sci.energy

On Aug 17, 8:13 pm, Bret Cahill wrote:
> I just use the oxen to get them thinking about beefing up the grid.
>
> That's where a greater % of our energy will be coming from in a couple
> of decades.
>
> Bret Cahill

Well, a modern version of the oldstyle street-car - or slot cars many
played with as children - is interesting to look at...

Coal fired power plants, are 38% efficient at converting fuel into
electricity, and you're around 82% efficient getting that electricity
to the wheels.. and you can get the equivalent of 120 mpg with a
smaller lighter simpler vehicle (no fuel tank,no fuel system, no
internal combustion engine, no exhaust system) - with 120 MJ per
gallon - that's 1 MJ per mile. A typical ICE operates at 15%
efficiency.. so,we're talking 150 kJ per mile for this electric
vehicle... which means you need about

150 kJ / (.38 x .82) = kJ/mile

A kg of of coal contains 23 MJ of energy - so, 21 grams of coal - is
the fuel cost. This coal produces 75 grams of carbon-dioxide - per
mile. At $50 per metric ton, that's 1/10th cent per mile - in fuel
cost.

An automobile getting 120 mpg paying $4 per gallon pays $ per mile
for fuel cost. At 30 mpg that's more like $ per mile for fuel
cost. And since a gallon of gasoline produces about 9 kg of carbon
dioxide - that means at 120 mpg fuel economy a car releases 75 grams
of carbon-dioxide per mile, and at 30 mpg a car releases 300 grams per
mile.

The infrastructure to produce road powered automobiles can be quite
costly, but the difference in fuel costs can easily pay for it.
Adding a mileage tax of say $ per mile 'wheeling' cost - means
that a million vehicles operating 20,000 miles per year would generate
$180 million per year. This is sufficient to support $2 billion worth
of infrastructure at typical discount rates - and at $200,000 per road
mile, add on cost to create and maintain a powered roadway, this is
enough to support 10,000 miles of roadways for each 1 million
motorists.

Furthermore, the carbon dioxide produced at the power plant could be
displaced one day with hydrogen, or solar power or even nuclear power
none of which emit carbon. And the carbon dioxide is produced
centrally so it can be easily sequestered if that is an issue.

Powered roadways for vehicles - their time has come!

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