what extent solar power can meet the energy needs of the US and China in the next several decades

1: An introduction, which defines the question clearly, including a brief description of the different forms of solar power and the physical processes involved in extracting useful energy from sunlight.
2: A middle section, presenting facts relevant to the question, including expected energy needs, estimated from the textbook and elsewhere, with sources properly referenced; an estimate of the amount of energy available from sunlight; and the efficiency of the different forms of solar power currently in use. Discuss the shortcomings of solar power and the means that might be used to address them. Use the principles you have been learning in class to make estimates, and compare those estimates to the information you can find in the library or from the textbook (again, properly sourced).
3: A concluding section, in which you draw the best conclusions you can, based on the information from Section 2. Can we rely on solar energy for a significant fraction of our energy needs in the future? Can we rely on it for all of those needs?