Let's shift this from talking tech to talking policy a bit.
This is a pie chart of CO2 emissions by country. Note the following points while looking at it.
CO2 emissions by the US have been going down over the past two decades. The US contribution to CO2 is 15%. about half of China even though the US economy is larger.
China is building hundreds of new coal powered generating plants and although they are getting more efficient their emissions are increasing quickly. Ditto for India.
In a few years, by continuing what is the US is already doing, without any special additional renewable efforts by the US, The US is going to be 5% or less of global emissions.
www.ucsusa.org/resources/each-countrys-share-co2-emissionsIn truth, so long as the developing world continues to build fossal fuel plants, and they are because they need cheap energy to develop, global CO2 is going to rise.
This is one of the features of the "Paris Treaty", it essentially exempts China, India and what is called "Rest of the world" on the graph (56% of CO2 emissions today) with the result that those emissions will double over the next 10 years and probably comprise 90% pf emissions.
In short, if you are sincere about the desire to reduce CO2 emissions, focusing on the US is useless.
So what are your proposals for getting China, India, and the "Rest of the world" to reduce emissions, or at least emission growth? The "low hanging fruit" opportunity to slow the growth in emissions might be to develop more natural gas resources in the short run, but I am guess you won't favor that.
As a practical matter, focusing attention on massive revisions to the US economy to reduce CO2 emissions is a inefficient way to proceed.
The 80/20 rule applies in that the big improvements (reductions) are cheaper and easier like switching from coal to gas. Doing that in China and India would do more to reduce emissions than taking the US to zero, and at far lower cost.
Renewables make sense in certain applications, and over time will get better. But today, renewables are not going to make much difference, and especially if you are concentrating on deploying them in the US.