Abstract The variable nature of the irradiance can produce significant fluctuations in power generated by large grid‐connected photovoltaic (PV) plants. Experimental 1 s data were collected throughout a year from six PV plants, 18 MWp total. Then, dependence short (below 10 min) fluctuation on plant size has been investigated. analysis focuses study frequency as well maximum value registered. An analytic model able to describe given for certain day is proposed. Copyright © 2010 John Wiley...

Abstract The power generated by large grid‐connected photovoltaic (PV) plants depends greatly on the solar irradiance. This paper studies effects of irradiance variability analyzing experimental 1‐s data collected throughout a year at six PV plants, totaling 18 MWp. Each plant was modeled as first order filter function based an analysis in frequency domain and output signals. An empiric expression which relates parameters size has been proposed. simple model successfully validated precisely...

ABSTRACT The quality and the reliability of power generated by large grid‐connected photovoltaic (PV) plants are negatively affected source characteristic variability. This paper deals with smoothing fluctuations because geographical dispersion PV systems. fluctuation frequency maximum registered at a plant ensemble analyzed to study these effects. We propose an empirical expression compare attenuation both size number grouped. convolution single distribution functions has turned out be...

Abstract Field data of soiling energy losses on PV plants are scarce. Furthermore, since dirt type and accumulation vary with the location characteristics (climate, surroundings, etc.), available optical are, necessarily, site dependent. This paper presents field measurements (dust) irradiance incidence angle along 2005 a solar‐tracking plant located south Navarre (Spain). The proposes method to calculate these based difference between measured by calibrated cells several trackers calculated...

We report an experimental study of porous silicon-based rugate filters. performed filter apodization, following a half-apodization approach, which successfully attenuated the sidelobes at both sides photonic stop band. achieved successful reduction interference ripples through insertion index-matching layers on first and last interfaces. An apodized dielectric mirror are compared: Appreciable differences in harmonic presence stop-band performance were observed commented on. Bandwidth control...

Abstract A battery model is proposed as a tool to simulate and optimize photovoltaic (PV) / storage systems. the normalized form of equations with respect capacity allows us generalize its use for any type size lead‐acid batteries. The validity this represent voltage evolution during charge, overcharge discharge processes predict performance solar systems under different operational conditions analysed. Moreover, efficiency losses are presented function upper regulation thresholds charge...

Abstract When analysing the influence of shade on photovoltaic (PV) systems, intuitive assumption is that conversion architectures with more inverters, such as string‐ and module‐inverters, will have lower energy losses associated partial shading generators. However, other phenomena which can affect a system's response to shade, for example, way in inverter performs maximum power point tracking (MPPT), mean modular configurations are not always least susceptible effects. We present case...

Abstract Energy yield and occupation of land are two parameters that must be optimized when designing a large PV plant. This paper presents the results simulating energy flat panels for some locations different tracking strategies as function ground cover ratio. Some interesting design purposes, such optimal solar trackers depending on availability or gains every strategy, shown. For example, associated to one north–south axis tracking, referenced static surfaces, ranges from 18 25%, 37 45%...

ABSTRACT This paper presents the impact of non‐homogeneous deposits dust on performance a PV array. The observations have been made in 2‐MW park southeast region Spain. results are that inhomogeneous leads to more significant consequences than mere short‐circuit current reduction resulting from transmittance losses. In particular, when affected modules part string together with other cleaned (or less dusty) ones, operation voltage losses arise. These can be several times larger leading power...

Abstract This paper presents a review of back‐tracking geometry not only for single axis but also two‐axis tracking and analyses the corresponding energy gains. It compares different strategies with ideal in terms yield concluding, on one hand, that is more useful horizontal than vertical one, other efficient when applied primary tracker. Copyright © 2011 John Wiley & Sons, Ltd.

ABSTRACT This paper reports on the IES‐UPM experience from 2006 to 2010 in field of characterization PV arrays commercial large plants installed Spain within framework profitable economic scenarios associated feed‐in tariff laws. has extended 200 MW and provided valuable lessons minimize uncertainty, which plays a key role quality assurance procedures. The deals not only with classic I – V measurements but also watt‐metering‐based Particular attention is paid selection irradiance cell...

Abstract Due to high competitiveness in the PV sector, despite low degradation rate of crystalline silicon modules (below 0.5%/year), it is still important for utilities know its actual value due impact on energy yield and hence, profitability, over lifetime a plant. However, uncertainties related both influence downtime periods problems that may appear under normal operation commercial plant measurement rates at level make this challenging task. In order obtain significant value, paper,...

Abstract Solar tracking is used in large grid‐connected photovoltaic plants to maximise solar radiation collection and, hence, reduce the cost of delivered electricity. In particular, single vertical axis tracking, also called azimuth allows for energy gains up 40%, compared with optimally tilted fully static arrays. This paper examines theoretical aspects associated design taking into account shadowing between different trackers and back‐tracking features. Then, practical installed at 1.4...

Abstract This paper details an investigation into the appearance of hot‐spots in two large grid‐connected photovoltaics (PV) plants, which were detected after visual inspection trackers whose energy output was decreasing at anomalous rate. Detected appeared not only solar cells but also resistive solder bonds (RSB) between and contact ribbons. Both types cause similar irreversible damage to PV modules, latter are main responsible for decrease output, confirmed experimental testing campaign....