Here’s a surprising new fact about energy in the United States: the percentage of our electricity coming from the greenest sources — that is, the non-hydroelectric renewables such as solar, wind, geothermal and biomass — has doubled in just four years to nearly 6 percent. (Thanks to climate uberblogger Joe Romm for uncovering this data from the Energy Information Agency).

This significant win for clean energy has gone mostly unnoticed in the press. If anything, the story has been the opposite: recent reports herald the decline of wind, and for a year the media has made a big deal out of the demise of solar panel manufacturer Solyndra.

Given this negative drumbeat, it’s not surprising that the business world tends to perceive renewable energy as an altruistic, rather than fiscally prudent, investment. But this view is dead wrong. The renewable energy industry is growing very fast… and not because it’s a philanthropic effort.

Let’s look at the plight of solar panel manufacturers again. Every growing industry experiences painful shakeouts driven by rising competition. In the case of solar, vast investments in production capacity in China have quickly brought down the cost of panels — a jaw-dropping 65 percent slide in just 18 months. This is good news for people buying solar, but it’s not great for many manufacturers.

By lowering the “China price,” the world’s low-cost manufacturer is doing to solar what it did to the apparel and electronics sectors: driving higher-cost producers (usually in the West) out of business.

Aside from China’s role specifically, all of this should look familiar to any students of business history. Adam Shor studies the solar sector for the Electric Power Research Institute. As he put it to me, “Show me a mature industry with more than five big players.” In the most oft-cited parallel example, a century ago there were hundreds of car manufacturers.

But all of this context misses a critical point that most business people are overlooking: problems for manufacturers do not equal problems for the entire sector. MORE …