Under the microscope: Stationary energy storage units: From car to grid: Daimler is gradually expanding in the field of stationary energy storage units
It's not just on the road that Daimler is helping the energy transition to gather momentum: with its subsidiaries Deutsche Accumotive GmbH und Co. KG and Mercedes-Benz Energy GmbH, the company offers efficient battery systems for electric and plug-in vehicles as well as stationary energy storage units for industrial applications and households. Daimler is systematically advancing electric mobility in a series of innovative projects: as an example, used batteries from electric cars are getting a second lease of life outside of the vehicle as 2nd-life battery storage units. Also, a "living spare-parts store" for battery systems destined for the smart electric drive fleet is helping to stabilise the German power grid. This efficient dual use improves the lifecycle assessment and the life cycle costs of electric mobility.
Daimler AG is tapping into new growth opportunities and actively helping to bring about an energy transition in the non-automotive sector, too. It is doing this by becoming involved in the field of stationary energy storage units for industrial customers and household applications through its wholly owned subsidiaries Accumotive and Mercedes-Benz Energy, the latter having been founded in summer 2016.
Accumotive develops, produces and markets drive batteries for Mercedes-Benz and smart-branded hybrid and electric vehicles based on lithium-ion technology. Its extensive battery know-how in the automotive sector is now benefiting stationary battery storage units as products that have proved themselves over millions of kilometres under the toughest conditions, such as heat and cold, are also ideal for stationary use.
As part of an innovative business model, Mercedes-Benz Energy GmbH is responsible for the development, sale and distribution of stationary energy storage units under the Mercedes-Benz brand. Mercedes-Benz energy storage units can already be ordered for households in Germany, the Benelux countries, South Africa and the USA, for example. Installation on customer premises is performed in cooperation with selected partners. Representation in the USA was established in November 2016 in the form of Mercedes-Benz Energy Americas LLC, which is developing the first products for the US market.
There are numerous possibilities for stationary energy storage units, as the concept goes well beyond industrial applications. The business model, developed in collaboration with Lab1886, the Daimler think-tank for new business ideas, also includes operations in small and medium-sized businesses, such as supermarkets. Here, too, the stationary energy storage units can assist at times of peak demand, such as on hot days.
Mercedes-Benz energy storage units are also suitable for private use. Daimler AG started supplying these home energy storage units in late April 2016. The new generation impresses with its Mercedes-Benz quality made in Germany. Compared with the first generation of energy storage units, battery performance is up to three times greater with 120 percent system capacity. Up to eight battery modules each with a capacity of 3 kWh can be combined to form an energy storage unit with a capacity of up to 24 kWh. Households with their own photovoltaic systems can therefore store surplus solar power with virtually no losses. By combining renewable energy sources with a local battery storage unit, private households can increase their self-consumption of generated energy to as much as 65 percent, thereby bringing about their own "private energy revolution".
Re-use of discarded batteries from electric cars
The life cycle of a plug-in or electric-vehicle battery does not have to end after it has done its duty in the vehicle, as it can be re-used for stationary energy storage units. That's because stationary applications are not susceptible to minor power losses, which means that economical stationary operation is possible for at least ten more years, it is estimated. Re-using the lithium-ion modules in this way almost doubles their economical usage.
The world's biggest 2nd-life battery storage facility went online in October 2016 at the REMONDIS headquarters in Lünen in the Westphalia region of Germany. This 13-megawatt-hour project is a joint venture between partners Daimler AG, The Mobility House AG and GETEC. A total of 1000 used battery systems from second-generation smart electric drive vehicles are combined to create a stationary storage facility and marketed on the German primary energy balancing market.
Spare-parts store as energy storage facility
Even battery systems that have not yet been used in electric cars and are instead stored as spare parts can double up as energy storage units. In 2016, collaboration partners Mercedes-Benz Energy and enercity (Stadtwerke Hannover AG) started building a new battery storage facility. Its special characteristic is that this is a spare-parts store for battery systems used in electric mobility solutions. Around 3000 of the battery modules set aside for the present smart electric drive vehicle fleet are being pooled to create a stationary storage facility at the enercity site in Herrenhausen. With a storage capacity totalling 17.5 MWh, the facility is one of the largest of its kind in Europe. After completion, the energy storage facility will be marketed on the German primary energy balancing market (PRL).
In this way, the business model makes an important contribution to stabilising the power grid and making electric mobility economical. In the event of increasing fluctuations in electricity feed-in from renewable energies such as wind and solar energy, such storage units help to ensure optimum balancing of the grid frequency, which must be kept constant.