And why we are probably screwed by our own blindness
A number of articles have appeared in the popular press, mainstream media, and even science magazines or journals, suggesting that we could produce all of our energy needs from renewable energy sources such as solar (photovoltaics and concentrated solar generation), wind, and some tidal and geothermal thrown in for good measure. I am always profoundly amazed at these claims because they hinge on the substance of what our energy needs actually are or will be by the time the requisite infrastructure is in place. Those needs are generally predicated (or certainly implied to be) on our current economic systems and a consumer-oriented civilization. Even with a massive effort to improve process efficiencies across the board (e.g. the Smart Grid for delivering electricity, electrifying transportation, insulating houses and office buildings, switching to low power per lumen lighting, etc.) the total required energy needs of the US and the world (remember we have to think of this as a global problem) are so vastly huge compared with the current output of installed alternative energy systems that one has to take pause. If we want a civilization that is essentially equivalent to what we have today, only run on alternative, renewable energy sources, the scale of the needed energy capture and conversion equipment is literally mind blowing (for those with some technical background and interested in seeing the numbers, this Wikipedia article is reasonable, though contested in some areas - keep in mind it isn't the estimates of total available energy from each source, but the rate of capture and conversion, or extraction, that is what we should focus on).
The basic problem is one of energy density of the source, and power (energy per unit time) recoverable for useful work. Fossil fuels are high density with respect to weight. They combust at high temperatures so that they can deliver power required to run our engines and appliances, etc. Sunlight and winds (except for hurricanes, maybe) have a very low power density meaning that you need very large collection surfaces to capture enough energy to be equivalent to what is generated by fossil fuels burning.
So the scale of building out an infrastructure, which would also include nuclear power, equivalent to the energy infrastructure that we presume we will need (due to population and economic growth and development of underdeveloped countries) that does not depend on fossil fuels is so large that it would probably take 50 to 100 years to accomplish with an all out (WWII-style) effort. If you've never been involved in a large and complex building program (and note that assumes that we don't have any basic new technology to invent along the way) you will have great difficulty imagining the problems involved. Deploying just-developed industrial-grade technology is a slow painful process. Among other problems you have to address is what to do with the sunk costs in existing infrastructure. Financially-minded folks (the owners of existing infrastructure) won't consider tossing installed capital unless the new capital promises to pay extraordinarily high profits to offset the losses from capital write offs. This where capitalism will be the enemy of the future, even more so than it has been the enemy of the present in the sense that it created this dilemma in the first place. Under market economy rules with profit-motivated free agent firms doing the work, no one is going to step up to the plate to start investing in the kinds of projects needed to accomplish the goal, even in a longer time frame.
There is a closely related issue in that we are going into a rapidly declining energy available from fossil fuels regime. That means, simply stated, we have less and less energy available to do economic work; to create real wealth. As things stand all solar panels and wind generators are built using fossil fuel based energy (small exceptions for hydroelectric inputs in some parts of the world). They are transported to the sites with oil. In the foreseeable future the massive infrastructure we are talking about will be almost completely dependent on fossil fuel inputs for construction. We could imagine a 'bootstrapping' approach in which we build a huge solar panel array to power a solar panel production plant which would build more panels to power electric transport vehicles, and then more to power the suppliers of materials and services to the plant, and then more panels to electrify farms that grow the food to nourish the plant employees, and... You can see where this is going. By the time we did all of that we might have a self-sustaining solar power production capability but we haven't yet addressed the need to supply excess energy to the society that needs the energy.
I honestly think that something like a bootstrapping operation is called for. But it won't happen with private enterprise and market economics. From a political philosophy point of view, since energy is the most fundamental resource people need to live let alone have a civilization I think there is a strong argument for nationalizing (actually globalizing) energy production and distribution. Take the profit motive out of the equation and by directive make the necessary investments to get this working before we run out of fossil fuel energy resources completely. I realize this raises all kinds of issues (aside from the fact that libertarians and republicans will go ape shit). Managing such an enterprise efficiently and effectively is a daunting task. But a little judicious application of hierarchical control theory (see the series Sapient Governance might go a long way in the hands of competent leadership.
Which brings up the other major hurdle that could prevent even getting started on such a project: democracy. Very few people are going to vote for the leaders who tell them the truth, that they are going to have to make huge sacrifices in the near (and not so short) term in order to make this feasible. People want to hear how the politicos are going to create jobs and wealth and profits. Those are the ones they will vote for.
So you see it comes down to some pretty fundamental barriers for which there is no consensus basis for overcoming. The scale is too big to accomplish and not have a downturn in our level of material wealth, the energy to do the work needed would have to be siphoned off from other consumption-directed work, it cannot be even contemplated as a profit-making venture so our market economy won't go for it, and no one (except possibly the Chinese) will be in a politically powerful position to make it happen.
I hate this role of being a Cassandra. Oh, I know there are a few readers out there who actually do see this, so it isn't completely the case that no one believes any of this doomish stuff. But it is frustrating to see how things are going down while knowing it doesn't have to be this way. There is a way to salvage a future for our grandchildren or maybe great grandchildren if we could but wise up. But I just don't see that happening. There are a lot of far more eloquent writers and speakers than me out there who are pitching similar messages or warnings already. Some are nearly household names or at least have been recognized by the media. And still, very few of the masses or the media are paying attention. Contraction and depression don't sell. So I continue to write in my meager way, pointing out what would work, yet knowing it won't even be considered. And I think about the future, after the crash of civilization and population. What kind of world might we prepare for in that time by understanding what we are doing wrong now?
And my research continues in spite of this schizophrenic (a state characterized by the coexistence of contradictory or incompatible elements) mindfulness because there is always hope.