http://m.theregister.co.uk/2015/05/31/rare_metals_mineral_re...
The problem with both is extraction cost. How can we effectively extract it that provide a profits at this current price. It wasn't until recently US mastered the technique of flasking oil we have more then what we need.
These technologies are currently only accessible to highly-determined and resourceful people (those willing to make fundamental changes to their electricity consumption patterns, or those with 2+ sigma annual disposable income to fund their individual solution), and are still not ready for mass, de-centralized adoption. Grid-scale deployments might be another story, but any talk of a mass wave of private individuals adopting this technology is not matching up with the numbers I've run.
A combination of energy conservation and energy production technologies and techniques, I can see gaining traction, but that is a long, long (2+ decades) ways off in the US (Germany is potentially leading the way here IMHO).
So you'd be getting (saving) 4K annually from a 40K investment? Try getting that kind of return elsewhere.
Seriously though, the best solar strategy for the homeowner is do-it-yourself ground mount installs. If DIY is not your thing at a minimum get separate quotes for install and supply. The markup solar installers add to equipment is outrageous.
I checked again last year about installing an array on my roof. My original outlay would be in the 30-40K range with an ROI of over ten years. If you want solar to take over the world and be a viable alternative to low income families, this isn't going to cut it.
Also, does the author know there's a limited amount of lithium in the world while his projections are pretty rosy for electric, the facts don't seem to align with his assumptions:
William Tahil, the founder of Meridian International Research, a technology consultancy in Martainville, France, has argued that there simply isn’t enough economically recoverable lithium on the planet to support the auto industry’s ambitious plans. Tahil estimated that only 4.4 million tons of the world’s lithium resources can be extracted without prohibitive cost, a supply he believes will be quickly exhausted if lithium-ion batteries become a staple of next-generation cars.
http://www.forbes.com/forbes/2008/1124/034.html
So why people are focusing on lithium to herald in the new electric car revolution, we should probably already be looking beyond electric cars as a viable long term solution.