Several posts have referred to the “smart grid.” This site in fact aims to help “green the grid.” First, in order to “green it” one must consider what the grid is and what it does. As currently set up, the electrical grid transmits electricity from a power station through a set of wires to various consumers. Some utilities, such as Ameren UE which services parts of Missouri and Illinois, obtain 85% of the electricity generated from coal, because the law requires them provide electricity using the lowest cost source of energy. Across the nation, coal provides more than 48% of the energy for electricity generation. It is a locally available energy source, which is plentiful in the United States. There are several major trade-offs though:

1. Coal is a nonrenewable source of energy which must be extracted from the lithosphere (the outer crust of the Earth).
2. Coal produces an exorbitant amount of waste, including the collection of ash in holding ponds. For the potential side effects, consider the recent breach of the retaining wall in Tennessee late last year.
3. In addition to the waste from the burning of coal, the pollution released into the atmosphere in the form of both heavy metals and greenhouse gases is staggering.
4. Lastly, and perhaps most deceiving, coal is on average only 33% efficient. In other words, of the energy stored in 1kg of coal, only 1/3 is converted into electrical energy. The amount of heat lost to the atmosphere during the combustion necessary to release coal’s energy is roughly double the amount transformed into electricity.

- Eric Wilson

(Note: The 85% figure comes from a personal correspondence with Mr. Timothy Fox at Ameren UE, 2007)