Category EuroSun2008-11

Greenius – A simulation tool for renewable energy utilisation

J. Dersch1*, K. Hennecke1 and V. Quaschning2

1 DLR – German Aerospace Center, Linder Hohe, 51147 Koln, Germany
2 FHTW Berlin, Berlin University of Applied Sciences, Marktstrasse 9, 10317 Berlin, Germany
* Corresponding Author, juergen. dersch@dlr. de

Abstract

Greenius, a software tool for fast calculation of the technical performance and economical figures of merit for different renewable energy systems has been extended to simulate also the usage of concentrating and non-concentrating solar collectors for process heat generation. A case study for a site in southern Spain was made, varying the temperature level of the generated heat...

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. Functionalities of macro-spatial management

The macro-spatial management is constituted of 5 distinct blocks:

Installed photovoltaic systems and types of application;

Description of type, operacional situation, fault and model of all the components of the installed photovoltaic systems;

Maintanance and training centers;

Phase of installation according to PRODEEM and Infrastructure of transmission lines, roads and airports.

Fig. 3 shows the photovoltaic pumping systems installed in the states of Paraiba (a) and Pernambuco (c)...

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Calculation of thermo-mechanical loads on polymeric collectors

The geometry of polymeric collectors differs from standard flat plate collectors due to material properties, the mentioned production methods and the resulting degrees of freedom in design. Various approaches to design a polymeric collector are under discussion. Mechanical stresses

occur during operation and stagnation due to thermal expansion and external loads on the collectors. These stresses have to be determined for investigating the durability of the product.

The efficiency calculations mentioned above lead to operating conditions of the collector which the chosen materials have to resist. Stress distribution and deformation show potential risks for the stability and durability of the collectors...

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Validation of Simulation Output

The vacuum tube collector implemented and simulated in OptiCAD was also investigated experimentally at the outdoor test facility of the “Test Centre for Solar Thermal Systems (PZTS)” at the Fraunhofer ISE according to the guidelines of EN 12975-2. The tests include the measurement of the optical efficiency p0 and the IAM-values in the longitudinal and transversal plane.

The following problem has to be considered: The measured optical efficiencies are evaluated with respect to the measured global radiation. However, the simulations in OptiCAD are conducted by applying direct radiation. In order to compare simulated IAM-values with measured ones the specific fraction of diffuse radiation recorded during the measurement has to be taken into account...

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Which way should it face?

Influences of climate, load profile and energy storage on the optimum inclination and orientation for thermal and photovoltaic solar energy

collectors

Brian Norton

Dublin Energy Lab Dublin Institute of Technology Dublin, Ireland president@dit. ie Abstract

Climatic and operational factors influencing the optimal orientation of solar energy, primarily photovoltaic, collectors are discussed in the context of relevant previous research. An example is provided of how being in a climate with diffuse components of insolation and winter loads that are generally high gives rise to an optimal inclination with a far greater slope angle than the latitude.

Keywords: Photovoltaics, system design, climate, inclination, orientation.

1. Introduction

When building integrated photovoltaics (BIPV) walls, roof...

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Simulation based energy consumption calculation of an office building using solar-assisted air conditioning

S. Thomas* and P. Andre

Department of sciences and environmental management, University of Liege 185 Avenue de Longwy, 6700 ARLON, Belgium Corresponding Author, sebastien. thomas@ulg. ac. be

Abstract

To minimize environmental impact and CO2 production associated with air-conditioning system operation, it is reasonable to evaluate the prospects of a clean energy source. The targets of the study are to evaluate cooling energy consumption to maintain thermal comfort in an office building and to point out solar energy to satisfy these cooling needs. Simulations were carried out with three different cooling systems in the same operating conditions to determine as accurately as possible the potential use of solar energy...

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Comparison of hot water use between different days of the week

Подпись: Mon Tue Wed Thu Fri Sat Sun Figure 6. Measured variation in energy use for hot water between different days of the week for June and October, year 2005 and 2006 respectively.

The variation in measured hot water use was also investigated on a daily basis to examine a possible difference between different days of the week. The results are found in Figure 6 for two different months the two years of available data. The trend is similar for both years and the variation between different days is small. Measured data seem to follow a similar pattern for 2005 and 2006 respectively, where the daily use is lower in 2006. Data for a certain month, however, does not coincide for the two years under investigation.

4. Discussion

The measured hot water use in the 24 apartments is similar for the two years investigated so far. The minimum in load is located in July and August, although the use is generally lower during 2006...

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ICS-SWH Design

The tested aluminium ICS-SWH was designed and manufactured with 3mm thick aluminium sheets incorporating fins to improve the thermal efficiency and structural stability of the heater.

Подпись: Figure 1: Solar water heater assembly, a: Plain view, b: Explode view

The water tank was placed in a hard wooden box insulated with layer of fibre glass wool on all sides and bottom as shown in Figure 1. A gap of 35mm between the absorber plate and glazing was used to reduce heat losses by restricting air movement.

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