Bill Yenne, in his book The World's Worst Aircraft wrote, "Like any great technological leap with a timetable set by politicians, (it) takes longer than expected to evolve"  It fails anytime it is "really more a political venture than an economically justifiable commercial one."

Let me simplify.
If there’s no “R”, it’s not and “I”, it’s an “E”.
If there’s no Return, it’s not and Investment, it’s an Expense.

We keep “Expensing” into alternative fuels before anyone even understands the physics.

Bio Fuels
The physics of fuels. Diesel has 138,000 BTUs of energy per gallon; gas 125,000 BTUs, natural gas 90,000 BTUs, bio-fuel 80,000 BTUs and a car battery has 3,500 BTUs. Natural gas needs to sell for 35% less than diesel to yield the same energy per dollar. For Bio-fuel it’s 42% less. And it requires 40 car batteries to yield the same energy as a gallon of diesel.

Replacing imported oil with wind power is a noble idea.
But it will require 2.04 Trillion Dollars to buy the wind turbines. We import 3.6 Billion barrels of oil a year. The BOE (Barrel of oil equivalent) is 58 Million BTU per barrel. That means that we import 208 Quadrillion BTU’s of energy. A 600 KW wind generator produces 1.5 Million KW per year (running at the World Wide average of 28% efficiency). 1 kWh is 3,412 BTUs. A 600 kWh wind generator produces 51.2 Billion BTUs of energy a year. It would require 4.1 million generators to replace imported oil. The average cost for a 600 kW generator is $500,000. The cost for just the wind generators would be 2.04 Trillion Dollars. Double that to include updating the grid. Then figure out how to pay to replace all the cars…

Replacing imported oil with solar.
First, solar doesn’t like the heat of Arizona. It loses 30% of its efficiency during summer.
I just checked “sunnyportal” and a 4 kWh system I’m monitoring produced 700 kWh in May. To reach the BOE yield from oil imports, we will need 854 Million solar systems at a cost of $42,000 each for a total price of 36 Trillion Dollars. Considering the Government and Power Companies rebate half, the Federal Government only needs 18 Trillion Dollars to replace imported oil with solar. The grid, however, wouldn’t need as much work because solar can provide localized power. But we still need to replace all those cars…
 

Alternative sources of power will create a ROI someday.  Until then, the best use of money is investing in research.  Mass production of a technology that is not cost effective is an expense that we cannot afford today.

If we keep expensing into alternatives, and don't rid our dependence on foreign oil, we compound the problem by paying interest on the dept and paying for foreign oil.