EnVisaGe Plus project

EnVisaGe Plus continues the monitoring of implementation projects from the EnVisaGe project and addresses additional new research questions.

Three different research questions are the focus of this follow-up project to EnVisaGe:

• How efficient are decentralized innovative local heating networks? Two implementation projects from EnVisaGe, a plus-energy district with large-scale geothermal heat supply and SmartGrid components and a solar thermal supported biomass local heating network are compared with the plus-energy district Ludmilla-Wohnpark in Landshut.  
• Can urban industrial sites be supplied with energy from rural areas? Possible synergies between rural generation regions as "energy belts" for neighboring industrialized metropolitan areas are investigated using the plus-energy community of Wüstenrot and industrial customers of Stadtwerke Schwäbisch Hall. A systemic approach with transferable, integral solution approaches is to be developed.
• Building on the findings from EnVisaGe, the project will investigate how sustainable heating networks can be implemented in rural areas, both for new construction areas and for existing buildings.

1. monitoring and cross-comparison:

Through intensive monitoring of the implementation projects from the previous EnVisaGe project (plus energy neighborhood, Weihenbronn heating network, school electricity storage facility), the efficiency of the technologies and control strategies used are analyzed, optimization strategies are developed and evaluated in a cross-comparison with the Ludmilla Residential Park "+Eins" in Landshut.

2. Rural areas as an energy supplier for urban centers:

Coupling of intelligent system control (heat pumps and electricity storage) with yield forecasts for PV and wind systems. Connection to the virtual power plant of Stadtwerke Schwäbisch Hall, in order to serve as a rural "energy cell" from an "energetic belt" as an energy supplier for large-scale consumers in neighboring conurbations and to generate local added value.

3. Sustainable heating networks in rural areas:

Based on the two innovative heating networks implemented in EnVisaGe, the research team investigates how sustainable heating networks can be realized in rural areas. In addition to new LowEx heating network concepts with decentralized solar thermal feed-in or isolated solutions that can grow together to form networks, various innovative investment, participation and operating models are also being examined here that will allow municipal utilities to increasingly implement and profitably operate heating networks for rural areas in the future.

Together with the Nuremberg University of Technology and the Schwäbisch Hall municipal utility, the HFT made a research contribution on how rural areas can be used as electricity suppliers for urban centers and how existing and future heating networks in rural areas can be operated efficiently and profitably.

Intensive monitoring focused on the systems implemented in a previous project, such as the plus energy settlemet and the areal energy network of the Georg Kropp School, but especially on the innovative heating networks of the municipality of Wüstenrot (a cold local heating network with a large geothermal collector and a biomass-powered network with solar thermal feed-in). Here, interesting comparisons could be made with the heating networks in the project "+Eins" in Landshut and, at the same time, optimization potential could be identified. Continuous monitoring is important in order to operate heating networks efficiently. Causes for e.g. high return temperatures (causing higher heat production costs) are often hydraulic problems of a few consumers on the secondary side. If these consumers can be identified, efficiency can be increased quickly.

Variants for the central use of solar thermal feed-in to heating networks were simulated in detail to be able to recommend an optimal design of solar thermal plants and buffer tanks as components in future projects. The simulation included investment and operating costs as well as payback calculations to find the optimal investment solution.

The results of the cross-comparison and the recommendations for the planning and construction of heat networks in rural areas are summarized in a guideline (german) entitled "Economical and sustainable heat networks in rural areas", which is available on the homepage EnVisaGe Plus | HFT Stuttgart (hft-stuttgart.de).

Through intensive analyses, this project was able to show how local, renewable electricity can be used directly, e.g. through electromobility, load shifting or Power-2-Heat and/or as surplus electricity from the rural community in the regional environment or in the German balancing energy market. Various options were considered for activating controllable energy feeders and loads, as well as integrating energy storage. The most promising scenarios for using the municipality's surplus electricity were analyzed together with Stadtwerke Schwäbisch Hall and subcontractor ZSW in a detailed economic analysis. The results and recommendations are summarized in detail in a guide (german) entitled "Load Shifting Potentials and Control Strategies for Rural Areas and Adjacent Metropolitan Areas," which can be viewed on the EnVisaGe Plus | HFT Stuttgart website (hft-stuttgart.de).

Here are the two planning guides:

1. Load shifting potentials and control strategies for rural areas and adjacent urban centers (Download: "Planungsleitfaden - Lastverschiebepotentiale und Regelungs-strategien für den ländlichen Raum und angrenzende) Ballungszentren").
2. Economic and sustainable heating networks in rural areas (> download soon)

•  Experiences from practice
•  Potentials for optimization of local heating networks
•  Experiences in the operation of low temperature networks