solar energy

presented by group iv

ramir angeles marvin veran lea alonzo

kyra sandejas caisa subia

the sun

yellow dwarf star in the center of the solar

system

diameter = 1,392,000 km, 109 times of earth’s

mass = 2×1030kg, 330,000 times of earth’s

99.86% of the solar system’s total mass

¾ hydrogen, the rest is mostly helium

primary source of energy in the earth

solar energy

the earth receives 174 petawatts [1015 watts] from the sun

30% is reflected into space and the rest is absorbed by land, oceans, clouds etc.

the total energy absorbed by earth’s atmosphere, oceans, land mass is 3,850,000 exajoules [1018 joules] per year

energy entering the earth from the sun is twice the energy harnessed from all non-renewable sources of energy combined

photovoltaics

generating electrical power by converting solar radiation into dc electricity using semiconductors that exhibit the photovoltaic effect

The photovoltaic effect is the creation of voltage or electric current in a material upon exposure to light

first observed by Alexandre-Edmond Becquerel in 1839

the photovoltaic cell

also called solar cell, is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect

made of monocrystalline silicon or polycrystalline silicon or amorphous silicon or cadmium telluride, or copper indium selenide/sulfide

first built by Charles Fritts in1883 by coating the semiconductor selenium with an extremely thin layer of gold

the photovoltaic cell

the photovoltaic cell cont.

photons in sunlight hit the solar panel and are absorbed by semiconducting materials, such as silicon

electrons are knocked loose from their atoms, and current starts flowing through the material and this electricity is captured

an array of solar cells converts solar energy into a usable amount of direct current [DC] electricity

“nellis solar power plant” contains 70,000 solar panels that will generate 25 million kilowatt-hours

“solar one”, california 1,800 sun-tracking mirrors reflect heat to a central collector

a solar farm in the philippines…

pisay

advantages

solar energy is a renewable source of energy

in the presence of solar power, use of non-renewable sources of energy like petroleum can be lessened which also lessens pollution

unlike others, solar energy can be harnessed and used in remote locations like mountains

even though solar panels are expensive, the total amount that would be saved makes the price of the panels will seem small

disadvantages

solar panels are expensive solar power is inefficient in cloudy

areas batteries and solar panels occupy more

space solar power maintenance is a problem

especially to those who doesn’t know the proper technician

disposal is difficult for the batteries and solar panels when they have broken down because they contain toxic chemicals like lead, sulfuric acid & cadmium telluride

sources

http://www.solarenergy-solarpower.com

http://www.wikipedia.org [wikipedia]

http://www.google.com [google images]

the world of science, vol 10, technology of change