http://barmersolar.blogspot.com
http://renewableenergyconsult.com
Solar basics: The sun is unlimited source of energy. Trillions watts of solar energy is generated due to nuclear fusion of hydrogen atoms. Produced heat by fusion heats the outer surface of the sun. From outer surface also called chromo sphere heat or energy reaches to outer layer of earth’s atmosphere by radiation. Chromo sphere is just like a hot body having temperature more than 5800°K (0°C is 273°K and 100°C is 373°K). Each and every time 1366 watts per meter square (1366w/M^2) energy comes at the outer atmospheric layer of earth. The solar energy is made of tiny waves having size in nm (1 neno meter = 10¯9 Meter). The composition waves or rays are 7% ultraviolet rays (UV), 46% visible rays & 47% infrared. The size of ultraviolet rays are 0 to 280 nm, visible rays are 280 nm to 780 nm & infrared 780 nm and above. Out of energy reached at the outer atmospheric layer of earth, some reflects back to sky, some absorbed by the atmosphere and remaining about 1000 watts/M^2 reaches to earth's surface. The sky is seems blue due to reflection of ultraviolet rays(UV).
http://renewableenergyconsult.com
Solar basics: The sun is unlimited source of energy. Trillions watts of solar energy is generated due to nuclear fusion of hydrogen atoms. Produced heat by fusion heats the outer surface of the sun. From outer surface also called chromo sphere heat or energy reaches to outer layer of earth’s atmosphere by radiation. Chromo sphere is just like a hot body having temperature more than 5800°K (0°C is 273°K and 100°C is 373°K). Each and every time 1366 watts per meter square (1366w/M^2) energy comes at the outer atmospheric layer of earth. The solar energy is made of tiny waves having size in nm (1 neno meter = 10¯9 Meter). The composition waves or rays are 7% ultraviolet rays (UV), 46% visible rays & 47% infrared. The size of ultraviolet rays are 0 to 280 nm, visible rays are 280 nm to 780 nm & infrared 780 nm and above. Out of energy reached at the outer atmospheric layer of earth, some reflects back to sky, some absorbed by the atmosphere and remaining about 1000 watts/M^2 reaches to earth's surface. The sky is seems blue due to reflection of ultraviolet rays(UV).
In broad classification solar energy is used in electric generation and heating systems. Further electricity
generation is done by two different processes by photovoltaic cell & solar
thermal. Solar heating is used in solar coolers, water heating, incineration of
liquid & solid waste, vapour absorption refrigeration and air conditioning,
space heating etc.
Definitions: Two dimension Geometry is used in solar
system. The systems of measurements are Cartesian
Coordinates & Polar Coordinates.
All the measurements are taken from observer (the place where we are standing
for measurements). These coordinates length and breadth can be measured by tap (in
feet or meter), angle by inclinometer or GPS.
Latitude: Consider the Earth as a
circle. Draw a line through a centre of circle, it meets at the points on the
periphery of circle at two points, say them N and S. Draw another line
through centre “O” perpendicular to NS,
it is E and W. “N” denotes the North pole of Earth and “S“ denotes the south
pole of Earth. “E” denotes for east and “W” denotes for west. I am living at
Barmer (Rajastahn)- India situated at point “P” on the periphery of circle
between point NE. Draw a line from point “O” to “P”. Now the angle APOE is 25°46’( 25 degree and 46 minutes). This
is the Latitude of Barmer called by name 25°46’N. Point EW lies on
Equator and is “zero” Latitude. The upper portion of EW called Northern
hemisphere and lower portion called southern hemisphere of Earth. Barmer is in
Northern hemisphere. We can determine latitude by Google Map.
Longitude: The lines joining North
pole to South Pole is called longitude. Zero time or zero longitude passes
through “Grean Which” in the England. The world standard time is GMT (Green
witch mean time). The periphery of earth is divided in 360°. The earth rounds
in its axis in 24 hours. Thus the each degree of rotation is 4 minutes. The
lines eastward of this line are East longitude and of it are western longitude.
Indian standard time is at 82°30’E longitude. It means if GMT is 2.30pm than
IST is 8.00pm(difference of +5.30 hours). Our Barmer (Rajasthan)-India is
71°41’E
Location of site: The location of any place is determined by Latitude &
Longitude. The location of Barmer is (25°46’N, 71°41’E)
Azimuth Angle: The plan perpendicular to
the line joining the sun is divided in 360°.If you are in space and visiting
Earth. Divide the Earth four points NESW . The azimuth angle at North is zero,
at East it is 90°, at South it is 180°, at West it is 270° and again North it
is 360° or 0°. Generally for measurement
purposes azimuth angle is taken 0°.
Solar Noon: It is also called mid day.
To find the mid may take a difference of sunset and sunrise times, divide by
two and add to sunrise time.
Hour angle: The solar time is
represented by angle. 24 hour time is divided in 360° and 1 hour is 15°. At
solar noon hour angle is zero.
True South and True North: There is difference
between geographic north and magnetic north. But for lower latitudes it is
almost same. We can find the True south & True north without compass box.
At the solar noon erect a 5 to 10 feet rod vertical to the earth. The shade of
rod will be in the south and north.
For more accuracy one can go to the site:
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Zenith angle: It is the angle between line joining the observer to Sun and
vertical line from Earth. If the sun is exactly above the observer head than
the zenith angle is zero. At sun rise and sun set it is 90°. It is a function
of azimuth angle and altitude angle.
Altitude angle: The angle between the horizontal line from
observer to line joining sun. It is zero at sunrise and sunset.
Example: The altitude angle at solar noon on 21st
March is =90°-Latitude of that place. For Barmer it is (90 - 25°46’ = 64°14’).
On 21st December (64°14’-23°45’ = 40°29’). The value 23°45’ is the
inclination of earth axis. Two positions 21st March and 21st
September are called spring and fall equinoxes. On these days night and day
both are equal on any part of the Earth. 21st December and 21st
June are winter and summer Solstices.
Normal radiations: It is the radiation from sun is vertical
line joining the sun and observer. The sun should be over head the observer.
Diffused radiation: These are deflected radiation from
atmosphere, snow, water, clouds.
Global Radiation: It is the total radiation. Add of
Normal radiation and diffused radiation.
Solar
cell:
