Energy-basis of car,modern appliances,... is bening ran out more and more.Peoplle nowasdays don't think too much about the energy,they think when they pay money,they can use it forever.But they wrong,and energy also make the air pollution increase.For example,every year,humans use about 14 x 10^16 kWh,and most of them a coal,oil-about 90 percent,which are making the earth more dirty.You are thinking about nuclear ?No,it's not a good choice because it's so dangerous and can't still for long time.Hmmm,Water energy???It's make the weather in the country change and the water we use make energy is clear water,not water from sea,,and clear water are only 1% in the earth right now.For the surmount,energy from Sun,Wind is the most effective to help the earth.So from now,you can help the earth by using less dirty energy and using more clear energy .

Solar energy captured by solar panels is a limitless form of energy, as the earth is bombarded with extreme amounts of solar energy every day, according to the National Renewable Energy Laboratory. It's also clean, producing no carbon dioxide, and is very low-maintenance, since solar panels have no moving parts.

Unfortunately, the National Renewable Energy Laboratory says its high installation cost makes it up to four times more expensive than the cost of electricity from a standard utility company. For optimal operation and maximum energy production, it requires year-round sunny weather and is very expensive if repair is necessary, according to the U.S. Environmental Protection Agency.