Who are the main players in the energy storage systems market? Which ones to focus on?
Details of emerging trends are in the full report.
Energy storage: which are the five main technological solutions for the energy storage
Renewable energy sources are characterized by their intermittent nature, so that in order to be fully reliable in the future they need efficient and cost-effective storage systems.
In order to fully exploit the environmental benefits of the increasingly efficient and quantitatively relevant use of renewable energy, it is essential to know how to conserve it. While it is clear and evident that renewable energy plays a key role in mitigating and countering climate change by advancing the energy transition; on the other hand it is equally obvious that the widespread and efficient use of renewable sources inevitably passes through energy storage systems that store excess of clean energy to distribute it when it is necessary.
At this historical stage, the costs for renewable energy production are constantly decreasing, in contrast to storage systems that still have high prices and face several significant challenges including, in particular, a way to reduce energy losses during conversion processesLe fonti di energia rinnovabili sono caratterizzate dalla loro natura intermittente, quindi per potervisi affidare pienamente in futuro abbisognano di sistemi di accumulo efficienti e dai costi contenuti.
Which are the main renewable energy storage systems and what functions do they perform
Storage systems perform various functions for energy management such as frequency regulation, and the transfer of load from the environmental availability in peak hours of energy demand. The energy storage solutions being explored are manifold, and to understand their mechanisms and opportunities can be grouped according to the respective physical principle.


Mechanical solutions and their characteristics: from gravitational accumulation to flywheel storage
Mechanical solutions provide energy conversion yields, but they involve high costs and low energy density. In detail, low energy-density sources may require more resources and space to store the same amount of energy. An example of this type of solution is gravitational accumulation, which uses potential energy by lifting weights or exploiting the gravitational energy of water. During periods of energy surplus, such as in hours of sunshine or wind, the weights are lifted and maintained at heights above the ground. When there is an energy need, the weights are released by producing electricity through a generator.
Another interesting technology is flywheel storage, which uses the kinetic energy of a rotating flywheel to store and release energy efficiently.
Electrical solutions: how capacitor and inductor technologies work
Turning to electrical solutions, in electronic circuits the technology of capacitors works when a voltage is applied and, through the two plates they are composed of, there is a phenomenon of accumulation of opposite electric charges. Thus, energy is maintained, one plate accumulates positive charges while the other accumulates negative charges, and the electric field is created. Another electrical solution already on the market is inductors, which are essentially coils of conductive wire. When a current flows through the coil, a magnetic field is generated which retains the energy. These technologies require little maintenance but are expensive and have limited storage capacity compared to other technological solutions already on the market.
Chemical solutions: from green hydrogen to ammonia via biomethane, biodiesel and ethanol
Some chemical compounds can be used as energy carriers with high density and flexibility among their main characteristics, but in most cases, they may have a negative environmental impact. Hydrogen, on the other hand, is emerging for its potential in decarbonization of various industrial sectors because it can be produced from renewable sources, with "green" one playing an increasingly central role in the energy transition, as it is the "cleanest" among the other existing types. Another example is ammonia (NH3): it can be easily liquefied, converted into hydrogen or burned directly as fuel. In addition, alternatives to natural gas include bio-methane, while for fuels biodiesel and ethanol are obtained from biomass through anaerobic digestion or thermochemical gasification processes and, therefore, they are proposed as a possible alternative to fossil fuels.


Thermal solutions: advantages and challenges to be addressed
Thermal solutions are low cost, but they are particularly prone to the risk of thermal losses. Depending on the application, they can be distributed or centralized, sharing however the purpose: to store energy in the form of heat within a material.
In this sense, there are several ways to do it. For example, through sensitive accumulation, the temperature of a material (water, rock, sand, metals) is increased and when it heats up it absorbs heat, releasing it later on when it cools down. Finally, latent accumulation is used to exploit the change in phase of a material (paraffins, salts and some metals) by melting or vaporization. These solutions therefore use readily available materials, which is a major advantage.
Electrochemical solutions: lithium batteries and flow batteries
Electrochemical solutions are modular but complex and require the use of critical raw materials.
Lithium-ion batteries are an example of this category. They are ideal for residential and commercial applications where a reliable, rechargeable power source is required. Their modularity allows them to adapt size and capacity to the specific needs of users, making them versatile for various uses from portable electronics to electric vehicles, Although currently the reduced energy storage capacity and longevity of these represent challenges to be addressed not only for energy efficiency, but also for low environmental compatibility in lithium extraction and disposal (although technologies already exist to limit their impact through recycling).
Flow batteries use liquid electrolytes to store energy, and are particularly suitable for large-scale applications such as energy storage for electrical networks.
Energy Storage Report by Intesa Sanpaolo Innovation Center
With the increasing integration of variable and intermittent renewable energy sources to the electricity transmission and distribution grids, operators face a number of challenges in balancing production with energy demand. The Industry Trend Report - Energy Storage, curated by Intesa Sanpaolo Innovation Center, analyses the different technologies that can be used to address these challenges.