The Growing Need to Store Excess Energy

Today’s electricity grid has virtually no method of storing excess energy. The minimal facilities that do exist typically use pumped hydropower, a method of pumping water uphill into a reservoir when excess electricity is available. As the water then flows back down hill, electricity is generated. However, these systems are not sophisticated enough to manage today’s ever-growing and ever-evolving grid.

Modern electricity grids, with their increased demand and expanded variety of energy sources, cannot continue without improved energy storage systems. These essential storage facilities are needed as buffers for generation and load peaks, as control instruments and as long-term storage systems. There is a considerable amount of research and investment going into the future of energy storage and currently, battery storage technologies are showing great potential as a solution to this problem.

Power density in battery storage

Most of us are familiar with battery storage systems for electrical energy, like the rechargeable batteries we find in household appliances, in cars and other machines. On a larger scale however, storage of energy from the electricity grid requires storage of exceptionally large volumes of energy. Put simply, it requires exceptionally large battery storage systems.

The world’s current largest battery storage system is based in California, USA. The project consists of a colossal 396 power packs, across just 6,000 meters squared. The system can store an impressive 80 MWh of power, while outputting 20 MW of power. When compared to a pumped hydropower storage facility — like the Limberg II pumped-storage power plant in Austria — the power density of these batteries are 21 times higher, creating a more space-efficient option than pumped hydropower.

However, the advantages of battery storage are not limited to improved power density. These systems are also beneficial in managing renewable energy sources.

Renewable requirements

The age of renewables necessitates more than solar panels and wind turbines, it also requires energy storage systems that can manage these volatile resources. As it stands, today’s minimal efforts for energy storage are not suitable for leveraging excess renewable energy.

The conventional and traditional techniques of storage often fail because of low efficiency or the high levels of investment needed to build them. What’s more, because energy from these sources tend to fluctuate widely, it can create a huge balancing problem for the grid. However, batteries can be used as stabilizers in these instances.

Let’s imagine that the wind suddenly drops. At a wind park, the amount of energy generated will instantly decrease. If this happens too quickly, the balancing systems in traditional grids are often unable to compensate. However, this rise and drop of power outputs can be dampened by batteries. This dampening reduces a steep rise or drop in output, giving the balancing systems enough time to compensate accordingly.

There are already several examples of batteries that are used to store renewable energy. In 2017, BMW commissioned a colossal battery storage farm on the grounds of its wind power generation plant in Leipzig, Germany. The site can house up to 700 second-life electric vehicle batteries, capable of storing excess renewable energy, before it is fed into the grid.

Communicating with the grid

Large installations, like BMW’s Leipzig facility, have also deployed software to manage and maintain their complex operations. Energy automation software, like zenon, can be used to provide a clear graphical display of the operation of the storage system and its connection to the grid.

COPA-DATA’s zenon operates by creating a simple, graphical dashboard of the system energy storage system, to provide the operator with a clear overview of how much energy is being stored and distributed. What’s more, if the energy is coming from renewable sources, the system will illustrate how the battery system is helping to stabilizing this energy. Looking to the future, this software will become a vital addition to energy storage installations, particularly for renewable sources.

Batteries are highly versatile and giving our changing approach to energy sources, they have an important role to play in the future of energy storage and distribution. However, we’re still a while away from seeing this technology being rolled out universally. There’s still room for the technology to mature before batteries become the norm in energy storage. Looking to the future however, there’s no doubt that the role of batteries for energy storage will become even more prevalent — with the right software