Solar photovoltaic array

Hybrid Renewable Energy System - A renewable energy system that Includes two different types of renewable energy technologies that produce the same type of energy for e.g., a wind turbine and a solar photovoltaic array combined to meet a power demand. 

Pig. 1. An integrated high concentration photovoltaic array that achieved a solar conversion efficiency exceeding 20% in a 2000-W testbed (7). 

Unlike solar thermal systems or PV concentrator systems, the PV flat plate systems work well in cloudy locations because these latter convert diffuse as well as direct sunlight to electricity. On an aimualized basis, the energy produced by a photovoltaic array varies by only about 25% from an average value for the contiguous 48 states of the United States. As a result, it is practical to use photovoltaic systems in normally cloudy locations such as Seattle or northern Maine. 

Solar Power With improved technology and production methods considerable use is being made of solar power in remote locations. The output of photovoltaic arrays is used to maintain conventional storage batteries in a state of charge. The cathodic protection system is in turn energised from the batteries. It is usual to incorporate sufficient battery storage to accommodate a number of no-sun days. Whilst in theory the capacity of equipment is unlimited, a practical maximum would be ca. SOO W. 

Thomas, R. E. Gaines, B. G. "Methodology for Designing Accelerated Aging Tests for Predicting Life of Photovoltaic Arrays" Department of Energy/National Bureau of Standards Workshop on Stability of Thin Film Solar Cells and Materials, Washington, D.C., May 1-3, 1978. 

A solar photovoltaic system contains, in addition to solar cells and module(s), an array structure to support the modules, power-conditioning circuitry for control and modification of the output, and a means of storing energy if required. All elements beyond the module are referred to as balance-of-system (BOS) components. The cost of BOS items is nominally about equal to the cost of the PV module. However, the BOS fractional cost contribution can vary from one- to two-thirds of the total installed cost of a system, depending on application. 

The assumed conditions used in evaluating characteristics of the systems are summarized in Table 2. The total areas of the solar collectors and photovoltaic arrays are assumed to be 10 ha. In the solar thermal and hybrid systems, the type of collector is parabolic trough, the condenser outlet pressure 0.1 kg/cm a, and the capacity (maximum net power output) has been determined so as to minimize the unit cost of generated power energy. In the solar photovaltaic system, the conversion efficiency at the array is assumed to be 15 %. The tracking scheme of the solar collector and photovoltaic array is single north-south axis. 

Encapsulants are necessary for electrical Isolation of the photovoltaic circuit. They also provide mechanical protection for the solar cell wafers and corrosion protection for the metal contacts and circuit interconnect system over the 20-year design life of a photovoltaic array. The required components Include the solar cell circuit, the rigid or structural member, the pottant, and the outer cover/insulator. Surface modifications may be needed to develop strong, stable bonds at the Interfaces in the composite. If the module is to be framed, edge sealants may also be required. The functions of the Individual components and the performance requirements as they are now known are described. Costs are ccmipared where possible and candidate materials identified. 

Array (Solar) - Any number of solar photovoltaic modules or solar thermal collectors or reflectors connected together to provide electrical or thermal energy. 

Inverter - A device that that converts direct current electricity (from for example a solar photovoltaic module or array) to alternating current for use directly to operate appliances or to supply power to a electricity grid. 

Photovoltaic (PV Solar) Array - A group of solar photovoltaic... 

Solar Power Satellite - A solar power station investigated by NASA that entailed a satellite in geosynchronous orbit that would consist of a very large array of solar photovoltaic modules that would convert solar generated electricity to microwaves and beam them to a fixed point on the earth. 

A solar photovoltaic (PV) system is a collection of PV cells known as a PV string, that forms a PV array and collectively are called a PV generator which turns sunlight directly into electricity. PV systems may be stand-alone power supplies or be designed to operate in parallel with the public low-voltage distribution network, that is, the a.c. mains supply. 

The photovoltaic array is nothing but modules connected in series and parallel. The PV array for the SRFCs consists of several modules, which in turn consist of solar cells. The solar cells used in designing the present PV array are crystalline Si solar cells. The appropriate cell details are given in the Table 12.2. 

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