Solar charging

Further applications for ASA in the area of solar energy include, for example, sunlight sensors, solar-powered battery chargers and solar-charged flashlights. 

Much use has been made of micellar systems in the study of photophysical processes, such as in excited-state quenching by energy transfer or electron transfer (see Refs. 214-218 for examples). In the latter case, ions are involved, and their selective exclusion from the Stem and electrical double layer of charged micelles (see Ref. 219) can have dramatic effects, and ones of potential imfKntance in solar energy conversion systems. 

Four different types of junctions can be used to separate the charge carriers in solar cebs (/) a homojunction joins semiconductor materials of the same substance, eg, the homojunction of a p—n sibcon solar ceb separates two oppositely doped layers of sibcon 2) a heterojunction is formed between two dissimbar semiconductor substances, eg, copper sulfide, Cu S, and cadmium sulfide, CdS, in Cu S—CdS solar cebs (J) a Schottky junction is formed when a metal and semiconductor material are joined and (4) in a metal—insulator—semiconductor junction (MIS), a thin insulator layer, generaby less than 0.003-p.m thick, is sandwiched between a metal and semiconductor material. 

Action of Vacuum on Spacecraft Materials. For service beyond the atmosphere, the vacuum environment allows materials to evaporate or decompose under the action of various forces encountered (1,18,19). These forces include the photons from the sun, charged particles from solar wind, and dust. The action of space environment on materials and spacecraft can be simulated by a source—sink relationship in a vacuum environment. Thus, for example, the lifetime of a solar panel in space operation may be tested (see Photovoltaic cells). 

Charger Technology. Alkaline storage batteries are commonly charged from rectified d-c equipment, solar panels, or other d-c sources and... 

Solar array efficiency depends on its orientation to the sun. The best result is achieved if the array faces the sun at an angle of 90° to S5°. Precise orientation can be achieved either through the rotation of the whole spacecraft, or the rotation of the solar arrays only. To ensure constant electricity flow regardless of changes in spacecraft orientation, solar arrays charge... 

Cooling loads are most significant on hot summer afternoons when electric utilities typically have annual peak loads. Lower solar heat gains lead to reduced peaks, which reduce peak demand charges and power plant capacity requircliiclits. 

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. 

The chapter is organized as follows the second section will discuss the photophysics of conjugated polymer/fullerene composites as a standard model for a charge-generating layer in plastic solar cells. Pristine polymer devices will be discussed in the third section while bilayer and interpenetrating network devices are presented in Sections 4 and 5. Section 6 contains some remarks on large area plastic solar cells and Section 7 conclusions. 

In two-component charge transfer systems, such as in the bulk-heterojuncdon solar cells presented here, deviations of the V,K. from the results of pristine single layer or bilayer devices are expected for two reasons first, some pan of the available difference in electrochemical energy is used internally by the charge transfer to a lower energetic position on the electron acceptor second, the relative posi-... 

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