Energy Sources
I remember coming across an exchange a long time ago in a blog or newsgroup in which one poster was pointing out that consumers received less energy than was available in the amount of coal burned, and that this was proof that we are losing energy. A respondent pointed out that energy must always be lost when transforming from one form to another. That's true, but the problem is that the forms of energy we currently use to "create" electricity (yes, I know, I know) aren't sources of energy, but rather stores of energy. This outline might help students to the energy debates place energy sources conceptually:
Sources:
For use in transportation systems, we can either hook the system to the grid (electric trains) or carry energy in some sort of transportable form (fuel or batteries). Fuel happens to be a very good way to both distribute and carry stored energy because it is very compact. Batteries and electricity are not as efficient. I recall reading one time that if you tried to fill up electric cars at the same rate as you add energy into standard gasoline powered cars, the grid would only support a few cars at a time (few as in only 5-10 cars in NYC at one time).
[Update: I did the calculations using the energy content of gasoline and the assumption that the average consumer pumps 15 gallons of gas in 5 minutes. That's 1,963 MJ in 300 seconds, approximately 6.54 MW. The Indian Point Nuclear Plant has two generators capable of 971 and 984 MW capacity. Less than three hundred cars could fuel up at any given time. Since they already run at 98% and 88% capacity, the real number of cars that could fuel would be much less at peak hours. You could fill about 570 cars off the Palo Verde plant's three generators. Also, to replace a 100 hp engine (not very large), you would need a 75 kW motor. That's pretty large for a dc motor, especially running about 1681 rpm or so (that's what it would take to go 120 mph in a direct drive vehicle with a 2' total diameter). I think the real problem with dumping that much energy into a vehicle in 5 minutes is going to be the current required; most people won't be able to lift the cable(s).]
That's a problem, but it doesn't completely negate the idea of electric vehicles. After all, you could plug in and trickle charge both at work and at home (and at the supermarket, the fuel station, etc.). Furthermore, people have suggested other means of getting electricity into the car, including solar, fuel cells, and trading batteries at the future version of a gas station. In fact, it has been widely suggested that you could fill a fuel cell car with hydrogen from a filling station, and then plug the vehicle in at your destination and use it to power the grid. Pretty cool, if you can pull it off!
Sources:
- Solar
- Nuclear
- Gravitational
- Petrochemicals (oil, coal, natural gas)
- Chemical
- Natural
- Biomass
- Manmade
- Batteries
- Fuel (gasoline)
- Non-chemical
- Wind
- Tide
- Capacitors
- Electricity (the "grid")
- Fuel
- Natural gas pipeline
- Gasoline and diesel distribution system
For use in transportation systems, we can either hook the system to the grid (electric trains) or carry energy in some sort of transportable form (fuel or batteries). Fuel happens to be a very good way to both distribute and carry stored energy because it is very compact. Batteries and electricity are not as efficient. I recall reading one time that if you tried to fill up electric cars at the same rate as you add energy into standard gasoline powered cars, the grid would only support a few cars at a time (few as in only 5-10 cars in NYC at one time).
[Update: I did the calculations using the energy content of gasoline and the assumption that the average consumer pumps 15 gallons of gas in 5 minutes. That's 1,963 MJ in 300 seconds, approximately 6.54 MW. The Indian Point Nuclear Plant has two generators capable of 971 and 984 MW capacity. Less than three hundred cars could fuel up at any given time. Since they already run at 98% and 88% capacity, the real number of cars that could fuel would be much less at peak hours. You could fill about 570 cars off the Palo Verde plant's three generators. Also, to replace a 100 hp engine (not very large), you would need a 75 kW motor. That's pretty large for a dc motor, especially running about 1681 rpm or so (that's what it would take to go 120 mph in a direct drive vehicle with a 2' total diameter). I think the real problem with dumping that much energy into a vehicle in 5 minutes is going to be the current required; most people won't be able to lift the cable(s).]
That's a problem, but it doesn't completely negate the idea of electric vehicles. After all, you could plug in and trickle charge both at work and at home (and at the supermarket, the fuel station, etc.). Furthermore, people have suggested other means of getting electricity into the car, including solar, fuel cells, and trading batteries at the future version of a gas station. In fact, it has been widely suggested that you could fill a fuel cell car with hydrogen from a filling station, and then plug the vehicle in at your destination and use it to power the grid. Pretty cool, if you can pull it off!
Labels: energy
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