What is our goal? To safely provide enough energy for the current and future population to allow for development and enjoyment of a lifestyle demanding as much energy as Americans now are privileged enough (and wasteful enough) to permit themselves.
This is 3,000 quadrillion BTUs. That’s how much energy a population of 9.5 billion humans (the probable population in 2075) would use if they used the same energy per capita as we do in the U.S. (327 billion BTUs per person right now). Note that most of Europe gets by on far less, and they have a pretty good lifestyle, so 3,000 is certainly an upper limit, not a conservative estimate.
Just to state the obvious, we probably cannot and certainly don’t want to do this with fossil fuels–not unless we want the world to look like China’s most polluted cities. We’ll certainly continue to use them–but they’ll get hard enough to find and prepare that they’ll be much more valuable commodities than they are today, and we’ll be using renewables shortly because they’re cheaper and easier to produce.
Last year renewable energy provided us with 52 quads. That seems like a very long ways from 3,000. But thanks to the miracle of compound growth and endless innovation, to reach 3,000 quads from renewables by 2100 only needs an annual growth rate of 4.6%. To do it by 2050 would require heroic growth–about 10% per year.
Is this feasible? The workhorses of renewable power right now are hydroelectric power and combined heat and power (also known as cogeneration). Hydroelectric power is set to double over the next 20 years, and CHP is growing so fast that nobody can keep track of it.
The renewables that get all the press–wind, solar and biofuels–have grown strongly over the past decade, but from such a small base that one has to wonder if they can continue at the same rate. I certainly think that wind has peaked–at least temporarily, due to the fall in the price of its natural competitor, natural gas. I think biofuels have a long ways to go in terms of fourth generation algae, but ethanol and biodiesel can fill in for the moment.
My long term bet is on solar power, which is dropping in price and spreading in terms of deployment and possibilities. From simple solar thermal for home water heating to complex concentrated solar power stations, solar is spreading like wildfire.
But for all the possibilities, the total energy from renewables has only grown 2% per year since 2007, in a favorable investment climate and with all the good will in the world.
We’re going to have to do better, which is why I’m certain we’ll have to look at nuclear.
And while we’re doing so, we can certainly look at the other elephant in the room–energy efficiency, or ‘negawatts’ as Bush the Elder termed them.
We currently waste half the fuel we burn in producing electricity, and there are endless opportunities to improve energy efficiency in our homes, offices, manufacturing plants and in the appliances and machinery we stick inside them. We could save billions and reduce power consumption greatly by being a bit more diligent in this regard.
For the moment, the final score is that renewables can and probably will play an important part in our energy future–but they won’t be enough on their own. Nuclear power and improving efficiency will have to step in to get us over the hump.
But note the above–we don’t need to invent a new technology or completely turn our economies on their heads. We just need to keep doing what we’re doing, take it seriously, and trust the innovation engine inherent in free market societies to do the job.
And we’ll get there.