Solar irradiation measurements in Jordan and comparisons with Californian and Alpine data

Durisch, W.; Keller, Johannes; Bulgheroni, Willy; Keller, Lothar; Fricker, H.

doi:10.1016/0306-2619(95)00030-v

Cited by 13 publications

(7 citation statements)

References 5 publications

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“…In order to decrease the influence of rapid wind changes, tests were conducted during sunny (summer) weather (presented measurements were taken on 21-22 July 2016 at summer solstice, so the 1100 W/m 2 of solar radiation was taken into account) at Grobnik airport (elevation above sea level 300 m), near Rijeka, Croatia [30,31,33]. Furthermore, the intention was to sustain constant speed and latitude and to test the flight range and flight time for the standard airplane model [23].…”

Section: Uniform Flight Testsmentioning

confidence: 99%

“…On the other hand, in India and Australia, a solar radiation of 135 kW/m 2 is used frequently in calculations. In that context, it is interesting to mention research provided for Europe in comparison to other parts of world [30,31]. Solar radiation in Europe generally has lower values than in Australia, however occasionally could obtain values up to 1.1 kW/m 2 , which is measured in Alpine [30] or Mediterranean regions [31].…”

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confidence: 99%

“…In that context, it is interesting to mention research provided for Europe in comparison to other parts of world [30,31]. Solar radiation in Europe generally has lower values than in Australia, however occasionally could obtain values up to 1.1 kW/m 2 , which is measured in Alpine [30] or Mediterranean regions [31]. Geographically, Croatia is situated on the Mediterranean with a hilly central and southern part and the Pannonia plane on the northern border with Hungary.…”

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confidence: 99%

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PV System Design and Flight Efficiency Considerations for Fixed-Wing Radio-Controlled Aircraft—A Case Study

et al. 2018

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The list of photovoltaic (PV) applications grows longer every day with high consideration for system efficiency. For instance, in spite of many recent PV aircraft designs, aircraft propulsion was mainly reserved for nonelectric motors. Lately, the Solar Impulse flight across the world shows the possibilities of larger PV powered electric aircraft. In order to obtain this goal efficiency of flight, PV conversion, power converters and electric drives have to be maximized. These demands led to a 63.4 m wingspan. The purpose of this paper is to present that PV power could be used for improving the performance of fixed-wing radio-controlled aircrafts with smaller wingspans (1 m). In order to improve the performance of battery powered electric unmanned aerial vehicles (UAV), a model without PV cells (commercial Li-ion battery powered UAV) was compared with UAV powered both from battery and PV modules. This work shows details about Boost DC/DC converter and PV system design for small size fixed-wing electric UAVs, investigating the possibility of the application of PV powered drones, as well. Theoretical findings involving efficiency improvements have been confirmed by measurements combining the improvements in electrical engineering, microcontroller application and aerodynamics.Energies 2018, 11, 2648 2 of 12 from an energetic point of view. For example, conventional airplanes consume large quantities of kerosene, so there are efforts to reduce that consumption in order to achieve both economic and ecological impact on modern life [11].In this paper, an improvement of radio-controlled aircraft with a PV system addition has been investigated. The Solar Impulse project has shown that PV powered airplanes can fly across great distances [5,12,13], but what about smaller planes at lower altitudes? Is it possible for them to stay in the air for a few days? In this paper, a radio-controlled unmanned aerial vehicle (UAV) with a fixed-wingspan of less than 1 m has been tested without a PV supply. Different flight data like flight speed, range and time have been measured. Mass increase of the UAV (PV modules are no exception) results in shorter flight time. On the other hand, additional PV energy could compensate for battery discharging and increase flight time. Compared to the same problem in road vehicles, airplanes and their models are more exposed to periodic wind blows, sun radiation fluctuation and nonlinear phenomena of thermal air flows. In the literature, different approaches could be found, including the axiomatic approach [14] or more conventional approaches [15][16][17][18][19][20]. After the calculations, an additional PV source has been added to the wings including a Boost DC/DC power converter with a maximum power tracking (MPPT) function [21,22]. Special care has been added to the DC/DC power converter in order to reduce its mass, so different approaches were tested and compared. Finally, a new fixed-wing radio-controlled UAV based on [23] was designed at this time with a flying stability problem. After solving t...

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Section: Uniform Flight Testsmentioning

confidence: 99%

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confidence: 99%

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confidence: 99%

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PV System Design and Flight Efficiency Considerations for Fixed-Wing Radio-Controlled Aircraft—A Case Study

et al. 2018

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“…A PV cell model is implemented here that is based on the work Durisch et al A semi-empirical efficiency model was developed in this work and verified against observations made in Jordan (Al Quawairah) [39] over a three year period [40], with further comparisons made against Californian and Alpine data (making its application in the present case study appropriate). The developed efficiency model is summarised by equation (28), where the parameters h PV (the Ross coefficient [39]), p PV , q PV , m PV , r PV , s PV , and u PV are manufacturer/model specific.…”

Section: Comments On Turnaround Efficiency and A Case Study Applicatimentioning

confidence: 99%

A series hybrid “real inertia” energy storage system

Rouse

Garvey

Cárdenas

et al. 2018

Journal of Energy Storage

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The wide scale market penetration of numerous renewable energy technologies is dependent, at least in part, on developing reliable energy storage methods that can alleviate concerns over potentially interrupted and uncertain supplies. Many challenges need to be overcome, not least among them is allowing capacity for the wide range of time scales required to ensure grid stability. In thermal power plant, high frequency/short duration demand fluctuations, acting at the milliseconds to several seconds time scale, are addressed passively by the inertia of the grid. Here, grid inertia can be thought of as the mechanical inertia of spinning steel in steam and gas turbines. This allows time for active control measures to take effect at the tens of second to hours time scale and for the system to recover without a supply frequency deviation that is noticeable to the customer. It is of paramount importance that, as thermal plant is retired, renewable energy generation and storage systems account for the loss of this inertia. In the literature, strategies to address the loss of "real" inertia have often relied on emulation rather than actual replacement. The present work focuses on the preliminary development of a novel energy storage system that makes use of real inertia to address short term supply/demand imbalances while simultaneously allowing for extended depths of discharge. The concept looks to combine flywheel and compressed fluid energy stores in order to power a synchronous generator. By combining these energy storage technologies through a differential drive unit, DDU, it is anticipated that the benefits of high system inertia can be exploited in the short term while allowing energy to be continually extracted from the flywheel in the long term during storage discharge. The use of a DDU makes the present design particularly novel and distinct from other hybrid systems. In essence, this inclusion allows energy to be extracted entirely from the flywheel, inducing "real" inertia, or entirely from the secondary store, inducing "synthetic" inertia, or some combination of the two. Fundamental sizing calculations for a 50MW system with 20MWh of storage capacity are presented and used to design a suitable control system that allows for the operation of both primary flywheel and secondary compressed fluid energy stores. The transient behaviour of the system is simulated for several charge/discharge time profiles to demonstrate response stability for the system. Comments on system turnaround efficiency, which is dependent upon loading history but for the intended applications can be considered to be greater than 90% are also made here, along with a case study application to an isolated Californian solar powered grid.

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“…There is an average of about 10 h of sunlight per day and 3200 h of sunlight per year. According to the measurements taken by Durisch of the Paul Scherrer Institute (PSI) in Switzerland between May 1990 and April 1991, the total annual direct normal irradiation in Jordan ranges from 2400 kWh/m 2 yr to over 2700 kWh/m 2 yr and is counted among the best insolated areas in the world [5,6].…”

Section: Introductionmentioning

confidence: 99%