As I see it, switching to alternative sources of energy is another ploy to keep growth (with all its destructive concomitants) moving along without disruption, guilt or thought. We'll have cleaner air, but we'll have electric cars on every road, human population growth continuing, aquifer depletion (name your own greatest environmental problem – alternative energy will provide an alternative means for that "problem" to continue [with a clean, clear individual/business/government conscience – we will make what our politicians call a "tough decision" and delude ourselves that we have made a choice that is clearly in the direction of a biosensitive society]). Only a few cranks like me will be out on a limb, pointing out that the emperor has no clothes and criticized by those who regard our position as ungrateful and politically/economically/socially naive and unrealistic, no matter how biologically real it is. Alternative energy is an alternative way - possibly a slower way - of progressing towards overshoot. It is not a way to avoid overshoot.
Think back to the 1970s, before we were seduced by microchips and plastic (which – directly and indirectly – made the use of energy far easier and far more permeating as a part of daily comforts). In the 1970s we thought seriously about conservation. Conservation (in its broad, non-anthropocentric sense) is central to biosensitivity. But conservation is passe today and defensively dismissed as mere "tree hugging". The poignant plea of Dmitry Orlov “Are we going to continue destroying the planet, just to be somewhat more comfortable for a little while?” has been answered in the affirmative in the 1980s and ever since - by our actions and in our deep minds. 
Alternative technology can be a negative as well as a positive influence. At its worst, it provides a second-rate replacement for ways people in third world economies can satisfy their first world consumer desires.
1. Pentti Linkola makes a similar point in his Can Life Prevail?: "The foundational argument for technology is that it makes life easier: easier and easier, invention after invention. In reality, man has been dominating the globe without rivals ever since the discovery of the stone axe, and our life has been unnaturally and hopelessly comfortable. Since then, our only real problems have been our physical ease, meaninglessness, rootlessness and frustration." p 145. In this book Linkola outlines a program for sustainability, one which would – if implemented and maintained – avoid overshoot.
Evfit home More on conservation as an alternative to 'alternative energy'
Page up-dated 20 July 2009