DESIGN OF CONSUMMER THERMAL SUBSTATIONS FOR THE INTEGRATION OF DISTRIBUTED SOLAR TECHNOLOGIES IN DISTRICT HEATING SYSTEMS

In most cases, building service designers choose between Solar thermal (ST) and District Heating (DH) technologies for their integration in buildings. By doing so, only a fraction of the buildings within a particular district is used for ST, while at the same time energy intensity in DH networks can be reduced. In some cases, building-integrated solar thermal systems are connected to DH networks by means of dedicated pipes. In all these cases, sub-optimal situations are reached with lower fraction of renewable heat, reduced network strength and/or additional heat losses. In this paper, a consummer substation concept is proposed with reversible heat flow and net metering, which avoids local thermal storage in the solar loop. Adaptations required for multi-dwelling buildings are presented.European Commission's H2020, 768567, RELaTE

RELATED, A FLEXIBLE APPROACH TO THE DEPLOYMENT AND CONVERSION OF DH NETWORKS TO LOW TEMPERATURE, WITH INCREASED USE OF LOCAL SOLAR SYSTEMS

District heating (DH) systems are key systems for the de-carbonization of heating energy in European Cities. In order to allow for this transition, while guaranteeing competitive energy costs, conversion of DHs is required. DH operation temperature needs to be reduced in order to increase the performance of renewable systems and operation criteria needs to be adopted for the introduction of weather-dependent, distributed heat sources such as solar systems. This paper presents the RELaTED decentralized Ultra-Low Temperature DH network scheme, and its adaptation to several operational schemes such as new and existing DH networks, with different levels of complexity. Transitory phases in the conversion process are discussed.European Commission's H2020, 768567, RELaTE

RELaTED, decentralized & renewable Ultra Low Temperature District Heating, concept conversion from traditional district heating

District Heating (DH) are a very efficient system for heating in urban areas and they are considered as key elements for the de-carbonization of the European Cities. High performance levels and low operational energy costs are part of the identity of these heating networks. The reduction of supply-line temperatures allows the possibility to introduce new low-grade and renewable source energy production, reducing dependence on fossil fuel-based energy plants. Moreover, heat-losses in distribution pipelines are also reduced, since the gradient temperature between supply line and ambient temperature is reduced. Operation of decentralized & Ultra Low Temperature (ULT) systems may adapt for the introduction of weather-dependent, distributed heat sources such as solar systems. Furthermore, although very dependent on local availability, waste heat streams from commercial and industrial installations are also considered because of the stability of heat supply all year round, resulting in minimally carbon intensive processes. Regarding building features, the reduced heat load derived from the transition from current buildings to Nearly Zero Energy Buildings (NZEB), RELaTED allows for the novel concept called prosumer, where buildings can deliver energy to the grid from decentralized energy sources installed in the building. In RELaTED, different subsystems are being developed by different industrial partners, to prove their efficiency in 4 real demonstration sites: Tartu (Estonia), Belgrade (Serbia), Vinge (Denmark) and Iurreta (Spain). A 3-FS (3-Function Scheme) DH substation that permits buildings to become prosumers. Two types of solar collectors, one is an all polymeric glazed collector and the second one is an unglazed collector, both as components of Building Integrated Large Solar Thermal Systems (BILSTS) solar loop. Finally, a reversible and high efficiency heat pump for domestic hot water is being developed. In this paper, an approach to ULT concept is studied, including transitory phases of the conversion.Research output presented in this paper has performed under project RELaTED (RELaTED, 2017). RELaTED project partners are: TECNALIA, Danish Technical Institute, Fortum Tartu, Beogradske Elektrane, Basque Government, Metro Therm, Nibe, Aventa, Industrias IMAR, Basque Energy Agency, Mazovia Energy Agency, Institute of Baltic Studies, FEDARENE, El Taller De Comunicación y CIA. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 76856

Triple function substation and high-efficiency micro booster heat pump for Ultra Low Temperature District Heating

District-Heating (DH) covers around the 9% of the total heat demand in the EU, with a proven highperformance levels and low operational costs. DH may suffer adaptations in order to maintain competitiveness with individual heating systems. The most important one is the reduction of supply temperatures up to 50°C, emerging the concept of Ultra Low Temperature (ULT) DH. ULT DH allows the transmission and distribution heat losses minimization, since heat losses are proportional to the temperature-gradient between supply line the ambient, increasing overall system performance. Furthermore, enables the integration of low-grade energy sources with low marginal costs, such as solar thermal energy or waste heat from industrial and commercial buildings. This study presents the combination of a novel 3 function-scheme (3FS) substation and a micro booster heat pump for domestic hot water. The novel design of the substation allows different operation modes between the grid and the building according to the temperature level and demand range every moment. Regarding the microbooster, this unit is used directly to lift the temperature of the domestic hot water (DHW), so that risk of legionella is avoided and that the required comfort temperature is reached. Preliminary test for the energy performance of the booster heat pump was measured on serially produced units according to tapping profiles and methodologies of standard EN16147. DHW coefficients of performance of 5.2 and 8.5 were measured for heat source supply temperatures respectively of 25 and 40 °C and return temperatures of 22 and 30 °C. This paper explores the possible operational modes of a 3FS in combination with a Building Integrated Solar Thermal System (BISTS) and a Microbooster heat pump

EstuPlan: Methodology for the development of creativity in the resolution of scientific and social problems

[EN] Creative thinking is necessary to generate novel ideas and solve problems. "EstuPlan" is a methodology in which knowledge and creativity converge for the resolution of scientific problems with social projection. It is a training programme that integrates teachers, laboratory technicians and PhD students, master and undergraduate students which form working groups for the development of projects. Projects have a broad and essential scope and projection in terms of environmental problems, sustainable use of natural resources, food, health, biotechnology or biomedicine. The results show the success of this significant learning methodology using tools to develop creativity in responding to scientific and social demand for problem-solving to transfer academic knowledge to different professional environments. Bioplastics, Second Life of Coffee, LimBio, Algae oils, Ecomers, Caring for the life of your crop and Hate to Deforestate are currently being developed.Astudillo Calderón, S.; De Díez De La Torre, L.; García Companys, M.; Ortega Pérez, N.; Rodríguez Martínez, V.; Alzahrani, S.; Alonso Valenzuela, R.... (2019). EstuPlan: Methodology for the development of creativity in the resolution of scientific and social problems. En HEAD'19. 5th International Conference on Higher Education Advances. Editorial Universitat Politècnica de València. 711-717. https://doi.org/10.4995/HEAD19.2019.9205OCS71171

RELaTED, An Approach to a decentralized Ultra Low Temperature District Heating

Trends for heating energy in European Cities are the decarbonization of energy sources and the reduction of heat loads. District heating (DH) networks are key systems to reach the targets due to the cost competitiveness and high performance levels they show. However, DH networks require a conversion to adapt for the need of the future. It is necessary to reduce the operation temperature so that it is possible to increase the performance of renewable systems and operation criteria needs to be adopted for the introduction of weather-dependent, distributed heat sources such as solar systems. In this paper is presented the RELaTED, a novel DH networks scheme with decentralized Ultra-Low Temperature performance. This way, it is possible the adaptation of new and existing networks to several operational schemes. Transitory phases for the conversion of actual DH and how this affects the whole system are discussed along the paper.H2020, 768567, RELaTE

Intercropping Practices in Mediterranean Mandarin Orchards from an Environmental and Economic Perspective

Crop diversification is becoming increasingly important for preserving soil and ecosystems’ health and, subsequently, crop productivity and sustainability. Intercropping practices adopted in monocultural woody crops, with herbaceous crops covering the otherwise bare alleyways, foster ecological interactions and can provide both environmental and economic advantages. In this study, intercropping practices were implemented in a traditional mandarin orchard in south-eastern Spain, which was monitored for three years to assess their impact on the environmental footprint and profitability. The footprint was quantified with a cradle-to-gate life cycle assessment (LCA), while the costs and revenues assessment was based on materials, labor, and machinery used in the trial. The calculated LCA indicators evidenced that, although the cultivated surface area increases with the integration of the intercrops (fava bean, purslane, cowpea, and barley/vetch mix), this does not imply any additional detrimental effects (resource depletion, acidification, eutrophication, global warming). The economic analysis showed that while intercrops may involve additional production costs, the correct choice of intercrops, purslane, and fava bean, in this case, can reduce the market risks for farmers. Overall, this study shows that positive environmental and economic impacts are to be expected of co-integrated herbaceous crops within the same field as mandarin trees

Intercropping Practices in Mediterranean Mandarin Orchards from an Environmental and Economic Perspective

Crop diversification is becoming increasingly important for preserving soil and ecosystems’ health and, subsequently, crop productivity and sustainability. Intercropping practices adopted in monocultural woody crops, with herbaceous crops covering the otherwise bare alleyways, foster ecological interactions and can provide both environmental and economic advantages. In this study, intercropping practices were implemented in a traditional mandarin orchard in south-eastern Spain, which was monitored for three years to assess their impact on the environmental footprint and profitability. The footprint was quantified with a cradle-to-gate life cycle assessment (LCA), while the costs and revenues assessment was based on materials, labor, and machinery used in the trial. The calculated LCA indicators evidenced that, although the cultivated surface area increases with the integration of the intercrops (fava bean, purslane, cowpea, and barley/vetch mix), this does not imply any additional detrimental effects (resource depletion, acidification, eutrophication, global warming). The economic analysis showed that while intercrops may involve additional production costs, the correct choice of intercrops, purslane, and fava bean, in this case, can reduce the market risks for farmers. Overall, this study shows that positive environmental and economic impacts are to be expected of co-integrated herbaceous crops within the same field as mandarin trees