Solar Water Stills: Principles And Application

Since the 1980s, no large-capacity solar distillation plants have been built, mainly for the following reasons: Large installation areas are needed, solar distillation plants have low efficiencies, and solar water desalination has been developed, which in some cases can replace solar distillation (e.g., for medium-size communities). (more…)

Solar Water Desalination: Reverse Osmosis, Electrodialysis, and Mechanical Vapor Compression Desalination Methods

Solar energy desalination is a method by which the sun’s energy is used to desalinate brackish or seawater to produce fresh drinkable water. There are two methods for using solar energy: directly by heating and evaporating the brackish or seawater in a solar still (this method is called solar distillation) and indirectly by capturing solar energy using one of the techniques that transform solar radiation into thermal or electrical energy to drive a conventional desalination method (the indirect method is called solar-assisted or solar-driven desalination). (more…)

Solar Dryer: Agriculture and Food Drying Systems

Solar dryers are special structures that enhance the drying power of the sun and protect the agricultural product from dust, dirt, and insects. Table below shows a block diagram of an active solar drying system, consisting of solar air collectors, a drying unit or chamber, and an air handling unit. An active solar drying system can accommodate the use of a backup heat source when there in not enough solar heat available. (more…)

Solar Drying: Process, Definition and Background

Drying is one of the most important post harvest steps. It enhances the storage life of the crop products, minimizes losses during storage, and saves shipping costs. The drying process is the removal of water from the wet surface of the food. In this process, heat is transferred by convection and radiation to the surface of the produce. This heat raises the temperatures heat and evaporates the moisture from the exterior of the agricultural products, diffusing the interior moisture to the surface and replenishing the evaporated surface moisture. (more…)

Solar Distillation Process

Solar distillation is the process in which solar heat is used to purify water from an impure water source by evaporation and condensation. When solar distillation is used to purify water from saline water, the process is also called solar desalination. Desalination converts saline water with high salt content, about 3.5% by weight in seawater and about 0.6% in brackish water, into fresh water suitable for drinking and other purposes. Use solar energy can be used for desalination, either as thermal energy through the use of solar thermal collectors or solar ponds, or as electricity. mainly through the use of photovoltaic cells. (more…)

Earth’s Warming and Cooling Cause by Natural Factors

Earth’s climate is a complex system of interacting natural components. These components include the atmosphere, the ocean, and the continental ice sheets. Living things on earth—or, the biosphere—also constitute an important component of the climate trends system.

Numerous factors influence Earth’s climate system, some of them natural. For example, the slow drift of continents that takes place over millions of years, a process known as plate tectonics, influences the composition of the atmosphere through its impact on volcanic activity and surface erosion. (more…)

Solar Tower: Wind and Solar Combination

The solar technology is not only in the flat solar collector or photovoltaic panel. I follow the process ID and proof of this is the prototype plant to produce solar electricity. (more…)

Causes of the Greenhouse Effect

causess greenhouse effect
Since preindustrial times, ambient concentrations of the greenhouse gases have exhibited substantial increases, inter alia CO2 by 30% to about 360 parts per million (ppm), CH 4 by 145% to more than 1700 parts per billion (ppb), and N20 by 15% to more than 300 ppb. The growth rates in the concentrations of these gases in the early 1990s were lower than predicted; while subsequent data indicate that the growth rates are comparable to those averaged over the 1980s. (more…)

Greenhouse Effect and Global Warming

greenhouse effect global warming
Since the early 1960s, climate change and air quality have become major and often controversial issues in many countries and among groups from governments to various scientific communities. Prominent among these issues is the greenhouse effect, in which the gradually increasing tropospheric concentrations of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N20) are believed to trap an excessive amount of solar radiation reflected from the earth. (more…)