A look at the larger renewables picture Excerpt from :
Feels Like I'm Dying...From that Old Used-to-Be$this->bbcode_second_pass_quote('', 'B')ecause most people don't grasp that solar panels, or wind generators or ethanol aren't a magic bullet unless they represent a self-perpetuating system. Oil was nicely self perpetuating, at least for a good long time - you used oil based equipment to get oil out of the ground in a nice ration of energy returned over energy invested (EROEI) of 100-1. But we don't have the infrastructure, or the grid system, or the renewables, or the tools, or in some cases the technology to make things like solar panels or wind generators entirely out of renewables. They take fossil fuels at 20-50 different spots along the ride. When you add up all the fossil fuels involved, the
EROEI of most renewables is somewhere between 1 to 1 and 20-1, probably on the low side for most of them. That means that even to match our current energy needs, we'd need 5 times as much power generated from wind as coal and 50 times as much generated from solar as natural gas. Do you begin to grasp the scale of the problem?And these alternative energies aren't a permanent solution - it is true that a solar panel might last 20-30 years. It is also true that they might not, and that the batteries certainly won't. That grid intertie that keeps you from having batteries - that uses lots of fossil fuels quite regularly and needs quite a lot of regular maintenence and other energy inputs. And even if your windmill lasts you two decades, unless we can make them again with renewables, that means that we're just sticking the problem on our kids.
That is, let's say we do a massive build out of windmills and solar panels, enough to keep our whole society going (never mind that we could never fund it or engineer it). We use up a huge amount of our remaining fossil reserves to keep everyone comfy and in their cars, and we go into massive debt to do it. Well, five years from now, all the solar panels need new batteries. But we don't have any manufacturing plants that make batteries from solar panels. So we need to do it again, with fossil fuels, plus fix the solar panels that got broken and replace a few parts on the windmill. And all the metal, and the chemicals and the little pieces need to be made, mined, manufactured...with fossil fuels. And then five years later we have to do it again, and then a decade after that we have to do it on an even bigger scale - to replace all the worn out windmills and solar panels. And as we go along, supply constraints are increasing, and prices of fossil energies are rising. Capital costs go up, investment costs go up, and remember, since energy costs are way up, there may not be as much money around to invest.
Where is the energy and the money for all these fossil inputs going to come from in our nice, "renewable" society? In order to keep things going on renewables, we'd have to vastly *expand* our existing infrastructure - not only would we have to make enough windmills to keep the grid going, but also to run the electric cars, to power the mining equipment, to make bioplastics, and smelt aluminum, to manufacture titanium parts - all things that were done comparatively efficiently with oil and gas (because they are heat intensive) now must be done much less efficiently by electricity. So we'd have to build enough windmills not just to power things as they are, but to produce 3 times as much electricity - and rebuild the grid. This would costs trillions of dollars, tons of oil and natural gas...and in a few years, we'd have to do again.
Whenever I bring this up from people looking for techno solutions, they all tell me that eventually we'll be able to make things from renewables, of course. Hmmm...of course. That is, we're betting our kids lives on the hope that at some point renewables will become self-perpetuating, even though we have no idea how that will happen, that would require major, multiple large scale technical breakthroughs in many cases that might or might not happen, AND, we're not willing to do it now, when we have energy to burn, lots of money and no crisis - instead, we're going to bet the farm (and lives) on the fact that we'll be able to do this 20 or 30 years into a depletion crisis with much less money, much less oil, much less availability in a society that we simply don't know the shape of. That is, we're going to stick the next generation with the problem, and hope it isn't too serious. But if we can't do it now, when we have lots of energy and lots of money and all the time in the world, the chances are excellent we won't be able to do it.