Open letter: National Grid Electricity Transmission’s deferral of £480m of RIIO-T1 allowances

Correspondence and other

Publication date

Industry sector

  • Supply and Retail Market
  • Distribution Network
  • Transmission Network

Our electricity transmission price control (RIIO-T1) provides National Grid Electricity Transmission (NGET) with allowances to invest in its electricity transmission infrastructure. These allowances are ultimately paid for by energy consumers through their electricity bills.

On 28 March 2017, National Grid plc announced that it would voluntarily return £480m of its RIIO-T1 allowances due to deferred investment. The effect of this will be a relative reduction in network charges from 2019/20 onwards. This will help to reduce energy bills relative to what they otherwise would have been. 

This letter sets out how we propose to reduce NGET’s price control allowance.