Improved photovoltaic energy output for cloudy conditions with a solar tracking system

Kelly, Nelson A.; Gibson, Thomas L.

doi:10.1016/j.solener.2009.08.009

Cited by 159 publications

(73 citation statements)

References 11 publications

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“…For both algorithms the increase in the performance over the surface with latitude tilt was between 28 and almost 40% as the mean number of daily searches, N, varied from 5 to 44, which is in accordance with literature (Kelly & Gibson, 2009). It was observed that, when the number of mean daily searches was around 5, the fixed time interval algorithm performed better, but as the number of searches increased, the difference decreased, until, for N bigger than 23 the proposed algorithm started performing better.…”

Section: Resultssupporting

confidence: 90%

“…On this site, the set of trackers allows for 50% increase in performance on cloudy days, when compared to fixed flat panels. (Kelly & Gibson, 2011). According to Gómez-Gil, Wang and Barnett (2012), about 24% of the Spanish systems have one axis tracking and 13% with two axis tracking, which presented a performance increase of about 22 and 25%, respectively, and thus, better economic feasibility.…”

Section: Introductionmentioning

confidence: 99%

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<b>Development of a closed and open loop solar tracker technology

et al. 2017

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ABSTRACT. Solar energy is among the renewable energy sources that received greater addition in installed capacity. However, it accounts for a small fraction of the energy matrix of most countries. Desenvolvimento de tecnologia de rastreamento solar com controle em malha fechada e em malha aberta RESUMO. A energia solar está entre as fontes de energia com maior incremento em sua capacidade instalada, mas ainda representa uma pequena fração da matriz energética mundial. A geração de energia a partir de sistemas fotovoltaicos pode ser melhorada por meio do rastreamento solar. O objetivo deste trabalho foi desenvolver e comparar sistemas de rastreamento solar com controle em malha aberta e malha fechada. O sistema com malha fechada foi desenvolvido utilizando resistores dependentes da luz. Um algoritmo de rastreamento em malha aberta foi desenvolvido com base na relação geométrica entre o sol e o módulo fotovoltaico. Este algoritmo foi comparado com um algoritmo de rastreamento a intervalos fixos de tempo por meio de simulação para condição de céu claro e para cinco latitudes. Não foi observada diferença significativa entre o algoritmo desenvolvido e o rastreamento em intervalos fixos de tempo para os casos avaliados. Os sistemas de rastreamento em malha aberta e malha fechada foram comparados experimentalmente para a cidade de Rio das Ostras, Brasil (22,49ºS 41,92ºO). Foi observado um aumento médio de 28,5 e 33,0% para os sistemas de rastreamento em malha aberta e malha fechada, respectivamente, em relação a um sistema fixo com inclinação igual à latitude.Palavras-chave: energia solar, rastreamento biaxial, sistemas fotovoltaicos.

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Section: Resultssupporting

confidence: 90%

Section: Introductionmentioning

confidence: 99%

<b>Development of a closed and open loop solar tracker technology

et al. 2017

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“…However, in cloudy conditions the efficiency of the tracking system is reduced, as the solar radiation is isotropically distributed. In a study [81], a horizontal PV module produced almost 50% more than a 2-axis solar tracking system during cloudy conditions.…”

Section: Factors Affecting the Power Production Of A Pv Systemmentioning

confidence: 98%

Electrical efficiency study of alternating current and direct current power topologies in office building with integrated photovoltaics in Matlab-Simulink environment

Viitanen

Halonen

2014

Journal of Renewable and Sustainable Energy

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Ene rgy e ffic ie nt l igh t ing syst e ms in buil dings w it h int e grat e d ph o t o vo l t aic s J a nne V i i t a ne n D O C T O R A L D I S S E R T A T I O N SAalto University publication series DOCTORAL DISSERTATIONS 18/2015 Energy efficient lighting systems in buildings with integrated photovoltaics Janne Viitanen A doctoral dissertation completed for the degree of Doctor of Science (Technology) to be defended, with the permission of the Aalto University School of Electrical Engineering, at a public examination held at the lecture hall S1 of the school on 6 March 2015 at 12. Aalto University School of Electrical Engineering Department of Electrical Engineering and Automation Lighting Unit AbstractThe goal of this thesis was to study how a building integrated photovoltaic system, choice of lighting technology and the selected system voltage affect the energy efficiency of an office building. The quality of the lighting was considered also, as it is essential that users accept the lighting.The energy production of photovoltaic system (PV) was evaluated in Southern Finland through onsite PV measurements from several different compass points and tilt angles during 2010-2013. Based on the measurements, the PV system was sized to provide energy for lighting and office appliances. The energy efficiency of the devices had considerable effect on the sizing of the PV system. The seasonal variations in the PV production were considerable, as only few per cent of the summer time insolation was available during the winter.The energy efficiency and quality of lighting was studied. Fluorescent lighting (FL) and LED lighting were compared, as they are the most used options in offices today. Lighting measurements and a user study was conducted. Different illuminance levels and correlated colour temperatures (CCT) were studied. The studied parameters included glare, reading task performance, identification of detail, colour naturalness and pleasantness, illuminance level sufficiency and pleasantness, pleasantness of the lighting in general and naturalness of the shadows. The subjects also set their own preferred illuminance levels and CCTs. No major differences were found in the subjective preferences at equal illuminance levels between luminaire types. On average, an illuminance level around 600 lx and a CCT around 4000 K were preferred. LEDs were found more energy efficient than FLs and the difference increased when the luminaires were dimmed.In the last part of the research the electricity consumption of an office building was compared with system voltages 12 VDC, 24 VDC, 48 VDC and 230 VAC through computer simulations in a Matlab-Simulink environment. It was found that 230 VAC was the most energy efficient option as a general system voltage, with the selected components and system variables. The 24 VDC was the most energy efficient option with fluorescent lighting and the 48 VDC with LED lighting, if only the lighting system was considered. Aurinkosähkön tuotantoa Etelä-Suomessa tutkittiin mittausten avulla eri il...

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“…It has been suggested that, using solar-angle tracking for PV systems can increase power output by up to 50% [20]. Although this is not considered in the present work, it is nevertheless being considered by the authors in ongoing work.…”

mentioning

confidence: 93%

Solar-Powered Direct-Current Loads in Small Buildings

Sarnobat¹,

Lannon²

2015

JEPE

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Traditional light bulbs (e.g., incandescent, fluorescent) use too much electricity, convert very little energy into light of sufficient quality and in their production use toxic contaminants. During the last few years, a new type of light source, LED (light emitting diode) bulb, has gained increasing popularity and its costs are set to plunge even further. LED bulbs offer many advantages over traditional sources, and they can be used as a direct replacement to existing lighting. This paper will use a spreadsheet-based analysis with hourly solar data supplied by Ecotect to show that, the efficiency of LED installations can be increased when used in conjunction with photovoltaic modules, as the two generate (and use) DC (direct-current) electricity, thereby eliminating intermediate-level losses in the electronic circuitry. If a storage battery is included, the solar panels generate electricity during the times when the occupants are not necessarily using the lighting, but the stored electricity can be used to power the lighting when the energy is required. The latest results demonstrate that, a slight reduction in the required floor area to be lit allows the solar-battery-LED system to be implemented in small buildings using a storage battery size that is within the range of present commercial devices.

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Improved photovoltaic energy output for cloudy conditions with a solar tracking system

Cited by 159 publications

References 11 publications

<b>Development of a closed and open loop solar tracker technology

<b>Development of a closed and open loop solar tracker technology

Electrical efficiency study of alternating current and direct current power topologies in office building with integrated photovoltaics in Matlab-Simulink environment

Solar-Powered Direct-Current Loads in Small Buildings

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