The Sun illuminates the Earth with about 174 petawatts -- that's 174 million billion watts! This is about 10,000 times more power than we, as humans, consume via electricity. So why, as you ask, do we have an energy problem? The answer is that, as with all energy forms, it's tricky to convert the Sun's radiant energy into a usable form. One way this is done is by using solar panels, which are often called photovoltaic (or PV) cells. Photons interacting in the PV cells deposit energy and produce a tiny electrical current. By collecting the currents produced by many photons, we can build up enough energy to do useful work. The main two challenges in constructing solar panels, then, are to (1) collect a lot of photons -- for example, by building large panels; and (2) make the PV cells very efficient so that as much energy as possible can be collected from each photon. Constructing PV cells uses a lot of the same principles and techniques as fabricating computer chips, and the technology is evolving rapidly. So if you have a great idea about how to make an efficient PV cell, or how to make one cheaper, this is a fantastic field to go into!