It is a well-documented fact that partial shading of a photovoltaic array reduces it output power capability. However, the relative amount of such degradation in energy production cannot be determined in a straight forward manner, as it is often not proportional to the shaded area. This paper clarifies the mechanism of partial PV shading on a number of PV cells connected in series and/or parall...

Many maximum power point tracking techniques for photovoltaic systems have been developed to maximize the produced energy and a lot of these are well established in the literature. These techniques vary in many aspects as: simplicity, convergence speed, digital or analogical implementation, sensors required, cost, range of effectiveness, and in other aspects. This paper presents a comparative s...

Direct solar-to-fuels conversion can be achieved by coupling a photovoltaic device with water-splitting catalysts. We demonstrate that a solar-to-fuels efficiency (SFE) > 10% can be achieved with nonprecious, low-cost, and commercially ready materials. We present a systems design of a modular photovoltaic (PV)-electrochemical device comprising a crystalline silicon PV minimodule and low-cost hy...

Transormerless inverters are attractive solution for the grid connected photovoltaic (PV) systems. Unfortunately, it has issues on galvanic isolation between PV systems to the grid. When the galvanic isolation disappears from the PV inverter, leakage currents will flow in a resonant circuit formed by the ground capacitance, the converter, the ac filter and the grid. In order to avoid the leakag...

this paper proposes a new configuration for solar energy conversion systems. one challenging issue of the photovoltaic (pv) systems is partial shading, and in this paper module integrated converters (mic) are used to overcome this problem in pv arrays. a few boost converters are employed as mics to mitigate the shading effect. furthermore, to reduce the cost and to increase the system performan...

The photovoltaic (PV) systems exhibits nonlinear I-V characteristics and maximum power point varies with solar radiation or insolation and temperature. An intermediate pulse width modulation dc to dc converters can increase efficiency of the system by providing impedance matching between the PV system and the load and operating the PV cell arrays at their maximum power point using MPPT techniqu...

A number of photovoltaic pilot projects have been started in Botswana since 1990. The first photovoltaic project was Manyana PV project which started in 1992. The Japanese International Cooperation Agency (JICA) PV solar pilot project is the most recent PV solar project in Botswana, which was launched in 2003 at Kudumatse, Motlhabaneng, and Lorolwana villages. The primary objective of all these...

This paper proposes a novel approach based on Lyapunov function method to analyse the stability of photovoltaic (PV) systems. The Lyapunov function is formulated using the method of quadratic forms, i.e., Krasovskii’s method. The stability of the photovoltaic systems under different operating conditions is analysed based on the formulated Lyapunov function. A comparison of stability analysis us...

A methodology that permits testing the level of integration of the photovoltaic technology in urban areas is presented. The percentage of coverage of the electricity demand of grid-connected photovoltaic systems installed on the roofs of buildings were investigated in a district of the city of Palermo (Sicily). After classifying roofs according to their shape, orientation and pitch by means of ...

Installing sustainable and renewable energy systems is a promising way of relieving Hong Kong’s dependence on imported fossil fuels. Solar photovoltaic (PV) technology is a perfect solution for Hong Kong as it fits the economic and geographic situation. Through a review of the PV development history of five leading PV countries, Germany, Japan, Italy, Mainland China, and the USA, this paper ser...