Good practice

Multipurpose rainwater use in southern Germany

Multipurpose rainwater use in southern Germany
© joachimplehn, image #123135532, source:
Energy, Materials, Water, Carbon
Annual saving:
Resource savings: Energy:
66 % reduction in energy consumption or 2 million kWh
Resource savings: Raw material:
80 tonnes of Ethylacetat saved annually
Resource savings: Waste water:
80 % reduction of waste water originating from fresh water consumption
Resource savings: Water:
80 % reduction in fresh water consumption
Associated cost savings: Raw material:
Associated cost savings: Energy:
Co2 emission reduction:
700 tonnes
Size of company:
Medium (less than 250)
Advancement in applying resource efficiency measures:
Intermediate, Advanced

Rainwater collection was just the start...

  • Rainwater collection reduced fresh water consumption by 80 %
  • An integrated heating and cooling application cut energy consumption 66 %, saving € 55 000 a year

Emil Frei GmbH & Co. KG, a varnish manufacturer in southern Germany, installed a rainwater collection, purification system and 1 000 m3 storage tank several years ago for a range of applications including toilet flushing, cooling, heating and potentially firefighting. This saves the company money, while reducing fresh water use and cutting back on chemical cleaners.

The water is used for both manufacturing (cooling water is heated to 18 °C to produce coating powder) and heating/cooling offices, the warehouse and other buildings and processes.

Key benefits

Thanks to the rainwater collection, fresh water consumption was reduced by 80 %, from 15 793 m3 (1995) to 3 295 m3 (2011). In the same period, the production output nearly doubled. Furthermore, the rainwater can be used to clean production equipment and tanks instead of Ethylacetat, of which 80 tonnes was needed at a cost of around € 120 000 annually.

The integrated heating and cooling application also helped to reduce energy consumption at Emil Frei by some 66 %, or about 2 million kWh. This translates into a saving of € 55 000 in energy costs and about 700 000 kg in CO2 emissions.

Want to know if relevant support is offered in your country?