Posted 28 February 2012 - 07:17 AM
It is all about Energy Returned over Energy Invested (ERoEI). In the early days of oil, the ratio as 20 to 1, as the oil was close to the surface and easy to get- so for every barrel of oil worth of energy you expended, you got 20 barrels of oil as a reward. The more depleted the source gets, the harder it is to get the oil out (you need to drill deeper, add sea water to improve pressure) and the ratio gets worse and worse. You could have a million barrels of oil sitting underground and it could be worthless if it takes a million barrels of oil to get it all out of the ground.
And here is the problems with alternative fuels-
Natural Gas- America, Mexico and Canada are all past their gas peak, importing more gas than they produce. American gas production is declining at about 5% per year, a rate which is expected to multiply, due to declining supplies of gas. US gas supplies were so low in 2003 the government considere shutting down parts of its gas supplies to customers to triage the situation.
If the gas supplies fall too low, pressures will drop in pipeline networks. If this happens, peoples pilot lights may go out. When pressure is restored, those lights will lead to explosions. Repressurization of pipelines is very difficult and costly.
The costs of transporting gas are astronomical, and can only be done on a large scale.
For america to replace oil with natural gas, it would have to vastly upgrade its port facilities (to incredibly expensive facilities that can change the state of the gas as part of unloading) to bring in the needed gas.
Hydrogen- Hydrogen takes more energy to manufacture than the hydrogen produces. Fuel cells are more a battery than a true power source.
Hydrogen is also extremely dangerous- it takes up alot of space, has to be compressed and stored in high pressure fuel tanks, and it takes alot of energy to compress it. The required carbon fibre tank might even survive high speed car crashes- the plumbing connections wouldnt. The high pressure hydrogen would escape and fill a large area around the crash rather quickly.... and then the hydrogen would self ignite from the heat of decompression.
You know how in the movies the cars always explode on the slightest impact? That isn't unrealistic at all if the cars are hydrogen powered.
Coal-
Coal used to be used for heating, and even powering locomotives, but was abandoned when better alternatives came along- it produces terrible amounts of polluting smoke. We have already mined all of the easy to reach, best quality coal. Most of what is left would be a net energy loss to mine. Coal causes birth defects, asthma and acid rain, and produces alot of waste, and has a crappy ERoEI compared to petrol. It is also only useable in rail transport, not car transport.
Hydro-
This is a good source of electricity for local communities, is useless for transportation.
Solar-
Oil and coal are both essentially solar cell batteries that have been saving up energy for millions of years- this alone shows that solar generators are really damn slow to collect energy for us. You need silicon, plastic and metal to make solar cells, and plastic/lead for the batteries. None of these things are doable without the oil based technological paltform. This is very expensive in energy to put together and is unreliable, with a crappy ERoEI.
Wind-
Everyone should know how bad wind power is by now.
Synthetic Oil-
Requires you to add hydrogen to coal, very expensive and energy intensive to do. The only practical application for Synfuel has been to provide militaries with oil when they are desperate and as a corporate tax scam.
Nuclear-
A must have. It is the only viable power source to keep the lights on when the fossil fuels drop out from beneath us, but it cannot power cars. We cannot produce nuclear reactors without fossil fuel based technology however.
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