Bosch Solar Energy


  • Holger von Hebel, CEO
  • Stefan Hartung, Chairman of the Board

Bosch Solar Energy AG (formerly ErSol Solar Energy AG ) based in Arnstadt is a company that silicon-based photovoltaic products, especially solar cells and crystalline solar modules manufactured.


The company was founded on 12 March 1997 as ErSol Solar Power GmbH & Co. KG. The first production line was a production line for multi-crystalline silicon solar cells in size 100 mm × 100 mm.

In 2001 the company was converted as chief executive officer in a corporation with Claus Beneking and changed its name since then as ersol Solar Energy AG. In the context of a capital increase after the IPO in 2005 of Ventizz Capital Fund II entered as the majority shareholder. With the acquisition of the ingot and wafer producers ASi Industries GmbH in Arnstadt ersol Group expanded. The company sales grew to 64 million euros and operating profit of 9.5 million euros.

In February 2006, ersol acquired the Californian silicon recycler Silicon Recycling Services Inc. (SRS ). In July 2006, then the ground was broken for the thin film factory ( ersol Thin Film GmbH ). A second solar cell plant in Arnstadt was started later and was inaugurated in November 2007. To finance the expansion ersol signed in October 2006 a syndicated loan led by Deutsche Bank over 157 million euros.

At the turn of 2006/2007 there were changes in the board structure. On the 22nd European Photovoltaic Solar Energy Conference and Exhibition ( PVSEC ) in Milan ersol presented in the 10- year company anniversary together with the project partners Crystal Growing Systems GmbH (CGS ), the Solar Center, Erfurt, Roth & Rau AG and Day4 Energy Inc. a solar panel based on 16 monocrystalline Supersize solar cells. On 31 December 2007, the Group employed more than 800 employees.

On 2 June 2008, Bosch announced to take over 50.45 per cent of " ersol Solar Energy AG " in order to expand its business in the field of renewable energies. At the same time submitted Bosch the outstanding shareholders a voluntary takeover offer. On 12 August 2008, the acquisition was completed with the approval of all relevant antitrust authorities.

By resolution of the Annual General Meeting of 23 July 2009, all shares of the minority shareholders were transferred in the course of a squeeze-out of the "Robert Bosch GmbH". On 1 September 2009, the renaming of the " ersol energy AG " followed in the " Bosch Solar Energy AG ".

After nearly two years of construction, the company opened in the summer of 2011, its new competence center in Arnstadt with new module manufacturing, headquarters, research and training center. Since January 2012, Arnstadt is now also the official headquarters of Bosch Solar Energy. In spring 2012, after eight months of renovation time, there was also the former Bosch site for diesel injection pumps in Vénissieux, near Lyon, a manufacturing facility for crystalline solar modules. In December 2012, Bosch Solar Energy closed the plant in Erfurt. Thus, the Solar Energy adopted by the micron -Si thin-film technology and focused more on the crystalline module technology and the CIS thin film.

On March 22, 2013 announced Bosch to opt out of solar technology and close all sites in this area. The production of ingots, wafers, cells and modules is set up in early 2014 and sold the individual areas as soon as possible. From step especially Thuringia is affected: At its headquarters in Arnstadt employs Bosch Solar Energy AG of around 1,800. Overall, working in the solar division of Bosch around 3,000 employees, mainly in Germany and France.

The end of 2013 it was announced that the production facilities are taken from Bonner Solar Group Solar World of Bosch Solar in Arnstadt. SolarWorld receives from Bosch for the acquisition of staff and maintenance of the manufacturing facility a dowry of 130 million euros.


On 30 September 2005, the IPO took place. The stock listed on the Prime Standard of the Frankfurt Stock Exchange, was represented in the ÖkoDAX since 19 December 2005 TecDax and from 4 June 2007. The stock was removed from the Nasdaq and the ÖkoDAX on 22 September 2008. With effect from 8 September 2009, the listing of its shares on the Frankfurt Stock Exchange has been set.

Structure and products

Bosch Solar Energy is an integrated manufacturer of photovoltaic products:

  • At the company headquarters in Arnstadt the company manufactures monocrystalline ingots, wafers, solar cells and crystalline solar modules. Here are monocrystalline ingots through a drawing process - the so-called CZ method - produces. It will then thin "slices" - the wafers - sawn. Their thickness is from 160 microns freely selectable. ersol Wafers (until 2009) was one of the first production outside the United States with its own treatment of the cutting liquid ( "slurry ").
  • The core business is the production of solar cells in the format of 156 mm × 156 mm and the production of crystalline solar modules. At a cell thickness of about 200 micrometers, the efficiency of monocrystalline solar cells reaches up to 18.4 percent. The production is carried out by the parent company, Bosch Solar Energy AG in Arnstadt.
  • Based on the mono crystalline solar cells, the company produces crystalline solar modules with 48 or 60 cells. The manufacturing module is integrated into the overall complex in Arnstadt.
  • As a key new business sales of large-scale solar projects have been built since 2009. The company takes on the construction of solar parks from the planning to the turnkey handover.