There are still problems with any plant-based biofuels, but they're problems with scaling, crop rotation, pesticides, and the current state of the art of ag in countries where sugarcane is grown.
But the energy return of sugarcane ethanol is high enough to make it non-silly.
Compared to solar, they're all silly. You live the glow a giant nuclear reactor, so large it is contained only by its own gravity. A .01% yield on the energy incident on earth would power everything we ever need.
A .01% yield on the energy incident on earth would power everything we ever need.
I can never understand why people trot out this sentiment. Humans are a biological species subject to normal ecological principles. One of those principles is that, in the absence of a limiting factor in our environment, we will grow. If energy availability is removed as a limiting factor, we will grow ("gettin' larger in waist and taste") until it is again. Anyone who pretends otherwise has not stepped outside to notice all the millions/billions of people clamouring for food, clean water, jobs, holidays, new computers, clothes, homes, education, etc etc. Imagining that, unlike every time in the past where human societies have chafed against resource limits and hoped that just a little more would fix everything, this time human needs will finally be satisfied, is the oldest fallacy in the book. It's just not how life works.
You live in a valley full of aurochs, horses, and boars, more than any man could eat. Taking just a fraction of these bountiful riches would give us all the food we could ever need.
I'm not sure it's broad ecological principal - humans are not simple animals - however I do think if we had "limitless" energy, we would all start flying around in personal aircraft, terraforming deserts, creating subsea buildings, and doing all sorts of wasteful things - until energy somehow became a problem again. In doing so, we would likely find other ways to disrupt our environment - just because energy is cheap and clean, doesn't mean using it has no effect.
Every time I buy a new laptop, I can't imagine how I'll fill up the drive, but I know I will.
Humans don't eat electricity or oil. Sure, they may be used to increase yields of harvests, but the limitation is still how fast plants grow and how much area they need.
Effectively we do eat oil. We replenish soil fertility with fertilisers made with oil energy, we farm large areas with machines powered by oil, etc. etc. We grow more plants faster, with shorter turn-over times, and use less human effort to do so, thanks to oil. There might be a few intermediaries but the end result is that energy from oil ends up converted into human biomass. I can guarantee you if we had never discovered oil there would be far fewer people, with far slimmer waistlines.
"is that energy from oil ends up converted into human biomass"
No, that's the whole point!
Humans surely cater to farming using oil, and we would be a lot worse without it.
But in the end food came from two sources: energy from the sunlight and CO2 (matter) from the atmosphere. (Well, then we could say we're eating car emissions).
Unless you're converting oil directly into food (let's say carbohydrates), no, all energy from plants comes from solar energy. You could of course have a giant oil powered lamp that produces light and shine that over the crop.
Water? With unlimited ultra cheap energy, there is plenty of sweet water in the oceans.
On the other hand: what is stopping us now from combining salt evaporation ponds with sweet water production in e.g. the coastal regions of the Sahara?
Except for nuclear, geothermal and tidal wave generation (and other lesser used energy sources) all energy in planet Earth is solar, accumulated during different time frames.
Sure, solar is great, except current technology is really bad at using it.
Solar has one really great aspect, it can be installed easily at the point of use. Tranporting power on the grid results in a lot of loss, by being at the point of demand solar gets an instant bump in terms of value.
>A .01% yield on the energy incident on earth would power everything we ever need.
This sounds like the Chinese soda analogy [1] in a different form. The fact that we only need 0.01% doesn't indicate the ease of capturing 0.01% in the form of usable energy.
Guy Kawasaki: "If a company can get just 1% of the people in China to drink its soda, it'll be selling a ton of soda. This is true. At the same time, it glosses over the difficulty of getting 1% of any market to use a particular product".
