That's Vaclav Smil, the prolific University of Manitoba thinker writing in this month's issue of Scientific American. When Smil says something I usually listen. In the last two decades he has written more than 30 books on almost every imaginable aspect of energy, the environment and the biosphere. The typical Smil approach - and one that has recently led Bill Gates to call him one of the authors whose books he most looks forward to - is to wrap an energy related topic in a tight blanket of facts and figures, transporting discussion from speculation and wishful thinking into hard data. Vaclav Smil is where the clouds of starry eyed energy dreams meet the cold mountain of numbers and reality.

Smil's core argument is simple and one which I have often advanced on this blog: While reasonably promising, renewable energy is simply not quick and widespread enough. It has delivered very little in terms of overall contributions to the nation's energy portfolio, and barring unexpected breakthroughs or radical policy changes, it seems set to continue on this excruciatingly slow track. This is contrary to the starry eyed dreams of renewable enthusiasts who seem to think that a renewables-dominated energy future is right around the corner.

Smil starts by noting an underappreciated fact, that only 3.35% of the 10% of so energy that renewables are providing right now comes from "new" renewables, namely solar, wind and liquid biofuels. The majority of renewables are still of the "old" variety, hydroelectric power and wood chips. We are unlikely to see any significant expansion in the latter category, so all the promise projected for renewables would have to come from the new ones, especially from solar and wind. Sadly these two currently provide a tiny fraction of national energy needs (wind: 1.19%, solar: 0.16%).

These numbers also seem consistent with the history of energy usage. When it comes to dreams of rapid renewable expansion, as Smil tells us, history is not on our side. Even traditional sources like coal, oil and natural gas took about 50 to 75 years to contribute significantly to the energy portfolio, and unlike renewables these were sources for which base load was not a problem and the technology was largely available and cheap. The latter two factors are already stacked against renewables, which makes any possibility of their expansion in just a few decades a very tenuous proposition to say the least.

Smil describes the three major challenges for renewables that make their projected rapid growth murky and pessimistic. The first factor is simply the sheer growth required to meet energy needs; it's a point that cannot be stressed often, but the stark fact is that increasing the share of say wind from 1.19% to 50% is not simply a matter of additional investment. Given the history of energy, the whole energy infrastructure and political establishment would have to be shaken up to even try to effect this kind of change. Concomitantly world demand, especially in the developing countries, is increasing so rapidly that even fossil fuels have a hard time keeping up, so renewables are already trying to inch uphill.

Nor are these efforts likely to bear fruit in the face of what was always a constant headache for renewables: their inability to provide base load power, something which was handily accomplished by fossil fuels as soon as they appeared on the grid:

Wind and solar can contribute to the base load, but they alone cannot supply all of it, because the wind does not always blow, the sun is down at night and that supply cannot be predicted reliably. In countries such as Germany, where renewables have already grown substantially, wind and solar may supply anywhere from a negligible amount to roughly half of all demand during certain sunny and windy hours. These large fluctuations require backup from other power plants, typically coal- or gas-fired, or increased electricity imports. In Germany, all this variability can cause serious disruptions in electricity flow for some neighboring countries.

The third reason why renewables will face stiff opposition is largely a political and economic one, but it's still one that's daunting since it involves rejecting a way of life that has been ingrained in the economic and corporate life of this country for more than a century.

The final factor leading to a prolonged shift is the size and cost of existing infrastructure. Even if we were given free renewable energy, it would be economically unthinkable for nations, corporations or municipalities to abandon the enormous investments they have made in the fossil-fuel system, from coal mines, oil wells, gas pipelines and refineries to millions of local filling stations—infrastructure that is worth at least $20 trillion across the world.

The scenario for renewables, especially as it pertains to measurable and quick expansion, thus looks rather dismal. What can we do to make this transition at least somewhat easier? Energy efficiency for one is a very pressing need; as Smil says, "Recent studies have shown that there are no insurmountable technical problems to reducing energy use by a third, both in the affluent world and in rapidly modernizing countries, notably through efficiency gains".

The second solution is to stop heavily subsidizing renewables. As Todd Myers wrote in the Wall Street Journal,

Why is solar popular? Huge taxpayer subsidies hide the actual cost. Other renewables receive a subsidy of about one cent per kwh, solar energy receives about 96 cents per kwh. We pay solar’s cost in the form of taxes instead of as electric rates.

Last year a study led by eminent environmental economist William Nordhaus pointed out that subsidies on green energy can actually increase carbon emissions, a good example if there was any of the law of unintended consequences.

The problem with subsidies actually highlights a bigger issue noted by Smil. We live in era where fashions often trump facts, where governments, corporations and a public which is often fed biased information love to pick favorites. Solyndra is only one example of wasteful spending and dashed hopes engendered by wishful thinking. Technology is an unpredictable and fickle beast and its development cannot be engineered by bureaucratic fiat.

One way to do this (to avoid investing in failed energy policies) is to avoid picking energy winners. Governments cannot foresee which promising research and development activities will make it first to the free market, and hence they should not keep picking apparent winners only to abandon them soon for the next fashionable option (remember fast breeder reactors or fuel-cell cars running on hydrogen?). Spending on a variety of research activities is the best strategy: Who would have guessed in 1980 that during the next three decades the best return on federal investment in energy innovation would come not from work on nuclear reactors or photovoltaic cells but from work on horizontal drilling and hydraulic fracturing (“fracking”) of shale deposits?

That last line actually tells us why it is indeed dangerous to hold our dreams hostage to the promise of uncertain dreams of renewable energy. In 2000, who would have foreseen the enormous and wholly unexpected economic windfall resulting from fracking, a technology that has not only led to unprecedented energy gains and independence but has also made a measurable dent in reducing greenhouse gas emissions and power plant pollution. The tale of renewables and fracking confirms something that Niels Bohr told us decades ago: prediction is very tough, especially about the future.