Imagine Buenos Aires In 2030

[PhilipDT]

I found this publication linked to in a wikipedia article which has a very very detailed analysis of the costs of solar energy specifically in germany.

I haven't read it all but if you're interested in the subject it might be worth skimming.

 

[camino no tomado]

from the article:

... Even the figure of €20 billion is disputable if you include all the unintended costs and collateral damage associated with the project. " ...

Fossil fuels don't look so good either when you factor in all the externalities.

 

[camberiu]

Besides that: your whole argument doesn't make sense

I beg to differ. based on the laws of thermodynamics, I think the argument makes perfect sense. Solar energy is very abundant but highly diffused. If you had a solar panel that had 100% efficiency, the maximum energy it could potentially generate in the best possible scenario (clear day, on the equator, at noon) is 1,367 Kw per square meter. Today, the most efficient home solar panel has an efficiency rate of 16%. Which means that it takes a square meter of solar panel (on a clear day, on the equator, at noon) to generate about 200 watts. That is not very impressive.

Now consider this: Almost all sources of energy on this planet are ultimately solar. Even fossil fuels came from plants that converted solar power into sugar and other organic materials. The difference is that it took millions of years and a lot of pressure to convert that highly diffuse energy into the highly concentrated form (coal, oil, gas) that we burn today. So it took lots of time and energy (gravity, pressure) to make the fossil fuels we use today. It takes energy (lots of it) to concentrate solar power into something that we can actually use. Fossil fuels are cheap and efficient because nature and the Earth already did that work for us though millions years. Now, with solar, we have to do that. We have take pure solar energy and concentrate it and convert it to something that we can use. And that takes lots of power in itself. That is why solar can never be efficient. That is why solar can never be cheap. You can argue that over time, we will make solar panels more efficient. Granted, that may indeed happen. But the more efficient they become, the more power they will require to be manufactured.
The solution to our energy woes is not solar. Taking a highly disperse energy and packaging it in a way that our technological and industrial society can use is simply not viable. We do it today because we use fossil fuel to power our manufacturing. Without it, building solar plants would be impossible, as the energy output would be negative. We need sources of power that are already highly concentrated. Thorium is one of them. Hydrogen is another. Maybe geothermal is one (I don't know). But solar it is not.

 

[scotttswan]

Modern solar panels already payback what they cost in energy within a year - year and a half after that its free power. They've changed a lot since the 70's and will continue to do so. No one is saying use only solar but use solar in combination with all the other energy sources that don't pollute as bad as fossil fuels.

 

[camberiu]

Really, half a million square kilometers of solar panels to power the world by 2030? You think that is not a lot? How many tons of rare earth minerals would it take? How much power will it take to produce those half million square meters of panels? The silica rock used to make those solar panels needs to be melted on 3000 degree Celsius ovens. Where do you think the power to melt enough silica rock to produce that many solar panels will come from? Also, producing these many panels require lost of rare earth minerals. And the mines we use to extract those materials are devastating to the environment. Now imagine extracting enough rare earths to build half-million kilometers worth of solar panels.

 

[PhilipDT]

I beg to differ. based on the laws of thermodynamics, I think the argument makes perfect sense. Solar energy is very abundant but highly diffused. If you had a solar panel that had 100% efficiency, the maximum energy it could potentially generate in the best possible scenario (clear day, on the equator, at noon) is 1,367 Kw per square meter. Today, the most efficient home solar panel has an efficiency rate of 16%. Which means that it takes a square meter of solar panel (on a clear day, on the equator, at noon) to generate about 200 watts. That is not very impressive.

Now consider this: Almost all sources of energy on this planet are ultimately solar. Even fossil fuels came from plants that converted solar power into sugar and other organic materials. The difference is that it took millions of years and a lot of pressure to convert that highly diffuse energy into the highly concentrated form (coal, oil, gas) that we burn today. So it took lots of time and energy (gravity, pressure) to make the fossil fuels we use today. It takes energy (lots of it) to concentrate solar power into something that we can actually use. Fossil fuels are cheap and efficient because nature and the Earth already did that work for us though millions years. Now, with solar, we have to do that. We have take pure solar energy and concentrate it and convert it to something that we can use. And that takes lots of power in itself. That is why solar can never be efficient. That is why solar can never be cheap. You can argue that over time, we will make solar panels more efficient. Granted, that may indeed happen. But the more efficient they become, the more power they will require to be manufactured.
The solution to our energy woes is not solar. Taking a highly disperse energy and packaging it in a way that our technological and industrial society can use is simply not viable. We do it today because we use fossil fuel to power our manufacturing. Without it, building solar plants would be impossible, as the energy output would be negative. We need sources of power that are already highly concentrated. Thorium is one of them. Hydrogen is another. Maybe geothermal is one (I don't know). But solar it is not.

You're not still trying to justify that stupid graph you posted a few pages back are you?

I'm actually with you in the sense that I don't think solar panels are a realistic solution to our energy needs.

However, implying that one source of energy generation is better than another because of the efficiency of converting the energy density of the fuel into power energy without considering the characteristics of that fuel is ridiculous.

 

[ajoknoblauch]

so will you please enlighten us to why you esteem MIT so much? or are you that intellectually bankrupt you cant think of anything else?

MIT, admittedly, is no UBA.

 

[camberiu]

You're not still trying to justify that stupid graph you posted a few pages back are you?

I'm actually with you in the sense that I don't think solar panels are a realistic solution to our energy needs.

However, implying that one source of energy generation is better than another because of the efficiency of converting the energy density of the fuel into power energy without considering the characteristics of that fuel is ridiculous.

I am sorry, but I fail to see the point of your argument. Yes, of course energy generation efficiency cannot be the main criteria for every case. Batteries (like AA batteries) are a very inefficient power source, but extremely practical and useful for specific scenarios. I'd prefer to use AAA batteries to power my digital camera than a small bottle of more efficient gasoline. But when you are talking about a main energy source for broad day-to-day use (homes, industry, mass transit, water purification) for an entire society, comparing energy efficiency across multiple proposed energy sources is a critical factor.

 

[PhilipDT]

I am sorry, but I fail to see the point of your argument. Yes, of course energy generation efficiency cannot be the main criteria for every case. Batteries (like AA batteries) are a very inefficient power source, but extremely practical and useful for specific scenarios. I'd prefer to use AAA batteries to power my digital camera than a small bottle of more efficient gasoline. But when you are talking about a main energy source for broad day-to-day use (homes, industry, mass transit, water purification) for an entire society, comparing energy efficiency across multiple proposed energy sources is a critical factor.

The point of my argument is this: If you can produce electricity with 50% efficiency by burning $100 bills or at 10% efficiency when running on dogshit you're better off burning the poo poo.

 

[camberiu]

The point of my argument is this: If you can produce electricity with 50% efficiency by burning $100 bills or at 10% efficiency when running on dogshit you're better off burning the poo poo.

So for you the value of that $100 bill does not affect the calculation of the efficiency of the energy output when burning it? I'd argue that you are not getting 50% efficiency when you compute in the value of the dollar bill. You are actually getting a much shittier output (cost per watt) than the dog shit. I think we are arguing over semantics here.