Like most investment stories involving China, it pays to read the fine print on First Solar’s (FSLR) announcement that it has signed a deal to build a huge 2 gigawatt solar plant in China.

That’s a huge deal because 1) the proposed plant, at 2 gigawatts, is major-league utility size, and 2) China has seemed very determined to shut out foreign solar companies as it developed a domestic solar industry.

But the deal may not be as big a breakthrough as it seems. And I stress the “may not” because frankly no one knows exactly what this announcement really boils down to.

First, there’s the little matter of how and how much First Solar will get paid. The deal structure in the announcement suggests that First Solar will build the plant and then sell it to a Chinese utility.

At what price? To be determined.

So it’s hard to know what kind of profit First Solar might make. The company says that building a comparable plant in the United States would cost $5 to $6 billion but that construction will e cheaper in China because of lower Chinese labor costs.

And then there’s the little matter of the when. First Solar announced plans to begin with a 30 megawatt plant and then scale up to the final 2 gigawatts (or 2,000 megawatts.)

That kind of logical schedule implies that the infrastructure to actually deliver the electricity somewhere useful is in place or at least in planning or at worst is at least a proposed budget line in a minister’s office.

 But China’s efforts to increase supplies of any kind of electricity have been hamstrung by a lack of transmission lines. And all too typically the responsibility for building a plant and for financing the transmission infrastructure have been divided between different state bureaucracies.

In a worst case scenario First Solar could well find out that it has a deal to build the plant but that there’s no financing available for transmission lines.

I hope the deal is exactly what it seems on paper: a clear sign that China isn’t going to close its domestic market to overseas solar companies. China’s solar market is already among the biggest in the world and it has the potential for massive annual growth.

But I worry that this deal is really just a paper tiger designed to demonstrate to foreign governments and international trade organizations that China’s market is open while in reality all the huge potential from the Chinese solar market is kept safely reserved for domestic Chinese companies.