Energy toolbox : framework for the development of a tool for the primary design of zero emission buildings in european and asian cities

This paper discusses the framework for the development of an Energy Toolbox (ETB). The aim of the ETB is to support the design of domestic Zero Emission Buildings (ZEBs), according to the concept of net zero-energy buildings during the early architectural design and planning phases. The ETB concept is based on the calculation of the energy demand for heating, cooling, lighting, and appliances. Based on a building’s energy demand, technologies for the onsite conversion and production of the specific forms and quantities of final and primary energy by means of renewable energy carriers can be identified. The calculations of the ETB are based on the building envelope properties of a primary building design, as well as the physical and climate parameters required for the calculation of heat transfer coefficients, heat gains, and heat losses. The ETB enables the selection and rough dimensioning of technologies and systems to meet, and, wherever possible, reduce the thermal and electric energy demand of a building. The technologies included comprise green facades, adaptable dynamic lighting, shading devices, heat pumps, photovoltaic generators, solar thermal collectors, adiabatic cooling, and thermal storage. The ETB facilitates the balancing of the energy consumption and the production of renewable energies of a primary building design

Hybrid Renewable Energy System Based On Intelligent Optimization Techniques

La energía renovable tiene como objetivo generar más energía ecológica y no contaminante y para eso, son esenciales para el desarrollo sostenible de la sociedad. La generación con energías renovables debe tener en cuenta las deficiencias y limitaciones que surgen debido a la capacidad intermitente de la fuente de alimentación. Los sistemas híbridos de energía renovable basados en recursos solares y eólicos son los sistemas de energía de generación más prometedores debido a su complementariedad para explotar los recursos naturales; sin embargo, la instalación de un sistema híbrido solar-eólico depende de las condiciones climáticas y eso hace que la dimensión del sistema sea compleja. Un diseño óptimo del sistema híbrido a ser implementado se vuelve crítico para tener la mejor relación costo-confiabilidad. La aplicación de técnicas de optimización inteligente hace posible encontrar un diseño óptimo en un momento adecuado. La literatura muestra que la técnica de optimización más utilizada es la de los algoritmos genéticos. Esta tesis de maestría, propone utilizar tecnologías inteligentes para dimensionar de manera óptima un sistema híbrido de energía renovable que utiliza energía solar y eólica. El enfoque propuesto requiere la configuración del sistema, proporcionar o no conexión a la red, almacenamiento de la batería y los enfoques de optimización. Se presentan los resultados experimentales y las conclusiones que enfatizan las ventajas de las técnicas de optimización inteligentes para la mejora de los sistemas híbridos de energía renovable.MaestríaMagister en Ingeniería Eléctric

A review on the complementarity of renewable energy sources: concept, metrics, application and future research directions

It is expected, and regionally observed, that energy demand will soon be covered by a widespread deployment of renewable energy sources. However, the weather and climate driven energy sources are characterized by a significant spatial and temporal variability. One of the commonly mentioned solutions to overcome the mismatch between demand and supply provided by renewable generation is a hybridization of two or more energy sources in a single power station (like wind-solar, solar-hydro or solar-wind-hydro). The operation of hybrid energy sources is based on the complementary nature of renewable sources. Considering the growing importance of such systems and increasing number of research activities in this area this paper presents a comprehensive review of studies which investigated, analyzed, quantified and utilized the effect of temporal, spatial and spatio-temporal complementarity between renewable energy sources. The review starts with a brief overview of available research papers, formulates detailed definition of major concepts, summarizes current research directions and ends with prospective future research activities. The review provides a chronological and spatial information with regard to the studies on the complementarity concept.Comment: 34 pages 7 figures 3 table

A domestic solar/heat pump heating system incorporating latent and stratified thermal storage.

Both solar and heat pump heating systems are innovative technologies for sustaining ecological heat generation. They are gaining more and more importance due to the accelerating pace of climate change and the rising cost of limited fossil resources. Against this background, a heating system combining solar thermal collectors, heat pump, stratified thermal storage and water/ice latent heat storage has been investigated. In order to investigate and optimise the heating system, a dynamic system simulation model was developed. On this basis, a fundamental control strategy was derived for the overall co-ordination of the heating system with particular regard to the performance of the two storage tanks. In a simulation study, a fundamental investigation of the heating system configuration was carried out and optimisation derived for the system control as well as the selection of components and their dimensioning. The influence of different parameters on the system performance was identified, where the collector area and the latent heat storage volume were found to be the predominant parameters for system dimensioning. For a modern one-family house, a solar collector area of 30m² and a latent heat store volume of 12.5m³ are proposed. In this configuration, the heating system reaches a seasonal performance factor of 4.6, meaning that 78% of the building’s and users’ heat demand are delivered by solar energy. The results show that the solar / heat pump heating system can give an acceptable performance using up-to-date components in a state-ofthe- art building. A novel but most significant component of the heating system is the latent heat store, working with water / ice as phase change material. For that reason, the store was developed in a systematic manner with special regard to the heat exchangers. Based on a detailed specification and a functional analysis, concept solutions were investigated and evaluated. A sheet matrix heat exchanger was eventually chosen as it fulfils the specialised requirements of the heating system. The heat exchanger’s behaviour and its performance during phase change were analysed in laboratory tests. In addition, a storage tank design was developed and a preliminary storage dimensioning carried out for the heating system as defined by the simulations, showing that five polymer tanks with 3.3m³ each and 14 sheet matrix heat exchangers in each tank are required

Study and development of a web-based software for hybrid energy system design and solar prediction analysis

La sfida di integrare la potenza intermittente proveniente da fonti energetiche rinnovabili nella rete elettrica non può essere considerata come un problema isolato, ma deve essere visto come uno strumento per integrare e mettere in primo piano i sistemi energetici rinnovabili. Questo progetto di tesi di dottorato presenta l'analisi, lo studio e lo sviluppo di un software ad interfaccia web in grado di progettare sistemi energetici ibridi in qualsiasi luogo del mondo, in grado di migliorare l'affidabilità, la disponibilità e la sostenibilità sia di sistemi connessi alla rete che di sistemi isolati. Il software EHS (Energy Hybrid System) è stato sviluppato per ottenere la configurazione ottimale per varie tipologie di sistemi energetici ibridi. Lo studio della configurazione ottimale del sistema ibrido si basa sul valore del LCC (Life Cycle Cost) calcolato sulla durata potenziale dell'intero sistema considerando tutti i costi presenti e futuri. La tesi presenta un caso di studio di progettazione, effettuata tramite software EHS, di un sistema energetico ibrido situato in Uganda. I risultati rivelano che la configurazione ottimale del sistema ibrido (generatori FV-baterie-diesel), nonostante il suo elevato costo di investimento, presenta un beneficio economico del 25,5 e del 22,2% rispetto all'utilizzo di solo FV e generatori diesel e solo generatori diesel e una riduzione del consumo di carburante pari rispettivamente al 74,7 e al 77%. Al fine di migliorare l'efficienza del sistema energetico ibrido, il progetto di tesi propone anche uno sviluppo di uno strumento in grado di fare una previsione affidabile della produzione fotovoltaica attraverso uno strumento sperimentale chiamato "predittore solare". In questo studio è stato utilizzato un sistema di acquisizione di immagini, basato su una fotocamera digitale commerciale, utilizzate per ottenere l'elaborazione delle immagini, rilevamento dei corpi nuvolosi, previsione del loro movimento e predizione dell’irraggiamento.The challenge of integrating fluctuating power from renewable energy sources in the electricity grid cannot be looked upon as an isolated issue but should be seen as one out of various means and challenges of approaching sustainable energy systems. The presented PhD thesis project illustrates the analysis, study and development of a web-based software able to design hybrid energy systems in any location of the world, able improve the reliability, availability and sustainability of both grid-connected and isolated energy systems. The software EHS (Energy Hybrid System) is programmed to evaluate the optimal design for various configuration of energy hybrid systems. The evaluation of the optimal hybrid system configuration is based on the value of the LCC (Life Cycle Cost) calculated along the potential lifetime of the entire system, considering all the future costs. The thesis presents a design case study, carried out through EHS software, of a hybrid power system located in Uganda. The results of the simulation through the software EHS show that the usage of battery storage is economically crucial. Results disclose that the optimal configuration of the hybrid system (PV-storage-diesel generators), despite its high investment cost, presents an economic benefit of 25.5 and 22.2% compared to the usage of only PV array and diesel generators and only diesel generators and a reduction of fuel consumption equal to 74.7 and 77%, respectively. In order to improve the hybrid energy system efficiency, the thesis project also proposes a development of an instrument able to make a reliable prediction of PV production and a solar irradiance forecast methodology to predict the photovoltaic production through an experimental instrument called "solar predictor". Within this study a sky image system, based on a commercial digital camera, has been used and characterised with respect to get image elaboration, cloudy shape detection, motion estimation and tracking

Approximate g-functions for selection of borehole field configurations used with ground-source heat pump systems

The arrangement of boreholes in ground heat exchangers used with ground-source heat pump systems is commonly based on pre-computed libraries of g-functions with standard configurations, e.g. placing the boreholes on a uniformly-spaced rectangular grid. Particularly for larger fields with many boreholes in situations with significant annual heat rejection/extraction imbalance, these configurations may be far from optimal. That is, depending on the space constraints, it may be possible to reduce the number of boreholes and amount of drilling required by shifting the positions of the boreholes to make better use of the available space. These configurations of boreholes are unlikely to be found in any library. Furthermore, manual arrangement of boreholes in complex-shaped fields is tedious and time-consuming for the engineer. Therefore, tools are needed that can automatically arrange boreholes in candidate configurations to fit the available land area, calculate the g-function for these configurations, select the best configuration, and determine the required depth for the best configuration. These tools need to be reasonably fast in order to be practical for the design engineer. This paper reports on a fast method for calculating approximate g-functions using non-uniform segments and pre-computed integral tables. Despite being “approximate” g-functions, the difference between a g-function calculated with a more detailed method and the approximate g-function is usually under 1% RMSE. The g-functions for borehole fields with 300, 500, and 1000 boreholes can be calculated in about 2, 6, and 30 seconds on a run-of-the-mill desktop PC. The paper presents the methodology, quantifies the computational time requirements and accuracy of both the g-function and the resulting designs.Mechanical and Aerospace Engineerin

The PLUG-N-HARVEST Facade: A Second Skin with Active and Passive Components

The construction of office buildings in particular, as well as multi-family dwellings, are largely based on regular planning grids, and the widths of such grids appear to be repetitive across Europe.   In the EU project, PLUG-N-HARVEST, a multi-modular façade system for refurbishment, based on these planning grids, is developed. To achieve a comprehensive improvement of the building´s energy efficiency, different solutions for active and passive energy demand reduction, as well as harvesting of heat and power were combined, while also taking into account the existing building structure, climatic region, and usage profile. The PLUG-N-HARVEST façade is designed to enclose the existing façade like a second skin. Thus, the remaining protection provided by the existing outer shell allows continuous usage. The modular approach enables economic efforts by serial production with a high degree of prefabrication and thus shortened assembly time. At the same time, the toolkit design follows the principles of the circular economy. In visual terms, various façade surfaces will be available to allow both an orientation to the existing building and an aesthetic reorientation. In 2019, pilot buildings in Greece, Spain, the United Kingdom, and Germany aim to show the adaptability of the modular toolkit to different façade geometries and to assess its ecological and economic benefits

District heating and cooling optimization and enhancement – towards integration of renewables, storage and smart grid

District heating and cooling (DHC) systems are attracting increased interest for their low carbon potential. However, most DHC systems are not operating at the expected performance level. Optimization and Enhancement of DHC networks to reduce (a) fossil fuel consumption, CO2 emission, and heat losses across the network, while (b) increasing return on investment, form key challenges faced by decision makers in the fast developing energy landscape. While the academic literature is abundant of research based on field experiments, simulations, optimization strategies and algorithms etc., there is a lack of a comprehensive review that addresses the multi-faceted dimensions of the optimization and enhancement of DHC systems with a view to promote integration of smart grids, energy storage and increased share of renewable energy. The paper focuses on four areas: energy generation, energy distribution, heat substations, and terminal users, identifying state-of-the-art methods and solutions, while paving the way for future research