Among the photo-optical transmission methods, £inar (1995) has considered the collection of radiation by focused collectors. On the other hand, Baojun et al. (1995) have investigated the solar energy relationships with fiber-optic radiation. The most advanced and recent method of solar energy collection, as well as trans­mission, is by using fiber-optics. Collection of energy directly […]

Instead of flat plate collectors, solar ponds are used for thermal electricity produc­tion. A solar pond is similar to a large salty lake as shown in Fig. 7.8. In such a pond, salty water is required to be at the bottom with fresh water at the top. The difference in salt concentration causes a gradient […]

It is necessary to have tilted surfaces for the maximum collection of solar energy. The angle of tilting is dependent both on the latitude and the day of the year. If the tilt angle is equal to the latitude then the sun’s rays will be perpendicular to the surface of collector at midday in March […]

If high temperatures are needed then the collector surface is manufactured as a curve for focusing (concentrating) the solar radiation at certain points by a mirror or lens. Mirrors are cheaper to construct than lenses. The mirror collectors may have spher­ical parabolic or linear parabolic shapes as shown in Fig. 7.5. In a parabolic mirror […]

Logically, in order to collect the maximum radiation for each unit surface area of collector, it is necessary to direct the collector surface at right angles to the direc­tion of direct radiation. Continuation of maximum benefit by the collector during a day is possible by keeping the collector surface perpendicular to the incident so­lar radiation […]

The flat plate collectors are based on two important principles: a black base that absorbs the solar radiation better than any other color and a glass lid that is needed to keep the heat in. Figure 7.2 shows the cross-section of the most commonly used flat plate collector. Its surface should be located perpendicularly to […]

Typical uses of solar radiation collectors can be grouped into four different cate­gories depending on the purpose: 1. As a low-temperature heat source which may be used for domestic hot water or crop drying purposes. 2. In order to power heat engines, relatively high heat collectors can be used. 3. Depending on the climate, the […]

A hot body may lose heat by radiation through emission of EM waves (Chap. 3). The maximum power which can be radiated from a body at a given temperature is called the black body radiation corresponding to that temperature. The radiation power, P, from a black body increases as the fourth power of the absolute […]