Chronicles of a Medical Education: Field trip to the power plant

I have officially started my studies for my master's in tropical medicine and hygiene (which is a master's in public health, plus extra courses in tropical medicine and international health). No, I am not doing things out of order with my education--the MTM&H is, in fact, only offered to physicians, because there's so much clinical stuff that requires a med school background.

Anyway, this is the pre-fall quarter, which is a half quarter (the year will end with another half quarter in the summer); it's only six weeks long, and it's pretty much just the basics. We have Intro to Public Health, Computer Systems in Public Health, Social and Behavioral Sciences, Selected Topics in Occupational Medicine, and Intro to Environmental Health. The fun thing about the environmental health class is that we have field trips every Tuesday and Thursday.

Yesterday was our first field trip, to Mirant power plant in Alexandria, VA. It's a coal plant (half of the nation's electricity still comes from coal; sadly, very few people have the fortune of living in the Pacific Northwest and getting hydroelectric power). Here's the basics of how electricity gets from coal to the home:

1) Coal is burned, which boils water to make steam. The steam then turns the turbines, which makes electricity.

2 and 3) The electricity is sold to Pepco (which I think is the only power distributer in the area), and transmission lines carry high-voltage electricity to load centers

4) Distribution centers lower the voltage

5) Power cables transmit lower voltage electricity to homes and businesses (and the Pentagon)

Since it is an environmental health class, we spent quite a lot of time discussing air and water pollution. One thing that I was very fascinated by is that the emissions are completely invisible--it looks like there's nothing coming from the stacks (the two active stacks are circled in black). The steam, which is the real driving force (it turns the turbines and makes power), doesn't really escape in visible quantities, either.

Here's a timeline of energy sources for our country (energy sources, not electricity sources... we use a lot of petroleum, but that's for driving, not turning on light switches). Like I said, most electricity comes from coal, which natural gas also playing a large role. Nuclear is next, renewables below that, and hydroelectric is rather low. And sadly, there's no room to increase that number (we don't have enough fast-flowing rivers like the Columbia)

And here's a picture of the power plant from the Potomac River. It's literally right on the river, and right across the street from the residential areas of Alexandria, sitting on about 23 acres (very small for a power plant)