Sunday, December 14, 2008
Everyone knows that additional carbon dioxide in the atmosphere is a terrible thing. For example, at concentrations of 7%, which is only 6.97% higher than the current level, people experience "dizziness, headache, visual and hearing dysfunction, and unconsciousness within a few minutes to an hour (reference)." So clearly we need to do something about the problem now, before unconsciousness happens.
The question is what to do. The internal combustion engine in most cars today runs at about 20% efficiency. That means for every 10 energies that are produced, 8 of them are wasted. 8 of them!
In contrast, consider electric cars. Most electric power in the U.S. is produced by coal fired power plants, the turbines of which run at about 35% efficiency. This is higher than 20%, and in this context higher is better. Of course, your car isn't plugged in to the turbine, so when the power is transmitted it loses another 7% along the way. Oh yeah, and then batteries are only 80% efficient, so then it loses another 20%. And I almost forgot, coal produces way more CO2 per pound of energy than gasoline.
Wait a second, actually now that I think about battery powered cars don't seem to be that great of an idea.
The question is what to do. The internal combustion engine in most cars today runs at about 20% efficiency. That means for every 10 energies that are produced, 8 of them are wasted. 8 of them!
In contrast, consider electric cars. Most electric power in the U.S. is produced by coal fired power plants, the turbines of which run at about 35% efficiency. This is higher than 20%, and in this context higher is better. Of course, your car isn't plugged in to the turbine, so when the power is transmitted it loses another 7% along the way. Oh yeah, and then batteries are only 80% efficient, so then it loses another 20%. And I almost forgot, coal produces way more CO2 per pound of energy than gasoline.
Wait a second, actually now that I think about battery powered cars don't seem to be that great of an idea.
