Let me provide you more context.
The solar market is a great econ-101 story. PV production and installation have grown at 45% to 50% per year for the last decade. That is epic, as the remainder of global energy growth is only increasing at 1% annually. In 2002... total capacity sold was something like 10 megawatts per year. This year, it'll probably be eighteen gigawatts. That's nearly a 2,000-fold increase in less than a decade. At the same time, cost has been plummeting. Four years ago, when I was buying solar panels for Google, it was $3.20 per watt using extremely mature technology. Today the global average price per installed watt is below $1.30. I'm on calls night and day coming up with even more radical price reductions. It's weird to be in a business where one of the major goals is to find a way to sell our product for less money, but that's exactly what's happening.
Now I'm more confused. Would you please paraphrase the whole sentence in red? And what is "installed watt"? Do we need the word "installed" there?