Quote:
quote:Originally posted by JohnM
Quote:
quote:Originally posted by Casey
While there is a shifting of pollution as you describe, it also results in a decrease in pollution per given unit of power generated. It is easier to control particulate and gaseous discharges in a central location than in small individual locations. The main problem with centralized power generation is the huge losses in power lines on the way to the consumer.
Further cleaning up fossil fuel burning automobile exhaust has gone about as far as it can go. Under some situations now, cars expel cleaner air than than take in.
Alternative "clean" energy sources are going to have to replace fossil fuel if they are going to gain further in eliminating air pollution.
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Yet everyone is clamoring for the day when each Segway will have it's own stirling engine. Your centralized pollution control will go right out the window.
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You overestimate the usefulness of the Segway
and the Stirling engine. You still need a heat source to generate the temperature differential required to power the Stirling engine. This requires electricity or fuel cells. Fuel cells require hydrogen or methane. Hydrogen must be generated using electricity or extreme heat. This leads back to my example of a centralized pollution source. Stirling engines still are not very efficient. They are more efficient than motors and combustion engines, but heat (energy) is still lost from the system to the surroundings.
As for automobiles being efficient... I've never heard anything far from the truth. The internal combustion engine is far from efficient. If you calculate the energy released from the combustion of gasoline, with the actual energy used to propel your automobile and used by the alternator, you have extreme amounts of energy wasted as heat. The current gasoline engine is, at best 50% efficient. Current small engines are 15% efficient, with automobile engines being 30% efficient. Less than 15% actually makes it to driving the wheeels.
There exists 43 MegaJoules of energy per every kilogram of gasoline. There is approximately 3 kg of gas in every gallon. Do the math.