I think that energy use will be precipitously lower no matter which future we receive. But even in Kunstler's worst prognosis, the current increases in energy efficiency and production should allow more than 'a few hours of electricity a day'. LED lighting, time-pulsed fridges, low-energy laptops and potentially memristors should mean that the bare essentials will take a fraction of the power we use today.

Advances in solar, wind, geothermal and marine are increasing exponentially, with huge capacity increases nad price decreases approaching. Storage technology is also improving (although it could be more advanced). Barring utter collapse of all manufacturing across the entire world for a decade, I can't see these new technologies not being widely available.

That means lighting, computer access and food storage should be available at least 18 hours a day (10 hours of sun, 8 hours of wind), with brownouts probable during days without natural resources. Desert installations of solar thermal (with 24 hour storage from molten salt), goethermal installations, tidal and energy storage improvements should help with this even in worst case scenarios.

The biggest challenges efficiency-wise (ignoring luxury items) are transportation, cooking and internet servers. Those are the three things I think are hardest to provide for in a low-energy/resources scenario.

I think some of the world could end up like Kunstler predicts, in particular badly run countries and/or countries with little solar/wind/marine resources (although pretty much everywhere can use geothermal if drilling tech improves). His idea of a completely collapsed society of dirt farmers is simplistic and too homogenised - there are resources both natural and human that will keep technology around.

I agree with a lot of his comments about what's wrong with today's society but find his predictions are too dismissive of human ingenuity and the natural resources we are already beginning to exploit. Our future won't be dystopic but patchy, with some regions perhaps falling back to lower standards of living as they fail to adapt and those regions who invest in energy-efficient infrastructure and renewable energy struggling but succeeding in having a dynamic economy and society, if different from today's.