Decision on the calculation of Interest During Construction (IDC) and the IDC rate to apply during 2018/19 for offshore transmission and future cap and floor interconnectors

Publication date
30th July 2018
Information types
Policy areas

We published our consultation on 23 January 2018. We received five responses to the consultation. This letter sets out our decision on the IDC rates for offshore transmission and electricity interconnectors under the cap and floor regime, to apply to projects which take a Final Investment Decision (FID) during 2018/19.

Following a public consultation process and a careful consideration of stakeholders’ views, we have decided the following:

  • Offshore IDC – to confirm the IDC cap rate at 6.50% (pre-tax, nominal) for offshore transmission projects reaching FID during 2018/19.
  • Interconnector IDC – to confirm the rate at 2.84% (real vanilla) for any cap and floor Window 2 interconnector projects reaching FID during 2018/19.
  • Interconnector IDC – to confirm that we are ending the approach of setting IDC for interconnector projects on a project-specific basis at the time of FID. This decision will affect Window 2 and future interconnector projects.