The sun radiates more energy than the world can use in one year.
The sun is a star made up of hydrogen and helium gas. It produces radiant energy in a process called nuclear fusion.
Harnessing radiant energy from the sun is difficult because the energy that reaches Earth is very spread out.
Only a small amount of solar energy is radiated to earth.
It takes the suns energy just over 8 minutes to travel 93 million miles to Earth.
Fact/ Advantage/ Disadvantage
Solar energy is a renewable energy source.
Solar energy is used to heat passive solar buildings and water to generate a small amount of electricity.
The amount of solar energy reaching an area depends on the time of day, season of the year, cloud coverage, and geologic location.
Solar water heaters can reduce energy bills by half when installed.
A solar collector can be used to capture sunlight and change it into useable heat energy.
An active solar home in the Northern Hemisphere uses special collectors facing the south to absorb sunlight and change it to heat. Air or water flows through the collector and is warmed by the heat.
Passive solar homes do not depend on mechanical equipment to transform radiant energy into heat energy.
Photovoltaic cells can convert radiant energy from the sun directly into electricity.
Photovoltaic comes from the word "photo", meaning light, and "volt", meaning electricity.
Photovoltaic - or PV - systems have long payback periods.
False (They only take 1-3 years) /Advantage
Small PV cells are used to power roadside telephones, calculators, and toys.
Crystalline silicon PV cells convert about 16 percent of the energy they receive into electricity.
False (Over 16%)/Advantage
Electricity from PV cells has a price range of $0.12-0.30 kWh. The average cost of electricity (Mostly from fossil fuels) is about $0.117-0.12 kWh.
Large solar systems can take up a large amount of land or can be placed on large flat roofs.
Solar energy does not pollute the air.