EBC Annex 64 - LowEx Communities

The IEA EBC Annex 64 – LowEx Communities aims to demonstrate the potentials of low exergy thinking on a community level as energy and cost efficient solutions to achieve 100% renewable and GHG emission-free energy systems. Central challenges are the identification of promising and efficient technical solutions for practical implementation. Aspects of future network management and business models for distribution and operation are as well essential for successful implementation and will be covered in the working phase. Aspects of transition management and policy will ensure the feasibility.

Within the project a discussion on appropriate additional indicators, supplementing the exergy assessment was initialized to obtain a common understanding of local potentials and supply options under the preconditions of local availability. In this context the application of exergy analysis provides the necessary basis for greater local energy autonomy and impulses for local economy.

LowEx Communities - Optimised Performance of Energy Supply Systems with Exergy Principles

Communities are characterized by a wide range of heating and cooling energy demands. The required energy is mainly provided by the combustion of fossil fuels, which is responsible for a large fraction of the greenhouse gas (GHG) emissions. While a lot has already been achieved in the energy efficiency sector, there are still large potentials in providing more efficiently energy for heating and cooling purposes. At the community level, different renewable sources are available. These energies are characterized by high fluctuations and different qualities: e.g. photovoltaics as electricity (high-exergy) or low temperature (low-exergy) heat from renewable energy sources. Low energy qualities are of particular interest for heating applications at moderate temperature levels, because this low exergy supply is very efficient. The main objective of the EBC Annex 64 is to demonstrate the potential of low exergy thinking on a community level as energy and cost efficient solution to achieve 100% renewable and GHG emission-free energy systems. Central challenges to reach this main objective is the identification of the most promising and efficient technical solutions for practical implementation. Aspects of future network management and business models for distribution and operation are as well essential for successful implementation and will be covered in the working phase. Aspects of transition management and policy will ensure the feasibility.

Within the EBC Annex 64 a discussion on appropriate additional indicators, supplementing the exergy assessment was initialized in order to come to a common understanding of local potentials and supply options under the preconditions of local availability. In this context the application of exergy analysis provides the necessary basis for greater local energy autonomy and impulses for local economy.

Objectives

The main objective of the annex is to demonstrate the potential of low exergy thinking on a community level as energy and cost efficient solution in achieving 100% renewable and GHG emission-free energy systems. The intention is to reach these goals by providing and collecting suitable assessment methods (e.g. holistic balancing methods). Furthermore it is planned to provide guidelines, recommendations, best-practice examples and background material for designers and decision makers in the fields of building, energy production/supply and politics.

During the course of this activity, the aim is to develop and improve means for increasing the overall energy and exergy efficiency of communities through demand adapted supply and inclusion of renewable energy sources. Therefore the central focus of all considerations is thermal energy at different exergy levels. Electrical energy will be taken into account as auxiliary energy. Electricity from a renewable fluctuating supply should be discussed as a contribution to the heat and cold supply of a community if it is thermally stored (e.g. storage tanks or usage of the building mass) and used for heating or cooling purposes (e.g. heat pumps).

Outcomes

The following results were addressed through the activities within the framework of the International Energy Agency (IEA) EBC Annex 64:

• Analysis concept and design guidelines with regard to the overall exergy performance of community supply and demand. This could include a possible classification of technologies in terms of performance, improvement potential and innovation prospects.
• Overview of the feasibility, efficiency potentials and impacts of integral energy system solutions for existing community settings, criteria for decision making in the project development phase.
• Analysis framework and open-platform software and tools for community energy system design and performance assessment.
• Summary of intelligent management and control strategies and system solutions for an efficient energy supply system at community level based on exergy principles.
• Set of existing and close to market systems and technological solutions and best integration into overall energy system design.
• Description and collection of good practices and examples of system concepts, technologies, management and control strategies for maximum share of renewable energy sources and maximum efficiency of the energy and exergy potentials available on a community scale.

The primary deliverable is an easy to understand and practical, applicable design guidebook for key people in communities. It is to contain an executive summary for decision makers and will cover issues on how to implement advanced supply technologies at a community level. Further it is focused on how to optimize supply structures to ensure reduced costs for the system solution, while providing a high standard of comfort to the occupants of the buildings.

 

Annex 64 factsheet: Optimized Performance of Community Energy Supply Systems with Exergy Principles

 

 

Acknowledgement

This project has been financially supported by the German Federal Ministry for Economics and Technology.