Land use dynamics and the environment

We build a benchmark framework to study optimal land use, encompassing land use activities and environmental degradation. We focus on the spatial externalities of land use as drivers of spatial patterns : even if land is immobile by nature, location's actions affect the whole space through pollution, which flows across locations resulting in both local and global damages. In contrast to the previous literature on spatial dynamics, we prove that the social optimum problem is well-posed, i.e., the solution exists and is unique. Taking advantage of this result, we illustrate the richness of our model by means of a numerical analysis. Considering a global dynamic algorithm, we find that our model reproduces a great variety of spatial patterns related to the interaction between land use activities and the environment. In particular, we identify the central role of abatement technology as pollution stabilizer, allowing the economy to achieve stable steady states that are spatially heterogeneous.Land use, spatial dynamics, pollution.

Respostas dos animais ectotermos terrestres à variação microclimática

Understanding the effects of microclimatic variation on living beings requires, at least, three steps: 1) Knowing the principles for variation of climatic parameters and the responses of living beings to these variations. 2) Detecting climatic variation patterns in the scales within climate interacts with living beings, and response patterns of living beings. 3) Synthesizing predictive theories from this knowledge. Studies about the effects of temperature and AETs are extremely abundant and it is necessary to advance in the direction of producing a theoretical synthesis. In this paper, I apply the above mentioned steps for proposing a primordial theory about temperature effects on AETs, along several organizational levels. The same procedure may be applied to other climatic variables or ectotherm’s characteristics in a path of theoretic synthesis of increasing generality.Entender de maneira útil os efeitos da variação climática sobre os seres vivos requer de, ao menos, três passos: 1) Conhecer os princípios que explicam a variação dos parâmetros climáticos e as respostas dos seres vivos a esta variação. 2) Detectar os padrões de variação do clima nas escalas em que este interage com os organismos, e os padrões de resposta dos seres vivos. 3) Sintetizar teorias preditivas a partir deste conhecimento. Estudos dos efeitos da temperatura em animais ectotermos terrestres (AET) são extremamente abundantes, o que faz possível e necessário avançar sua síntese teórica. Neste texto, aplico os três passos referidos para propor um primórdio de teoria preditiva dos efeitos da temperatura sobre a biologia dos AETs em diferentes níveis organizacionais. Este mesmo procedimento pode ser aplicado a outras variáveis climatológicas ou características dos ectotermos não tratadas aqui, em um caminho de síntese teórica de abrangência cada vez maior

Heat pump for radiant cooled and heated floor driven by a microphotovoltaic system

This paper reports a solar trigeneration system installed at the Solar Energy Experimental Plant owned by the Spanish National Research Council (CSIC), located in Arganda del Rey, 20km east from Madrid.The authors want to express their gratitude to the Ministerio de Economía y Competitividad of Spain for funding the research project ENE2010-20650-CO2-01

Photovoltaic self-consumption heating system: analytical model, experimental results and autonomy prospects

Mención Internacional en el título de doctorIn the European Union, buildings are responsible for 40% of energy consumption and 36% of CO₂ emissions, which contribute significantly to anthropogenic climate change. Since heating represents the major portion of energy consumption in buildings in Spain, renewable heating systems emerge as an alternative to mitigate this problem. This thesis proposes a heating system in which the PV production is self-consumed by a heat pump. For this purpose, a photovoltaic off-grid system that feeds an air-water heat pump to heat a small building through radiant loor has been designed and built. The building, despite the aim of being independent, incudes connection to the grid, so the heat pump supply can be switched between the photovoltaic microgrid and the conventional grid. The photovoltaic array, with a total area of 15.7m² and useful area of 14m², is composed by 12 modules, nominal power of 180W each. Heat pump's nominal heating power is 6kW, which is in fine with building's maximum thermal load. To size properly this type of photovoltaic system, it is necessary to go beyond peak sun hours term commonly used by installers and to simulate realistically photovoltaic production over time. The method known as five-parameter model, details the working curve of a module for a given cell temperature. In this thesis, production has been addressed from a physical point of view, emphasizing the influence of solar cells' temperature on their efficiency. A heat transfer model has been developed, which allows to determine accurately cell temperature under changing meteorological conditions, and then to calculate the photovoltaic production in each moment, basing on technical specifications commonly provided by the modules' manufacturers. This dissertation includes the experimental validation of both cell temperature and photovoltaic production models. The efficiency of the used modules, according to their total area, is 13.73% at 25°C, 12.08% at 50°C and 10.76% at 70°C. The proposed method is easily adaptable to any type of photovoltaic module, once its material composition is known, and its output can be simulated for any tilt angle and location, for where meteorological data are available. Depending on obtained working temperatures, the use of hybrid photovoltaic/thermal modules can be considered. The photovoltaic production model was simulated for the heating period from 4/12/2012 to 30/04/2013, predicting an achievable production of 1265.8kWh and an average cell temperature of 21.3°C, which reaches an average daily maximum value of 47.5°C. The intercepted solar energy during that period was 8869.4kWh, so the efficiency of the array according to its useful area would be 14.3%, instead of the nominal value of 15.4%. The photovoltaic heating system was experimentally tested during the same heating period. The array produced 820.8kWh of electricity. The seasonal photovoltaic efficiency was 9.26%. The achieved production was significantly lower than the achievable one, according to the simulation. The heat pump was fed with 723.9kWh of electricity, 501.4kWh of which carne from photovoltaic source: useful efficiency of the system 5.7%. Several factors caused that efficiency, such as electrical losses in diverse conversions, control system's limitations, storage system's capacity and fit of the production to the demand. The ammount of heat supplied to the radiant floor was 2321.9kWh. The seasonal COP was 3.2 and system's global efficiency was 18.2%. The system was isolated from the grid at 69.3%. Greenhouse gases emissions saved were 170.5kgco₂ comparing to feeding the theat pump with conventional electricity (for an emission factor of 0,34kgco₂ /kWh); 835.9 kgco₂ comparing to supplying the same heat ammount through a gas-oil C boiler; 573.6 kgco₂ comparing to a natural gas boiler. On the other hand, refrigerant leaks were equivalent to 132.1 kgco₂.Actualmente, en la Unión Europea los edificios demandan un 40% del consumo total de energía y son responsables del 36% de emisiones de gases de efecto invernadero, contribuyendo significativamente al calentamiento global antrópogénico. Dado que la calefacción supone la principal porción del consumo energético en los edificios en España, los sistemas de calefacción renovable surgen como una alternativa para mitigar dicha problemática. Esta tesis plantea un sistema de calefacción fotovoltaica en el que la producción eléctrica es auto-consumida por una bomba de calor. Para ello se ha diseñado y construido un sistema fotovoltaico sin inyección a red para alimentar una bomba de calor aire-agua que calienta un pequeño edificio mediante suelo radiante. El edificio, tendente a la autonomía, incluye conexión a red, por lo que el suministro a la bomba de calor puede permutarse entre la micro-red fotovoltaica y la red convencional. El campo fotovoltaico, con un área total de 15,7m² y útil de 14m² , está compuesto de 12 paneles, de 180W de potencia nominal cada uno. La potencia térmica nominal de la bomba de calor es de 6kW, al igual que la carga térmica máxima del edificio. Para dimensionar adecuadamente un sistema fotovoltaico de estas características es necesario simular realísticamente la producción fotovoltaica a lo largo del tiempo. En esta tesis, se ha abordado la producción desde un punto de vista físico, haciendo hincapié en 'la influencia de la temperatura de las celdas solares en su eficiencia. Se ha desarrollado un modelo de transferencia de calor que permite determinar con exactitud la temperatura de celda para condiciones meteorológicas cambiantes y, a partir de ahí, la producción fotovoltaica en cada momento, basándose en especificaciones comunmente suministradas por los fabricantes de módulos. La validación experimental del modelo, tanto para la predicción de la temperatura de celda como para la producción fotovoltaica, es incluida en la presente tesis. La eficiencia de los módulos utilizados, respecto a su área total, es de 13.73% a 25°C, 12.08% a 50°C y 10.76% a 70°C. El método planteado es fácilmente adaptable a cualquier tipo de módulo fotovoltaico a partir de los materiales que lo componen, y su producción simulable para cualquier ángulo de inclinación y localización, para la que se disponga de datos meteorológicos. Dependiendo de las temperaturas de trabajo obtenidas, la utilización de paneles híbridos fotovoltaicos/térmicos puede ser planteada. En concreto, el modelo de producción fotovoltaico fue simulado para el periodo de calefacción entre el 4/12/2012 y el 30/04/2013, prediciendo una producción fotovoltaica alcanzable de 1.265,8kWh y una temperatura media de trabajo de celda de 21,3°C, que alcanza una máxima diaria media de 47,5°C. La energía solar interceptada durante ese periodo fue de 8.869,4kWh, por lo que la eficiencia del campo considerando su área útil sería del 14,3%, frente al 15,4% nominal. El sistema de calefacción fotovoltaica fue estudiado experimentalmente durante el mismo periodo de calefacción. El campo produjo 820,8kWh de electricidad, por lo que la eficiencia fotovoltaica estacional fue del 9,26%. La producción obtenida fue inferior a la potencialmente alcanzable, de acuerdo con la simulación. La bomba de calor fue alimentada con 723,9kWh de electricidad, de los cuales 501,4kWh provenían de la fuente fotovoltaica: eficiencia útil del sistema del 5,7%. Multiples factores provocaron dicha eficiencia, tales como las pérdidas eléctricas en las diferentes conversiones, limitaciones del sistema de control, capacidad del sistema de almacenamiento y ajuste de la producción a la demanda. El calor suministrado al suelo radiante fue 2.321,9kWh. El COP estacional de la bomba de 11 calor fue de 3,2 y el rendimiento global del sistema del 18,2%. El sistema operó autónomo de la red a un 69,3%. Las emisiones de gases de efecto invernadero ahorradas fueron de 170,5kgco₂ respecto a alimentar la bomba de calor con electricidad convencional (para un factor de emisión de 0,34kgco₂ /kWh); de 835,9kgco₂ respecto a suministrar el mismo calor a partir de gas-oil C; de 573,6 kgco₂ respecto al uso de gas natural. Por otra parte, las fugas de refrigerante equivalieron a 132,1 kgco₂.Los resultados científicos que se presentan son fruto de la financiación por parte del Ministerio de Ciencia e Innovación del proyecto Diseño, construcción y evaluación experimental de un sistema de refrigeración solar y trigeneración de alta eficiencia para edificios e invernaderos (ENE2010-20650-C02-01) y de la ayuda FPI (BES-2011-050706). El Ministerio de Economía y Competitividad financió la Estancia Breve (EEBB-I-13-06021) en la Universidad de Wisconsin-Madison.Programa Oficial de Doctorado en Ingeniería Mecánica y de Organización IndustrialPresidente: Francisco Javier Rey Martínez.- Secretario: María Carmen Venegas Bernal.- Vocal: Rafael Antonio Salgado Mangua

Energy and economic analysis of domestic heating costs based on distributed energy resources: A case study in Spain

Energy electrification is part of the European strategy for the decarbonization of the building sector and energy transition in cities. The present paper compares the heating costs of covering the heating demand by different systems: (i) domestic gas boiler and an air-to-air heat-pump, (ii) without and (iii) with local PV backup; in order to analyze the effects of the electric price volatility along with the weather condition dependency of the renewable systems. The study presents a heat pump model and a PV generation model to estimate the hourly performance of both systems. These models are then applied in an average dwelling in Bilbao, Spain, in November 2020, and November 2021. Results show that in November 2020 the combined use of a heat pump with PV generation to cover the heat demand was 66% cheaper than covering the same demand with a natural gas boiler. By contrast, the combined use of the PV and heat pump resulted in a 15% higher energy bill compared to the natural gas in 2021 due to the increase of the electricity prices (3 times higher), the lower temperatures (25%) and less solar radiation (70%)

Domestic space heating dynamic costs under different technologies and energy tariffs: Case study in Spain

Dynamic energy tariffs facilitate engaging domestic consumers on demand management, contributing to grid’s stability, but requires of informed decision enabling tools. This paper presents a domestic heating costs calculation method for different heating technologies (gas boiler, heat-pumps) and a range of energy tariffs. Based on physical modeling, effect of outdoor temperature in the COP of heat-pumps is assessed. The methodology is applied to the 2018/19 heating season in Madrid (Spain), calculating the heating costs under four diverse energy tariffs (static gas tariff, static electricity tariff, real-time-price electricity tariff, dynamic time-of-use electricity tariff) for a typical home demand. The hourly results for two representative days are detailed, along with the aggregated results for the whole season. Along the season, the continuous changes in energy wholesale market prices and weather conditions make one heating technology and/or tariff more convenient each time. For the whole season, the dynamic time-of-use tariff considered would imply heating costs up to 40% lower than the static gas tariff. The results are strongly conditioned by climate conditions and national energy market evolutions. Day-ahead information on the actual heating costs might lead to domestic end-users to adapt their behavior and consumption patterns for more cost-effective use of the energy.Research leading to these results has been supported by HOLISDER project. This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 768614. This paper reflects only the authors’ views and the Commission is not responsible for any use that may be made of the information contained therein

La protección consular como derecho humano, a la luz de las reformas Constitucionales y el derecho internacional

The purpose of this article is to provide the reader with the necessary information regarding Consular Assistance and Consular functions in light of the Constitutional Reforms on Human Rights of June 10th, 2011. Which is responsible for ensuring respect, protection, and safeguarding of Mexicans abroad when they face a problem of various kinds and do not have the possibility of immediately going to any foreign authority. The Consular function translates into the assistance provided by the state to its nationals outside its territory, through Consular Offices accredited in another State.El artículo tiene por objeto brindar al lector la información necesaria, sobre la definición de protección consular, función consular a la luz de las reformas Constitucionales en materia de derechos humanos del 10 de junio de 2011,en México, a quien corresponde velar por el respeto, protección y salvaguarda de los mexicanos en el exterior, cuando enfrenten algún problema de diversa índole y no tengan posibilidad de acudir de manera inmediata ante alguna autoridad extranjera; la función consular que se traduce en la asistencia que brinda el Estado a sus nacionales fuera de su territorio, mediante las Oficinas Consulares acreditadas en otro Estado

Energy, Environmental and Economic Analysis of Air-to-Air Heat Pumps as an Alternative to Heating Electrification in Europe

Heat pumps (HP) are an efficient alternative to non-electric heating systems (NEHS), being a cost-effective mean to support European building sector decarbonization. The paper studies HP and NEHS performance in residential buildings, under different climate conditions and energy tariffs, in six different European countries. Furthermore, a primary energy and environmental analysis is performed to evaluate if the use of HPs is more convenient than NEHS, based on different factors of the electric mix in each country. A specific HP model is developed considering the main physical phenomena occurring along its cycle. Open data from building, climatic and economic sources are used to feed the analysis. Ad hoc primary energy factors and greenhouse gas (GHG) emission coefficients are calculated for the selected countries. The costs and the environmental impact for both heating systems are then compared. The outcomes of the study suggest that, in highly fossil fuels dependent electricity mixes, the use of NEHS represents a more efficient decarbonization approach than HP, in spite of its higher efficiency. Additionally, the actual high price of the electric kWh hampers the use of HP in certain cases.European Commission's H202

HOLISDER Project: Introducing Residential and Tertiary Energy Consumers as Active Players in Energy Markets

Although it has been demonstrated that demand-side flexibility is possible, business application of residential and small tertiary demand response programs has been slow to develop. This paper presents a holistic demand response optimization framework that enables significant energy costs reduction for consumers. Moreover, buildings are introduced as main contributors to balance energy networks. The solution basis consists of a modular interoperability and data management framework that enables open standards-based communication along the demand response value chain. The solution is being validated in four large-scale pilot sites, which have diverse building types, energy systems and energy carriers. Furthermore, they offer diverse climatic conditions, and demographic and cultural characteristics to establish representative results.Research leading to these results has been supported by HOLISDER project. This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 768614. The APC was funded by HOLISDER project

Physiological thermal niches, elevational ranges and thermal stress in dendrobatid frogs: An integrated approach

Aim: We investigated the relationship between thermal physiology, elevational distribution and thermal stress among nine closely related dendrobatid frogs during their aquatic stage by employing an integrated approach, combining thermal physiology, environmental temperature modelling and predictive assessments of current and future exposure to thermal variation. Location: Ecuador. Taxon: Amphibians; Anura, Dendrobatidae, Epipedobates, Hyloxalus. Methods: We determined the thermal performance curves (TPCs) of larval growth for each species and modelled the thermal variation in contrasting aquatic larval environments for both present and future times. This allowed us to estimate the expected elevational distributions and forecast periods of exposure to stressful temperatures that inhibit larval growth due to elevation and global warming. Results: We found significant correlations between optimum temperature (Topt), 50% maximum performance temperature (maxB50), 50% minimum performance temperature (minB50) and cold resistance (survival at 9°C) with the current elevational distributions. However, thermal physiology predicted lower than observed distributions for high-elevation dendrobatids and higher than observed maximum elevations for lowland species. Nonetheless, our models predicted that low thermal variability habitats (i.e. streams and deep permanent ponds) can buffer the future temperature increase for all taxa, even when considering the most extreme scenario. In contrast, all species within high thermal variation habitats (open forest temporary ponds) are expected to experience stressful temperatures under present conditions. Main Conclusions: The findings indicate that thermal physiology may not be a limiting factor for dendrobatid frog species' ranges in this equatorial mountain gradient. Highland species may need to adapt to suboptimal performance, while some lowland species could occupy higher elevations. This study emphasizes the importance of habitat buffering to mitigate thermal stress in the face of climate change for amphibians in tropical mountainsEx situ frog management was funded by the General Academic Board of PUCE through research grant L13227 to AMV. This research was supported by AECID (AP/038788/11) and MINECO (CGL2012-40246-C02-01) grants to MT and AMV and SeveroOchoa (SEV-69) funds to MT. PP was supported by an MAE-AECIDgrant (BOE-A-2015-12270). Ministerio del Ambiente of Ecuador provided the permits to conduct this research (003-15/012-015/00216IC-FAU-DNB/MA). AC was supported by a MSCAH2020: 897901fellowshi