Thermal Energy Storage Market (2026-2036)

The growth of this market is mainly driven by the need to decarbonize industrial heat, the integration of variable renewable electricity, and the expansion of district heating and waste heat recovery. However, high upfront costs and long payback periods compared with fossil fuel boilers, dependence on low-cost electricity and grid connections, lower round-trip efficiency for power-to-power applications, and policy uncertainty restrain the growth of this market.

Furthermore, data center heat reuse and cooling, concentrated solar power with long-duration storage, and electrified steam for industry are expected to offer growth opportunities for the stakeholders in this market. However, site requirements and integration with existing processes, bankability and performance track records for new technologies, materials durability, and competition from lithium-ion batteries and heat pumps remain major challenges impacting the growth of this market. Additionally, the rapid scaling of industrial heat batteries, large seasonal storage facilities, solid-media storage using low-cost materials, and hybrid systems combining storage with heat pumps and electric boilers are prominent trends in this market.

The Thermal Energy Storage Market comprises systems that store energy as heat or cold for later use, allowing energy to be captured when it is abundant or inexpensive and released when needed. The market covers sensible heat storage, using molten salt, water, and solid media such as carbon, brick, concrete, rock, and sand; latent heat storage, using phase change materials and ice; and thermochemical storage. Systems range from short-duration storage for daily load shifting to long-duration and seasonal storage, and from low temperatures for buildings and district heating to high temperatures above 1,000 degrees Celsius for industrial processes. Applications include industrial process heat and steam, district heating and cooling, power generation, including concentrated solar power and power-to-heat-to-power systems, buildings HVAC, and data center cooling and heat reuse. Electrochemical batteries and pumped hydro storage are excluded. The ecosystem spans storage technology developers, engineering and construction firms, utilities, district heating operators, industrial energy users, concentrated solar power developers, HVAC manufacturers, and policymakers.

Heat is the largest form of energy demand. According to the International Energy Agency, heat accounts for almost half of global final energy consumption, and much of the heat used in industry is supplied by burning natural gas, coal, and oil. Thermal energy storage allows industries and utilities to convert low-cost renewable electricity into heat and store it, providing continuous heat or steam even when wind and solar output varies. Antora Energy's 50-megawatt, 5-gigawatt-hour thermal battery project at POET's Big Stone City bioprocessing facility in South Dakota, comprising more than 200 thermal batteries that store electricity as heat in insulated blocks of solid carbon, was completed from initial construction to commissioning in under 12 months, and Antora raised USD 550 million in a Series C round in 2026 to accelerate deployment and establish a second U.S. manufacturing facility.

District heating is another major application. In the Nordic countries, heat consumption in summer is only about one-tenth of peak winter consumption, and Vantaa Energy is building Varanto, the world's largest seasonal thermal energy storage facility, in Vantaa, Finland. The facility will store 90 gigawatt-hours of heat in three underground caverns about 20 meters wide, 300 meters long, and 40 meters high, filled with 1.1 million cubic meters of pressurized water at up to 140 degrees Celsius, charged by two 60-megawatt electric boilers using low-cost renewable electricity and by waste heat from data centers and other sources, with completion expected in 2028 at an estimated cost of about EUR 200 million, supported by a EUR 19 million government grant.

Molten salt storage paired with concentrated solar power is the most established large-scale thermal storage technology, enabling solar plants to generate electricity after sunset; the 950-megawatt Noor Energy 1 complex in Dubai includes concentrated solar power with 15 hours of storage, and Chile's Cerro Dominador plant provides 17.5 hours of storage. Ice and chilled water storage shift building cooling loads to off-peak hours. At the same time, the market faces challenges, including high upfront costs, dependence on low-cost electricity, lower efficiency for converting stored heat back to electricity compared with lithium-ion batteries, and the performance risks illustrated by earlier projects such as the Crescent Dunes concentrated solar power plant in Nevada, which suffered a molten salt tank leak in 2016.