Settlement water management

There are many options for saving electrical and thermal energy in Austria's municipal facilities, as well as untapped potential for generating it. The possibilities range from replacing pumps in water supply and wastewater disposal, optimizing wastewater treatment plants and insulating digestion towers on the savings side to optimizing the use of sewage gas to generate electricity or heat, increasing the use of photovoltaics and the thermal use of wastewater on the generation side. This report examines the implementation potential up to 2027.

It shows that the thermal use of wastewater represents by far the greatest potential after the sewage treatment plant. Although this consumes electrical energy, it has massive positive effects on the heat balance and the greenhouse gas balance.Net electrical energy consumption in the urban water management sector would be reduced from the current 282 GWh/a (637 GWh/a consumption and 355 GWh/a own generation) to 221 GWh/a if all options were implemented, and even to 0 GWh/a without the thermal use of wastewater (which requires electricity for heat pumps).

Currently, thermal energy consumption and thermal generation in the urban water management sector each amount to around 300 GWh/a. A surplus of up to 883 GWh/a could be generated by 2027, primarily through the thermal use of wastewater.

The investment costs amount to around 804 million euros if all measures are implemented. This could reduce energy costs by 35.6 million euros per year. However, this does not take into account future energy price increases.

Greenhouse gas emissions in the municipal water sector currently amount to 277,714 tons of CO2 equivalents per year. By implementing all options, the balance would improve to minus 31,662 tons of CO2 equivalents per year, making the urban water management sector a greenhouse gas sink. Without thermal use of wastewater, net emissions of 158,719 tons of CO2 equivalents would remain.Furthermore, there would be an employment effect of over 4,000 annual full-time equivalents.  

Report: Our water makes a good climate

Client	BMK
Project management	Franz Zach