Magaldi Thermal Energy Storage (MGTES)
Based on fluidized sand bed technology, MGTES allows to store surplus energy from renewable sources and dispatch it when it is needed
As renewables are gaining ground in the energy system, the development of efficient energy storage systems is imperative for balancing intermittent renewables.
Energy storage is the key to unlocking renewable power’s full potential: it not only helps to balance out the variability in generation but also reduces the need to feed excess electricity back into the grid.
Magaldi developed the Magaldi Green Thermal Energy Storage (MGTES) system to produce green thermal energy – steam or hot air – which can be used directly in industrial plants or for generating electricity by using steam turbines. This system, whose expected useful life is 30+ years, has all credentials to play a crucial role in the global decarbonization process.
Working concept
Designed for both short (<4 hours) and long duration (4+ hours up to days and weeks) large-scale energy storage applications, the system consists of insulated modules that contain silica sand, heated to temperatures above 600°C.
The MGTES system is operated in three steps:
- Charging. Surplus energy from renewable sources is used to charge the system. An array of electrical resistors (in case of electrical energy), or an integrated heat exchanger (in case of thermal energy), is immersed in a fluidizable bed of sand. The fluidization of sand particles dramatically increases the heat exchange coefficient and the response time of the whole system.
- Storing. The fluidization is switched off and the sand packs at the bottom of the module. The absence of convection and the insulation of the tank limit the heat exchange with outside, thus minimizing energy losses.
- Discharging. The system is discharged by reversing the integrated heat exchanger within the fluidized sand bed. Stored energy is released as superheated steam of hot air. To generate electricity, MGTES can be used in combination with a power block.
Key features
The MGTES system stands out for:
- Sustainability. It is mainly made up of silica sand and steel, thus representing an environmentally friendly solution, which does not contain or produce pollutants.
- Flexibility. MGTES provides great flexibility in the power generation system (the electrical grid, thermoelectric power plants, industrial plants, renewable plants) in which it is integrated, decoupling energy generation from consumption.
- Efficiency. Thermal losses are dramatically reduced to negligible amounts (typically <2% per 24h) and thermal energy can be stored for up to several days. It has been proved that, in the case of a thermal-to-thermal application, the Round-Trip Efficiency (RTE) is greater than 90%.
Main applications
MGTES can be used for:
- Power-to-Power applications. The system is designed to absorb electricity from a renewable power plant or from the electric grid. The input energy is stored as thermal energy and used, later, to produce steam for driving a power block to convert stored thermal energy into electricity.
The power block can be recovered from thermoelectric plants in the decommissioning phase. - Green heat production 24h/7. MGTES can be used to replace traditional fossil fuels in industrial processes from 120° to 400°C (i.e. pulp & paper, food & beverage, chemical, plastic, etc.).
- Thermoelectric power plants. MGTES can be integrated into the steam section of existing thermoelectric power plants to reduce the minimum load and offer backup thermal power to be used when needed.
