Clearly energy is an important topic. We all like to live with stuff that uses energy: driving, computers, the internet, lights, heating and cooling. So, where does all our energy come from?

First an important note. What do I mean by “come from”? We always see energy being conserved. This means that the total energy before something happens is the same as the total energy after something happens. Suppose I drop a ball of clay onto the ground and it goes “splat”. Right before it hits the ground, the ball has kinetic energy. However, after the “splat” the ball is stopped. The total energy is still the same, it is just in a different form. In this case, the clay changed shaped, warmed up and the collision made a sound. If you could measure all of these values, you would see it is the same as the initial kinetic energy.

So, let me look at some of the common power production sources (see, I just implied that the energy is produced – which it isn’t).

There are a couple of ways solar energy can work. The common method is a device that produces an electric potential difference when light hits it – you know, solar panels? There are other ways to use solar energy though. One such way takes mirrors and focuses the sunlight to a particular point (like a solar oven). At this point, you can increase the temperature of something and use that to generate electricity in a similar manner to fossil fuel power (see below).

So, where does this solar energy come from? For now, let me just say “the Sun”. Duh.