NESO procures 40GW in T-4 auction, with energy storage winning 6.4% of capacity

The UK's T-4 capacity market auction for 2029/30 delivery cleared at £27.10/kw/year on March 10, 2026, a substantial decrease from the previous year's £60/kw/year, indicating increased competition and potentially lower perceived risk for future capacity. National Energy System Operator (NESO) procured 40,108.608MW of obligations, exceeding its 39,400MW target to ensure future electricity supply across the UK. Energy storage technologies secured 6.4% of the awarded capacity, with battery energy storage systems (BESS) winning 1,224MW (3.05%) and pumped hydro storage securing 1,352MW (3.337%). While gas projects still dominate with 58.5% of the capacity, the significant allocation to storage underscores its growing role in grid stability and flexibility for the UK. This auction saw several prominent renewable energy and infrastructure players secure BESS contracts, reinforcing their commitment to the UK's energy transition. Grenergy, an international renewable energy company focused on solar and storage, and Gresham House, a specialist alternative asset manager with expertise in renewable energy and battery storage, both won obligations. Eku Energy, a global renewable energy developer, and European Energy, active in battery storage and Power-to-X projects, also secured capacity. Harmony Energy, an owner-operator of utility-scale battery storage across Europe and New Zealand, and Amp Clean Energy, further expanded their UK portfolios through this tender. NESO, as the new public corporation taking over UK electricity and gas system operation in 2024, successfully managed this critical mechanism for 2029/30 supply.