For the IEA this is being radical and going out on a limb! The realities of oil prices, availabiltiy and security will have their impact long before 2030. I'd be willing to bet we'll have been forced further towards biofuels, electrical and maybe even fuel cells long before 2030.

Predictions can be very difficult, especially those about the future - Niels Bohr. Here's my own hunch for the next decade or so:

First: NOx store, SCR and wall-flow DPFs plus ULSD alone are giving regular ICEs a second lease of life. Together with direct injection, managed turbochargers and more sophisticated engine control, stratified GDI and clean diesel will fairly soon become must-have options for all car brands in Europe as well as the US, Japan and other countries. Purely mechanical transmission choices will shake out to manuals, AMTs and ATs with bypass clutches as carmakers squeeze their supply chain to contain costs.

Second: refineries will enforce biofuel standards and slowly raise blend level iff required to do so by law. High blends will enjoy significant market share in certain areas only. Ethanol will play a growing role as EROEI is improved and the logistics problems are solved with new technology/process management. Biobutanol is a wildcard to watch. Biodiesel will make even greater inroads, especially in countries near the equator. Europe may have to increase its xTL production capacity as it shifts from oil to gas and biomass to manage its energy supply risks.

Third: innovations in battery chemistries are pushing the envelope faster and further than anyone thought possible even a few years ago. If the new US Congress is smart, it will steer R&D grants for the Big Three away from hydrogen/fuel cells and electrified drivetrains, because they can deliver greater benefits (energy security, CO2 mitigation) on a far broader scale much sooner, at comparatively low risk. Unfortunately, affordable PHEVs and BEVs technology will be available long before it can be adopted in the numbers needed to bring prices down - investments in power plants and distribution grids are expensive and have long lead times due to rampant NIMBYism.

The speed at which these three simultaneous transition will happen depends primarily on supply, demand and the perceived risk of crude oil. OPEC countries are anxious to keep the world addicted to their black gold for as long as possible. Iraq may quiet down a year or two, but only if both Iran and Saudi Arabia et al. decide to accept a stalemate in their proxy war rather than risk having the chaos spill over the borders. Right now, Iran has too little to lose.

If the US engages with Iran, I expect crude oil will remain the dominant energy source for transportation, as gasoline and diesel ICEs continue to improve. Biofuel contribution will stay below 15%, and most hybrids will be stop/start or mild versions due to stubbornly high system cost. Hydrogen will become a white elephant.

If the US further antagonizes Iran (and others like Venezuela), biofuels and hybrids will feature more heavily. NIMBYs will be overruled to enable a new generation of nuclear power plants to be built, even though the waste problem remains unsolved. Distribution grids in the US and Europe will be beefed up accordingly and PHEV/BEV solutions get adopted. Hydrogen will still be a damp squib.

Rafael:

I am wondering how many millions of dollars IEA would burn to come up with analysis you just provided for free? Seriously.

Couple of comments, thought:

Biofuel contribution probably will stay below 10%, not 15.

Most probably you overestimate the role of US foreign policy on future of oil.

Mild and stop-and-go hybrids will be only marginally cheaper then full scale hybrids when mass-produced, especially if R&D and re-tooling costs will be eventually written-off.

The beauty of PHEV is that it does not require massive investments in infrastructure.

Nuclear power in Europe? Pipe dream (except France, of course).

Additional wild guess: LED lighting.

Mild hybrids would need to represent 60% of global new light-duty vehicle sales in 2030 - that would be an awesome 70th birthday present for me :)
The new dem congress is going to have to start talking up a carbon tax for 2008!

Raphael:

"there is the question of whether voters will accept the CO2 impact of shifting from oil to coal as the primary energy source for transportation."

I assume you are talking about CLT.

BEVs (and PHEVs) running on electricity produce less CO2 than gasoline ICE cars.

Even if we exagerate and say that electricity from coal generates twice as much CO2 as electricity from petroleum (probably closer to 20% more - http://www.eia.doe.gov/cneaf/electricity/page/co2_report/co2report.html)
and that an ICE car only produces as much CO2 as using petroleum to generate electricity (highly unlikely), the fact that BEVs are at least twice as effecient as a gasoline ICE car http://teslamotors.com/display_data/21stCentElectricCar.pdf) means that a switch to BEVs have the equivalent CO2 emissions even in the worst case. Never mind the fact that electricity from other sources is cleaner.

Please excuse the run-on sentence.

Rafael:

Your forecast may be better than many but you seem to under-estimate the rate of development of electicity storage devices.

If our governments decide (under pressure from voters and for environmental reasons) to stop the huge give aways (tax credit and various incentives) to Coal, Oil and Natural Gas producers and redirect the same funds to the development of low cost storage devices + wind, solar and wave energy + PHEVs and BEVs + power grids upgrades + V2G programs... the transistion could come much sooner, even without other OIL wars.

Of course, two or three new OIL wars would force the price of oil over $100/barrel and accellerate the development of alternative energies. However, one Irak fiasco is enough for any adminstration to live or die with and one may have doubts about the success of another similar war.

We need some kind of international Marshall plan to transistion from dirty fossil fuel energy to clean mostly electrical energy economy.

Andrey -

the common elements are all commodity items running on a 12V grid. A full hybrid absolutely needs a second, high-voltage grid with all the associated safety issues (e.g. 240V battery, 400V grid, 650V electric motors in Toyota's current solution) plus sophisticated integrated drivetrain management. A chain of electrical/power electronics equipment rated at 50kW really is a lot more expensive than a 2kW belt alternator-starter. All you need for that is a beefier 12V battery, yielding far better total cost of ownership for the customer.

Given that the NiMH batteries currently in series production cannot charge up efficiently during recuperative braking (which lasts only seconds, not minutes or hours), the primary incremental benefit of a full hybrid is load leveling of the engine. The losses inherent in the four additional energy conversions limit what is possible, though.

From an energy security / climate change perspective, ten million cars with BAS systems would have a much greater impact that one million full hybrids. There are good arguments for requiring carmakers make no-idling functionality an available option on all of their LDV and LDT models by e.g. 2015, regardless of prime mover.

BAS uses a 48 volt system. Very inexpensive to design and manufacture. FFV upgrades cost about $200 per vehicle and every manufacturer knows how to do them. E10 across 100% of the country does more than E85 in 5% of the country. 10 million BAS do more than 1 million hybrids.

I forgot to point out that direct start technology only works for direct injection engines.