Efficient interaction between energy demand, surplus heat/cool and thermal storage in building complexes

Easily accessible reliable low-cost energy has been important parameters in the development of high standards of living in the industrial countries. This has resulted in a sharp increase in energy consumption worldwide. Increased energy efficiency is one of the most important tools for reducing greenhouse gas emissions and ensuring future energy supply. Increased focus on improving energy performance for buildings and reduced primary energy consumption is attainable through new legislation. This bring about completely new boundary conditions for design and energy interaction in buildings. INTERACT is a competence building project funded by the Research Council of Norway in 2013. The project is co-financed by Aspelin Ramm, COWI AS, Rema1000 Norway, Sweco AS and Statkraft Varme. The project ends in the summer of 2017. The main objective is to develop methods and models for efficient energy interactions between energy demand, surplus heat / cooling, thermal storage and third party delivery to district heating / cooling plants. Heating and cooling demands in buildings occur at different times and differ from hour to hour and over seasons. Even though the annual energy balance may be offset, it still means that varying energy flows result in high energy consumption. The mapping of different concepts, and how variations in day and year can be compensated, with special focus on possibilities for thermal interaction between buildings and thermal storage in energy wells and storage tanks, have been completed. Dynamic thermal storage is one of four main themes in the project. Thermal storage appear as a key issue as energy production and consumption rarely occur at the same time. Participants from several different academies (NTNU IGB, University of Dalarna, Universidad de Vigo, SINTEF) are involved in this work and provide good academic skills. During the period, the report "Software for modeling and simulation of ground source heating and cooling systems" has been completed and approved by the SC. The report looks at various software used for the design of groundwater system. Models for simulating borehole storage, heat pumps and system components such as water storage, hydraulics and building load are included. Software focus is EED, TRNSYS, Polysun, Modelica, IDA ICE, and Matlab / Simulink + Carnot, and limitations and models are evaluated, resulting in a summary of the pros and cons of using the various software. The usability is related to the level of flexibility in the models. Higher flexibility often means less user-friendly programs and vice versa, and EED, Polysun and IDA ICE assume more user-friendly software while Modelica, TRNSYS and Matlab / Simulink + Carnot are more flexible. The model that covers most of the borehole simulations is the TRNSBM model in the TRNSYS and the INTERACT 2016 Modelica model. One main objective of the project is to develop a method that can be used for decision support and early-stage profitability when planning efficient energy centers that support energy interactions between several parties. This method will contain models for production and recovery of heat and cooling, accumulation and exchange with third parties (including district heating and cooling). The work is supported by the PhD work, which will develop background models and management strategy for predictable and optimal energy flow between sources, loads and intermediate storage. A dynamic model has been chosen as simulation tool, and a simple energy system analysis is designed to show the potential. It works in parallel at the system level with control systems and strategy for a thoughtful tool, at the same time as the component and subsystems and numerical efficiency of these. The project has developed 11 master and project students in the theme "Energy-efficient building complexes" as well as two summer researchers at SINTEF. Demand for tasks within this theme is redoubtable and demonstrates the importance of further developing students together with partners who are partners in the project. The project is publishing well and there are 10 journal articles and 27 'other' publications (conference contributions, newsletters, etc.) as well as 4 technical reports. There have been 6 open workshops with invited guests during the project period.

Easy access to reliable low cost energy has been an important parameter in developing the high living standard in industrialised countries. Increased energy efficiency is one of the most important measures to curb greenhouse gas emissions and secure futur e energy supply to maintain and improve the living standard globally. Focus on energy performance of buildings and reduction of primary energy creates a potential for energy interaction. Energy efficiency can also be seen as a major energy source and an o pportunity for value creation. Increased utilization of surplus heat/cold has been pinpointed by the Norwegian Energy21-report as an important strategic research area. INTERACT will contribute to release the potential for energy efficiency by fostering kn owledge, technology and development of tools that can be a game changer in utilization of surplus heat. Efficient interaction between energy demand, surplus heat/cool and thermal storage and third party deliverance to the district heating/cooling DHC grid in building complexes is the key to obtain global energy saving goals. Enablers, barriers and frame conditions for decision-making consequences of realizing such systems will be studied. Key work is to develop bridging models and merging tools to connect several branches. This requires multi-disciplinary skills and close cooperation with the partners. The traditional gap between different technical divisions with their own vendors and appurtenant controlling and management systems has to be linked. INTER ACT results will improve energy efficiency since there is a mismatch between simulation and operation of most current systems. Zero Emission Buildings and plus-houses will need to balance uneven supply and demand. INTERACT will develop robust methods and tools for optimal energy interaction between energy demand, surplus heat/cool, thermal storage and third party deliverances. This fundamental knowledge is required for successful installation in the future.