Mankind will always do what they are forced to do, after they eliminated every other option.

I'm off form and you are being pedantic this morning. I like it the sentence, to me, it makes sense. Thing A will never be possible unless Thing B occurs. My wording's not great, mind you, but then I'm still half asleep still.

Do you believe in fairy tales?

Well, thing B will definately happen eventually (assuming manking doesn't stop making technological progress), so thing A is bound to happen too. You should also have some coffee.

It's an exaggeration, but when resources start running out, or when the environment reaches a pathetic state, things won't be pretty, you can be sure of that.

In this case Thing A (renewable power) needs the Thing B (investment and improvement) to occur else it's stuck, big investors being more then happy to stick with fossil fuels because it's most profitable now.

This article seem to be looking at Renewable energy as though it is today's technology and resources ignoring many advancements that humanity has made to make wind, sun or tide/wave over the last 50 years. Another 50 years and this might not be an issue if the right investment is made. 

A couple of criticisms

1) He virtually ignores the renewable source that accounts for over 90% of renewable energy, hydroelectric power.

2) He points out that photovoltaic energy and wind energy can't get more efficient because there is a maximum amount of energy at a certain point. However this point has not nearly been reached, with current pholtovoltaic cells only about 25% efficient.

But yes, nuclear power certainly will have a place in the future. Probably best for countries with large populations that aren't likely to be hit by natural disasters.

@Kasz. Also this article is not about why renewables aren't feasible - that's just false. It's about why converting the entire world to purely renewable power within twenty years isn't feasible. Renewable energy itself is feasible and often cost effective.

Get builders/construction workers/scientists/suppliers to volunteer, otherwise shoot them. 

You will soon get a lot of renewable energy sources built.

The 'country sized' solar cell requirement is deliberately misleading. The smallest country in the world is 0.2 square miles, so 'country sized' is not particularly informative. I shall present an accurate figure for the total land area needed. I shall detail every step so that you can see where all this is coming from, and I am currently doing honours in renewble energy so I can assure you I know what I am talking about.

The total energy use (for the entire world, mind. Not just Europe and Africa) in 2008 is 143 851 TWh http://en.wikipedia.org/wiki/World_energy_consumption

=1.438 * 10^ 11 kWh/year

The average insolation on the Earth's surface is 6 kWh/m2/day. Lets assume that we are building the solar cells in average spots, although, in reality, we would not be. The reason that I am taking average, as opposed to picking locations, is because there will be energy losses in power transmission.

Multiply this by 365.25 (number of days in a year)

2191.5 kWh/m2/year

Lets take 35% as our solar cell efficiency, well below the maximum efficiency found in the lab of 43.5%. Doubtless, the study linked to in the OP used cheap cells with efficiencies of about 25%, because the first thing they wrote for that experiment was the conclusion. For solar power generation on this scale, we will be using concentrators, which means that we use mirrors to shine a lot of light onto a small area of solar cells. This provides two advantages in that solar cells are more efficient at high light intensity, and we can use expensive, efficient cells because we dont need a large surface area of cell.

http://en.wikipedia.org/wiki/File:PVeff(rev110408U).jpg

This means that we are actually getting 767.025 kWh/m2/year. This can be converted to

7.67025 *10 ^ 8 kWh/km^2, as there are 10^6 m^2 in a km^2

Divide the power needed by power/unit area gives 187544 km. Now, this is just the area of mirror that we need. of course, there will be some wasted space. Looking at the picutre below we estimate about 25% of the ground would reflect light to the tower as required. This then means that we need 750 000 km^2 of land area to power the entire world. This represents slightly less than a third the area of Algeria. 

So far from "Yes, you read that right—solar power facilities the size of entire countries. [to power Europe and Africa]"

We actually end up "Yes, you read that right --solar power facilities a third the size of a country. [To power the entire world]"

This also is assuming that we go 100% large scale solar. This assumption has been made because this guy is trying to prove a point, and doesn't want science to get in the way.

As pointed out in that very news site the OP linked us to, an actual plan for powering the Earth is NOT based on 100% large solar. It is based on things more along the lines of "deploying 3.8 million large wind turbines, 90,000 solar plants, and vast numbers of rooftop solar arrays and geothermal and tide devices."

If you were to install solar panels on your roof, that would produce power but take up no area.

Wind power produces more energy per unit area than solar does in the right areas.

Hydro produces a lot of energy, and takes up a negligible amount of land area.

Please don't just believe everything you read because it is written on a news site.

Exactly. The author seems to have the viewpoint that "things will never change, they will always be this way". A very conservative view, regardless of what the author claims his convictions are.