1Q 2023

Inter-Seasonal Energy Storage Will Play a Key Role in Decarbonized Energy Systems

The share of solar and wind penetration in electricity generation is expected to rise substantially in the next decade. As the penetration of renewable energy sources increases and fossil-fuel-based thermal generation is phased out, power systems must adapt to one of the key characteristics of wind and solar: variability, which changes with seasons. As the electrification of heating increases, so will demand. Hence, inter-seasonal storage will be required to match increased demand when renewable generation can no longer supply enough power to the system.

The energy storage market is dominated by short duration (up to 4 hours) solutions, but recently longer-duration technologies (4-12 hours) have gain more attention. Currently, inter-seasonal storage is dominated by natural gas, with carbon-free technologies occupying only a small portion of the segment. The popularity of technologies like pumped hydro have been limited by low natural gas prices, hence most pumped hydro projects are more than 40 years old. Other technologies suitable for inter-seasonal storage are less mature and in need of development.

This Guidehouse Insights study reviews future demand for inter-seasonal storage and the key characteristics of inter-seasonal energy storage solutions, including carbon-free inter-seasonal storage. It assesses the selected technologies in relation to key characteristics and their technological readiness level. These characteristics help define the shortcomings of each technology and indicate where change in the energy system must happen to accommodate carbon-free inter-seasonal energy storage. The study concludes with recommendations for grid regulators, technology developers, regulatory bodies, and policymakers.

Pages 16
Tables | Charts | Figures 5
  • What are the key characteristics of inter-seasonal energy storage technologies?
  • What low-carbon technologies are suitable for inter-seasonal energy storage?
  • How will the demand for inter-seasonal energy storage shape in the future?
  • How can natural gas energy storage be replaced by low-carbon technologies?
  • Does inter-seasonal storage need to be centralized?
  • Grid regulators
  • Inter-seasonal energy storage developers
  • Government agencies and policymakers
  • Energy storage developers
  • Technology developers




Increasing Penetration of Renewable Energy Sources Requires Seasonal Energy Storage to Adapt

Technologies Used for Inter-Seasonal Storage Require Further Research


Reservoir Hydropower

Pumped Storage Hydropower 

Case Study: Norwegian PSH Plants

Thermal Energy Storage

Sensible-Heat Energy Storage

Underground Thermal Energy Storage

Liquified Air Energy Storage 

Power-to-Gas: Hydrogen to Replace Natural Gas

Grid Operators Must Incorporate Metrics to Measure the Need for Inter Seasonal Storage in Their Resource Adequacy Assessments

Regulators Must Find Policies That Incentivize Further Development of ISS Technologies and Their Deployments by 2030

Developers Must Identify New Business Models and Revenue Streams to Accommodate Decentralized Seasonal Storage

Technology Developers Must Explore the Space to Prepare Their Products for Widespread Adoption

  • Average Gas and Electricity Consumed by EU End-Users in 2019, 2020, 2021 in GWh
  • Seasonal Cycle of a PSH Plant Operation in Norway
  • Outline of Aquifer Thermal Energy Storage (Left), ATES Used for Cooling (Right), ATES Used for Heating
  • Flow Scheme of a Liquified Air Energy Storage System
  • Assessment of the Inter-Seasonal Storage Key Technological Characteristics
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