Concentrated Solar Power system with Thermal Energy Storage
STEM® - Solar Thermo-Electric Magaldi

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.
Its technology is characterized by three major innovative features:

  • 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 and cold tanks and a heat exchanger vessel.

Magaldi STEM® has been designed having a keen eye to environment, using components completely recyclable and eco-compatible. STEM® is capable of delivering an energy trifecta - 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.
The high storage capacity of STEM makes it ideal to produce green electricity on demand, or as part of a 24/7 continuous cycle, also in combination with other renewable sources such as PV.

The subsequent addition of more modules in the system or of more systems in the same area, gives the possibility to boost production, following changes in power demand over time.
STEM® can be considered as a permanent infrastructure for distributed power production in all the sunny areas of the world.

Although STEM® already represents a disruptive technology, it is not time to stop looking for ways to make it even better, so Magaldi continues to set new challenging objectives and raise the bar higher and higher.