Improving the Hybrid Photovoltaic/Thermal System Performance Using Water-Cooling Technique and Zn-H2O Nanofluid

Hashim A. Hussein,Ali H. Numan,Ruaa A. Abdulrahman

doi:10.1155/2017/6919054

Hashim A. Hussein, Ali H. Numan + Show 1 more

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https://doi.org/10.1155/2017/6919054

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Abstract

This paper presented the improvement of the performance of the photovoltaic panels under Iraqi weather conditions. The biggest problem is the heat stored inside the PV cells during operation in summer season. A new design of an active cooling technique which consists of a small heat exchanger and water circulating pipes placed at the PV rear surface is implemented. Nanofluids (Zn-H2O) with five concentration ratios (0.1, 0.2, 0.3, 0.4, and 0.5%) are prepared and optimized. The experimental results showed that the increase in output power is achieved. It was found that, without any cooling, the measuring of the PV temperature was 76°C in 12 June 2016; therefore, the conversion efficiency does not exceed more than 5.5%. The photovoltaic/thermal system was operated under active water cooling technique. The temperature dropped from 76 to 70°C. This led to increase in the electrical efficiency of 6.5% at an optimum flow rate of 2 L/min, and the thermal efficiency was 60%. While using a nanofluid (Zn-H2O) optimum concentration ratio of 0.3% and a flow rate of 2 L/min, the temperature dropped more significantly to 58°C. This led to the increase in the electrical efficiency of 7.8%. The current innovative technique approved that the heat extracted from the PV cells contributed to the increase of the overall energy output.

Highlights

Photovoltaic (PV) systems represent a solution for the problem of low carbon, nonfossil fuel used to generate electricity.Solar radiation absorbed and converted by semiconductor devices can provide a supply of electricity to meet energy needs
photovoltaic thermal system (PV/T) system can be broadly categorized into two systems: photovoltaic and solar thermal system
The PV/T system refers to a system that uses heat transfer fluid to extract heat from the panel

Summary

Introduction

Photovoltaic (PV) systems represent a solution for the problem of low carbon, nonfossil fuel used to generate electricity.Solar radiation absorbed and converted by semiconductor devices (solar cells) can provide a supply of electricity to meet energy needs. Photovoltaic (PV) systems represent a solution for the problem of low carbon, nonfossil fuel used to generate electricity. Greater light absorption, a high absorption at visible wavelengths, and a low emissivity at infrared wavelengths can be achieved, and sunlight can be directly converted into useful heat as presented by Taylor et al [4]. Nanoparticles have the following advantages in solar power plants: (1) the extremely small size of the particles ideally allows them to pass through pumps and plumbing without adverse impacts, (2) nanofluids can absorb energy directly skipping intermediate heat transfer steps, (3) the nanofluids can be optically selective (i.e., high absorption in the solar range and low remittance in the infrared), (4) a more uniform receiver temperature can be achieved inside the collector (reducing material constraints),

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