Economics of Hybrid Photovoltaic Power Plants

The global power supply stability is faced to several severe and fundamental threats, in particular steadily increasing power demand, diminishing and degrading fossil and nuclear energy resources, very harmful greenhouse gas emissions, significant energy injustice and a structurally misbalanced ecological footprint. Photovoltaic (PV) power systems are analysed in various aspects focusing on economic and technical considerations of supplemental and substitutional power supply to the constraint conventional power system. To infer the most relevant system approach for PV power plants several solar resources available for PV systems are compared. By combining the different solar resources and respective economics, two major PV systems are identified to be very competitive in almost all regions in the world. The experience curve concept is used as a key technique for the development of scenario assumptions on economic projections for the decade of the 2010s. Main drivers for cost reductions in PV systems are learning and production growth rate, thus several relevant aspects are discussed such as research and development investments, technical PV market potential, different PV technologies and the energetic sustainability of PV. Three major market segments for PV systems are identified: off-grid PV solutions, decentralised small scale on-grid PV systems (several kWp) and large scale PV power plants (tens of MWp). Mainly by application of ‘grid-parity’ and ‘fuel-parity’ concepts per country, local market and conventional power plant basis, the global economic market potential for all major PV system segments is derived. PV power plant hybridization potential of all relevant power technologies and the global power plant structure are analyzed regarding technical, economical and geographical feasibility. Key success criteria for hybrid PV power plants are discussed and comprehensively analysed for all adequate power plant technologies, i.e. oil, gas and coal fired power plants, wind power, solar thermal power (STEG) and hydro power plants. For the 2010s, detailed global demand curves are derived for hybrid PV-Fossil power plants on a per power plant, per country and per fuel type basis. The fundamental technical and economic potentials for hybrid PV-STEG, hybrid PV-Wind and hybrid PV-Hydro power plants are considered. The global resource availability for PV and wind power plants is excellent, thus knowing the competitive or complementary characteristic of hybrid PV-Wind power plants on a local basis is identified as being of utmost relevance. The complementarity of hybrid PV-Wind power plants is confirmed. As a result of that almost no reduction of the global economic PV market potential need to be expected and more complex power system designs on basis of hybrid PV-Wind power plants are feasible. The final target of implementing renewable power technologies into the global power system is a nearly 100% renewable power supply. Besides balancing facilities, storage options are needed, in particular for seasonal power storage. Renewable power methane (RPM) offers respective options. A comprehensive global and local analysis is performed for analysing a hybrid PV-Wind-RPM combined cycle gas turbine power system. Such a power system design might be competitive and could offer solutions for nearly all current energy system constraints including the heating and transportation sector and even the chemical industry. Summing up, hybrid PV power plants become very attractive and PV power systems will very likely evolve together with wind power to the major and final source of energy for mankind.

Socio-economic characterization of integrated cropping systems in urban and peri-urban agriculture of Faisalabad, Pakistan

Faisalabad city is surrounded by agricultural lands, where farmers are growing vegetables, grain crops, and fodder for auto-consumption and local marketing. To study the socioeconomic impact and resource use in these urban and peri-urban agricultural production (UPA) systems, a baseline survey was conducted during 2009–2010. A total of 140 households were selected using a stratified sampling method and interviewed with a structured questionnaire. The results revealed that 96 % of the households rely on agriculture as their main occupation. Thirty percent of the households were owners of the land and the rest cultivated either rented or sharecropped land. Most of the families (70 %) were headed by a member with primary education, and only 10 % of the household head had a secondary school certificate. Irrigationwater was obtained from waste water (37 %), canals (27 %), and mixed alternative sources (36 %). A total of 35 species were cultivated in the UPA systems of which were 65% vegetables, 15% grain and fodder crops, and 5% medicinal plants. Fifty-nine percent of the households cultivated wheat, mostly for auto-consumption. The 51 % of the respondents grew cauliflower (Brassica oleracea L.) and gourds (Cucurbitaceae) in the winter and summer seasons, respectively. Group marketing was uncommon and most of the farmers sold their produce at the farm gate (45 %) and on local markets (43 %). Seeds and fertilizers were available from commission agents and dealers on a credit basis with the obligation to pay by harvested produce. A major problem reported by the UPA farmers of Faisalabad was the scarcity of high quality irrigation water, especially during the hot dry summer months, in addition to lacking adequate quantities of mineral fertilizers and other inputs during sowing time. Half of the respondents estimated their daily income to be less than 1.25 US$ and spent almost half of it on food. Monthly average household income and expenses were 334 and 237 US$, respectively.

Nitrogen and carbon dynamics in grassland soils and plants after application of digestate

A better understanding of effects after digestate application on plant community, soil microbial community as well as nutrient and carbon dynamics is crucial for a sustainable grassland management and the prevention of species and functional diversity loss. The specific research objectives of the thesis were: (i) to investigate effects after digestate application on grass species and soil microbial community, especially focussing on nitrogen dynamic in the plant-soil system and to examine the suitability of the digestate from the “integrated generation of solid fuel and biogas from biomass” (IFBB) system as fertilizer (Chapter 3). (ii) to investigate the relationship between plant community and functionality of soil microbial community of extensively managed meadows, taking into account temporal variations during the vegetation period and abiotic soil conditions (Chapter 4). (iii) to investigate the suitability of IFBB-concept implementation as grassland conservation measure for meadows and possible associated effects of IFBB digestate application on plant and soil microbial community as well as soil microbial substrate utilization and catabolic evenness (Chapter 5). Taken together the results indicate that the digestate generated during the IFBB process stands out from digestates of conventional whole crop digestion on the basis of higher nitrogen use efficiency and that it is useful for increasing harvestable biomass and the nitrogen content of the biomass, especially of L. perenne, which is a common species of intensively used grasslands. Further, a medium application rate of IFBB digestate (50% of nitrogen removed with harvested biomass, corresponding to 30 50 kg N ha-1 a-1) may be a possibility for conservation management of different meadows without changing the functional above- and belowground characteristic of the grasslands, thereby offering an ecologically worthwhile alternative to mulching. Overall, the soil microbial biomass and catabolic performance under planted soil was marginally affected by digestate application but rather by soil properties and partly by grassland species and legume occurrence. The investigated extensively managed meadows revealed a high soil catabolic evenness, which was resilient to medium IFBB application rate after a three-year period of application.

Simultaneous Drying and Separation of Composite Agricultural Material for Hay Processing

In composite agricultural materials such as grass, tee, medicinal plants; leaves and stems have a different drying time. By this behavior, after leaving the dryer, the stems may have greater moisture content than desired, while the leaves one minor, which can cause either the appearance of fungi or the collapse of the over-dried material. Taking into account that a lot of grass is dehydrated in forced air dryers, especially rotary drum dryers, this research was developed in order to establish conditions enabling to make a separation of the components during the drying process in order to provide a homogeneous product at the end. For this, a rotary dryer consisting of three concentric cylinders and a circular sieve aligned with the more internal cylinder was proposed; so that, once material enters into the dryer in the area of the inner cylinder, stems pass through sieve to the middle and then continue towards the external cylinder, while the leaves continue by the inner cylinder. For this project, a mixture of Ryegrass and White Clover was used. The characteristics of the components of a mixture were: Drying Rate in thin layer and in rotation, Bulk density, Projected Area, Terminal velocity, weight/Area Ratio, Flux through Rotary sieve. Three drying temperatures; 40°C, 60° C and 80° C, and three rotation speeds; 10 rpm, 20 rpm and 40 rpm were evaluated. It was found that the differences in drying time are the less at 80 °C when the dryer rotates at 40 rpm. Above this speed, the material adheres to the walls of the dryer or sieve and does not flow. According to the measurements of terminal velocity of stems and leaves of the components of the mixture, the speed of the air should be less than 1.5 m s-1 in the inner drum for the leaves and less than 4.5 m s-1 in middle and outer drums for stems, in such way that only the rotational movement of the dryer moves the material and achieves a greater residence time. In other hand, the best rotary sieve separation efficiencies were achieved when the material is dry, but the results are good in all the moisture contents. The best rotary speed of sieve is within the critical rotational speed, i.e. 20 rpm. However, the rotational speed of the dryer, including the sieve in line with the inner cylinder should be 10 rpm or less in order to achieve the greatest residence times of the material inside the dryer and the best agitation through the use of lifting flights. With a finite element analysis of a dryer prototype, using an air flow allowing speeds of air already stated, I was found that the best performance occurs when, through a cover, air enters the dryer front of the Middle cylinder and when the inner cylinder is formed in its entirety through a sieve. This way, air flows in almost equal amounts by both the middle and external cylinders, while part of the air in the Middle cylinder passes through the sieve towards the inner cylinder. With this, leaves do not adhere to the sieve and flow along drier, thanks to the rotating movement of the drums and the showering caused by the lifting flights. In these conditions, the differences in drying time are reduced to 60 minutes, but the residence time is higher for the stems than for leaves, therefore the components of the mixture of grass run out of the dryer with the same desired moisture content.

Determination of the silvo-melliferous regions of Benin: a nationwide categorisation of the land based on melliferous plants suitable for timber production

Perennial plants are the main pollen and nectar sources for bees in the tropical areas where most of the annual flora are burned in dry seasons. Therefore perennial plants constitute the most reliable bio materials for determining and evaluating the beekeeping regions of the Republic of Benin. A silvo-melliferous region (S-MR) is a geographical area characterised by a particular set of homogenous melliferous plants that can produce timber. Using both the prevailing climatic and the agro-ecological conditions six S-MRs could be identified, i.e. the South region, the Common Central region, the Central West region, the Central North region, the Middle North region and the Extreme North region. At the country level, the melliferous plants were dominated by Vitellaria paradoxa which is common to all regions. The most diversified family was the Caesalpiniaceae (12 species) followed by the Combretaceae (10 species) and Combretum being the richest genus. The effect of dominance is particularly high in the South region where Elaeis guineensis alone represented 72.6% of the tree density and 140% of the total plant importance. The total melliferous plant density varied from 99.3 plants ha^(−1) in the Common Central region to 178.0 plants ha^(−1) in the Central West region. On the basis of nectar and pollen source, the best region for beekeeping is the CentralWest region with 46.7% of nectar producing trees, 9.4% of pollen producing trees and 40.6% of plants that issue both, this in opposition to the South region which was characterised by an unbalanced distribution of melliferous trees.

Flora medicinal y sus conocimientos asociados : lineamientos para una reglamentación

En este texto se presenta un espacio de intercambio de conocimientos desde una perspectiva científica, técnica y jurídica, para contribuir a la protección de los recursos naturales. Debido a la importancia de establecer mecanismos para proteger la biodiversidad y posibilitar la preservación de los conocimientos asociados especialmente al uso de la flora medicinal, la Línea de Investigación en Política y Legislación, del Grupo de Estudios en Sistemas Tradicionales de Salud de la Facultad de Medicina, y la Línea de Derecho Ambiental y Grupos Étnicos, del Grupo de Derechos Humanos de Jurisprudencia de la Universidad del Rosario, desarrollaron este libro a través del cual la Universidad se propone profundizar en el panorama actual de la reglamentación y política –Internacional, nacional y local—respecto a la flora medicinal y al patrimonio cultural inmaterial asociado a esta.

Lineamientos para una reglamentación de la flora medicinal

Lineamientos para una reglamentación de la flora medicinal Tres décadas después de que la Organización Mundial de la Salud (OMS) avalara el uso de las plantas medicinales en los sistemas nacionales de salud, Colombia aún no cuenta con una legislación que le permita proteger y aprovechar su flora medicinal en beneficio de la población. Para subsanar este vacío, el Grupo de Estudios en Sistemas Tradicionales de Salud de la Facultad de Medicina (GESTS) y el Grupo de Investigación en Derechos Humanos de la Facultad de Jurisprudencia de la Universidad del Rosario decidieron analizar los avances legislativos desarrollados en todo el mundo, con el fin de sentar las bases de una reglamentación nacional que estimule el cultivo, aprovechamiento sostenible y uso terapéutico de las plantas y sus productos derivados.(...) Esta iniciativa cobra mayor importancia ante el incremento de reglamentaciones locales relacionadas con las medicinas herbáceas (...) . Mientras en 1995 sólo 42 de los 193 países miembros de la OMS tenían normas relacionadas con la medicina basada en hierbas, para el 2005 una encuesta realizada en 140 países mostró que en 92 de ellos ya se había reglamentado el uso de plantas medicinales. Se ha extendido tanto el uso de éstas plantas que el mercado mundial de medicinas elaboradas con hierbas basadas en el conocimiento tradicional supera los 60.000 millones de dólares(...)(cerca de la mitad del PIB de Colombia). Ésto se traduce, además, en una preocupación permanente sobre su tráfico y comercio inadecuado (...) , ante el inminente riesgo de extinción biológica de algunas especies, como lo advierten varios estudios de la OMS (...) (...) (*) . Ahora bien, aunque la propuesta de los investigadores podría sentar los lineamientos básicos para un proyecto de ley, la reglamentación no puede convertirse en un punto de llegada, ya que sin importar lo que diga la legislación, la gente seguirá haciendo uso –con viejas o nuevas maneras– de las plantas medicinales. Por tanto, el grupo interdisciplinario de investigadores, propone un marco conceptual que permita entender el universo de la botánica médica, estableciendo las fronteras de su estudio y precisando los lenguajes utilizados por la medicina moderna y la medicina tradicional.

Perfil logístico para el sector naturista en Colombia

Los productos naturistas buscan mejorar la salud a base de aplicaciones fito terapéuticas o uso extractivo de plantas medicinales. Dada la ausencia de datos y la informalización del sector naturista en Colombia se adelanta un proceso de investigación para implementar procedimientos que aseguren una óptima gestión en cada una de las áreas y determinar las necesidades de los clientes y el mayor grado de satisfacción. En desarrollo de lo expuesto, se identifican los elementos claves a considerar en el diseño de un modelo óptimo de gestión de suministros y abastecimiento del sector para garantizar la generación de resultados positivos, en cumplimiento de las políticas y estrategias del sector.

Community Health Managers: A Pilot Pedagogic Experience in the University of Rosario

The “Grupo de Estudios en Sistemas Tradicionales de Salud” from the School of Medicine of Universidad del Rosario, in agreement with the “Instituto de Etnobiología”, has designed a training course for a new health agent (the community health manager) meant to consider in its curriculum the difficulties, deficiencies and successes of the Primary Health Care Program. In particular, we have attended OMS suggestions in terms of adequate training of local leaders who should look for self-responsibility and selfdetermination in health care coverage. This training proposal is meant to take into account diverse cultures and traditions in order to offer health care models able to consider cultural particularities, epidemiological profiles, and contextual possibilities, with an intercultural point of view. Hence, the training course’s objective is to offer working tools so that community leaders be able to value and promote traditional health knowledge and practices; seek for food security by means of recovery of traditional productive systems or adaptation of appropriate technologies; environment conservation; use of medicinal plants especially in self-care, and stimulation of community and institutional health promotion activities. Preliminary evaluation suggests that this new health agent will be able to set bridges between communities and health care offers available, always looking for healthy ways of life, culturally and environmentally friendly.

Animals and plants.

Para el aprendizaje temprano del niño. Tiene las respuestas a muchas de las preguntas que un niño puede hacer sobre sí mismo y el mundo que le rodea. El texto tiene dos niveles de dificultad y varios tamaños de letra. El segundo nivel es el de mayor dificultad con un vocabulario apropiado pensado para lectores más expertos. Hay un glosario alfabético.

Plants in their environment : key Stage 1, Primary 1-3.

Proporciona una amplia gama de actividades para alumnos de primaria como parte del currículo de ciencias. Algunas actividades pueden realizarse en el aula, mientras que otras pueden realizarse en un entorno más amplio, como el trabajo de campo al aire libre, de manera que los alumnos puedan hacer sus observaciones y familiarizarse con las plantas,las semillas, su crecimiento y sus adaptaciones al medio ambiente, de acuerdo con el ciclo de vida de las plantas y sus interacciones con los organismos vivos, incluidos los microorganismos. Incluye ideas para la estructuración de las investigaciones y la introducción de los niños pequeños en los equipos y métodos científicos alentándolos a hacer sus propias hipótesis e investigar el mundo que les rodea. Cada tema incluye una descripción de la actividad y la información para los profesores. En algunas actividades, hay hojas de trabajo para los alumnos y para ayudar a construir conocimientos particulares. Para el desarrollo de habilidades de lectura y aritmética elemental. También hay enlaces multidisciplinares. Para niños entre cinco y siete años.

Dig and sow : how do plants grow?

Guiados por el elefante Archie y sus amigos, los niños, a partir de cinco años, aprenderán a realizar en casa o en el jardín doce sencillos experimentos confeccionando sus propios ensayos ya que no necesitan un equipamiento especial. Para descubrir las respuestas a preguntas como por qué la hierba es verde. El texto incluye adivinanzas. También hay un índice y un glosario.

Fly traps! : plants that bite back.

Historia sobre el mundo real donde se describe cómo un hombre investiga el mundo de las plantas carnívoras. Escrita desde un punto de vista muy personal, mezclando hechos con sentimientos, anima a los niños a pensar, sentir e imaginar lo que aprenden. El diseño de página tiene interesantes variaciones al diferenciar entre la historia y la información. El viaje del hombre se cuenta en caracteres grandes, mientras que los hechos sobre las plantas carnívoras están escritos con una letra más pequeña,lo que da una gran cantidad de información en una forma entretenida. Especialmente interesantes son las descripciones de cómo las plantas comen los insectos que capturan. Al final hay notas para el profesor.

Plants and animals.

Una colección de proyectos de historia natural, incluyendo temas tales como las aves de jardín, semillas, naturaleza y senderos. El texto tiene dos tamaños de letra y una lista de los materiales que se necesitan para llevar a cabo los proyectos. Para que los estudiantes aprendan: las estrategias y técnicas que conducen al descubrimiento ; a utilizar el proceso científico como punto de partida para el descubrimiento; a utilizar el aprendizaje cooperativo, y otras estrategias para fomentar el aprendizaje por descubrimiento.

The wonderful world of plants.

Las plantas están sobre la Tierra desde hace millones de años y se han adaptado a distintos habitats. Crecen en medio del desierto, en lo alto de las montañas, en la tierra y en el agua. Algunas son grandes y otras microscópicas. Se explica cuáles son sus partes: la semilla y las hojas, así como su forma de reproducirse, la floración y sus funciones (fotosíntesis).Por último, conocemos su utilidad, para la alimentación humana y para la salud, en forma, de hierbas medicinales.