I suggest we focus on per capita emissions, which in China are around 3 to 4 tons per person as opposed to around 20 for the US.

Even better, focus on lifetime per capita emissions.

We must bring ours down to 3 or 4 tons to set a good example and because it is the right thing to do. We have created the problem with our emissions, it is only fair.

...mass protests related to environmental concerns have risen more than 5 fold in China over the last decade, and 17 of the world's 20 most polluted regions are in China.  China is suspected to have the world's largest amount of pollution related deaths.

If things get too bad, the population will start to upchuck, and when that happens, the government will pretty much be forced to take action in order to avoid a revolution.

Horrible that it has to get that bad before somethin' is done though.

Can we fix the link to this recent paper, please?

Journalists have real problems with numbers.  It is easy, perhaps lazy, to be skeptical of the potential of solar when the story is limited to flat plate pv economics.  Nonetheless, the rapid growth of cost prohibitive Chinese solar pv indicates the huge China potential of cost effective solar technologies.  US Solar at $100 to $200 per square meter aperture has a simple payback of one to three years.  Expect mature Chinese solar to cost something like $50/m^2.  The market is global.

I remember the days when IBM predicted there would be maybe six computers, Bill Gates said the Internet was no big deal, cars will never replace horses, and planes were only good for entertainment of barn stormers and will not compete with passenger trains.  

The solar industry is positioned to become the largest industry on Earth.  China will become a very big player.

Why are so few solar thermal power plants being built?  

Sunflower,
Although I am skeptical that you were actually there when they said that cars would never replace horses and that airplanes were just for barnstorming, not for transportation, I do want to believe you about solars potential.  

What besides people being wrong about things before and the total energy that the sun shining gives to the earth is it that gives you so much optimism about solar energy?   This is not meant to be a trick question.   I'm just wondering what would be the top 2 or 3 reasons after solars great potential?  Aren't costs the barrier?

There are so many forms of solar energy that it is difficult to be brief and precise, remembering [reading history] that horses will not be replaced by cars.

I live in a passive solar house in Seattle climate which collects 20,000 watts for the price of glass, my favorite form of solar energy.  There are also flat-plate hot water solar collectors, attached greenhouses, Trombe walls, clotheslines, indirect solar heat like firewood, solar powered district heating, solar industrial process heat, high-intensity photovoltaic cells now at 42% efficiency, solar thermal power with 24 hour steam storage, and stuff I barely understand.

I know solar glass mirrors best.  One square meter collects each year the equivalent of burning one barrel of oil in Colorado climate, about half that in cloudy areas.  Natural gas is half the cost of oil, usually more.  BrightSource claims $150/m^2 for heliostats and tower, IdeaLabs $100/m^2 for dishes, Industrial Solar $170/m^2 troughs, and Sunflower (me) $99/m^2 for dishes.  Materials are commodities from existing industries:  mirror (glass, silver, palladium, paint), steel, aluminum, concrete, micro controllers, and small motors (a couple watts clock drive).  The primary market application is natural gas displacement.

I've had dignitaries from China, India, Middle East, South America, SE Asia all discussing rapid unbelievably large scale up of solar energy systems.  They want low capital tooling and high labor designs that can scale quickly with the force of humanity - lots of indigenous casual jobs.

The effort is all about simplicity.  How simple can it get?

   Sunflower is correct.  Most of the current manufacturing of solar pv in China is too expensive for the overall market.  But it is not so far off that this will not be true (growing wealth, declining costs).

   There are many demo projects going on, and lots of people are watching to see how they will work.  One concern that developers have is the payback period.  They tend to run on smaller margins than developers in the US, so this is of concern to them (especially for commercial developers).  

   The issue here is not the desire to go green, but really the economics and the technical knowledge.  But things are changing very rapidly.

   The Chinese are also looking at every possible method of meeting their power needs.  They are not ready to put all of their eggs in one basket.  

patrick in Beijing

Regardless of the solar cost reductions, it will require a cost effective storage system to allow solar to take over more than 20% or so of the electrical generation market. Sunrise and sunset can't be changed by technical advances. Until we find some real breakthrough in storage, there will be limitations.

It's true that we've had technical advances that most people thought impossible, but we've also had stagnation in areas that weren't anticipated. In particular, energy transfer and electrical generation run into limitations based in the laws of physics that are hard to work around. Also, renewables (wind and CSP) require, on a unit generation basis, more concrete and steel than combustion type generating facilities.

There are many areas to pursue, but assuming one (i.e solar) will be successful is probably a bad plan.

Storing steam does not "pencil out" unless you can store it reliably at high pressures (say 1000 psi). Otherwise the old second law of thermo zaps you again. I've heard claims of steam storage before but I've never seen a design that looks practical and I've never seen an operating system. I remain a skeptic.

I would hold on to my wallet looking at Solel's claims also. To the best of my knowledge no CSP has ever been viable without large subsidies and the biggest one (the Luz plants in California) went bankrupt and wrote off the entire capital cost even with subsidies.

Don't get me wrong - I'm in favor of developing and building these things but at some point they have to make sense. I'm concerned that solar may be the electrical generation version of ethanol.

Oh, by the way, tankers fill with saltwater when empty because they need the weight for stability. I'm not sure what that has to do with anything else.