Thermal storage is not a new idea. For centuries, people have used thermal mass to store heat or cold and release it when needed. What is new is the role it can play in a renewable electricity system.
Modern thermal storage can absorb low-cost or constrained renewable power, store it in materials such as sand, stone, brick, carbon or molten salt, and deliver it later as useful industrial heat.
Thermal Grid applies this principle to heat-intensive sites, selecting the right storage technology for the job rather than forcing every project into one design. The right technology depends on the customer’s heat temperature, demand profile, storage duration, available space, electricity supply route and commercial structure. Our role is to select and deliver the most practical storage architecture for each project.
Molten salt storage uses electrically heated salt as both a storage medium and a heat-transfer medium. The salt is heated in insulated tanks and later circulated through heat exchangers to produce steam, hot water or process heat. Molten salts are already well understood in high-temperature energy storage, particularly in concentrated solar power, and can be effective for medium-temperature industrial steam applications. They are generally more compact than low-temperature water storage and can provide controlled, dispatchable heat. The downside is operational complexity: salts must be kept above their freezing point, and the system needs pumps, tanks, valves, heat tracing, corrosion management and careful maintenance.
Ideal for temperature output up to 300°C.
Sand, gravel and other packed-bed materials store energy as sensible heat where electricity is used to heat air or resistive elements, which then heat a large insulated mass of low-cost solid material. Heat is later extracted through air, water or steam heat exchangers. This is an elegant solution in that the storage medium is cheap, abundant and non-flammable. It is well suited to hot water, district heat, hot air and steam applications, with typical useful outputs in the low-to-medium industrial heat range. The main trade-off is space: sand and gravel systems are usually larger than higher-temperature storage options, so they are best suited to sites with room for silos, vessels or containerised stores.
Ideal for temperature output up to 400°C.
Ceramic and refractory brick systems use electricity to heat dense, high-temperature materials similar to those already used in furnaces and industrial kilns. The bricks can store heat at very high temperatures, then release it through controlled air flow or heat exchangers to provide hot air, steam or process heat. Refractory materials can operate at high temperatures and can therefore store more useful energy in a small footprint. The trade-off is complexity and cost: higher temperatures require more sophisticated insulation, controls, safety design and integration.
Ideal for temperature output up to 1,500°C .
Carbon block systems store electricity as very high-temperature heat in solid carbon or graphite blocks. Because carbon can tolerate extremely high temperatures, this route can offer high energy density and a smaller footprint than lower-temperature storage media. It is well suited for hard-to-decarbonise industrial processes that need very high-temperature heat. The trade-off is complexity and cost: higher temperatures require more sophisticated insulation, controls, safety design and integration.
Ideal for temperature output up to 2,200°C.
Copyright © 2026 Thermal Grid - All Rights Reserved.