Aalborg CSP A/S and EnergyNest AS have jointly developed a cost-competitive thermal energy storage (TES) system. The cooperation have aligned world-class expertise from both companies to design and deliver a direct-steam-to/from-concrete storage system enabling predictable and on-demand power generation with low operation and maintenance expenses.

The direct-steam storage concept (patent pending) is based on EnergyNest's already patented thermal energy storage technology using Heatcrete® as storage medium with embedded heat exchangers combined with Aalborg CSP's efficient and reliable steam generator design, with natural circulation, that has already proven its superior performance in some of the world's leading CSP plants.

The newly developed direct-steam storage concept is a novel configuration of thermal energy storage and steam generation, ensuring on-demand power production during peak demand periods, when there is no or limited energy generation from the sun or other fluctuating renewable energy sources.

As an easy to install and operate add-on to the CSP plant, the direct-steam storage technology extend daily steam and power generation up to 24 hours, or more, enabling delivery of electricity at peak price periods and substantially increasing overall plant revenue.

The direct-steam storage concept is cost-effective compared to conventional molten-salt-based energy storage systems, as the safe and durable solid-state storage medium combined with the natural circulating steam generator with NO need for any electrical heat tracing, guarantees low parasitic load and significantly reduces operation and maintenance costs, while  increasing plant availability.

The operational and investment cost benefits, in addition to the flexible scalability of the system makes it well suited also for off-grid, co-generation and micro-grid applications, where plant availability and energy supply security are of outmost importance. Moreover, the modular storage elements are made from readily available raw materials that can typically be sourced locally.

The energy storage technology can be easily customized to fit project specific requirements including power generation, seawater desalination, process steam, district heating/cooling and so on.