Solar World: Recycling and Enviromental Benefits

As early as 2001, SolarWorld AG recognized the important role of recycling. In the Sunicon GmbH, they worked on transforming, refining and recovering silicon materials with various origins. This usually has to do with co-products from the semi-conductor and solar industries. Modern classification machines and a crushing system are available for quality control, classification of the silicon pieces, sorting by line type and for crushing work.

Sunicon GmbH offers a wide range of recycling services:

  • Purification, recovery and classification of silicon material from different sources
  • Surface treatment of wafers, cells and other silicon materials
  • Recycling of photovoltaic modules from various manufacturers that retains value
  • Production of special silicon blocks

Energy and climate protection

Solar World make the strongest impact on environmental sustainability by increasing energy efficiency and protecting the climate. Solar power generation replaces other sources in the energy mix, thus contributing to reducing greenhouse gas emissions and preserving fossil resources.

Fossil fuels in comparison to solar power production

fossil fuel comparison to renewable energyFor the generation of 1,000 kWh per year during a period of 30 years, 106,583 kWh of energy are needed if produced exclusively using coal. Thereby, 24,806 kg CO2eq are emitted. In comparison, gas comes out better: Only half of the energy is needed and 8,355 kg CO2eq are released. Solar power production, however, delivers much more energy than needed for its production: For 30,000 kWh in total, only 3,694 kWh are needed. The emissions during production are also minimal. Solar power production is a so-called zero emissions technology, as the few emissions from the production process are far more than offset during the life-time of the system.

Energy is needed throughout the entire production process of our products starting with the extraction of raw materials. However, the amount of energy used in production is far exceeded by the amount of electricity produced by the solar power system. In line with this, far more greenhouse gas emissions are reduced throughout the life cycle of the solar power system than are emitted throughout the entire production process. As a result, solar energy is a zero-emission source. Similar to the payback period of an investment, we use the terms energy payback time and CO2eq payback time to express how quickly the energy consumption and greenhouse gas emissions (measured in CO2eq) are compensated for.

Payback periods

For environmental reasons and to reduce costs, our goal is to lower energy consumption per production unit watt peak (Wp) along the entire value chain. This also allows us to reduce the greenhouse gas emissions associated with energy use. To achieve this, SolarWorld has been conducting life cycle analyses for several years. The result: While it takes a good year to compensate for energy consumption for the entire production process for a system in Bonn, it only takes eight months in San Francisco. In comparison: In 2008, energy payback was still 3.5 years in Germany (see Jungbluth et al.: Life Cycle Assessment of Photovoltaics: Update of ecoinvent data v2.0, Working Paper, ESU-services Ltd. (2008)). CO22eq emissions are compensated for the quickest for a system in the U.S. after a good year while it takes almost 10 years in France due to the high percentage of nuclear power.

Energy and CO2eq amortization times
Region/Country Representative place Power yield
Energy amortization time**
CO2eq amortization time ***
Southern Europe Sofia 1,270 0.86 (2010: 1.1)
Italy Perugia 1,260 1.09 (2010: 1.1) 1.61 (2009: 1.99)
France Poitiers 1,110 0.97 (2010: 1.2) 8.82 (2009: 10.89)
Spain Madrid 1,580 0.79 (2010: 0.9) 1.57 (2009: 1.94)
U.S. San Francisco 1,670 0.62 (2010: 0.8) 1.25 (2009: 1.54)
Germany Bonn 940 1.22 (2010: 1.5) 1.95 (2009: 2.41)

* Assumption based on “Methodology Guidelines on Life Cycle Assessment of Photovoltaic Electricity”, IEA PVPS Task 12, Subtask 20, LCA, Report IEA-PVPS T12 – 01:2009, October 2009
** Calculation using country-specific energy mix data (Ecoinvent database)
*** Calculated using current calculation tools of the GHG Protocol.
See Wetzel, Thomas; Feuerstein, Florian (2011): Update of Energy Payback Time Data for Crystalline Silicon PV Modules, 26th European Photovoltaic Solar Energy Conference and Exhibition, Hamburg, September 2011.


Positive CO2eq balance

co2 comparison to solar panels “By further developing our analysis, we have a more comprehensive view of our CO2eq balance for the first time and include the impact of the entire production process: With the volume of solar power modules sold in 2011, around 8.7 (2009: 4.6) million tCO2eq could be prevented. The costs for environmental damage avoided as a result amount to around € 610 (2009: € 324) million. The CO2eq emissions prevented exceed the CO2eq emissions caused along the entire production chain by a factor of 19 (2009: factor of 15).”



In 2011, the annual report of the Carbon Disclosure Project (CDP) Germany names SolarWorld AG as Sector Leader in the field of renewable energies for its transparent and detailed reporting. Each year, the CDP asks public companies around the world to report on their climate-relevant corporate data, strategies and specific climate protection measures. The CDP makes this data available to the capital markets and the general public. The aim of publishing the data is to create greater transparency regarding emissions of greenhouse gases which are harmful to the environment. Since the Carbon Disclosure Project was founded in Germany in 2005, SolarWorld has been taking part in the initiative.

For your information, we provide SolarWorld‘s answer to the CDP 2011 here: Programme Response CDP SolarWorld
These data are as well available on the Carbon Disclosure Project website: (registration needed)