Stationary Energy Storage

  Stationary energy storage is a system which uses battery systems for storage of excess produced solar energy to provide a solution for efficiently delivering smooth and predictable power for usage or back to the grid.  

Why is stationary energy storage needed?

A fundamental factor for successful transition of energy and for guaranteeing an independent energy supply is storage technologies. A major challenge for storage and capacitors is ensuring high-performance storage systems that can be produced cost-effectively and can be used in large scales for local storage of renewable energy. Energy needs to be available when required. For this reason, the high volatility of the power grids needs to be balanced with the increasing number of renewable energy. This increases the demand for load balancing technologies and for high performance intelligent, battery storage systems. As the use and demand of renewable energies increases, the importance of energy storage systems increases as well. These systems can be used to store solar energy so it would be available for use whenever required. This provides options for saving money and gives the freedom of being fully independent of the grid. Storage and usage of self generated renewable energy is suitable for small businesses, agriculture and industrial companies as well. In many parts of the world, energy infrastructure can either be underdeveloped, lacking or very unreliable. Common energy storage technologies can include lead-acid to lithium.  

Uses of stationary energy storage

There is a rapid growth in the international market for stationary battery storage systems (BSS). Grid-connected BSS have evolved - within less than a decade -  from a niche product to a mass market product, for which energy and automotive companies are competing for market shares today. A recent study has shown that almost 4GW of new battery storage systems were installed worldwide in 2018 and this number is expected to double by 2021. According to this, the IRENA (International Renewable Energy Agency) predicts a total storage capacity of up to 420GWh to be installed by 2030. The Grid-connected storage systems today are used for many purposes, ranging from as residential home storage systems and other small scale applications, to multi megawatt batteries which provide balancing solutions and mitigate the grid congestion problems on different voltage levels. The three main market segments of stationary storage systems include:

• private household installations
• larger commercial buildings installations
• storage for balancing services

 

Stationary energy storage and Home storage systems

Over the last decade, an increasing number of households have adopted battery storage systems in combination with solar PV systems. These battery storage systems (BSS) are used to store excess produced solar energy during the day and make it available for self-consumption later at night. This provides benefits for the battery operator and the distribution grid: the operator of a BSS decreases the amount of money spent on electricity from the grid on one hand. BSS on the other hand can stabilize power grids with generation of high amounts of renewable energy. Through storage of PV power during peak generation periods, local voltage stability problems or thermal overloading of electric equipment can be mitigated.   Several studies have shown that BSS usage can reliably limit the maximum feed in of Photovoltaic installations to nearly 40% of their rated power without restraining unwarranted amounts of renewable energy. This can be explained as that BSS can increase the maximum PV penetration of a certain distribution grid by a factor of up to around 2.5 without any need to upgrade the electrical equipment. In other cases, BSS can also offset higher tariffs at night by benefiting from time-of-use schemes and thus generating additional revenues.