Producing drinkable water from brine is accomplished in a solar still, where salty water is evaporated. The salt becomes concentrated in the bottom of the still basin, while the water vapor rises, condenses on the still cover as fresh water, and is drawn off.

The solar cooking stove has become an important device in tropical countries where firewood is in short supply. The stove may be simply a hot box, an insulated container, perhaps with a mirrored cover that intensifies the Sun's heat. More complex stoves have reflectors that focus sunlight directly on the cooking area, or they use separate heat-collector devices that transfer heat to water inside a steam cooker.

Solar heat is also used throughout the world to dry agricultural crops, fruits, and vegetables.

Both water and space heating are among the

A typical space heating system consists of a roof-mounted collector array whose tilt angle is equal to the local latitude plus 15 degrees, a heat-storage tank or bin, pumps or a fan, and a network of pipes or ducts through which the heat is sent.

If poor weather reduces the amount of available sunlight, the solar system will produce no hot water. Then the conventional water-heating system will take over the task of providing domestic hot water.

Passive systems avoid the use of mechanical components. The simplest passive system, the direct-gain system, involves larger-than-normal south-facing windows, with a massive floor slab that serves as the heat storage. This system is particularly effective in bringing up the temperature of a house quickly in the morning, but it can cause overheating problems in sunny climates if sufficient storage is not available.

Solar collectors are devices that absorb solar energy and produce heat. They are mounted on the roofs of buildings or in other areas that are open to direct sunlight, and they are used for space heating and cooling and for heating water.

Concentrating, or focusing, solar collectors focus the Sun's rays on a tube (trough type), a point (dish type), or a concave mirror to provide higher temperatures for special purposes, such as industrial-process heat. Such collectors must be able to move both vertically and horizontally in order to track the Sun across the sky in all seasons.

Solar water heating is an old and simple application of solar heat, and an inexpensive system for many buildings. The most common system consists of a collector located outside the building and tilted at an angle that favors uniform yearlong solar input. (The tilt angle is approximately equal to the local latitude.) In addition to the collector, there is a small fractional-horsepower pump for water circulation and a tank to store the heated water for later use. A simple controller that compares tank and collector temperature operates the pump. Whenever the collector is warmed to a temperature greater than that of the tank, the pump is turned on.

Some common words found in the essay are:
Collectors Solar, SOLAR ENERGY, Heating Solar, Space Heating, Conversion Photovoltaic, ENERGY Sun's, Heating Passive, Sun Steel, Power Production, Process Heat, solar energy, solar heat, space heating, hot water, solar collectors, solar radiation, solar power, heat-transfer medium, solar cells, applications solar, solar space heating, hot water day, solar power plants, equal local latitude, auxiliary heat source,
Approximate Word count = 1981
Approximate Pages = 8 (250 words per page double spaced)