[NeilBlanchard]

Biodiesel certainly has a chance to be greener than battery powered cars, using our current grid, etc. But, I doubt they included anything other than the actual diesel fuel itself; whereas the electric numbers had to include all the embedded energy.

Oil has a lot to account for:

Exploration is getting harder all the time; and can take years; and lots of energy is consumed doing so.

Drilling is very hard to do, and takes a lot of energy, including making a lot of "drilling mud", which takes a lot of energy to make, and to inject deep down underground. Look it up! The BP drilling rig is nowhere the deepest at ~23,000 feet below the surface of the ocean.

Extraction takes a lot of electricity (with all of it's overhead!) -- possibly more than refining(!); never mind the energy to build and move and operate those gigantic oil rigs.

Transportation to land is expensive, and super tankers burn a lot of fuel, with it's overhead of embedded energy. The routes taken now have to be lengthened to avoid pirates, and pipelines are hard to build and maintain.

Oil then has to be pumped into tanks onshore for storage, and/or into pipelines. Any energy used along the way has it's own overhead of embedded power.

It then has to be transported to refineries; burning more fuel with it's embedded overhead.

Refineries use a lot of electricity (and all it's overhead!) and they use a lot of natural gas to heat the oil, in a process that takes days. There is a lot of blending and other chemicals used, all of which that have to be made ahead of time, using yet more energy and all of it's overhead. The various fuels and by products are then pumped again to storage tanks.

Then the gasoline/diesel is pumped and transported using pipelines, trucks, and trains, burning more fuel and using electricity, added yet more to the overhead.

It then has to be pumped into the storage tanks at the filling stations, and then pumped out again into the cars, using more electricity, adding that overhead of energy.

I HAVE PROBABLY OVER SIMPLIFIED THIS LONG AND ENERGY INTENSIVE PROCESS.

Electricity from coal, on the other hand is fairly easy: mining takes a lot of effort and energy, then moving it around in the storage yards, then transporting it on trains, then moving it on storage yards, then burning it, and disposing of the ash waste.

Electricity generated from natural gas is more similar to making gasoline/diesel, except for the refining stage.

Grids losses are not as bad as you might think: the average is a bit less than 8% loss on the grid. Any and all of the overhead for electricity that is used at all the various stages along the way to produce oil -- get added to the oil! So, the 7.5kWh PER GALLON of gasoline could instead just be used directly to move a car 30-60 miles *rather* that making the gasoline.

By rights, we should also include the military used to defend and maintain our access to oil, and maintaining stability in oil prices. There are huge hidden subsidies in foreign policy, too. Don't fool yourself to think that much of our battle with terrorism is tied to this whole messy and corrupt situation. Do you know how much oil gets stolen in the Congo or in Iraq?

I almost forgot -- it isn't just the fuel! ICE engines require a lot of lubrication and maintenance: you have to add in all the steps to find, produce, transport, store, refine, store, transport, use, then dispose of the engine oils used in the ICE. So, many of the same steps I listed above have to be repeated for the other consumable carbon based things used by ICE machines, including the lubrication oils and the filters, etc. This accumulates even more carbon footprint.

Electricity can come from renewable sources: solar PV, solar heat, wind power, geothermal (by drilling deep holes!), biomass (methane from plant and animal waste and others), wave power, tidal power, small scale hydro, etc. The more we use of these, the smaller the carbon footprint becomes in the future, as we make the new wind turbines from renewable energy, and so on, and so on.

All of these use energy from our sun, in one form or another -- much more directly that oil an gas.

Each gallon of petroleum fuel represents ~100 TONS of biological material, that is millions and millions of years old. We are squandering it -- using so little of it potential. We should use it only when absolutely necessary.

We *must* think very long term, if we are to survive on this Eaarth we share. We can live without a lot, but we cannot live without the Eaarth.