A comment on a posting earlier this week got me thinking about why solving our energy problems looks deceptively simple, when it's actually so difficult. That didn't just lead me to another recitation of my usual "energy is big" mantra, but to the notion that we're dealing with something that's big and incredibly complicated. It takes both of those concepts to explain why energy efficiency and renewable energy, as promising as they are, can solve only some of our energy problems, and only after they have penetrated the market to a much greater degree than they have. That's not a knock on either approach, both of which will be necessary in addressing climate change and energy security. It merely reflects the challenges inherent in the interconnection of so many different forms and uses of energy.
Think of all the energy we use as a gigantic tree, a Sequoia redwood. The trunk and root system represent all of our primary energy sources, amounting to 443 quadrillion BTUs in 2004. That's the equivalent of 240 million barrels of oil per day, or 117,000 gallons every second. Petroleum only accounts for about 35% of that. Now think about the tree's branches. Some of the biggest are very familiar, including liquid fuels for transportation and other uses, and the various fuels for generating electric power. Each of these has sub-branches, of course, such as the fuels for vehicles, aircraft, and ocean-going vessels. Home heating fuels are intertwined sub-branches off the liquid fuel and natural gas main branches. To put today's alternative energy efforts into perspective, consider that one of the smaller branchlets off the liquid fuels branch, representing kerosene for cooking and illumination in developing countries like India, is bigger than the entire global biofuels industry.
Wind power, one of the largest and fastest-growing sources of renewable, low-carbon electricity, could be thought of as comprising some medium-sized twigs on the mid-load (non-peak, non-baseload) electricity sub-branch. Wind contributes enough energy today to displace about 0.2% of the volume in the natural gas main branch. That's not as insignificant as it might seem, but even growing it by a factor of 10 won't alter our need to find new sources of natural gas, including bringing more remote gas to market as LNG. And note that the shifts on this branch have little effect on the baseload electricity branch, which relies on hydropower, nuclear, coal and a bit of natural gas. Changing that one will require some combination of carbon sequestration for coal, new nuclear power plants, and possibly geothermal energy.
At the risk of belaboring this analogy, there's simply nothing out there that can turn our redwood into an oak or cedar overnight. Grafting on entirely new branches, such as hydrogen, will be extremely difficult and require a lot of patience. At the same time, it's probably just as well if those who are working hard to make change happen can't see the entire tree, because it might cause them to lose heart. We can't afford that, because the tree's enormous fossil fuel roots can't carry us much farther into the future without some big modifications and important contributions for new energy sources. Problems as big and complex as this one aren't necessarily insurmountable, but solving them takes a lot longer than anyone might wish.