I'm not sure what you mean; cost is inextricably linked to EROEI, and vice versa. It's fundamental. Think about it. That's what cost is. How much work (energy) does it take to produce more energy? This concept is at the basis of ALL life on the planet. It is the deciding factor in how we and all creatures obtain the most fundamental source of energy and energy storage: food. If the cost (1/EROEI) is too high, we don't survive.

And just because the internal combustion engine is inefficient, don't take that to mean that even gross energy from renewable resources can even begin to approach the amount of energy currently extracted from oil in conventional automobiles, etc.- they can't.

As for net gain- of course renewable sources pale in comparison to the EROEI of fossil fuels. While estimations are difficult to construct, optimistic estimates of returns on solar power (which is the best renewable source known) is 10:1 [1]. More pessimistic estimates are more like 1:1 [2].

Biofuels: even if all of the arable land in the United States (including that which currently supplies, you know, food) were devoted to supplanting gasoline production/consumption, we would not scratch the surface of current use [3].

Again, think about it. Fossil fuels represent over 100 MILLION years of compressed, stored sunlight, graciously bequeathed unto us courtesy of the Carboniferous Period, 350 million years ago. It is a very, very potent source of energy. If you think of it in terms of drugs, fossil fuels are like heroin, to renewable energy's sugar pill.

I'm not saying we should not transition to every extent possible to renewable energy- we don't have a choice. But when we do, the current energy consumption rates CANNOT be sustained. Automobiles cannot exist in a system based on renewables- not even what is known as a totally 'solar powered' automobile. Trace the origins of that solar car, and a hell of a lot more energy went into building/maintaining the car, and the infrastructure supporting it, than will ever be retrieved from it over its lifetime.

We are going to have to downsize, in more ways than one. It is estimated that every fourth person on the planet is here because of petroleum/synthetic-nitrogen based farming[4]. If true, how we will deal with the peak of fossil fuel production is a tough pill indeed. Personally, I think part of the answer lies in getting smart, and fast, about organic farming and ecologically harmonious food production.


[1] Heinberg, 2003
[2] Odum, 1996
[3] Greer, 2003
[4] McKibben, 2010