BESS stands for "Battery Energy Storage System" and goes far beyond the mere storage of electrical energy, such as a simple battery. Such systems use networked battery groups to store electricity efficiently and release it again when required. A typical BESS can consist of over 100,000 lithium-ion battery cells, which are combined into modules and arranged in racks. Such Large-scale battery storage are then only characterized by the use of a battery management system (BMS) or a more comprehensive Energy management system (EMS) as BESS. Thanks to their extremely fast response time of just 10 milliseconds, they can compensate for grid fluctuations, better integrate renewable energies and reduce energy costs.
Why are BESS important?
The energy transition and the expansion of renewable energies require Flexible storage solutions. As wind and solar power are not generated constantly, a BESS can store surplus energy and make it available later. As a result, they stabilize both public and internal power grids and can serve as an emergency or backup power source. They also enable stand-alone operation so that companies can temporarily operate independently of the public grid.
Through Peak load capping and Load shifting (Peak Shaving & Load Shifiting), BESS contribute to the reduction of power prices and grid charges. At the same time, they increase the self-consumption of photovoltaic systems, which means that less electricity has to be drawn from the grid. In addition, the Arbitrage strategies reduce electricity procurement costs by storing cheaper electricity and using it at a later date. In addition, by marketing storage capacities on the Control energy market Additional income.
All these advantages contribute to more stable grid operation, reduce dependence on fossil fuels and enable companies in particular to use their self-generated solar power more efficiently.
Functionality and structure of a BESS
An intelligent BESS stores electrical energy when the electricity supply is high or the electricity price is low and releases it again when required. This enables efficient use of renewable energies and stabilization of the power grid. The structure of a BESS consists of several central components:
Battery cells
The focus is on the Battery cellswhich, depending on the application, are usually based on lithium-ion or sodium-ion technology. The choice of storage technology depends on factors such as performance, energy content, service life and costs. While lead-acid batteries were used in battery storage power plants in the 1980s, nickel-cadmium and sodium-sulphur batteries were used later. Since 2010, lithium-ion batteries have become increasingly popular as their costs have fallen significantly due to the growing electric vehicle industry. Today, lithium-ion batteries are the dominant technology for BESS, as they offer high energy density, a long service life and high efficiency.
Inverter
Since batteries store and release electrochemical energy in the form of direct current (DC), they are Inverter necessary to convert the electricity into alternating current (AC), which is used in the power grid. Additional safety mechanisms, including fire suppression systems, surge protection and temperature control, protect the system from power loss or failure. To minimize hazards and protect the components from external influences, BESS are often housed in separate buildings such as warehouses or containers.
Battery management system (BMS)
Another key component that distinguishes a BESS from a simple battery storage system is the battery management system (BMS). It monitors and controls the charging and discharging process of the battery cells in order to additionally optimize their Efficiency and Service life to be maximized. To do this, the BMS continuously measures important parameters such as the voltage, current and temperature of each individual cell and ensures that the battery remains within safe operating limits. It also balances cell voltages to ensure even ageing of the cells and optimum use of the capacity of the entire storage system. This minimizes risks such as overcharging or deep discharge.
Energy management system (EMS)
A useful addition to a BMS is a higher-level energy management system (EMS), such as the CUBE EfficiencyUnit. While the BMS monitors the internal safety and efficiency of the battery, the EMS controls the entire energy system of a company and optimizes the energy flow in coordination with other systems. It intelligently decides when to charge or discharge the BESS based on external factors such as electricity prices, grid load, weather forecasts and local energy demand. The EMS communicates directly with the BMS and the inverter in order to optimally coordinate the storage strategy with the available energy generation - for example from photovoltaic systems or wind power plants.
The combination of BMS and EMS ensures that a BESS not only works safely and efficiently, but is also operated economically. While the BMS protects and optimizes the condition of the battery, the EMS ensures intelligent control of the entire energy system in order to reduce costs, relieve the load on the grid and enable maximum use of renewable energies.
Battery technologies and materials used
BESS are based on different battery technologies that differ in terms of efficiency, cost, service life and area of application. The most commonly used battery types are Lithium-ion batteriesas they offer high energy density, a long service life and fast charging and discharging cycles. However, they consist of scarce raw materials such as lithium, cobalt, nickel, manganese and aluminum.
A promising alternative to this are Sodium-ion batteries They are safer than lithium-ion batteries, but have a lower energy density, which means they take up more space. Large industrial companies often use Redox flow batteries are used. This technology is characterized by a particularly long service life, as the electrochemical reaction takes place in liquid electrolytes outside the actual battery cells. They are flexibly scalable but also relatively expensive.
An older but proven technology are Lead-acid batteries. They are inexpensive and robust, but they have a significantly lower energy density, a shorter service life and higher maintenance costs compared to modern battery technologies. In general, the choice of suitable battery technology depends on various factors such as cost, safety, energy density and service life and should be carefully considered.
Advantages of BESS for companies
Depending on the location, battery storage systems offer different advantages. Large so-called. In-Front-of-the-Meter (FTM) systemsthat are directly connected to the public electricity grid primarily help companies in industry and the energy sector. They primarily contribute to grid stabilization by reducing bottlenecks and providing energy for times of high demand. They also serve as a reserve and emergency power source, which improves security of supply. Another advantage is the possibility of seasonal energy storage, which allows companies to use surplus renewable energy efficiently. They can also generate additional income by providing balancing energy or arbitrage transactions on the electricity market.
Behind-the-meter (BTM) systemsinstalled directly on a company's premises offer the operator economic advantages. They make it possible to optimize self-consumption by efficiently storing solar power and thus reducing grid purchases and energy costs. Peak load capping means that high grid charges can be avoided, while the uninterruptible power supply function safeguards critical processes even during grid fluctuations. A BESS is particularly beneficial for companies with e-mobility charging infrastructures, as it ensures a stable and efficient power supply without overloading the grid connection. If permitted by law, companies can feed surplus energy into the grid and thus generate additional income.
Combined BESS systems
A combination of FTM and BTM systems as BESS is also possible. This results in Synergy effectswhich enable a more efficient use of energy. A key advantage of the combination is the Greater flexibilityas both large-scale and local energy requirements can be optimally controlled. A modern EMS coordinates the use of both types of storage and ensures intelligent distribution of the stored energy. Especially in virtual power plants (VPPs) BTM systems are networked with FTM components in order to provide network services and generate additional revenue.
In practice, more and more Hybrid solutionsin which large FTM storage systems are combined with smaller BTM systems. These models ensure a reliable grid supply and at the same time offer companies the opportunity to increase their energy autonomy. The combination of both approaches creates a powerful and sustainable BESS that meets the challenges of the energy transition.
Challenges and solutions at BESS
Some BESS projects are currently still facing economic, technical and regulatory challenges. The volatile energy prices make profitability difficult, which is why operators rely on stable revenue models and maximum performance optimization. The Increasing system complexity and the inadequate networks require efficient control and strict quality checks. Lengthy approval procedures are slowing down projects, but new system designs and new political initiatives are accelerating implementation. While lithium-ion batteries still dominate, sodium-ion alternatives are becoming increasingly important. Grid integration of large storage capacities is being driven forward by the first large-scale projects. Flexible, usage-based guarantees ensure greater adaptability. Technological advances and regulatory adjustments are constantly expanding the potential of BESS.
Future and market development
The market for BESS is in a dynamic growth phase and is expected to grow to USD 114.05 billion worldwide by 2032 - with an annual growth rate of Growth rate from 20,88 %. In Germany, large-scale storage capacity is expected to increase to around 7 gigawatt hours by 2026. quintupled. This growth is being driven by the increasing integration of renewable energies, the growing need for grid stability and the increasing demand for energy storage on a supply scale. In addition, advances in storage technology and economies of scale are leading to falling costs - forecasts assume a Reduction in storage costs for large systems around up to 30 % by 2030. From a regional perspective, North America and Europe are investing heavily in the expansion of BESS, with Germany being one of the fastest growing markets. China remains the leader in global production and is a key driver of industrial scaling.
BESS: More than just storage solutions
BESS are far more than just storage solutions - they are a central component of the energy transition. Thanks to their ability to store electricity flexibly and supply it in a targeted manner, they make a significant contribution to grid stability, the integration of renewable energies and the optimization of energy costs. Despite economic and regulatory challenges, the market is growing rapidly, driven by technological innovations, increasing demand and political support measures. Companies and energy suppliers alike benefit from the versatility of modern BESS, which enable a sustainable, economical and secure energy supply. In the coming years, their role will continue to grow in importance and play a decisive role in driving the transition towards a decentralized, renewable energy infrastructure.