Alternative, non-fossil fuel sources of energy are critical for the world to avoid a greenhouse calamity - namely the runaway greenhouse effect. But that requires implementing enough exajoules of solar, wind, geothermal, etc. before the next 50 percent of oil reserves is removed.
President Barack Obama has said he aims to have fully 20 percent of U.S. electricity come from solar and wind by 2030. The question is: Is that goal feasible or pie in he sky? Looking at the energy numbers can shed a lot of light, and when one does so the future doesn't look so bright. In fact, human history has shown energy revolutions, transformations generally take lots more time (and effort) than humans assume.
For perspective, and as pointed out in an excellent WSJ article ('Power Up', Aug. 22, p.C1-C2) the contribution of solar photo-voltaic to global electricity has increased tenfold in the past six years. But is it enough to meet Obama's goals? Scenarios run by the author's firm show solar reaching 4- 9 percent by 2040. By the end of this year it could account for 1 percent of world electricity or 0.2 percent of total energy. Wind energy growth, meanwhile, in similar scenarios could reach 9- 13 percent of the global total by 2040.
It sounds doable but the joker running wild is population growth. Because unless that is also taken into account all bets are off. If, on the other hand, population remained stable or decreased then it might be feasible.
Global energy consumption rose from barely 21 EJ (exajoules) in 1900, to 318 EJ in 1988, to close to 400 EJ today. Solar, geothermal + wind by the end of this year, will therefore have contributed only:
(6/ 400) x 100% = 1.5% of the total global demand
But this is exactly the rate of increase in global population per year! In other words, the added total alternative energy benefit is sacrificed because we added an extra percentage of humans to consume the benefit! In effect, our energy predicament is like a rat spinning its toy wheels in a cage and getting no where.
The stage is set to add 25% MORE humans by 2050, topping off at 9 billion (hopefully!), which will necessitate - if we still plan to retain solar in the mix - converting an area the size of Europe to solar panel arrays. In addition, to feed all those hungry mouths, we will need to add an agricultural area the size of the whole continent of South America - especially given how the eating habits of Chinese and Indians have now altered to become more "American" (e.g. much more meat, like steaks, etc. - which require vastly more water and resources to produce)
When one does the math, and in particular pays attention to the 2nd law of thermodynamics and the ‘net energy equation’, Obama's goal isn't simple by any means. Nowhere near as simple as building 20 million wind turbines or laying down 400,000 acres of solar cells.
The key question is where will energy come from to support an industrial-energy intense and consumptive civilization? You can’t just say “new sources” and leave it at that. What new sources? Where? As Jay Hanson (www.dieoff.org) pointedly notes:
“The fact that our society can‘t survive on alternative energy should come as no surprise, because only an idiot would believe that windmills and solar panels can run bulldozers, elevators, steel mills, glass factories, electric heat, air conditioning, aircraft, automobiles, etc., AND still have enough energy left over to support a corrupt political system, armies, etc. Envision a world where freezing, starving people burn everything combustible -- everything from forests (releasing CO2; destroying topsoil and species); to garbage dumps (releasing dioxins, PCBs, and heavy metals); to people (by waging nuclear, biological, chemical, and conventional war); and you have seen the future. “
But how correct is he?
One needs to process that different kinds of energy resources have fundamentally different "qualities". For example, a BTU of oil (oil before it is burnt) is fundamentally different than a BTU of coal. Oil has a higher energy content per unit weight and burns at a higher temperature than coal; it is easier to transport, and can be used in internal combustion engines. A diesel locomotive wastes only one-fifth the energy of a coal-powered steam engine to pull the same train. Oil's many advantages provide 1.3 to 2.45 times more economic value per kilocalorie than coal.
This means you need that factor increase in coal to equal a similar amount of oil, to get the same work done.
Ditto with solar. Unlike energy derived from fossil fuels, energy derived from solar power is diffuse and also extremely intermittent: it varies constantly with weather or day/night. If a large city wants to derive a significant portion of its electricity from solar power, it must build fossil-fuel-fired or nuclear-powered electricity plants to provide backup for the times when solar energy is not available.Solar power currently has a capacity of about 20 percent. This means that if a utility wants to install 100 megawatts of solar power, they need to install 500 megawatts of solar panels. This makes solar power a prohibitively expensive and pragmatically poor replacement for the cheap and abundant fossil fuel energy our economy depends on, especially if one intends to use it operate missile factories.
Worse, calculations show that solar cells currently consume twice as much sej as they produce, so they're no bargain. Worse, an entirely solar civilization would most likely have to exist at the power output and potential (relative to electric grid capacity) of about one half where we are now. Plus, the collector area would have to expand to around that of the states of Colorado and Nevada combined.
H.T. Odum's solar "eMergy" (eMbodied energy) measures all of the energy (adjusted for quality) that goes into the production of a product. Odum's calculations show that the only forms of alternative energy that can survive the exhaustion of fossil fuels are muscle, burning biomass (wood, animal dung, or peat), hydroelectric, geothermal in volcanic areas, and some wind electrical generation. Nuclear power could be viable if one could overcome the shortage of fuel. No other alternatives (e.g., solar voltaic) produce a large enough net sej to be sustainable. In short, there is no way out.
Further, Matt Savinar (Life After the Oil Crash) has shown that NONE of the alter-sources usually cited: from methane hydrates, from coal, from geothermal hot dry rock technology, from natural gas, from oil shales and tar sands, from secondary recovery of existing oil fields, and so on- will do squat to totally replace the energy now being consumed for our entire infrastructure, from powering a military-industrial complex with umpteen bombers, and now missile defense, plus more tanks for occupations and wars, not to mention sustaining growth in industries, new computers, maintaining the electrical power grid and building new nuclear reactors.
The bottom line is that it is doubtful Obama's projections can be met unless either: a) the U.S. population's energy demand decreases in inverse proportion to the population increase, i.e. if the population increases by ten percent the energy demand must be reduced by ten percent, or b) new advances in solar and wind power efficiency can be made to balance the offsetting effects of population growth.
If neither of these hold then all bets are off for a brighter energy future.