Electricity is so important in the development of the civilization of our mankind.

However,the traditional fossile plant electric energy generation inherently produces substaintial amount of carbon di-oxide.

Which in turn causes the global warming of the earth and severe climate change.

On the other hand ,though the electricity from nuclear energy is clean without carbon di-oxide emission,it brings the serious concern of nuclear safety issues.

Historically,the chernobye nulear accident and Fakushima Daiichi accident have caused a lot of the life and financial loss.

Not to mention that the spent full rods produced by the nuclear power generators are putting a threat of nuclear weapon proliferation and the difficult final disposal method searching.

Therefore,we belive that we must develop the usage of renewable energy to support a better quality and sustainable life .

Among the technologies of renewable energy production,we focus on the solar photovotaic electricity generation .

Although the energy density of solar irradiation is relatively small,it is usable and viable everywhere on the earth.

As long as we use it correctly combined with good energy saving measures ,a civilization can be sustained for many generations to come without causing environmental impact to our mother earth.