Example of Rittal International GmbH & Co. KG

At the Rittershausen plant of Rittal International GmbH & Co. KG, a CHP unit operated with bio-oil having a capacity of 420 kW is operated for the basic heat requirement of the plant. In addition, two catalytic exhaust gas cleaning systems (KNV) from production are available as sources of heat. The main consumer of heat is the paint shop whose pre-treatment tanks need to be maintained at a constant temperature both in summer and in winter. In winter, the building heating plays a major role as the largest consumer of energy. In order to optimise the system, a multi-boiler control was implemented at the site in 2007. At the same time, the primary and secondary circuit pumps were replaced with speed-controlled pumps. The volume flow measurement required for the multi-boiler control was incorporated in the primary circuit (heating system), the secondary circuit (secondary consumers) was decoupled using a hydraulic gate. All the energy efficiency measures put together result in a reduction in energy consumption by about 1.3 million kWh and savings on the energy costs of about € 270,000 per year. The package of measures is very economical with a return on capital of 44 percent.

Reduction in gas consumption

8,056,000 kWh / year

Bio-oil consumption for heating

6,720,000 kWh / year

Absolute saving in energy

1,336,000 kWh / year

Energy savings in percentage

9 %

CO2 reduction*

1,095 tons / year



Cost reduction

€270,670 / year

Return on capital

44 %


* The following equivalent values as per Gemis are the basis for all the examples: Natural gas 244 g CO2 / KWh, rapeseed oil 129.6 g CO2 / KWh (BioSt NachV).

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