WHAT is solar energy?
- light and radiant from the sun
- heat and electricity generated from solar radiation
- a renewable source of energy
- an Inexhaustible fuel source that is pollution and noise-free
Solar energy use has been increasing at 20% annually in the past 15 years
Japan held 50% of the global solar cell market, but this is now down to about 20% as
more companies from different countries enter the market.
HOW does it work?
‘Photovoltaic’ means electricity produced from light
Photovoltaic systems are solar panels that convert sunlight directly into electricity - When
sunlight hits the cells, it knocks electrons loose from their atoms. As the electrons flow through
the cell, they generate electricity.
Advantages
●
Reduction in pollution. It does not create greenhouse gases such as oil based energy
does. It is far more quiet, reducing noise pollution required to convert energy to a useful
form.
●
Residential size solar energy systems have very little impact on the surrounding
environment (while wind/HEP requires larger amount of land)
Passive solar energy buildings
●
●
●
Renewable: available for collection each day
Lower energy cost: Necessary equipment can be expected to last for decades with only
minimal maintenance--->not much ongoing operational expense
To become less dependent on a scarce/ non-renewable resource
Disadvantages
●
●
Solar energy depends on the climate. An unreliable climate also means that solar energy
is unreliable as cloudy skies decreases the effectiveness.
Solar energy can only be harnessed during sunny daytime.
○ Would require energy collectors to store energy in order to be used at night
■ We could not be 100%
powered by solar panels
● Solar energy collectors requires batteries to
operate and these batteries are often large in size,
takes up space and needs replacing from time to
time
● Expensive for initial installation
● Large-scale solar power stations does not
match conventional energy stations in output or
costs
An example of large scale solar power
New scientific development of solar panels:
A number of companies are now using a new technique and material to manufacture solar
panels using different materials and building them in very thin layers.
This eliminates the costly problem of traditional solar panels due to:
● Less materials usage
●
Can be applied on bases like plastic, glass or metal, which traditional solar panels
cannot be used on
The new material used is copper indium gallium selenide
Major development in the use of solar energy:
1. USA’s “Solar Grand Plan”
● Unveiled in 2005
○ aim to end US dependence on foreign oil and fossil fuels
○ aim to provide 69% of USA’s electricity
However,
○ 30,000 square meters of land is needed
○ US government would need to invest over $400 billion over 40 years to
sustain development
2. Pacific Gas and Electric Company in California:
● signed the world’s largest solar energy deal
○ Produce three solar thermal plants
○ $2 to $3 billion deal to provide further plants to increase production
capacity
■ To provide energy for over 300,000 Californian homes
○ Build plants on Mojave Desert