Thermal Energy Storage

The energy radiated by the sun in just one second is enough to cover our energy needs for half a billion years.

The last frontier of innovation developed by Magaldi is a new type of Concentrated Solar Power system. Solar Thermo Electric Magaldi (STEM®) represents a technological breakthrough in the Concentrated Solar Power (CSP) sector.

Three major innovative features characterize this technology:

• the solar receiver and the thermal energy storage and heat transfer devices are integrated in a single piece of equipment, the Magaldi Integrated Receiver - MIR. The MIR is equipped with an innovative solid particles fluidized bed and incorporates the functions of solar radiation capture, storage of thermal energy (as sensible heat of solid particles) and heat transfer to the steam;
• the optical system is equipped with beam down configuration, allowing the solar receiver (MIR) to be based on the ground;
• the system is modular and scalable, allowing to build up an installation of the required size by connecting several STEM® modules in series or in parallel, in order to reach the needed output of steam.

A STEM® module is made of:

• heliostats field;
• secondary reflector;
• integrated solar receiver;
• fluidizing air system;
• automation and control system.

Solar radiation is captured by heliostats and concentrated on a secondary reflector, which directs it into a central solar receiver (MIR) containing a fluidized bed of silica sand. The MIR contains also heat exchangers within the fluidized sand bed for superheated steam generation.
The solid particles fluidised bed, directly irradiated by sunrays:

• guarantees unique capacity of absorbing intensive and variable solar power flux, with intrinsic safety;
• ensures high thermal diffusivity in the storage medium, with operating temperatures higher than those presently available for other CSP technologies;
• allows effective thermal power storage and transfer to the heat exchangers, immersed in the fluidized bed, for the steam generation.

Combining different functions into a single integrated solar receiver and using low cost materials (sand and air) for the fluidized bed enables a cost effective CSP solution, avoiding the need for separate hot tank, cold tank and heat exchanger.

Magaldi STEM® has been designed having a keen eye to environment, using components completely recyclable, eco-compatible, simple and highly reliable over time. System components also require low maintenance.

STEM® is capable of delivering electricity, high-quality heat and energy storage, thus providing on-demand generation of steam for a number of civil and industrial applications that, thanks to its thermal energy storage capabilities, can be dispatched also after sunset or during cloudy periods.

A number of STEM® modules, assembled in one system, can work in series or in parallel, allowing a flexible and dependable steam generation, tunable according to the user needs.

STEM®-CSP is therefore a highly flexible system for the generation of thermal energy that can be turned on and off when necessary without any technical or climatic constraints. Its characteristics make it an optimal solution for supplying electricity or steam, both for industrial and residential uses, in countries with a high level of insolation (DNI).

STEM®-CSP can increase the flexibility of any system, even pre-existing, of energy production and optimize its performance through the combination (hybridization) with the surplus of energy deriving from other non-programmable sources present on site (e.g. photovoltaic and wind power).

Although STEM® is already a "disruptive" technology Magaldi, thanks to the continuous internal activities of the Research and Development Department in the field of renewable energy innovation, is obtaining, testing and validating further important results of STEM® technology in different sectors and industrial and civil applications.