Investment viability: long duration energy storage
Supporting clients in understanding the technical suitability and commercial opportunity of investing in LDES for their energy market.
Challenge
Long Duration Energy Storage (LDES) is defined as storage with at least around 8 hours of discharge duration. It plays a critical role in delivering a low-carbon and flexible energy system, though for developers, the commercial opportunity of LDES still holds varying levels of uncertainty depending on the specific energy market.
According to NESO, Great Britain will require 4-6 GW of LDES capacity to achieve its Clean Power 2030 ambition. As a result, DESNZ has recently established a cap and floor mechanism to provide revenue certainty for LDES developers and support LDES deployment. The first round of procurement took place in June 2025 with the results expected to be available by Q2 2026.
In Europe, the policies or procurement mechanisms to support LDES are more limited, though emerging.
In Spain, the European Regional Development Fund recently awarded CAPEX grants for storage projects to be built by 2029. The projects awarded funding in 2025 include pumped storage projects with up to 30-hour durations.
In Ireland, Eirgrid recently launched a consultation for its Long Duration Energy Storage Procurement Mechanism which closed in November 2025. In this consultation, LDES was defined has having at least 4 hours of discharge duration and 10-year contracts were proposed. This consultation results are still pending but it is anticipated that the initial procurement round will take place in 2027 with the selected projects expected to be operational by 2030.
Approach
This study aimed to evaluate both the technical suitability and commercial readiness of LDES solutions in the context of projected renewable growth. We conducted a comprehensive literature review and market analysis, drawing on global case studies and technology benchmarks for several technologies, including:
- Lithium-ion
- Flow batteries
- Gravity Energy Storage System
- Metal Anode
- Compressed Air Energy Storage (CAES)
- Liquid Air
- Liquid CO2
- Pumped Hydro
- Hydrogen
The evaluation considered the suitability for each technology in terms of: technology readiness level; technology related locational constraints; energy delivery response time; size of energy storage in hours; and round trip efficiency.
The key difference between the technologies providing LDES compared to those providing short duration energy storage (which is dominated by Lithium iron phosphate – LFP – technology) is the higher CAPEX and varying levels of technology readiness. This is particularly important given the limited real-world examples of LDES assets to support investment. However, it should be noted that LDES projects using LFP are becoming increasingly common such as the 50MW/400MWh Limondale BESS in Australia recently commissioned.
A bespoke LDES sizing tool was developed to quantify commercial opportunities based on projected wind and solar curtailment at specific grid nodes, enabling location-sensitive analysis of deployment potential.
Results
The client was provided with a clear understanding of which LDES technologies are most viable in terms of technical suitability and commercial opportunity for near-term deployment in its market, meaning it was able to confidently identify key market entry points, policy enablers and investment considerations. The sizing tool offers a practical decision-support resource for evaluating future LDES projects tailored to the organisations desired profitability scores and energy output requirements, helping to inform strategic planning and investment in low-carbon, flexible energy solutions.