District Power-To-Heat/Cool Complemented by Sewage Heat Recovery

District heating and cooling (DHC), when combined with waste or renewable energy sources, is an environmentally sound alternative to individual heating and cooling systems in buildings. In this work, the theoretical energy and economic performances of a DHC network complemented by compression heat pump and sewage heat exchanger are assessed through dynamic, year-round energy simulations. The proposed system comprises also a water storage and a PV plant. The study stems from the operational experience on a DHC network in Budapest, in which a new sewage heat recovery system is in place and provided the experimental base for assessing main operational parameters of the sewage heat exchanger, like effectiveness, parasitic energy consumption and impact of cleaning. The energy and economic potential is explored for a commercial district in Italy. It is found that the overall seasonal COP and EER are 3.10 and 3.64, while the seasonal COP and EER of the heat pump alone achieve 3.74 and 4.03, respectively. The economic feasibility is investigated by means of the levelized cost of heating and cooling (LCOHC). With an overall LCOHC between 79.1 and 89.9 €/MWh, the proposed system can be an attractive solution with respect to individual heat pumps.This research was funded by the European Commission, H2020-project Heat4Cool, grant number 723925. The work has also been supported by the Swiss State Secretariat for Education, Research and Innovation (SERI) under Contract No. 16.0082

Absorption and compression heat pump systems for space heating and DHW in European buildings: energy, environmental and economic analysis

The selection of the proper device for space heating and domestic hot water for a building is crucial to achieve good energy and economic performances. For a single-family house, the most common heating device is the condensing boiler. Solar systems, electric heat pumps and gas driven sorption heat pumps represent suitable alternatives for improving the efficiency. Although the performances of each technology are well known, their ability to operate efficiently in bivalent heating plants depends on several variables and the choice of the most suitable heating system for a specific building is not straight-forward. The aim of this paper is to compare, under conditions typical of the European region, the seasonal performances of six system configurations that are obtained by combining the most commonly used heating technologies. The comparison is carried out in terms of primary energy consumption for three climatic conditions, changing the quality of the building envelope and the emission system typology. Although the results are sensitive to the primary energy factor for electricity, electric heat pumps generally result the most promising technology for conditions with low thermal lift, while gas heat pumps have the higher performances at high lift. Additionally, the systems are compared in terms of yearly CO2 emissions and economic feasibility, finding scattered results among countries, due to large differences in the local energy mix and energy prices

COMET: Co-simulation of Multi-Energy Systems for Energy Transition

The ongoing energy transition to reduce carbon emissions presents some of the most formidable challenges the energy sector has ever experienced, requiring a paradigm change that involves diverse players and heterogeneous concerns, includ- ing regulations, economic drivers, societal, and environmental aspects. Central to this transition is the adoption of integrated multi-energy systems (MES) to efficiently produce, distribute, store, and convert energy among different vectors. A deep understanding of MES is fundamental to harness the potential for energy savings and foster energy transition towards a low carbon future. Unfortunately, the inherent complexity of MES makes them extremely difficult to analyze, understand, design and optimize. This work proposes a digital twin co-simulation platform that provides a structured basis to design, develop and validate novel solutions and technologies for multi-energy system. The platform will enable the definition of a virtual representation of the real-world (digital twin) as a composition of models (co-simulation) that analyze the environment from multiple viewpoints and at different spatio-temporal scales

Optimization module for filtering and ranking alternative energy replacement systems, in an online ICT design tool for building retrofits

This paper describes the development of an innovative optimizer component as part of a calculation tool for evaluating and comparing a set of retrofitting options for domestic heating and cooling systems. At the initial stage of the process, a filtering sub-module has been developed to pre-process the information introduced by the user and generate a limited set of simulations, thus speeding up the calculation process. At a later stage, the optimizer collects and post-processes outputs from the simulation core before displaying them as a result. In this later stage, a series of performance indicators are calculated and an analytical hierarchical process (AHP) is performed to rank the results based on the user's prioritization weighting for each key performance indicator. As the main outcome of this contribution, the benefits of implementing this optimizer are evaluated in increasing the efficiency of the rest of the components of the tool and, consequently, of the overall calculation process.This study has been developed within the HEAT4COOL research project. This project has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement No 723925. This document reflects only the authors’ view and the Commission is not responsible for any use that may be made of the information it contains. The work has also been supported by the Swiss State Secretariat for Education, Research and Innovation (SERI) under Contract No. 16.0082

REVIEW OF THE EUROPEAN DWELLING STOCK AND ITS POTENTIAL FOR RETROFIT INTERVENTIONS USING SOLAR-ASSISTED HEATING AND COOLING

This study provides a characterization of the existing European stock of residential buildings, with a specific focus on their energy performance. Eight countries with different characteristics and climates have been selected as a representative sample. After identifying relevant parameters, data has been compiled from several sources, including national statistical bodies and European datasets from official and unofficial bodies, as well as previous research projects. Based on those projects as initial source of information, the study is complemented with energy efficiency related regulations as well as with external climate data. The collected information has been subject to a critical review and analysed to identify insights and trends related to the energy performance of European dwellings. The information gathered is intended to provide a general view about the current status for each of the assessed countries and by extension a global picture of the European stock. The outcomes of this study will constitute a realistic baseline scenario for identifying needs, potentials and constraints for renewable energy technologies, and will assist the development of a novel software tool for planning energy-efficient retrofits of residential buildings.This study has been partially developed within the HEAT4COOL research project. This project has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement No 723925. This document reflects only the authors’ view and the Commission is not responsible for any use that may be made of the information it contains. The work has also been supported by the Swiss State Secretariat for Education, Research and Innovation (SERI) under Contract No. 16.0082

Renewable Heating and Cooling Solutions for Buildings and Industry

This workshop brought together a selection of H2020 EU-funded projects involving experts from the biomass, geothermal, solar thermal, and heat pump sectors to discuss a common strategy for increasing the use of renewable energy technologies for heating and cooling for buildings and industry

Modelling and control optimization of a solar desiccant and evaporative cooling system using an electrical heat pump

AbstractThe aim of this work is the control optimization of a new solar assisted air-conditioning concept which combines a desiccant and evaporative cooling (DEC) system with an electrical heat pump. The DEC air handling unit configuration had to prevent return air from mixing with supply air. Therefore, a flat plate sensible heat exchanger is used instead of a rotary. Moreover an additional stream of outdoor air is used for the desiccant wheel regeneration. A reversible water/water heat pump is also included in the system. In summer, the heat pump cools the supply air stream and pre-heats the regeneration air when dehumidification is needed; in winter, the heat pump provides auxiliary heat if a minimum temperature is available in the heat storage, otherwise a backup boiler is used. The depicted system has been modelled and an extensive simulation work has been carried out in order to verify the control capability during the different operation modes. As a result an optimal control strategy has been identified. According to simulations, the system can deliver primary air at the requested temperature and humidity while holding the overall electricity consumption at significant low levels compared to reference system solutions

Modelling and experimental analysis of a GAX NH3-H2O gas-driven absorption heat pump

The experimental analysis of a gas-driven NH3-H2O heat pump whose cycle approaches the GAX concept is carried out. Full load operation is investigated by varying hot water temperatures and partial load operation is investigated by decreasing gas input down to 50% of the full load value. Numerical simulations bolster measurements accuracy and provide insight on the variation of cycle COP and Gas Utilization Efficiency (GUE), based on gross calorific value. A nearly constant GUE of about 1.5 is found for hot water temperatures lower than 50°C. The GUE steadily decreases above 50°C, reaching about 1.33 at 60°C. The COP varies more smoothly, from 1.73 at 45°C to 1.60 at 60°C. The GUE and COP reduction at 50% of the nominal gas input is 6.8% and 6.4%, respectively. Simulations suggest that performances at partial loads can improve if active control of solution mass flow rate is implemented. © 2016 Elsevier Ltd. and International Institute of Refrigeration. All rights reserved

Numerical investigation of the Castle of Zena energy needs and a feasibility study for the implementation of electric and gas driven heat pump

The building sector is one of the key consumers of energy in Europe; consequently, European Unionhas enacted several directives dealing, directly and indirectly, with energy efficiency in building aimingto reduce the buildings energy use. Those directives, while dealing with existing buildings, do not takecare of the Architectural Heritage in a specific uniform way adopting the derogation regime: exceptionsare available at the national level to exclude from their application buildings listed in the ArchitecturalHeritage as historic buildings. Thus any country can adopt its own rules to include or exclude buildingsfrom respecting the energy efficiency requirements for existing buildings. Consequently, up to now nogeneral rules, codes and standards are available for energy retrofit of historical and architectural valuablebuildings. On the other side, no international act, in the field Architectural Heritage conservation, dealswith energy and energy retrofit. Furthermore, the European Union Treaty does not comprise the CulturalHeritage as matter of European legislation. Thus to cover this gap between historic/historical buildingand energy retrofit a lobbying action is needed, managed by the national Cultural Heritage authori-ties, which can steers EU policy in a more effective way towards energy retrofit of historic/historicalbuildings