With fluctuating energy prices and concerns over global warming, solar power as a renewable energy is being seen in a new, more urgent light. We will explore the emerging world of Concentrated Solar Power (CSP), an evolving technology that concentrates the sun’s rays to heat liquid to extreme temperatures, in turn creating the power for electricity. New solar fields going online in Nevada and elsewhere are racing to tap the sun’s energy in more efficient ways. But the technology is still entirely dependent on one unpredictable factor: a sunny day. So, scientists are investigating ways to store solar heat so this green energy can be relied upon, whether rain or shine, day or night.