WHAT IS A SAND BATTERY? Green steam essential for industrial process decarbonization

25 August 2023

WHAT IS A SAND BATTERY? Green steam essential for industrial process decarbonization

Heat Reigns as the globe's premier energy consumer

According to the International Energy Agency (IEA), heat is the world’s largest energy end use, accounting for almost half of global final energy consumption in 2021, significantly more than electricity (20%) and transport (30%). Industrial processes are responsible for 51% of the energy consumed for heat, while another 46% is consumed in buildings for space and water heating, and, to a lesser extent, cooking.

Considering the policy landscape as of September 2021 – highlights the IEA Report – global heat demand is projected to expand by 17 EJ during 2021-2026. This increase of almost 9% is about three times larger than that during the decade 2011-2020. The industrial sector accounts for almost all of this growth”.

Critical thermal energy storage in industrial processes

The prospect of ensuring a fully sustainable industrial production, particularly for processes with substantial energy consumption tied to heat generation, stands as a pivotal challenge in the pursuit of decarbonization and energy autonomy.

Renewable energy and heightened electrification constitute key elements within the decarbonization blueprints of numerous countries. Nonetheless, renewable energy sources exhibit fluctuations, prompting an essential requirement for energy storage as the adoption of renewables grows. This storage becomes imperative to guarantee a steady supply of clean energy during periods of calm winds or diminished solar radiance.

Hence, the ability to store energy generated by renewable sources represents the pivotal endeavor in transitioning toward an energy paradigm entirely detached from fossil fuels. Energy storage technologies, particularly Thermal Energy Storage (TES) systems, play a critical role, especially within the industrial sector. 

What is a sand battery

TES - Thermal Energy Storage involves the process of heating or cooling a medium to harness the energy when needed.

Many different technologies can be used to achieve thermal energy storage and depending on which technology is used, thermal energy storage systems can store excess thermal energy for hours, days or months. 

A sand battery constitutes a thermal energy storage mechanism designed to capitalize on the impressive heat retention and discharge attributes of sand. Comprising a layer of meticulously chosen sand grains withstanding high temperatures, this battery functions as a medium to accumulate and convey surplus thermal energy produced by renewable sources such as solar or wind power, enabling its subsequent utilization.

During the charging phase, the sand bed is heated using the surplus thermal energy. As the sand bed gradually reaches its maximum storage capacity, any extra heat can be redirected to other applications or processes, ensuring the efficient utilization of renewable energy sources. When there is a need for the stored thermal energy, the discharging phase begins.

The sand bed conveys the stored heat to a heat transfer medium, such as air or water, which subsequently conveys the heat to its designated target. This stored thermal energy can serve diverse functions, ranging from generating electricity to heating water or fueling industrial processes.

The sand battery helps to ambitiously upscale renewables production by ensuring there’s always a way to benefit from clean energy, even if the surplus is massive.

MGTES: First worldwide zero-impact storage for industries

Made in Italy MGTES - Magaldi Green Thermal Energy Storage is the first worldwide zero-impact storage technology that helps to reduce the dependence of energy-intensive industries on fossils. Protected by 11 worldwide patents, the "sand battery" is developed by the Magaldi Group, world leader in the field of ultra-high temperature material handling, which specializes in developing technologies that can be used to produce and store clean energy. MGTES, based on a fluidized sand bed (sand battery), stores energy from renewable sources, which is then released in the form of steam at high temperatures (between 120-400°C).

MGTES - Magaldi Green Thermal Energy Storage technology stands out globally as a distinctive thermal storage solution meticulously tailored for industries, aiming to curtail industrial energy usage and accelerate the transition towards renewable energy processes. 

MGTES’ unique technology

Unlike other technologies, the MGTES system is the only one that uses a bed of solid particles, composed of simple silica sand, which is fluidized through a Magaldi patented air system to increase the performances. The fluidized sand bed allows for a greater thermal diffusivity of the storage medium, about 2-3 orders greater than in the fixed bed condition. Thanks to this system, there is the advantage of a higher speed of heat transfer within the storage mass, therefore less time to transfer energy from one element to another within the storage system, both in the charge and discharge phases. Furthermore, the MGTES system, having the electrical resistances useful for the charging phase directly immersed in the sand bed, allows direct heating of the storage medium through higher heat transfer coefficients. The same concept can be applied for the thermal energy generation phase, as the heat exchanger is also immersed in the sand bed.

The MGTES system represents a compact Thermal Energy Storage solution as it integrates the elements for the charge, storage and discharge phase in a single device. It also offers the possibility of being customizable, scalable and modular in accordance with the customer's requests in terms of installed power, thermal capacity and quality of the steam produced.

MGTES advantages

  • Faster heat transfer rates.The fluidized sand bed used in MGTES allows for much greater thermal diffusivity compared to fixed beds, resulting in faster heat transfer within the storage system during both charging and discharging. This enables more rapid storage and release of thermal energy.
  • Direct heating/cooling. The electrical resistances used for charging and the heat exchanger used for discharging are immersed directly in the sand bed. This allows for more efficient direct heating and cooling of the storage medium, without needing an intermediate heat transfer loop.
  • Simplicity and costBy using silica sand as the primary storage medium, MGTES takes advantage of a low-cost and abundantly available material. The system's simplicity, which eliminates the requirement for intermediate heat transfer fluids or containment vessels, can lead to reduced operational and maintenance expenses.

Regarding potential system applications, Magaldi Green Thermal Energy Storage is currently focused on scaling up its efforts. Following the successful completion of the initial 400 kW and 3.4 MWh prototype, the aim is to pioneer the world's inaugural industrial-scale implementation of a TES system for generating green steam at approximately 200°C within the food & beverage sector.

2023, MGTES implemented for Magaldi Group and Enel X agreement to drive industrial processes decarbonization

Magaldi Group and Enel X, the Enel Group’s company active in the areas of energy supply and efficiency, join forces to decarbonize industrial processes. Under the agreement, the ground-breaking MGTES - Magaldi Green Thermal Energy Storage system will be implemented for the continuous production of green steam, with a storage capacity of around 13 MWh per day.

Installed at the Magaldi Power plant in the ASI - Area di Sviluppo Industriale (Industrial Development Area) of the city of Salerno, Italy – sand battery MGTES, powered by a photovoltaic plant, stores energy, then releasing it in the form of high-temperature steam. The aim of the partnership is to integrate technology into industrial activities with a sustainable approach.

2024, first application will be at the plant of IGI, a food company that supplies Ferrero Group, in Buccino (province of Salerno)

MGTES technology will allow Enel X to supply its industrial customers with thermal energy in the form of steam at the desired temperatures and pressures, thereby reducing gas consumption and stabilizing the price of thermal energy. The first application will encompass providing green thermal energy to meet the energy needs of the food company IGI, a supplier of Ferrero Group, with headquarters in the Italian Industrial Development Area of Buccino.

It involves building a 5 MW photovoltaic plant and a 125 ton MGTES system with a daily storage capacity of 13 MWh of thermal energy. The MGTES system, which will become operational in the second half of 2024, is expected to reduce IGI’s total consumption by 20%, as well as saving up to 1,000 tons of CO2 annually, replacing them with renewable energy available throughout the day.


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