In 2013 the United States consumed 97.4 Quads of raw energy to produce 38.4 Quads of energy used by consumers and industry. The remaining 60% was lost as heat or thermal rejected energy. That is 1.028 X 1020 Joules or 9.74 X 1017 BTU of expended raw energy. To put that in perspective this equates to the amount of energy produced by 16.793 billion barrels of crude oil burned in one year. Today most of this energy consumed in the U.S. comes from fossil fuels.
Hydrocarbon fuels have an exceedingly high energy flux density meaning a small unit volume produces a large amount of energy. Nuclear is the only energy source of higher energy flux density than hydrocarbons but today’s nuclear fission processes may only be used for a few more decades because of nuclear waste issues coupled with public perception & policy. The energy flux density of solar, wind, geo-thermal, tidal, and the like is thousands of times lower per unit volume of collection apparatus than hydrocarbon fuels.
Fossil fuels are finite. The speed at which they are consumed is a factor of worldwide per capita energy use. Now, developed countries like the U.S., Canada, Europe, China, Russia, South Korea, Israel, and Australia are using 80% of world energy capacity. Demand is accelerating and can only continue to accelerate as the Internet and travel teaches people and countries of less developed means that they should aspire to greater means which takes more energy. Few professionals in the energy forecasting business have taken this into consideration but there is no denying this and no turning back. We must either increase energy levels for less developed countries and people or decrease it for developed societies to achieve a perceived “social equilibrium.” Needless to say, citizens of developed countries will not allow regression.
By mid-century fossil fuel reserves will no longer be economically and technically viable due the vast increase in international energy demand and the associated increases in extraction/production costs as more unconventional fossil fuel reserves must be taped coupled with environmental constraints and regulations.
Thus, an entirely new source of energy must be proven, demonstrated and commercialized over the next 2 decades or we risk destabilizing the security of all nations in the world and the health of their citizens. This energy must be extremely powerful in terms of energy flux density, abundant, clean, safe, and leave no long term waste products. The only realistic solution is fusion. There is no other scientifically conceivable energy source except the concept of matter anti-matter annihilation which is hundreds of year’s away, if ever, on Earth, as a means to produce energy.
And we must begin now because in 3 to 4 decades two significant events converge. As described above we deplete “proven reserves” which drives the cost of fossil fuels up enormously. And in the United States this is coincident with the retirement of the vast majority of our generation capacity due to their life cycle maturity or age.