Dissertations / Theses on the topic 'Solar irrigation'

Irrigation is a well established procedure on many farms in western Canada and is practiced on various levels around the world. It allows diversification of crops, while increasing crop yields. However, typical irrigation systems consume a great amount of conventional energy through the use of electric motors and generators powered by fuel.
The overall objective of this research was to determine the feasibility of using photovoltaic (PV) modules to power a water pump for a small-scale drip irrigation system in Montreal (Quebec, Canada). The study involved field observations, as well as computer simulations of global solar radiation and PV electrical output.
Field observations involved a summer and winter installation of two amorphous silicon 42 W PV modules, directly connected to a 12 V surface water pump. The parameters monitored were voltage, current, back-of-panel temperature, pressure, and flow. These observed parameters were used to determine PV electrical output and volume of water pumped. Site latitude, elevation, and panel tilt were applied to the solar radiation and PV electrical output models, along with the following meteorological data: daily average, maximum, and minimum temperatures, and global solar radiation.
Daily solar radiation prediction showed a linear correlation of 0.69 with the observed daily values, over the years 2000 to 2005. The correlation coefficient was improved to 0.91, when 7 day moving averages of both the observed and predicted solar radiation data were used. PV electrical output and volume of water pumped were monitored between August 2005 and May 2006. Both the power and water output observations were less than expected. However, the predicted daily PV electrical output ranged from 1.0 MJ d-1 in the summer to approximately 0.6 MJ d-1 in the winter. As expected, an increase in power caused an increase in the volume of water pumped.

Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2017.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 141-142).
A solar-powered irrigation system has been developed to address the lack of affordable irrigation solution for the marginal farmers in India. An MIT spinout, Khethworks, has designed an efficient water pump with low power rating, and created a low-cost irrigation system with the pump, a photovoltaic panel, and a battery. This thesis analyzes the electrical properties of such a configuration, and determines whether implementing maximum power point tracking (MPPT) can improve the system's performance. This is accomplished through modeling and conducting a system-level simulation. The amount of electrical energy generated by the photovoltaic panel and the amount of water delivered by the pump are chosen as the key measures of the system's performance. The simulation result indicates that implementing MPPT with the current version of the Khethworks irrigation system - using lower-power panels of the 48 or 60 cell variety - would not significantly increase its performance. However, an irrigation system with higher power rating (e.g., a 72-cell panel, such as with a 320 W rating) would significantly benefit from the MPPT, and the MPPT's benefits are consistent over the variation in location and time. Based on the finding, we identify circumstances under which each of the direct load line and the maximum power point tracking approaches are preferable, and recommend an action plan to Khethworks accordingly.
by Thipok Rak-amnouykit.
M. Eng.

Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2017.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 79-81).
This thesis presents a design and cost optimization for solar-powered, drip irrigation systems. Historical irradiance data and crop consumption data are considered and modelled during these design steps. A cost optimization is utilized in order to determine low-cost, optimum configuration that meets the required water consumption rate of a given crop. In this case, Jalgaon, India is used as an example to determine the configuration and cost per acre for solar-powered, drip irrigation systems for sunflowers, tomatoes, and barley. These configurations consisted of five 310 Watt solar panels coupled with a 5m³ water buffer, three 295 Watt solar panels coupled with a 5m³ water buffer, and three 320 Watt solar panels coupled with a 4m³ water buffer, respectively. These systems are projected to cost $4,600, $3,870, and $3,750, respectively. The results of this study show the value of a system optimization of solar-powered, drip irrigation systems.
by David Doan.
S.B.

Carbon offsets have been developed as one tool to incentivise investments by developed nations in climate change mitigation activities in developing countries. The carbon offsets can be used towards the countries’ own mitigation targets but are also meant to benefit developing countries by providing a pathway to clean development. Photovoltaic water pumping (PVWP) technology is a solution to use PV for irrigation, which can be used to restore degraded grasslands and help farmers adapt to climate change. Restoration of degraded grasslands increases the production of grass and will therefore increase the amount of carbon in the soil, a process that may mitigate climate change. However, poor farmers often have limited access to irrigation technology and this thesis assesses how carbon offsets may bring revenues to increase adaption of PVWP technology in remote areas of the Chinese grasslands. PV modules can be used to mitigate climate change in different ways; the most common is to produce electricity to replace fossil fuel power capacity. The novelty of this thesis is that it assesses the alternative mitigation possibilities for the PVWP project proposed here. Further, consideration of water constraints that limit the applicability of the technology and a framework to assess the trade-offs between potential downstream water impacts and environmental co-benefits of the project add to the novelty of this thesis. Policy barriers for the project will also be considered.  Used to restore severely degraded grasslands, PVWP projects show high carbon sequestration potential and successfully compete with grid electricity as carbon offset projects. A case is analysed and it shows that the carbon market could play a role in increasing the feasibility of PVWP projects. However, water issues make project implementation very site-specific and some indicators to determine feasibility is proposed to be blue water availability, evaporation recycling ratio and water productivity. Water use must also be looked at with respect to climate, food and energy security, calling for a nexus approach to evaluate the project suitability. In May 2016, grassland management projects are excluded from the Clean Development Mechanism to the Kyoto Protocol, and this limits project implementation to the voluntary markets.
Avhandlingen är ämnad att läsas av beslutsfattare inom klimatområdet samt aktörer på de olika klimatkompensationsmarknaderna. Klimatkompensation har utvecklats som ett verktyg för att stimulera industriländers investeringar i klimatprojekt i utvecklingsländer. Klimatkompensation kan användas för att nå industriländernas egna klimatmål men är också tänkta att gynna utvecklingsländer genom att tillhandahålla en ”ren” utvecklingsmöjlighet. Solcellsdrivna vattenpumpar (eng. photovoltaic water pumping: PVWP) är en teknik för att använda solceller för bevattning. Tekniken kan användas för att restaurera degraderade gräsmarker och för att hjälpa jordbrukare anpassa sig till klimatförändringarna. Restaurering av gräsmarker ökar produktionen av gräs vilket medför ökad mängden kol i marken, en process som kan mildra klimatförändringarna. Men fattiga bönder har ofta begränsad tillgång till bevattningsteknik och denna avhandling utvärderar hur klimatkompensation kan ge intäkter för att öka användningen av PVWP i avlägsna delar på den kinesiska slätten. Solceller kan användas för att mildra klimatförändringarna på olika sätt och vanligast är att producera el för att ersätta fossila bränslen. Det är därför viktigt att titta på alternativkostnaden för PVWP-projekten som föreslås här. Vidare begränsar vattentillgången projekten och ett ramverk för att tydliggöra avvägningar mellan vattenrelaterade problem och miljömässiga fördelarna med ett projekt är nödvändigt. Klimatpolitiska styrmedel sätter också upp vissa begränsningar för projekten. Om PVWP används för att återställa mycket degraderade gräsmarker, visar projekten hög klimatnytta och de kan framgångsrikt konkurrera med solel till nätet som klimatkompensationsprojekt. En fallstudie visar att klimatkompensationsmarknaden skulle kunna spela en viss roll för att öka antalet PVWP-projekt. Däremot gör vattenfrågan projektens geografiska plats viktig och indikatorer för att avgöra genomförbarheten föreslås vara ”blåvattentillgång”, ”förångningsåtervinning” och ”vattenproduktivitet”. Vattenanvändningen måste också ses i förhållande till klimat, mat- och energisäkerhet, vilket kräver en nexusstrategi för att utvärdera projekten. I skrivande stund (maj 2016) är projekt rörande skötsel av gräsmarker exkluderade från mekanismen för ren utveckling (CDM) till Kyotoprotokollet och detta begränsar projekten till de frivilliga klimat-kompensationsmarknaderna.

QC 20160711

Demonstration and Scale-Up of Photovoltaic Solar Water Pumping for the Conservation of Grassland and Farmland in China

This study has been conducted as a Minor Field Study (MFS). It focuses on solar water pumping for small-scale farmers in the Kilimanjaro Region of Tanzania. The purpose is to investigate the possibilities for rural farmers to operate their irrigation with solar power instead of their current option: fossil fuels, primarily petrol. The study was conducted in three phases, starting with pre-study in Sweden, followed by field study in Tanzania from January to March 2015 and finishing with summarizing and calculating in Sweden. Fuel powered water pumping has a cheap capital cost; however, it is expensive and problematic to maintain and operate. Solar powered water pumping is almost completely opposite. It has a higher initial cost; however, it is considerably cheaper to run. The results indicate that the investment in solar power might be too expensive for the farmers, as long as they do not receive external financial and educational support. Assuming that the farmers are able to obtain a solar water pumping system, results show that they will benefit and save a considerably amount of money over a long period of time. Also, solar water pumping is environmentally friendly compared to the systems in Tanzania today.

Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 81-86).
This thesis presents a mathematical model investigating the physics behind pressure compensating (PC) drip irrigation emitters and a design of a highly efficient solar powered centrifugal pump for small-acreage farmers drawing from shallow groundwater. The global community is facing a worsening crisis with regards to the water-energy agriculture nexus. Irrigation is a proven way to increase the agricultural productivity of a plot of land; however, with a growing population, it will be necessary to invest in methods of irrigation that are both energy- and water-efficient, and intensify the agricultural output per unit of land. Drip irrigation, a method of irrigation where water is delivered directly to the plant roots through a network of tubes and valves, is a highly water-efficient method that gives high yield per unit area. The current challenge to adoption facing drip irrigation is the high capital and operating costs. It is possible to cut these costs by developing a valve, called an emitter, that gives the desired flow rate at a lower pressure. This lower pressure in turn requires less energy from the pump, allowing for a smaller and less expensive pump, and even making a solar-powered system affordable for small-acreage farmers. In coming decades, it will become increasingly necessary to switch from fossil-fuel based energy to renewables, such as solar. For small acreage farmers in the developing world, this switch will not only alleviate the pains of paying the recurring and volatile costs for diesel fuel, it will also help to lighten the load on the electrical grid by those using electric pumps.
by Katherine Anne Taylor.
S.M.

Thesis: S.M., Massachusetts Institute of Technology, Engineering Systems Division, 2015.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 121-124).
Solar panels are not installed on an off-grid farm to save on home energy bills. Those systems are installed to enable communities to do activities that they could not do before. This thesis studies the application of design for value to distributed solar energy systems by considering how the energy system will enable new income generating activities. The work here couples business and energy models to optimize with value as an objective function. The interaction between energy production and value creation is complex, so multi-objective optimization is used as a tool to explore the design space and analyze the feasibility of such projects. This methodology is practiced in two case studies. One case study considers the design of a solar irrigation pump that is specifically designed for marginal-holding farmers in east India. The other case study analyzes the feasibility of small-scale concentrated solar powered (p-CSP) food processing with an organic Rankine cycle (ORC). In both cases, preliminary economic feasibility is established with the use of analysis by optimization and design for value. It was found that a solar pump could be produced which costs less than 500 USD cap-ex and meets 99% of a marginal-holding farmer's water demand. The solar food processing analysis showed that a system could be produced which costs 29,000 USD with a 15-year NPV of 33,400 USD at a discount rate of 18%. The programmatic tools that are used to explore this design space include genetic algorithms, pattern search, adaptive weighted sums, and Pareto fronts.
by Kevin Patrick Simon.
S.M.

This bachelor thesis consists of a field study conducted in the canton of Machacamarca close to La Paz in Bolivia. The global climate change has affected the weather in the area which has caused higher temperatures, irregularity in precipitation and unexpected frost. This has complicated the traditional cultivation methods and affected the harvest yield. One of the more important sources of income in the canton is the local diary that is processing milk from the local farmers. The main purpose of the thesis was to investigate the economic improvements that could be achieved in the canton with the implementation of an irrigation system driven by photovoltaic power, and to evaluate if it would be feasible. The simulation program Decision support system for agrotechnology transfer, DSSAT, has been used to simulate the cultivation and harvest of the two main crops for forage, alfalfa and barley. The required input data has been collected from the canton of Machacamarca and used to simulate the harvest yield for three scenarios, business as usual, ideal irrigation and limited irrigation calculated from the local conditions. A Matlab code based on numbers and parameters collected during the field study is used to create economical simulations from the different harvest results to receive economical results from several steps in the process. The final economical outcomes are compared to each other and to the cost for the chosen pump and irrigation system. Both scenarios considering irrigation show a stabilized and improved harvest yield, but only the third scenario is possible to implement in Machacamarca due to water restrictions in the area. This makes it possible to feed 0.47 more cows per hectare which will improve the farmers and the diary ́s income with 94.57 %. The water use for irrigation is 1.33 litres per square meter which makes the Shurflo 8000 water pump the most suitable option to provide water to the irrigation system powered by a 130 W solar panel and a battery. The investment cost for the system would go up to 6114 BOB equal to 883 USD and the system has a maintenance cost of 200 BOB every second year. This would make it economically feasible for the farmers to buy a system, but it would require investors or funding. With a payment plan the farmers would be able to pay off the investment without any problem.
Detta kandidatexamensarbete utgörs av en fältstudie i samhället Machacamarca utanför La Paz, Bolivia. De globala klimatförändringarna har påverkat vädret i området med högre temperaturer, oregelbunden nederbörd och oväntad frost. Detta har komplicerat det traditionella jordbruket och påverkat skörden. En av de viktigaste inkomstkällorna i samhället är det lokala mejeriet som producerar mejerivaror av mjölken från de lokala bönderna. Huvudsyftet med denna rapport är att undersöka den ekonomiska förbättringen samhället skulle få vid en implementering av ett bevattningssystem drivet av solenergi och ifall det skulle vara genomförbart. Simuleringsprogrammet, Decision support system for agrotechnology transfer, DSSAT, har använts för att simulera jordbruket och skörden för de två grödorna alfalfa och korn som i första hand används till foder. Nödvändiga data har hämtats ifrån Machacamarca och används för att simulera skörden för de tre scenariona, business as usual, ideal bevattning och begränsad bevattning bestämd från de lokala förhållandena. En Matlab kod baserad på nummer och parametrar funna under fältstudien används för att skapa ekonomiska simulationer för de olika skördarna för att få ekonomiska resultat från flera steg i processen. De slutgiltiga ekonomiska resultaten jämförs mot varandra samt mot kostnaderna för det valda pump- och bevattningssystemet. De båda bevattnade scenariona visar på en stabiliserad och förbättrad skörd, men endast det tredje scenariot är genomförbart i Machacamarca på grund av vattenbegränsningar. Detta gör det möjligt att föda upp 0.47 fler kor per hektar vilket förbättrar böndernas och mejeriets inkomst med 94,57 %. Vattenanvändningen när bevattning är nödvändigt är 1.33 liter per kvadratmeter vilket gör att Shurflo 8000 är det lämpligaste alternativet drivet av en 130 W solpanel och ett batteri. Investeringskostnaden för systemet skulle uppgå till 6114 BOB med en underhållskostnad på 200 BOB vartannat år. Detta skulle innebära att det är ekonomiskt möjligt för bönderna att köpa ett sådant system, men det skulle krävas investerare eller någon typ av finansiering. Med en avbetalningsplan så skulle bönderna kunna betala av hela kostnaden utan problem.

Orientador: Rodrigo Máximo Sánchez-Román
Banca: João Carlos Cury Saad
Banca: Hélio Grassi Filho
Banca: Gabriel Thomaz Queluz
Banca: Waleska Martins Eloi
Resumo: Associar o tratamento de água residuária doméstica (ARD) ao o uso pela agricultura familiar pode ser uma alternativa viável para a sustentabilidade ambiental no meio agrícola. No entanto, ainda são necessários diversos estudos sobre a reutilização desta água. O experimento foi realizado no Departamento de Engenharia Rural, Faculdade de Ciências Agronômicas (FCA) - Universidade Estadual Paulista (UNESP), Fazenda Experimental Lageado, no município de Botucatu, São Paulo, o qual consistiu em verificar diferentes porcentagens (0, 25, 50, 75 e 100%) de água residuária doméstica tratada, na lâmina total de irrigação e qual a relação desta com a produção, considerando a qualidade microbiológica dos produtos. Os objetivos deste trabalho foram avaliar a influência dos tratamentos estudados no entupimento da fita gotejadora, no solo e nas culturas da cebolinha 'todo ano', salsa 'graúda portuguesa' e abobrinha 'italiana' tanto na produção agrícola, quanto na presença de E. coli. O delineamento estatístico adotado foi em DIC (delineamento inteiramente casualizado), cada tratamento consistiu de cinco linhas laterais de irrigação, com espaçamento de 0,8 m entre linhas e de 0,3 m entre gotejadores, onde havia um emissor por planta para as culturas de cebolinha 'todo ano' e salsa 'graúda portuguesa', porém para a cultura da abobrinha 'italiana' o espaçamento foi de 1,2 m entre plantas. Os resultados obtidos na pesquisa foram: no solo observou-se algumas mudanças nas características químicas,... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Linking domestic wastewater treatment (RDA) to the use of family farming can be a viable alternative to environmental sustainability in agriculture. However, several studies are still needed on the reuse of this water. The experiment was carried out the Department of Rural Engineering, São Paulo State University (UNESP), School of Agriculture, Experimental Farm Lageado, in the city of Botucatu, São Paulo, and consisted in verifying different percentages (0, 25, 50, 75 and 100%) of treated domestic wastewater, in the total irrigation depth, and the relation between this and the production, considering the microbiological quality of the products. The objectives of this work were to evaluate the influence of the treatments studied on the drip tape clogging in the soil and on the 'all year' chives, 'Portuguese' parsley and 'Italian' zucchini, both in agricultural production and in the presence of E. coli. The statistical design adopted was CRD (completely randomized design), each treatment consisted of five lateral irrigation lines, spaced 0.8 m between rows and 0.3 m between drippers, with one emitter per plant for the crops of chives 'all year' and 'graúda portuguese' parsley, but for the 'Italian' zucchini culture the spacing was 1.2 m between plants. The results obtained in the research were: in the soil some changes in the chemical characteristics were observed, noting both increase and decrease in the levels of certain nutrients. The irrigation system presented a reduction in the coefficients of uniformity, however they were still close to 90%. In relation to the studied crops, there was a linear increase in the values observed in relation to domestic wastewater treated by solar radiation - ARD-TRS in the parameters of mean plant height, mean stalk number, mean stalk diameter, mean diameter of the clump and mass of the fresh and dry matter, for chives 'all year' and 'graúda portuguese'...
Doutor

Purpose - The thesis investigates effects of automatic variation of the deficit irrigation level with the growth stage of drip irrigated maize on grain yield and crop Water Use Efficiency (WUE). It further examines the impact of water-efficient irrigation controllers on the solar Photovoltaic energy level requirements for water pumping systems. Methodology - A Wireless Sensor and Actuator Network was deployed to monitor field conditions and actuate irrigation valves according to whether the level of moisture was within the set points. A Control Treatment (CT) field was fully irrigated using constant moisture threshold levels, while an Experimental Treatment (ExT) field had the highest level of deficit irrigation at the early and later growth stages. Full irrigation was applied at the middle growth stage. Irrigation depths and grain yields were measured, while WUE and the solar energy required by the water pumping system were calculated. Findings - The findings show that 880 mm and 560 mm of water were applied to CT and ExT fields, respectively. This represents a 36% water saving and a corresponding water pumping energy saving of 36% in the ExT field. The grain yields were 0.752 kg/m2 and 0.812 kg/m2 for CT and ExT fields, respectively. This shows that, despite applying a lower amount of water, the ExT improved the grain yield by 7.4%. Furthermore, the results show an increase in WUE from 0.86 kg/m3 for the CT field to 1.45 kg/m3 for the ExT field, representing a 69% improvement. Research limitations/implications - This study focused on the maize production under Malawi's weather conditions. However, the concept would easily be replicated in other crops and in other parts of the world with two modifications: firstly, sensor calibration must be done on-site; and secondly, the specific crop coefficient pattern must be used to develop the irrigation scheduling strategy.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Uma forma de verificar a eficiência de métodos de estimativa da evapotranspiração de referência é a comparação com o método de Penman- Monteith, recomendado pela Organização das Nações Unidas para Alimentação e Agricultura – FAO, como método padrão para estimativa da ET0. Com este estudo o objetivo foi avaliar três métodos de estimativa da ET0 e a influência dos erros diários na comparação dos métodos Makkink, Hargreaves e Radiação Solar, com o método de Penman-Monteith em quatro municípios da mesoregião do Triângulo Mineiro e Alto Paranaíba – MG. Para tanto, utilizou-se dados diários do ano de 2010 de radiação solar global, velocidade do vento, temperatura do ar e umidade relativa do ar obtidos nas estações meteorológicas automáticas do 5º Distrito de Meteorologia do Instituto Nacional de Meteorologia situadas nos municípios de Uberlândia, Araxá, Patrocínio e Ituiutaba. As análises dos resultados foram feitas para o período diário, utilizandose análise de regressão modelo linear y = ax, no qual a variável dependente foi o método de Penman-Monteith e a variável independente as estimativas da ET0 pelos métodos estudados. Foi utilizada metodologia que verifica a influência do desvio padrão diário da ET0 na comparação dos métodos estudados, indicando que entre os métodos de Radiação Solar e Penman-Monteith não se estabeleceu uma relação linear. Portanto, não podem ser comparados para as localidades estudadas. O resultado da análise de regressão indicou melhor ajuste para estimativa da ET0 para o método de Hargreaves para os quatro municípios estudados
A way to check the efficiency of estimating methods for reference of evapotranspiration is compared with the Penman-Monteith, recommended by the United Nations Food and Agriculture Organization - FAO, as the standard method for estimating ET0. With this study the objective is to evaluate three methods for estimating ET0 and the influence of errors daily in the comparison of methods Makkink, Hargreaves and Solar Radiation, with the Penman-Monteith in four counties from the middle of Triângulo Mineiro and Alto Paranaíba - MG. To this end, we used daily data of the year 2010 of the global solar radiation, wind speed, air temperature and relative humidity obtained from automatic weather stations of the 5th District of Meteorology's National Meteorological Institute located in the cities of Uberlândia, Araxá, Patrocínio and Ituiutaba. Analyzes of the results were made for the daily period, using linear regression model y = ax, where the dependent variable was the Penman-Monteith and the independent variable estimates of ET0 by the methods studied. Methodology was used to verify the influence of the standard deviation of daily ET0 in the comparison of the methods studied, indicating that among the methods of Solar Radiation and Penman-Monteith it was not established a linear relationship. Therefore, it cannot be compared to the studied cities. The result of the regression analysis indicated a better fit for the estimation of ET0 to the method of Hargreaves for the four studied cities

Orientador: José Eduardo Pitelli Turco
Banca: Renato Farias do Valle Junior
Banca: Pedro Henrique Ferreira Tomé
Banca: João Antonio Galbiatti
Banca: Teresa Cristina Tarle Pissarra
Resumo: Uma forma de verificar a eficiência de métodos de estimativa da evapotranspiração de referência é a comparação com o método de Penman- Monteith, recomendado pela Organização das Nações Unidas para Alimentação e Agricultura - FAO, como método padrão para estimativa da ET0. Com este estudo o objetivo foi avaliar três métodos de estimativa da ET0 e a influência dos erros diários na comparação dos métodos Makkink, Hargreaves e Radiação Solar, com o método de Penman-Monteith em quatro municípios da mesoregião do Triângulo Mineiro e Alto Paranaíba - MG. Para tanto, utilizou-se dados diários do ano de 2010 de radiação solar global, velocidade do vento, temperatura do ar e umidade relativa do ar obtidos nas estações meteorológicas automáticas do 5º Distrito de Meteorologia do Instituto Nacional de Meteorologia situadas nos municípios de Uberlândia, Araxá, Patrocínio e Ituiutaba. As análises dos resultados foram feitas para o período diário, utilizandose análise de regressão modelo linear y = ax, no qual a variável dependente foi o método de Penman-Monteith e a variável independente as estimativas da ET0 pelos métodos estudados. Foi utilizada metodologia que verifica a influência do desvio padrão diário da ET0 na comparação dos métodos estudados, indicando que entre os métodos de Radiação Solar e Penman-Monteith não se estabeleceu uma relação linear. Portanto, não podem ser comparados para as localidades estudadas. O resultado da análise de regressão indicou melhor ajuste para estimativa da ET0 para o método de Hargreaves para os quatro municípios estudados
Abstract: A way to check the efficiency of estimating methods for reference of evapotranspiration is compared with the Penman-Monteith, recommended by the United Nations Food and Agriculture Organization - FAO, as the standard method for estimating ET0. With this study the objective is to evaluate three methods for estimating ET0 and the influence of errors daily in the comparison of methods Makkink, Hargreaves and Solar Radiation, with the Penman-Monteith in four counties from the middle of Triângulo Mineiro and Alto Paranaíba - MG. To this end, we used daily data of the year 2010 of the global solar radiation, wind speed, air temperature and relative humidity obtained from automatic weather stations of the 5th District of Meteorology's National Meteorological Institute located in the cities of Uberlândia, Araxá, Patrocínio and Ituiutaba. Analyzes of the results were made for the daily period, using linear regression model y = ax, where the dependent variable was the Penman-Monteith and the independent variable estimates of ET0 by the methods studied. Methodology was used to verify the influence of the standard deviation of daily ET0 in the comparison of the methods studied, indicating that among the methods of Solar Radiation and Penman-Monteith it was not established a linear relationship. Therefore, it cannot be compared to the studied cities. The result of the regression analysis indicated a better fit for the estimation of ET0 to the method of Hargreaves for the four studied cities
Doutor

Although development organizations agree that reliable access to energy and energy services-one of the 17 Sustainable Development Goals-is likely to have profound and perhaps disproportionate impacts on women, few studies have directly empirically estimated the impact of energy access on women's empowerment. This is a result of both a relative dearth of energy access evaluations in general and a lack of clarity on how to quantify gender impacts of development projects. Here we present an evaluation of the impacts of the Solar Market Garden-a distributed photovoltaic irrigation project-on the level and structure of women's empowerment in Benin, West Africa. We use a quasi-experimental design (matched-pair villages) to estimate changes in empowerment for project beneficiaries after one year of Solar Market Garden production relative to non-beneficiaries in both treatment and comparison villages (n=771). To create an empowerment metric, we constructed a set of general questions based on existing theories of empowerment, and then used latent variable analysis to understand the underlying structure of empowerment locally. We repeated this analysis at follow-up to understand whether the structure of empowerment had changed over time, and then measured changes in both the levels and likelihood of empowerment over time. We show that the Solar Market Garden significantly positively impacted women's empowerment, particularly through the domain of economic independence. In addition to providing rigorous evidence for the impact of a rural renewable energy project on women's empowerment, our work lays out a methodology that can be used in the future to benchmark the gender impacts of energy projects.

Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2017.
Cataloged from PDF version of thesis.
Includes bibliographical references (page 20).
Two small-scale well-irrigation systems in rural Uttar Pradesh which had previously operated via diesel pumps have been modified to operate via solar pumps. The regions where the irrigation systems are located are currently experiencing drought, and the well of one of the systems runs dry during irrigation. It is hypothesized that the 3HP solar pumps installed in the systems are larger than necessary, and are overdrawing from the water supply. A pump-sizing software tool was developed in Excel Spreadsheets to model and analyze the two specific systems, as well as to aid in future pump-sizing for long-term water sustainability for similar types of irrigation systems operating in water-scarce conditions. It was determined that the 3HP pumps installed in the irrigation systems are not unreasonably large for the crop water demands, and that under drought conditions, it was inevitable that continued irrigation at the two sites studied would eventually lead to well depletion and is thus unsustainable. Focusing on pump-sizing for these types of irrigation systems in water-scarce conditions may not be as effective for water sustainability as adjusting the irrigation systems and methods at the sites.
by Christina Sung.
S.B.

The energy issue is a focus of important discussion today when the human activities are becoming increasingly dependent on resources that can supply the increased demand. From these problematics, it has been sought solutions in alternative energy sources, less impacting, which gradually tend to substitute conventional models toward a more diversified array. Solar energy becomes an option to consider in Brazil against the large existing potential, and the photovoltaic system of irrigation, one of the applications of photovoltaic systems. This paper proposes to study the potential use of solar energy in photovoltaic irrigation systems in Lagarto/SE. The study involves an estimated local solar radiation using the Angstrom- Prescott model by the determination of the equation coefficients and comparison between the estimated and actual values; the system design based on water demands of crops involved and cost compared to the conventional model. The results showed that for Lagarto/SE, the horizontal solar radiation can be estimated by the use of coefficients found in the monthly partition (coefficient a between 0.31 and 0.37 and b between 0.32 and 0.42) and insolation data (n). The estimated average annual solar radiation found in the region was 19.66 MJ/m²dia, with a minimum value of 14.45 MJ/m²dia in June and maximum of 23.94 M/ m²dia in November. The estimated solar radiation indices showed that the study area has a high potential for solar energy applications in general. The photovoltaic irrigation systems to supply the maximum water demand found in every 0.5 ha in systems of 5 to 60 m (head) are required installed photovoltaic modules of 310 Wp to 3.4 kWp. Compared to the conventional system, the photovoltaic is competitive in systems with head up to 30 m and their applicability varies with the source of water available.
A questão energética é um foco de importante discussão na atualidade na medida em que as atividades humanas estão se tornando cada vez mais dependentes de recursos que possam suprir o aumento da demanda. A partir dessa problemática têm-se buscado soluções nas fontes alternativas de energia, menos impactantes, que aos poucos tendem a substituir os modelos convencionais na direção de uma matriz mais diversificada. A energia solar torna-se uma opção a se considerar no Brasil frente ao grande potencial teórico existente, sendo o SFVI (Sistema Fotovoltaico de Irrigação), uma das aplicações dos sistemas fotovoltaicos. O trabalho presente propõe estudar o potencial do uso da energia solar em sistemas fotovoltaicos de irrigação no perímetro irrigado Piauí localizado no município de Lagarto/SE. Em sua metodologia, o estudo envolve a estimativa da radiação solar local através do modelo de Angstrom-Prescott a partir da determinação dos coeficientes da equação e do comparativo entre os valores estimados e reais; o dimensionamento do sistema fundamentado nas demandas hídricas das culturas envolvidas e comparação com o modelo convencional. Os resultados mostraram que para o município de Lagarto, a radiação solar global horizontal pode ser estimada através do uso dos coeficientes encontrados na partição mensal (com coeficiente a variando entre 0,31 e 0,37 e b entre 0,32 e 0,42) e os dados de insolação (n). A radiação solar média anual estimada encontrada na região foi de 19,66 MJ/m²dia, com o valor mínimo de 14,45 MJ/m²dia no mês de junho e máximo de 23,94 MJ/m²dia em novembro. Os índices de radiação solar estimados mostraram que a região estudada possui um elevado potencial para o uso de energia solar em geral. Nos sistemas fotovoltaicos de irrigação, para suprir a demanda hídrica máxima encontrada em cada 0,5 ha em sistemas de 5 a 60 m.c.a são requeridas potências instaladas dos módulos fotovoltaicos de 310 Wp a 3,4 kWp, conforme o gráfico de dimensionamento elaborado. No comparativo com o sistema convencional o SFVI é competitivo em sistemas com alturas manométricas de até 30 m.c.a e sua aplicabilidade varia de acordo com a fonte de água disponível.

A matriz energética brasileira atualmente está concentrada na geração de energia hidrelétrica. Mas, devido aos últimos acontecimentos de escassez de recursos hídricos, faz-se necessário diversificar a matriz energética por meio do investimento em energias alternativas. O Brasil ainda possui muitas pessoas na área rural sem abastecimento de energia elétrica, fato que limita a implantação de técnicas agrícolas como a irrigação. Nesse contexto, a energia solar fotovoltaica (FV) é uma alternativa para diversificar a matriz energética brasileira e ampliar o uso de sistemas de irrigação. Foram instalados dois módulos FV, um estático e outro com um sistema de rastreamento solar manual de três passos, na área experimental do Departamento de Engenharia de Biossistemas - ESALQ/USP (22° 42\' 30\'\'S, 47° 38\' 00\'\'W, altitude de 546 metros). Para cada módulo FV, estático e móvel, foram acoplados sistemas de bombeamento de água para um sistema simulado de irrigação. O objetivo foi avaliar o incremento de energia FV gerada, tempo de bombeamento, volume bombeado e área irrigada; com o uso do sistema rastreador. A partir dos dados encontrados, verificou-se que o sistema rastreador solar manual de três passos apresentou maior eficiência na captação de energia (8 - 19% dia-1), quando comparado com geradores fixos; o que refletiu no incremento significativo do tempo de bombeamento (40 - 160 min dia-1), no volume bombeado (884 - 3479 litros dia-1) e na área irrigada (196 - 773 m² dia-1 para uma lâmina de irrigação de 4,5 mm). Com isso, o rastreador se mostrou uma alternativa técnica viável para melhorar a captação de energia solar e aumentar a área irrigada com um mesmo tamanho de área de gerador FV. Em relação ao investimento, o sistema rastreador custou apenas 0,2% do custo total da instalação FV, e proporcionou a redução do tempo de retorno do investimento em 2 anos e 5 meses comparado ao módulo FV estático.
The current Brazilian Energetic Matrix is concentrated in the generation of hydroelectric energy. But, due the latest water resources scarcity, it is necessary to diversify the energetic matrix by investing in alternatives energies. Brazil still have a plenty of people living in rural areas without supply of electric energy, this fact limits the implantation of agriculture techniques like irrigation. In this sense, the photovoltaic solar energy (PV) is an alternative to diversify the Brazilian Energetic Matrix and expand the use of irrigation systems. It were installed two PV modules, one static and another with solar three steps manual tracking system, Biosystems Engineering Department - ESALQ/USP (22° 42\' 30\'\'S, 47°38\' 00\'\'W, at 546 meters altitude). For each PV module, static and moving, it was coupled water pumping systems for simulated irrigation systems. The goal was evaluate the gain of the PV energy generated; pumping time; pumping volume and irrigated area; using the tracking system. From obtained data, it was observed that the solar three steps manual tracking system shows more efficiency in the energy harvesting (8 - 19% day-1), compared to static generator; which resulted in significant gain of pumping time (40 - 160 min day-1), pumping volume (884 - 3479 liters day-1) and irrigates area (196 - 773 m² day-1 for a irrigation depth equal 4.5 mm). Therewith, the tracking system shows a viable alternative technique to improve solar energy harvesting and increase the irrigated area with same area of PV generator. In relation to investment of the tracking system, it cost only 0.2 % of the total cost of PV installation and provided the reduction in the return on investment time of 2 years and 5 month compared to static PV module.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Universidade Estadual Paulista (UNESP)
The determination of the necessary amount of water is one of the main parameters of an agriculture irrigation system. One of the efficient consequences of the measurements of the system is the increase of productivity, and therefore the profitable advantage of it. The satisfactory amount of water is therefore a very important condition for the growing accomplishment of the plant causing the production, with fewer costs. The aim of this work is the development of a mathematical model, based on the Fuzzy Theory, to determine the stream of latent heat, having as a result the calculation of the transpiration dissipated that defines the necessary amount of water for the cultivations of plants in protected environments; intending above all the balance of water usage and electricity in the agriculture activity. This model can be used in the implementation of a system that controls the outflowing of irrigations, determining the time and volume of water that is necessary for the furnishing of it. The required amount of water for the supplement of the system is the gathered through the determination of the stream of latent heat, for its highness is the equivalent to the volume of water transpired by the plant. The model adopts three variables to begin with, which are: the balance of solar radiation, stream of the soil heat and the air temperature, which are the amounts that are measured by the installed equipments in the planted area. Through this model is possible to determine the stream of latent heat (LE), having it as the variable of exit of the model. To have this model validated there were used data, that were obtained in the experiment that was done by the cultivation of Euruca Sativa L., in an incubator covered by polyethylene at the Department of Science, at Faculdade de Ciências Agrônomicas and the results were obtained trough simulations that were done in the Laboratory of this Institution...

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CAPES
The work was carried out in the Integrated Agroecological Production System (SIPA), known as Fazendinha Agroecol?gica Km 47, in the city of Serop?dica - RJ, Brazil. The objective was to evaluate the productivity, development and economic viability of the okra (Abelmoschus esculentus) of summer, in regrowth driving and in winter cultivation, when submitted to automated irrigation slides and solar photovoltaic energy. An area of 225 m2 was used and the experimental design of randomized blocks with 4 irrigation slides was used, referring to different flows of drippers (2.0, 4.0, 6.0 and 8.0 Lh-1), Arranged in 5 blocks with 4 replicates, totalizing 20 experimental plots. Irrigation management was performed by the Simplified Irrigation Trigger (ASI). Two cultivation cycles were carried out and characterized as a summer crop (October 2015 to April 2016) and later regrowth (April to August 2016) and winter crop (June to September 2016). The total and commercial yields were evaluated in the three periods, as well as quality indices and crop development. The monetary costs were realized considering the costs of implantation and conduction of the crop and the selling prices practiced in the organic and conventional retail market (free markets) and in the wholesale market, being determined the net income, the rate of return and the index of profitability. The monetary costs of the photovoltaic system were calculated from the irradiance data during the cultivation period and the energy consumption of the pump. There was no significant difference between the treatments tested for all variables, except for total and commercial productivity in the eleventh week of winter cultivation. The analysis of monetary costs confirmed the production results, indicating that the lowest applied blade is responsible for the greater profitability and efficiency of water use, even commercializing the production by the values practiced in the conventional wholesale market. Likewise, there was a profitability also with the increment of the photovoltaic system in the total costs of the production system, being smaller, however, when compared to the use of the electric energy for the pumping of water. The minimum yields to be achieved in order to avoid losses were within the range of productivity expected for the crop, for the summer, winter and year of production in the three commercialization systems, even with the cost increase due to the use of solar energy.
O trabalho foi realizado no Sistema Integrado de Produ??o Agroecol?gica (SIPA), conhecido como Fazendinha Agroecol?gica Km 47, no munic?pio de Serop?dica ? RJ, e teve como objetivo avaliara produtividade, o desenvolvimento e a viabilidade econ?mica do quiabeiro (Abelmoschus esculentus) no cultivo de ver?o, na condu??o de rebrota e no cultivo de inverno, quando submetido a l?minas de irriga??o automatizada e energia solar fotovoltaica. Foi utilizada uma ?rea de 225 m2 e adotado o delineamento experimental de blocos ao acaso, com 4 l?minas de irriga??o, referentes a diferentes vaz?es de gotejadores (2,0; 4,0; 6,0 e 8,0 L.h-1), dispostas em 5 blocos com 4 repeti??es, totalizando 20 parcelas experimentais. O manejo da irriga??o foi realizado pelo Acionador Simplificado para Irriga??o (ASI). Dois ciclos de cultivo foram realizados e caracterizados como cultivo de ver?o (outubro de 2015 a abril de 2016) e posteriormente sua rebrota (abril a agosto de 2016) e pelo cultivo de inverno (de junho a setembro de 2016). Foram avaliadas nos tr?s per?odos, as produtividades total e comercial, al?m de ?ndices de qualidade e desenvolvimento da cultura. Os custos monet?rios foram realizados considerando os custos de implanta??o e condu??o da lavoura e os pre?os de venda praticados no mercado varejista org?nico e convencional (feiras livres) e no mercado atacadista, sendo determinados a renda l?quida, a taxa de retorno e o ?ndice de lucratividade. Os custos monet?rios do sistema fotovoltaico foram realizados a partir dos dados de irradi?ncia durante o per?odo de cultivo e do consumo energ?tico da bomba. N?o houve diferen?a significativa entre os tratamentos testados, para todas as vari?veis, exceto para a produtividade total e comercial na d?cima primeira semana do cultivo de inverno. A an?lise dos custos monet?rios confirmou os resultados de produ??o, indicando que a menor l?mina aplicada ? respons?vel pela maior lucratividade e efici?ncia do uso da ?gua, mesmo comercializando a produ??o pelos valores praticados no mercado atacadista convencional. Da mesma forma, houve rentabilidade tamb?m com o incremento do sistema fotovoltaico nos custos totais do sistema de produ??o, sendo menor, por?m, quando comparada ao uso da energia el?trica para o bombeamento de ?gua. As produtividades m?nimas a serem alcan?adas para que n?o ocorram preju?zos ficaram dentro da faixa de produtividade esperada para a cultura, para o cultivo de ver?o, inverno e ano de produ??o, nos tr?s sistemas de comercializa??o, mesmo com o incremento de custo devido ao emprego da energia solar.

Orientador: José Ângelo Cagnon
Abstract: The determination of the necessary amount of water is one of the main parameters of an agriculture irrigation system. One of the efficient consequences of the measurements of the system is the increase of productivity, and therefore the profitable advantage of it. The satisfactory amount of water is therefore a very important condition for the growing accomplishment of the plant causing the production, with fewer costs. The aim of this work is the development of a mathematical model, based on the Fuzzy Theory, to determine the stream of latent heat, having as a result the calculation of the transpiration dissipated that defines the necessary amount of water for the cultivations of plants in protected environments; intending above all the balance of water usage and electricity in the agriculture activity. This model can be used in the implementation of a system that controls the outflowing of irrigations, determining the time and volume of water that is necessary for the furnishing of it. The required amount of water for the supplement of the system is the gathered through the determination of the stream of latent heat, for its highness is the equivalent to the volume of water transpired by the plant. The model adopts three variables to begin with, which are: the balance of solar radiation, stream of the soil heat and the air temperature, which are the amounts that are measured by the installed equipments in the planted area. Through this model is possible to determine the stream of latent heat (LE), having it as the variable of exit of the model. To have this model validated there were used data, that were obtained in the experiment that was done by the cultivation of Euruca Sativa L., in an incubator covered by polyethylene at the Department of Science, at Faculdade de Ciências Agrônomicas and the results were obtained trough simulations that were done in the Laboratory of this Institution...
Doutor

The study relates international knowledge of climatically responsive and energy-efficient design to work done in South Africa. It also explores the relevance of design devices from international regions to the climates of this country. The research approach explores existing analyses of the main climate regions and the effects of climate factors on human comfort in each, in order to derive appropriate design solutions for the climate of South Africa. In South Africa obstacles exist in the face of energy efficiency. The cheapness of electricity to the consumer and the virtual non-existence of appropriate legislation appear to be two of the most significant obstacles. Design and subsequent construction of suburban residences is carried out with little regard for climatic context. Water is shown to be a particularly scarce and unevenly distributed commodity, which the affluent have greater access to and consume in greater quantities. However, it is demonstrated that the South African climate is virtually ideal for several climate-responsive energy-efficiency techniques. Especially due to the high solar radiation levels there is potential for various active and passive solar design techniques and technologies. The impact of atmospheric temperature and humidity, wind, radiation and precipitation on human comfort is investigated. Humidity and wind are demonstrated to be very influential on human comfort, whereas radiation and wind are the most easily manipulated through design. Furthermore, the specific topography and location of a site can influence the microclimate and solar access of an area to a significant degree. The South African climate is predominantly either hot semi-arid or temperate. Most of the western interior is hot arid whereas the eastern interior and highveld is predominantly temperate, with temperatures increasing to the north and decreasing to the south. The only cool region of the country is found in the highlands of the Drakensberg, with a significant portion of the eastern coast being hot humid. Methodologies and guidelines for both layout, or macro design, and detailed design of residential suburbs are explored. The manipulation of solar radiation, sunlight and wind, as well as the management of rainwater and used household water is explored. It is shown that designing suburbs to create access to solar radiation forms the basis of solar design, with solar access control, material and surface treatment largely determining the success of individual designs. Wind manipulation is achieved mainly through planting design, influencing mostly heat loss and gain ratios into buildings. Effective household water management can substantially reduce its consumption. Further research is needed in all aspects of climate-responsive design, especially classification of the South African climate and development of design techniques adapted to this context.
Dissertation (M (Landscape Architecture))--University of Pretoria, 2006.
Architecture
unrestricted

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The production of petroleum is frequently accomplished with great volumes of water, that it is carried of the underground with the oil. It is a challenge of the present century the development of technologies that allow the use of waste water for purposes that consume great amounts of water and don't demand as rigid as the one of the drinking water requirements. The solar distillation has been configuring as an alternative of clean technology for desalination of brine and saline. Besides causing the minimum possible damage to the environment, it takes advantage of an abundant and free energy source: the solar energy. That study aims to develop a Solar Distillator for treatment of the produced water of the oil wells, to obtain an efluent to use in agriculture and vapor generation. The methodology for collection, conservation and analysis of the physical-chemical parameters obeyed the norms in APHA (1995). The sampling was of the composed type. Experiments were accomplished in the solar distillation pilot and simulation in thermostatic bathing. The operation was in batch system and for periods of 4, 6 and 12 h. The developed Distillator is of the type simple effect of two waters. It was still tested two inclination angles for covering; 20? and 45?. The Distillator presented minimum of 2,85 L/m2d revenues and maximum of 7,14 L/m2d. The removals of salts were great than 98%. The removal of TOC in the simulation was great than 90%. In agreement with the data of energy and mass balance, it was verified that the developed solar Distillator presented compatible revenues with those found in literature for similar types. It can be inferred that the obtained distilled water assists to the requirements CONAMA in almost all the points and could be used for irrigation of cultures such as cotton and mamona. As the distilled water has characteristics of fresh water it can be used in the generation of vapor
A produ??o de petr?leo ? realizada freq?entemente com grandes volumes de ?gua, que ? carreada do subsolo junto com o ?leo. ? desafio do presente s?culo o desenvolvimento de tecnologias que possibilitem ou uso ou reuso de efluentes para outros fins. A destila??o solar ? uma alternativa de tecnologia limpa para dessaliniza??o de ?guas salobras e salinas. Esse estudo visa desenvolver um Destilador Solar para tratamento da ?gua de produ??o de petr?leo, com vistas a se obter um efluente pass?vel de utiliza??o na agricultura e gera??o de vapor. A metodologia para conserva??o e an?lise dos par?metros f?sico-qu?micos obedeceu preconiza??o do APHA (1995). A amostragem foi do tipo composta. Foram realizados experimentos no destilador solar piloto e simula??o em banho termost?tico. A opera??o foi em sistema de batelada e por per?odos de 4, 6 e 12 h. O destilador desenvolvido ? do tipo simples efeito de duas ?guas. Testou-se ainda dois ?ngulos de inclina??o para cobertura; 20? e 45?. O destilador apresentou rendimentos m?nimo de 2,50 L/m2d e m?ximo de 7,5 L/m2d. As remo??es de sais foram superiores a 98%. A remo??o de TOC na simula??o foi superior a 90%. De acordo com os dados dos balan?os energ?tico e de massa, verificou-se que o destilador solar desenvolvido apresentou rendimentos compat?veis com os encontrados na literatura para seus similares. Enfatiza-se que o isolamento utilizado n?o estava nas condi??es de otimiza??o, logo, esse rendimento pode ser melhorado. Pode-se inferir que a ?gua destilada obtida atende aos requisitos CONAMA em quase todos os pontos, podendo ser utilizada, com ressalvas, na irriga??o de culturas n?o comest?veis como o algod?o e a mamona. Como a ?gua destilada tem caracter?sticas de ?gua doce pode ser utilizada na gera??o de vapor

Solar Irrigation Pumps (SIPs) are used to pump (ground and surface) water to irrigate farm lands. In a country with a historical mismatch of energy supply and demand, and almost 120 million families dependent on earnings from agriculture (Prachi Salve, 2014), SIPs offer great prospects. Unlike electric and diesel pumps – dominating the market till today – SIPs have almost zero marginal costs. This leads to extra crop production at negligible costs and also generation of electricity when not being used for pumping. Due to almost zero emissions, it simultaneously addresses the issue of climate change hence bringing prosperity to the population at all levels.SIPs are a new phenomenon in India and due to the comparatively1 high capital costs, SIPs require subsidies to make them affordable for a farmer. Support in the form of subsidies has been given to around 15,000 farms in the whole country. By introducing solar pumps on a subsidy scheme in 2009-2010, Rajasthan has become the pioneer state of India. Since then numerous solar pumps have been deployed and farmers have gained experience with their usage. These farmers appear to be happy with the functioning of the pumps; 95% of the farmers, who gained enough knowledge to answer the question, say that the pump works better than their diesel or electric pump. A surprising finding is that the project cost per pump is getting higher while the pumps are getting cheaper. This means that the government is using more money to run the project. To find the reasons for the rising project costs and to find a way to decrease them, further research is needed. If the project cost could be decreased more pumps could be supplied with the same amount of subsidy.It was also found that the SIPs were not successful in replacing the electric and diesel pumps. The diesel and electric pumps had more horse power (hp) so were able to pump more water resulting in irrigation of more land in the same amount of time. Farmers expressed they could fully switch to SIPs when more powerful pumps were supplied.Because the present SIPs are off grid systems, it is not possible to sell the excess electricity that is not needed for pumping water. Because there are no marginal costs, there is no incentive for switching off the machines either. The consequence is excessive pumping of water leading to groundwater depletion. An important improvement would be to connect these pumps to the electricity grid. The possibility to earn some money with delivering energy would probably be a good reason to stop needless pumping.The subsidy program that was in place in Rajasthan had an 86% capital subsidy (the farmer had to pay only 14% of the price of SIP). With the available money only 10,000 pumps per year could be supplied (Dr. Dinesh Kumar Goyal, 2013). When the subsidy per pump is decreased more pumps could be deployed and it was shown that even with a lower subsidy getting a SIP will still be attractive.One of the points of improvement for a quick roll out of SIPs might be found in the way these pumps are financed. Pumps have a high capital cost and are currently financed by 70-90% capital subsidies of the government. The amount of total subsidy is limited and so with a high percentage of subsidy a small amount of pumps are deployed by this subsidy. These subsidies could be dramatically reduced when a loan/lease product would be put in place. Without a bank loan farmers are unable to pay the major part of the capital cost of the pump. Offering a bank loan is a win-win situation for the farmers and the people of India, represented by the government. With these pumps farmers are able to sell electricity to the grid and earn extra income or they can sell water to other farmers for a price below the price of current diesel pumping. With this income they could pay off the loan in 7 years and earn a reasonable income. The people of India will not only benefit by having to pay less for subsidies, they will also benefit from less greenhouse gas emissions as solar has almost zero emissions compared to mainly coal based electricity pumps and diesel pumps.SIPs supplying electricity can have a big effect on grid stability. Hence, in chapter 6 the question of grid stability was raised. Under what conditions can the Indian grid deal with a large amount of electricity injected from SIPs. India currently has 70% of the electricity produced from coal power plants while 3% comes from Nuclear power plants (Trading Economics, 2011a). These sources have a response time of several hours which is not quick enough to respond to fluctuations in the demand of energy by for example households, or a change in production by other sources, for example solar. The present sources should be partly replaced by quick response sources like the renewable sources and gas turbines. Currently 6% of the installed capacity is a gas power plant (Central Electricity Authority, 2015) but this percentage should be increased. Also other solutions should be implemented, such as developing storage of energy and more interconnections between grids of states and other countries.Since the idea is that SIPs would not use electricity from the grid anymore unlike electric pumps, 25% of electricity currently used from the grid by agriculture will be less. The current electric pumps only get electricity for certain hours a day and are used to balance the grid, only at times of low electricity use of other users, farmers will get electricity. When the electric pumps are replaced by SIPs that do not use electricity from the grid the balancing function that the electric pumps currently fulfil will no longer be present. Having no experience with SIPs connected to the grid so far, it will be difficult for the state load dispatch centres, which manage the grid, to schedule the expected load. Hence, pilots should be set up to find out how these pumps are used throughout the day so that in the future these loads can be predicted. In Gujarat the solar installed capacity could easily be a fivefold without having to invest in extra capacity of quick responsive sources, since enough installed capacity of gas turbines is already in place but currently not used. Extra investment would be needed in the grid in order to be able to transmit so much electricity over the grid from the (distributed) solar plants.Solar irrigation pumps, when implemented correctly, can not only lead to much cheaper irrigation for farmers but also less groundwater depletion and a source of extra income. Solar pumps can lead the way to more prosperity for the Indian people, but new guidelines and plans have to be made by the government to realise this potential. Without policy changes as described in this thesis SIPs benefit a small number of lucky farmers at the expense of the larger whole (wasting public money and groundwater).

Emerging financial and environmental challenges associated with conventional power sources have increased global interest in consuming unpolluted, renewable energy sources for irrigation sector. Solar energy may be an attractive choice in this regard due to its strong influence on crop water use and related energy requirement. However, a comprehensive approach for a reliable and economically viable photovoltaic (PV) system design to produce energy from solar source is required to accurately explore its potential. This thesis describes the development and application of a reliability assessment model, identifies a suitable solar irrigation management scheme, and provides guidelines for evaluating economic viability of a solar-powered center pivot irrigation system. The reliability model, written in MATLAB, was developed based on the loss of power supply probability (LPSP) technique in which various sub-models for estimating energy production, energy requirement and energy storage were combined. The model was validated with actual data acquired from the study site located at Outlook, Saskatchewan, Canada and an excellent agreement was found. For example, normalized root mean square error (NRMSE) for the battery current was found to be 0.027. Irrigation management strategies (irrigation depth, frequency and timing) were investigated by comparing the PV system sizing requirement for a conventional (25-35 mm per application) and for a frequent light irrigation management strategy (5-8 mm per application). The results suggest that the PV sizing can be reduced significantly by adopting frequent light irrigations which utilize the power as it is produced during daylight hours, rather than relying on stored energy. The potential of a solar-powered center pivot irrigation system was revealed for three different crops (canola, soybean and table potato) at the site by conducting a detailed economic analysis for the designed PV system. High value crops with moderate water requirements such as table potatoes appeared to be the most feasible choice for the study site. However, the potential may greatly vary for different crops in altered locations due to management, agronomic, climate, social, and economic variations. It can be concluded that a holistic approach described here can be used as a tool for designing an appropriate PV powered center pivot irrigation system under variable operating and meteorological conditions. Furthermore, its potential can be accurately explored by conducting a detailed economic analysis for a given location, considering different available crop choices.

Tese de mestrado integrado em Engenharia da Energia e do Ambiente, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2014
Este trabalho tem como âmbito o estudo da possibilidade do uso de energia solar fotovoltaica em sistemas de bombagem de água. Foi sugerido pela Martifer Solar o dimensionamento de um sistema de irrigação para um relvado situado na sede da empresa, em Oliveira de Frades, Portugal. A área total do relvado é 16,119m2. Inicialmente foi feito o estado da arte, onde foram discutidas as várias aplicações destes sistemas e as suas vantagens. De seguida, é descrita uma metodologia de dimensionamento, servindo como um guia para dimensionar e otimizar um sistema solar de bombagem de água. Para o dimensionamento foi abordado um método apresentado em Firatoglu et al. [1]. Primeiro foi estudada a quantidade de água necessária para a irrigação. Por se tratar de um relvado, a quantidade diária de água necessária varia ao longo dos meses desde 15m3 até 80m3. Depois, foi estudado o recurso solar para o local. Foi logo concluído que a variação da quantidade de água necessária varia de forma semelhante com a radiação solar disponível. Através do estudo de parâmetros dos vários componentes, foi feita uma correspondência entre os módulos fotovoltaicos e o motor/bomba. Foram calculadas curvas de potência máxima e curvas de pontos de equilíbrio. O principal objetivo é modelar, usando o Matlab. as duas de forma a ficaram o mais próximas possível, sem o uso de qualquer controlador eletrónico. Após o estudo de várias configurações ficou concluído que o sistema seria constituído por 14 módulos fotovoltaicos(2S×7P, com um motor com os parâmetros Kv=0.18 V/rpm e Ra=0.50Ω e com tanques de armazenamento de água. A quantidade de água necessária fica assegurada ao longo de todo o ano.
This work has the objective of studying the possible application of photovoltaic solar energy to supply water pump systems. It was suggested by Martifer Solar to size an irrigation photovoltaic water pumping system. This system is studied for the location of the headquarters of the company, in Oliveira de Frades, Portugal. The total area to irrigate was 16,119 m2. A state-of-the art was made first, where advantages and different applications of these systems were presented. After, the methodology is described as a guide to sizing and optimize solar water pumping systems. For that sizing, a multi-step method was used presented in Firatoglu et al. [1]. First, water demand was studied. Because it is a grass field, values of water daily demand change from 15m3 to 80m3, depending on the month. After, average data from solar resource was studied. The first conclusion to achieve was that water demand changes seasonally in a similar way as solar radiation available. A match between PV array and motor/pump assembly was made, through the study of manufacturer’s data of the different components. Curves from maximum power point and equilibrium operation point were calculated. The main goal is to match as much as possible both curves, with no use of any electronic controller. The modulation of the system was made using Matlab. After the study of several configurations, it was concluded that the system would have 14 PV panels, (2S×7P) with a DC motor with Kv=0.18 V/rpm and Ra=0.50Ω and storage water tanks. It is assured that water demand is fulfilled throughout the year.