Executive Summary

• Up to 20 GW of long-duration storage could be needed in Great Britain by 2050, with 6- and 8-hour BESS projected to dominate new deployments.
• Pumped storage hydro remains the most established alternative, but no new plants have come online in 40 years, limiting its growth potential.
• By 2030, falling battery costs could make BESS more cost-effective than pumped storage for durations up to 10 hours, shifting investor preferences.

Subscribers to Modo Energy’s Research will also find out:

• Why batteries are more efficient than pumped storage but experience capacity degradation over time.
• How investment returns for 8-hour BESS compare to pumped storage, with projected IRRs.
• Why long-duration BESS could outpace pumped storage in buildout without additional policy support for hydro.

To get full access to Modo Energy’s Research, book a call with a member of the team today.

Introduction

Up to 20 GW of long-duration storage could be required by 2050 to ensure security of supply, as generation becomes increasingly intermittent. With falling Capex costs and a higher revenue potential, we project a large increase in battery energy storage capacity, driven by 6 and 8 hour systems. This would follow the trend from other markets such as California.

Pumped storage hydro is the main competitor for providing long-duration storage

Exact definitions of ‘long-duration’ energy storage differ. DESNZ defines it as a technology that can discharge at full power for at least 6 hours. Many different technologies are competing to provide long-duration energy storage to the grid. This includes the established technologies of pumped hydro and battery energy storage, as well as newer compressed air and iron-air technologies.