Thesis (M.S.)--University of Wisconsin--Madison, 1966. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1968. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

The Eppley Precision Spectral Pyranometer (PSP) is a shortwave radiometer that is widely used in global networks to monitor solar irradiances at the earth's surface. Within the instrument, a blackened surface is in intimate thermal contact with the hot junction of a thermopile. The cold junction of the thermopile communicates thermally with the large thermal capacitance of the instrument body, which acts as a heat sink. Radiation arrives at the blackened surface through one or two hemispherical dome-shaped filters that limit the instrument response to the solar spectrum. The voltage developed by the thermopile is then interpreted in terms of the incident irradiance. Measurements taken with the pyranometer are compared with results from theoretical models. Discrepancies between model results and measurements are used to isolate inaccuracies in the optical properties of the atmosphere used in the models. As the accuracy of the models increases, the reliability of the measurements must be examined in order to assure that the models keep up with reality. The sources of error in the pyranometer are examined in order to determine the accuracy of the instrument. Measurements obtained using the pyranometer are known to be influenced by environmental conditions such as ambient temperature, wind, and cloud cover [Bush, et al., 1998]. It is surmised that at least some of the observed environmental variability in these data is due to parasitic thermal exchanges within the instrument [Haeffelin et al., 1999]. Thermal radiation absorbed and emitted by the filters, as well as that reflected and re-reflected among the internal surfaces, influences the net radiation at the detector surface and produces an offset from the signal that would result from the incident shortwave radiation alone. Described is an ongoing effort to model these exchanges and to use experimental results to verify the model. The ultimate goal of the work described is to provide reliable protocols, based on an appropriate instrument model, for correcting measured shortwave irradiance for a variable thermal radiation environment. / Master of Science

Increased use of renewable energies that is taking place all over the world is having a very important impact on the photovoltaic solar energy industry. This means of obtaining electrical energy is one of the most promising ones nowadays, thanks to the fact that it is a technology of easy installation and maintenance. However, the number of hours that a photovoltaic system works at maximum power depends almost entirely on environmental conditions, mainly in terms of solar irradiance.Solar irradiance is a magnitude that measures the power released by sunlight per unit area; the higher it is, the more power the photovoltaic system will generate.Therefore, it is very important to measure this magnitude in order to obtain data that either can give information about which is the best place to install a photovoltaic system or expect the device performance.Unfortunately, sensors used nowadays to measure this magnitude are quite expensive. The most widely used are the so-called pyranometers, with an average cost of between 8000 SEK to 10000 SEK, and solar reference cells, which can be quite cheaper (1000 SEK), but also can be the most expensive devices on the market depending on the features they have (some reference cells cost 20000 SEK).In this thesis, a solar irradiance sensor based on the treatment of a current generated by a silicon photodiode has been designed, built and calibrated. The signal generated by the device is a voltage that has been obtained by means of a current-to-voltage converter amplifier stage. Once the construction of the circuit was completed, it was tested on the roof of Hall 45 located in the University of Gävle. The testing was carried out on 13, 14 and 15 May 2019, and it consisted in the comparison of the signal generated by the new device and the signals generated by a pyranometer and a solar cell.The result is a device priced at 200 SEK, which shows acceptable levels of accuracy during central daylight hours but shows a strong angular dependence on incident light during sunrise and sunset.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This master of science thesis was developed from the idea of research and the production of a pyranometer of easy construction and low cost. This work presents research to develop a sensor in order to quantify the intensity of solar radiation incident on the earth's surface. The main component used is a photodiode which is constructed by two pellets of different semiconductor crystalline solids, encapsulated by an electrically insulating and transparent to the wavelength of the operating radiation material. The methodology used was to compare the measures of the developed prototype and considered standard pyranometer. This comparison was obtained by estimating the statistical parameters of the readings of photoelectric current generated by using a prototype, spectrally selective semiconductor device, which operates in the wavelength range around CMP3 consideret pyranometer model. The prototype was stable in its final stage of development, proving to be of viable production as a tool for low cost to obtain experimental data on the intensity of solar radiation. / A presente dissertação foi elaborada a partir da ideia de pesquisar e divulgar a produção de um piranômetro de fácil construção e baixo custo. Esta apresenta a pesquisa para o desenvolvimento de um sensor com a finalidade de quantificar intensidade da radiação solar global incidente na superfície terrestre. O principal componente utilizado é um fotodiodo, que é construído por duas pastilhas de diferentes sólidos cristalinos semicondutores, encapsuladas por um material eletricamente isolante e transparente ao comprimento de onda da radiação de operação. A metodologia empregada foi a comparação entre as medidas do protótipo desenvolvido e um piranômetro considerado padrão. Essa comparação foi obtida mediante a estimativa dos parâmetros estatísticos das leituras da corrente fotoelétrica, gerada pelo protótipo que utiliza um dispositivo semicondutor, espectralmente seletivo, que opera na faixa de onda em torno de 940 ηm e um piranômetro modelo CMP3. O protótipo mostrou-se estável em sua fase final de desenvolvimento, provando ser viável sua produção como instrumento de baixo custo para a obtenção de dados experimentais da intensidade da radiação solar global.

This work deals with measuring of intensity solar radiation by pyranometer. In theory discusses the principle of solar radiation and its effects on photovoltaic cells. Also describes methods to measure different components of solar radiation. A task work is realize station for long time monitoring of global and diffuse components of solar radiation by pyranometer and measured values evaluace

The Eppley Precision Pyranometer (PSP) is a radiometer used in networks around the world to measure downwelling and upwelling diffuse and total hemispherical broadband solar irradiances. PSP's present an offset in the signal, called thermal offset, produced by a radiation heat exchange between the glass dome, which defines the spectral throughput and the detector. This offset can reach up to 15\% of the total value of the signal when measuring diffuse irradiance under clear sky conditions. The thermal offset is characterized by monitoring the temperature gradient between the dome and detector using thermistors at key locations. The temperatures are acquired by using thermistors. Relationships between the thermal offset and the temperature gradient are established using nighttime data and subsequently used to estimate the offset during daytime. To correct historical data the thermal offset is related to other variables such as the output of a Precision Infrared Pyrgeometer (PIR) or the fraction of cloud cover in the sky. The use of thermistors is a very reliable method to estimate and correct the thermal offset. The relationships between the offset and the IR output and between the offset and the cloud cover fraction provide good estimates of the thermal offset in historical data sets, reducing it 60% to 100% depending on the instrument and the relationship used. / Master of Science

This study addresses the use of a Solar blind system (SBS) instead of ordinary glass used on windows of buildings. To investigate the effects of using an SBS for electricity energy generation a fictitious wooden house as a prototype, a real building needed to be constructed. The purpose of experimental studies is to measure the effect and asses the performance by examining the optimal angle of inclination and evaluating the profitability of SBS. To calculate the electricity energy generation by it is then expected that general renovations of a building will be used in the system. To perform the different scenario for each inclination angle, the simulation software PVsyst was used where the measurements are validated according to the simulation results to confirm that models are suitable and which inclination angles produced the most electricity. After the validation process, a financial assessment, and an annual electricity production of the system for a fictitious building where SBS is applied were performed. The result for the annual electricity production at different angles of inclination turned out to be 2457 kWh/year at 30, 2235 kWh/year at 60   and 1781 kWh/year at 90 . The optimal angle of inclination was 30  , which also has the highest electricity production compared to the other angles. Electricity production does not differ much with the inclination angle of 60. The simulation for the annual electricity production was examined for ten windows in opposite directions. The investment cost for the use of SBS was extraordinarily high, landing at 28,120 SEK/kW. The reason for this high investment cost is that it includes high material costs and that the area for SBS systems is low, which is 1,696 m². The reason is that the low area in m² leads to a lower electricity generation and the higher the area m² leads to higher electricity generation, which turns into affecting the profitability and electricity production.

One of the main social challenges that society is facing nowadays is the energy crisis. So, head towards renewable energy resources such as solar, hydraulic, wind, geothermal and biomass, could be the best solution. Solar photovoltaic is one of the most promising sources to produce electricity due to its cleanness, noiselessness and sustainability, and the fact that it is inexhaustible. However, the power output of the PV systems varies notably because of the ambient conditions: temperature and solar radiation. The main aim of this thesis is to study if the PV system installed on the wall of the new football arena Gavlehov in Gävle is providing the amount of power promised before the installation. To achieve reliable results, the first step is to develop and install a monitoring system for recording the real power of the system and the ambient conditions at the same time. After that, an evaluation of the performance of the system during one week will be done, comparing the theoretical power and the real power obtained. The theoretical power will be calculated in two ways: using the data from a pyranometer and on the other hand, from a reference solar cell. This will permit to compare which one matches better with the reality. Different factors such as the temperature, the irradiance and the angle of incidence are studied to know the real influence that they have on the performance of a PV installation. The results obtained show that the measurement system installed is reliable and that the model used to evaluate the system is correct. It can be concluded that using a reference solar cell to calculate the theoretical power of the system is easier to align and it has the same angular behaviour as a PV module than employing a pyranometer. Regarding the installation, all the panels work similarly and the system works at nominal power. So, it provides the amount of power promised before the installation. Key words: Renewable energy, PV system, solar radiation, nominal power, pyranometer, solar cell.

The diploma thesis contains by renovation of the family House on the “nearly zero-energy consumption building”, the proposal is for a variety of energy measures to achieve this status.