Energy shortage is a huge problem for modern society, and it has a negative impact on people's daily life and economic development. Many elements account for energy shortage. Firstly, rapid economic development prompts an increase of energy consumptions in different industries. Secondly, population growth creates greater demands for household energy usage. Thirdly, people have yet to develop the sense of energy conservation. Actually we can do a lot to save energy in daily life. Turn off lights and fans when nobody is in the room; design buildings with the concept of energy saving; use public transit instead of private cars in rush hours... It is very easy for us to do these things as long as we have the sense of energy conservation, and we should do it right now!