Solar mirrors

In the foreground to the right are the auca-sirenas, mermaids keeping watch on the tranquil and resting yakurunas. These mermaids live within rocks, and when anyone tries to capture them, they simply approach a rock and disappear. The small pools of water atop their rocks are like solar mirrors that can be transformed into strong lasers with which they are able to capture even the most powerful of enemies. 

Of eight polymers screened, poly(methyl methacrylate) and possibly poly(vinylidene fluoride) and polyCethylene terephthalate) show promise as protective coatings for solar mirrors. Polymer-coated mirrors were exposed in a Weather-Ometer and analyzed periodically for mirror and polymer degradation. Failures resulted from physical delamination and chemical reaction (a) at the polymer/mlrror interface due to interaction with the degrading polymer or its additives and... 

The superiority of acrylic polymers used for concentrating collector mirrors or lenses has been underlined [29]. Studies on reactivity of different polymers used as protective coatings or in film form for solar mirrors have established PMMA(3M)/Al/adhesive to be the most durable of the polymer/ mirror systems. 

This ability of inorganic coatings is apphed for the protection of solar mirrors. Silver and aluminium first surface mirrors for solar collectors are protected from oxidation up to... 

Most schemes that have been proposed to propel starships involve plasmas. Schemes differ both in the selection of matter for propulsion and the way it is energi2ed for ejection. Some proposals involve onboard storage of mass to be ejected, as in modem rockets, and others consider acquisition of matter from space or the picking up of pellets, and their momentum, which are accelerated from within the solar system (184,185). Energy acquisition from earth-based lasers also has been considered, but most interstellar propulsion ideas involve nuclear fusion energy both magnetic, ie, mirror and toroidal, and inertial, ie, laser and ion-beam, fusion schemes have been considered (186—190). 

Solar-thermal technology uses tracking mirrors to concentrate sunlight onto a receiver. In turn, the receiver absorbs solar energy as heat, warming a fluid that then drives a turbine generator. Most solar-thermal plants requite cooling water. 

Fig. 3. The 10-MW Solar One plant, which advanced solar thermal power through the use of tracking mirrors to concentrate sunlight onto a central...

Fig. 4. In the Solar Two Project a molten salt system shown in the scheme replaces Solar One s water/steam system. In operation, "cold" molten salt is pumped from a storage tank to a receiver on a tower. Sunlight reflected from a field of sun-tracking mirrors heats the salt in the receiver to 1050°C. The heated salt then flows down into a hot storage tank where it is pumped to a heat exchanger to produce the steam that drives a turbine. Some of the hot molten salt can also be stored to produce steam on demand at a later time. Salt cooled to 550°C in the steam generator recirculates through the system and...

Sputtered silver mirrors are used for solar energy (qv) collectors and astronomical telescope mirrors. Approximately 3 t/yr of silver are used in the United States for low emissivity windows. 

Many grades of interlayer are produced to meet specific length, width, adhesion, stiffness, surface roughness, color (93,94), and other requirements of the laminator and end use. Sheet can be suppHed with vinyl alcohol content from 15 to about 23 wt %, depending on the suppHer and appHcation. A common interlayer thickness for automobile windshields is 0.76 mm, but interlayer used for architectural or aircraft glaring appHcations, for example, may be much thinner or thicker. There are also special grades to bond rear-view mirrors to windshields (95,96) and to adhere the components of solar cells (97,98). Multilayer coextmded sheet, each component of which provides a separate property not possible in monolithic sheet, can also be made (99—101). 

Methane reforming reaction is accomplished under the action of heat collected from mirror concentrator of solar light. The mixture of CO and H2 produced in this reaction can be stored and then, when necessary, converted into high-potential heat (with the temperature up to 950 K) in the methanation catalytic reactor. The efficiency of solar-to-chemical energy conversion as high as... 

Solar concentrators contract the solar radiation from a relatively large area onto a small area. A parabolic mirror of four feet in diameter covers an area of 4 pi, or 12.57 square feet (1.17 square meters). This surface area is measured on a plane and is slightly less than the surface area of the curved mirror. If the sun is about 20% down from peak strength, its strength should be about 800 watts per square meter. Then the total amount of energy striking the mirror is almost 1,000 watts. 

California has nine solar stations with 11 square miles of mirrors focused on steam drums that drive steam turbines. They can generate 413 megawatts (MW) of electricity which is less than 1% of the state s capacity. Because the sun sets at night and is sometimes attenuated by clouds, the plant production only averaged 0.3% of California s electricity. 

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