ABSTRACT
In this paper, an investigation study has been carried out to evaluate the photovoltaic module degradation, in a desert area of Algeria. In this view, a set of PV modules have been put into tests and assessment for more than 11 years. These modules were assembled into three PV generators composed of monocrystalline (mc-Si) and polycrystalline (pc-Si) PV modules. The I–V curve tracer, calibrated reference m-Si solar cell and Pt1000 temperature sensor tools were used to collect the data. Three degradation modes were examined namely: (i) the visual inspection characterized mainly by a discoloration of PV modules, (ii) I–V degradation characterized by an increase in the series resistance which corresponds to electrical losses in conductors and (iii) the degradation rate (DR) assessment. The main parameters affecting on PV system performance are the high temperatures and sandstorms that characterize desert regions. The results indicated that for monocrystalline and polycrystalline PV modules, the power degradation rates were 1.53% and 0.37% per year, respectively. This degradation rate was found to be 2.36% per year for modules with broken back-sheet and corroded junction box. The production situation of examined PV systems shown a decrease of about 9%, 13%, and 6.8% for PVG1, PVG2, and PVG3, respectively, throughout the operation period. In addition, cell discoloration was observed as the predominant mode of degradation mechanism in desert climatic conditions.
Nomenclature
DR | = | Degradation Rate, % |
EVA | = | Ethylene vinyl acetate |
HIT | = | Heterojunction with intrinsic thin-layer |
IEC | = | International Electrotechnical Commission |
LCT | = | Life-cycle-time |
NOCT | = | Nominal Operating Cell Temperature |
PV | = | Photovoltaic |
PVG | = | Photovoltaic Generator |
STC | = | Standard Test Conditions (1000W/m2, 25°C and AM=1.5) |
G | = | Irradiance W/m2 |
Im | = | Current at maximum power point, A |
I-V | = | Current tension characteristic of PV module |
ISC | = | Short circuit current, A |
Np | = | Number of PV cells in parallel |
Ns | = | Number of PV cells in series |
Pm | = | Maximum power, W |
P-V | = | Power tension characteristic of PV module |
Pmax0 | = | Maximum power given by the manufacturer at STC |
Pmax | = | Maximum measured power at STC |
T | = | Temperature of the PV cell, °K |
Vm | = | Voltage at maximum power point, V |
VOC | = | Open circuit voltage, V |
myDR | = | Yearly degradation, % |
α | = | Current temperature coefficient, K−1 |
β | = | Voltage temperature coefficient, K−1 |
Disclosure statement
No potential conflict of interest was reported by the author(s).