain in place for the whole period.

Less capacity under the scheme

The 2027-2028 calculation is based on around 25.2 GW of renewable capacity supported under the Renewables Obligation.

The lower obligation reflects, among other factors, the reduction in renewable capacity still supported under the scheme. According to DESNZ, this capacity is significantly lower than in the previous period because a large number of installations will reach the end of their support period on 31 March 2027.

The capacity considered includes approximately 9.9 GW of onshore wind, 6 GW of offshore wind, 7.5 GW of solar PV and 1.3 GW of biomass and waste technologies, alongside smaller volumes of hydro, marine energy, landfill gas and sewage gas.

The Renewables Obligation is closed to new capacity, meaning the calculation is based mainly on already accredited installations that will remain operational during 2027-2028.

To determine the obligation level, DESNZ estimates that 84.4 million ROCs will be issued before applying the regulatory 10% headroom. Including that margin, the total obligation rises to 92.8 million ROCs across the UK.