Newswise — In the field of alternative energy wishful thinking has become the norm. Politicians and pundits so want to ward off global warming by cutting back on carbon emissions that they have subsidized half-baked schemes for solar, wind, and biomass sources of energy.

Everywhere we have evidence of this triumph of hope over experience. That's why cloudy regions, such as Bavaria, have massively subsidized solar photovoltaic farms. It's also why the United States has jacked up the price of food worldwide by diverting roughly 40 percent of its corn crop to the production of ethanol fuel. The economic and human cost of both kinds of subsidies has been immense, though in the case of solar power, those subsidies have already been slashed.

Proponents of alternative energy have ignored technical and developmental problems. Among the technical objections to wind and solar power are their inherently low capacity factors--that is, the percentage of time that such installations can be run. When such generating plants lie idle, we must feed the grid from enormous (and expensive) banks of batteries or lakes' worth of pumped-water storage. Worse, because neither the wind nor the sun tend to be copious near to consumers or to existing transmission lines, these technologies cannot piggyback on existing infrastructure.

More serious is the developmental problem. Technologies take their own time to mature, and there is only so much governments can do to speed things up. History shows that it took coal nearly a century to replace wood, many decades for oil to replace coal, and--despite stupendous government subsidies--a similar period for nuclear power to become significant.

If we are to convert the energy budget of the entire world to non-carbon-emitting sources, we must be prepared to invest patiently, not merely for decades but for a lifetime.