I gave a three session course at OSHER, called The Grid: What Your Electricity Bill Won't Tell you.
The first session was an introduction to the course (power and policy) and Howard Shaffer's explanation of the physical grid....that is, electricity and how it flows.
The second session will be about policy and controversies on the grid, and the third session was the guest lecture by Christine Hallquist, CEO of Vermont Electric Cooperative.
Because of the interest in the course, our local Community Access TV (CATV8) station videotaped it, and is also putting it on VIMEO.
I embed the first video below.
Update 2018: The videos still exist, but their URLs have changed. Video link below.