A new methodology for modelling energy storage in long-term capacity expansion planning could be used as a precise tool in analysing the technological support needed for the shift to renewable energy – and it could help policymakers predict a nation's storage needs in the transition away from fossil-fuelled power generation.

The study – “Modelling energy storage in long-term capacity expansion energy planning: an analysis of the Italian system” – explores the role of energy storage technologies in achieving a fully decarbonised power sector in Italy by 2050.

The authors project that, by 2050, 10% of Italy’s electricity generation will need to pass through energy storage systems to ensure stable grid operations without reliance on carbon-intensive backup solutions such as natural gas. The analysis suggests short-duration energy storage technologies will be crucial in balancing supply and demand as Italy transitions to a more renewable energy mix. “The findings indicate that energy storage is crucial for fully decarbonising the Italian power sector by 2050 in the absence of a low-carbon baseload,” the paper states.

While the research focuses on Italy, the model’s flexible design allows it to be applied to any energy system, offering valuable insights for policymakers as they plan long-term energy strategies.

The approach highlights the potential role of energy storage in addressing the intermittency of variable renewable energy sources like solar and wind, which are expected to form a large share of future electricity generation. The research also examines different storage technologies and their economic feasibility over time, including alternative options like compressed air energy storage and sodium-sulphur batteries.

The model, a modified version of the Tools for Energy Modelling Optimisation and Analysis, enables detailed modelling of energy storage technologies – such as lithium-ion batteries, pumped hydro and hydrogen storage – within a long-term capacity-expansion context. It also accounts for daily and seasonal fluctuations in renewable energy production such as greater solar power generation during summer and reduced output overnight. In addition, it considers varying energy consumption patterns.

Considering technology competition scenarios, the study notes the availability of nuclear power could change the role of renewables and storage in the energy sector. “If nuclear is available, the system relies less on storage, which implies that storage becomes less competitive when nuclear power serves as a stable baseload.”

The authors emphasise the need for further research, particularly around the interplay between renewables, storage and nuclear power. Future studies should investigate how storage technologies could be optimised to enhance system resilience, particularly considering uncertainties around renewable generation and market volatility for critical storage materials, the study advises.