The Rheinhessen-Nahe Energy Services Company GmbH (EDG) has optimised the heating and electricity supply of the Nieder-Olm school centre and achieved high savings in energy consumption and costs as a result. The contractor implemented the project in collaboration with the Mainz-Bingen regional district and their climate protection manager.
EDG’s technical concept consisted of the following measures to reduce energy use and costs: The local heat network was converted to low temperature. To achieve this, all consumers, particularly ventilation and hot water supply facilities, were optimised in terms of their hydraulics and control technology by means of energy efficiency measures, so that the return temperature could be limited. For example, the injection-type switches of ventilation systems were converted to heating circuit controls, and all heating circuits fitted with high efficiency pumps.
Around 60 per cent of heat is renewably generated in a woodchip-fired biomass boiler, which is supplemented by a high-efficiency natural gas CHP plant with a downstream calorific value heat exchanger. Two large buffer tanks in EDG’s energy management system ensure that heat generation can be decoupled from heat requirements. In addition, the tanks guarantee that the CHP plant and biomass boiler operate optimally. EDG has constructed an internal low-voltage network on the school site in parallel with its heating network. This means that the CHP-generated electricity can be used to directly supply the buildings.