sonnen GmbH (proprietary name and abbreviated form: sonnen) is a company in the energy industry headquartered in Wildpoldsried in the district of Oberallgäu, Germany. It produces home energy storage systems for private households and small businesses. The company is considered the market leader in Germany and additional international markets. Moreover, it is the center of a community for supplying power from renewable energies.
Company development
Company
Christoph Ostermann and Torsten Stiefenhofer founded the company in 2010 as a GmbH (German limited liability company). The legal name of the company at that time was PROSOL Invest Deutschland GmbH. In December 2013, the shareholders' meeting decided to change the company name to sonnenBatterie GmbH, in order to adopt the name of its product range and to support the goal of internationalization. Since November 2015, the company has operated as sonnen, under which all the company's individual activities are organized.
Business development
From 2008 to 2010 above all founder Torsten Stiefenhofer developed a home battery marketed from 2011 under the name of sonnenBatterie. As a solar battery, the product is geared especially to independent homeowners with a photovoltaic system. As of mid-2016, eight generations of this power storage system have been developed and marketed. Germany is the main sales market for the devices. The company also distributes the home batteries in Austria, Switzerland, United Kingdom, Ireland, Slovakia, Czech Republic, Italy, Netherlands, Sweden, Norway, the United States and Australia (current as of: October 2016).
Along with the renaming of the company to Sonnen GmbH, the company announced in November 2015 that starting in 2016, it would establish its own power community, whose members can trade power among themselves. Since September 2016, owners of a sonnenBatterie, who are a member of this power community, can obtain electricity at a flat rate.
At the beginning of May 2017, TenneT and sonnen announced their plans to implement decentralized photovoltaic domestic storage batteries using blockchain technology to help stabilize the power grid and improve the integration of renewable energies. This offers a new source of income to sonnen customers who take part in the system. Furthermore, the planned blockchain pilot project is meant to improve and simplify the networking of storage batteries, photovoltaic systems and power grids, as well as make them more efficient. From an economic perspective, this technology and sonnen’s battery pool (sonnenCommunity) could reduce the redispatching costs for stabilizing the power grid.
Business fields
Power storage
Like other home storage systems, the sonnenBatterie from sonnen is also designed to increase the rate of own consumption of self-produced energy. Usually, a level of self-consumption of 30 to 55 percent can be reached with a photovoltaic system, when using smart-home functions. With a storage system, this rate is around 60 to 80 percent, as the self-produced electricity can be stored until it is consumed within the household. There is less need to source external electricity, especially mornings or evenings.
Since its market launch, the company has designed the sonnenBatterie as a fully integrated system. In addition to the battery modules, it has an integrated power inverter, a unit for power management, along with electronic meters for power consumption in the building, for photovoltaic power generation and for feeding power into the grid or power-sharing in connection with the sonnenCommunity. The power management system evaluates the user's consumption data and takes weather statistics into account, in order to determine the optimal time intervals for charging and discharging the storage system. Moreover, the sonnenBatterie can be combined with heat pumps, small wind turbines or combined heat and power plants.
The storage elements deployed are lithium iron phosphate batteries. Sony is the main supplier of these components. The various models of the system differ above all in their rated capacity, expressed in kilowatt hours. In Germany, Sonnen was one of the first suppliers of lithium ion batteries for stationary use in homes and is considered market leader in Germany and globally. Products are not distributed via wholesale trade but through selected specialty dealers. From 2011 to mid-October 2016, 15,000 units were sold. Most went to homeowners, along with farmers and small businesses.