Batteries: The Storage Form with the Greatest Potential

Batteries can be activated within seconds and are capable of storing electricity for several hours

Batteries beat other storage types in many respects. Their cost is expected to fall rapidly due to the rising popularity of electric cars.

Rechargeable batteries and especially lithium-ion batteries have the greatest potential among the storage technologies, experts estimate. There are several reasons for this assessment. Batteries can be activated within seconds and are capable of storing electricity for several hours, making them very dynamic. Their charge/discharge capability is high. Yet another advantage is scalability. This makes batteries suitable for a very broad range of applications: in private households, electric vehicles, small businesses, industrial plants, and in stabilizing the grid. Finally, their technical efficiency of up to 90 percent is higher than that of most other storage forms.

What is the status quo? According to an analysis by SNE Research, in 2012 Li-ion batteries used in energy storage systems accounted for a total of 243 megawatt-hours worldwide, forming a US$414 million market. Currently, the Li-ion battery market for these applications can be divided into a subsidy-oriented end-customer market and the power grid market, with a focus on demonstration projects. The US, Europe, Japan, and China are actively engaged in demonstration projects for energy storage using Li-ion batteries for large-scale power grids.

What does the future hold? Two trends favor batteries. The first is the rising use of photovoltaics in homes. Ideally, generated energy is used for covering homeowners’ consumption and need not be distributed. Experts forecast a large growth of photovoltaics worldwide due to its low electricity generation costs in southern countries. Second, economies of scale will bring down the price of Li-ion batteries, possibly by as much as 50 percent, since the number of electric cars is expected to grow. Currently, there are over 600,000 electric vehicles worldwide. Their number doubles every year. Californian car manufacturer Tesla is planning to invest up to US$5 billion to build a factory for Li-ion batteries. It is envisaged that after 2017, its “Gigafactory” will assemble 500,000 cars with batteries per year. Tesla believes that economies of scale will reduce the cost of batteries by more than 30 percent to less than US$200 per kilowatt-hour. Li-ion batteries are also used in many mobile devices, another rapidly growing market. Their popularity in portable consumer electronics is based on several factors: the absence of a memory effect, the fact that they face only a slow loss of charge when not in use, and their high energy density. After all, lithium is the lightest of all metals and the third-lightest element after hydrogen and helium.