The UK requires up to £70 billion ($94.5 billion) in grid investment by early next decade to prevent massive increases in consumer bills. The National Audit Office reports that delays in upgrading aging infrastructure have already added nearly £2 billion annually to customer costs through constraint payments. Without sufficient upgrades, these costs could reach £8 billion by 2030 as renewable energy generation grows.

Ofgem estimates transmission owners must quadruple investment to around £70 billion between 2025 and 2031 to meet the government's 2030 Clean Power target. Geoffrey Clifton-Brown, chair of Parliament's Public Accounts Committee, stated the grid has failed to keep pace with renewable growth, creating a dire need for upgrades. The NAO warns 88 key projects are at risk of missing deadlines, with failure to deliver just seven critical projects potentially raising constraint costs by £6.7 billion annually.

NESO faces criticism for sluggish grid connection progress and managing network strain during extreme weather.