Stuttgart sewage treatment plant to get solar folding roof

Stuttgart’s sewage treatment plant in Mühlhausen (Germany) is the largest in the country. It consumes a lot of electricity. Soon it will be generated in the plant itself to a greater extent than today.

The operation of the sewage treatment plant in Mühlhausen requires about 26 million kilowatt hours of electricity per year. The figure is just above that for all the street lighting and traffic lights in the city. Own generation now at 50 per cent: The sewage treatment plant’s own energy generation has been increased over the years through the use of a combined heat and power plant and a steam turbine. In the meantime, the plant produces about 13 million kilowatt hours per year, says Boris Diehm, head of the sewage treatment plant and canal operation department at the municipal sewage treatment plant (SES). So half of the electricity needed still has to be bought in. This purchase is to be gradually reduced. Diehm says that by 2035, the year set by the municipal council a few weeks ago as the target year for Stuttgart’s climate neutrality, the city wants to have 90 per cent of its own generation. (…)

Diehm and the SES staff have calculated the costs and returns of the modules hanging four metres above the ground and estimated a two-digit million sum for the investment. The expenditure would pay for itself after 24 years. That is a long time, but the value is relative: “We calculated with an electricity price of seven cents gross per kilowatt hour, now we are at 21 cents,” says the department head.

>see media article (in German)