The Task focused on the analysis of the future role of solar thermal in energy supply systems in urban environments. Based on an energy economic analysis - reflecting future changes in the whole energy system - strategies and technical solutions as well as associated chains for energy system analysis will be developed. Good examples of integration of solar thermal systems in urban energy systems were assessed and documented.
(a) Energy Scenarios
The role of solar thermal in the energy system of urban environments was identified with a horizon of 2050 and a 100% Renewable energy goal. The focus lied on a national or international level, but not necessarily 100% on a city or regional level solely.
The scenarios will reflect the combined view of electricity & heat as well as other key heat supply technologies like electrical and thermal heat pumps and CHP. Different district structures will be taken into account and different scenarios regarding the development of the energy system (e.g. IEA Energy Perspectives). The Scenario’s will reflect all sectors including mobility. They will be based on detailed time – series in order to reflect the dynamic of the solar energy availability and will use space discretised data.
(b) Integrating Design Tools for Urban energy supply systems
Existing tools for estimating the solar potential based on geographical information systems GIS are not yet linked to existing design tools for optimizing the structure of urban energy systems. Up to now, they take not into consideration the spatial and time resolution and variability of energy production and energy consumption induced by local renewable resources. The forecast of such fluctuations is observed especially in decentralized energy infrastructure, both energy production and energy consumption not only in time will also vary greatly in the future in space.
A key approach to stabilizing the operation is the use of energy storage – in the task’s scope heat storage in particular, fed by cogeneration and solar thermal systems – which are indirectly helping to operate the electricity grid stable. Existing local energy management tools for heat supply systems – in this case district network with solar thermal - have to be further developed in order deal with the change from demand driven energy supply systems towards production driven systems.
Tools and techniques for the transition process of the energy system towards a renewable one will be addressed and case studies will be documented.
(c) Demonstration and Operation
The implementation of solar thermal in existing or new urban districts as part of an integrated energy supply system was demonstrated and analysed. A focus was taken on the integration of solar systems in district heating systems addressing technical and economic aspects and operation schemes governed by the link to the electrical grid. Tools for operation will be analysed. Existing sites were included as base for identifying bottleneck’s, good practises as base for further analysis.
Based on these boundary conditions, observations and statements a critical review of the goal “Solar thermal energy systems will provide up to 50% of low temperature heating and cooling demand by 2030” – as formulated in the IEA SHC Strategic Plan – is planned within the proposed Task. Further on technically and economically feasible solutions will be identified and best practice examples will be documented.