I am a Global Warming skeptic, have been from the beginning. We think Oxygen is what makes us tick but in reality it is Carbon DiOxide. Carbon Dioxide is what plants use to make ALL our food. As far as the history of the earth is concerned our atmosphere has much less CO2 than it has had for most of its existence. I'm not worried about a little CO2. That being said there is nothing wrong with renewable energy if it is cost competitive.
There is promising research that may be an answer to some of our energy woes. One of them is oil from algae. another is liquid fuel from bacteria. The benefit is that it can be grown in a relatively small area, one of the Alge strains matures in about 24hours.
I see nothing wrong with renewable as long as it is not subsidized.
Now, you sound like you’ve done your homework on this subject. Competitive cost and no subsidy from government are key issues. I view the real point of the article posted as all the current alternative energy sources are really “miscellaneous” in that, yes they all compliment oil, gas, etc, but they cannot replace those sources. Therefore, and as you state, real replacement alternatives must be pursued.