How many protons does it take to turn on a light bulb?
Laurel Schmidt
Solar energy has the potential to become a major source of energy in the future as we move to a clean energy economy. In this talk, we will examine how energy travels from the Sun to a light bulb, determining how many protons must react every second in the core of the Sun to power a light bulb. Within the Sun, energy is generated in the core through fusion reactions, transported to the photosphere through radiation and convection, and converted into black body radiation. This radiation is modified through reflection and scattering as it travels through Earth’s atmosphere to Earth’s surface, where its energy can be captured by photovoltaics. The direct current produced by the photovoltaics is converted to alternating current by inverters and transformed to higher voltages to minimize losses during transmission. This current eventually heats up the tungsten filament in a light bulb, producing light. Examining these steps in more detail can shed some light on which steps in the energy flow should be targeted to make solar energy more efficient.