Some scientists in Germany say they've found an easier way to break water down into hydrogen and oxygen, possibly opening the way for solar-powered hydrogen production. Hydrogen probably remains our best hope for liberating the transportation network from oil, for reasons that Tom Lee recently explained to Ryan Avent:
I think this is a point that's worth making here and at some length: "presum[ing that] battery technology improves" is setting yourself up for failure.
In truth, there have only been a few noteworthy improvements in battery tech during Ryan and my lifetimes: longer-lived NiCd and NiMH batteries; some improvement in alkaline batteries; and the popularization of lithium batteries. But look closer and you'll realize that most of these aren't actually battery innovations, per se: they're benefits of the microprocessor revolution. Cheap, smart charging circuitry allowed us to avoid memory effects; to balance load across cells; and to monitor lithium cells' temperature and voltage as they charge so that they don't catch fire (well... usually), thereby finally making lithium a viable option for consumer electronics. Those are all important developments, but at this point we've wrung about as much as we can out of charging our batteries more cleverly.
None of this has done much to improve the fundamental energy storage densities of the underlying chemistries. These have been known for a long time now, and nothing is going to change them -- nor are there any more promising elements like lithium waiting to be tamed (well, none that aren't radioactive, anyway). The glacial pace of improvement in battery technology really can't be overemphasized. The lead-acid battery was developed in 1859, for pete's sake. It's really heavy relative to the energy it stores, can produce explosive fumes if overcharged, and sometimes requires the addition of distilled water. Yet it's still the best battery technology we have for supplying the high current necessary to turn over an engine. A century and a half and we haven't come up with anything better!
It may seem like batteries have improved dramatically -- consider the lifespan of an iPod Nano versus a portable cassette player. But this is misleading. In fact it's a byproduct of more energy-efficient technologies. Which isn't to dismiss energy effiency! But electric motors are already extremely efficient. And when it comes to vehicles, we're unfortunately dealing with hard physical limits related to how much energy it takes to move a car. So long as we're committed to EVs being able to perform like and drive safely near gasoline-powered cars, we will find ourselves with less room for improvement than people would like to think.
I don't mean to be a downer, but it's difficult to overstate what a serious problem this is, or for how long it's been one. Hydrocarbons are an unbelievably efficient way to store energy when compared to electrochemical cells, and I seriously doubt anything will change that. Hopefully I'll be proven wrong. But smart people have been working on the battery problem for decades and decades, propelled by the lure of the financial bonanza that a breakthrough would represent. And while they've made impressive improvements, none come anywhere close to competing with gasoline's energy density. We're still an order of magnitude away.
There's a lot of optimism on both the center-left and the right that all we really need to do to tackle the problem of global warming/peak oil is throw a hell of a lot of money at the problem, and presto! A new technology will arise that will obviate the need for any lifestyle change more obnoxious than keeping the house size to 3,000 square feet. But as I've said to liberals in re: other problems, the fact that there is a problem does not imply that there is a solution. Yes, we found petroleum to replace whale oil. This does not therefore mean, as night follows day, that we will find something to replace petroleum. We will find something to replace petroleum if there is something that can replace petroleum. There might not be. And if there is something, Tom's post implies that it probably isn't going to be hyper-efficient electric cars, which might at any rate merely shift the anxiety from petroleum supplies to lithium.
Hydrogen looks more promising in many ways. On the other hand, finding a way to make the stuff cheaply out of clean energy is necessary, but not sufficient, to solve our problems. You also have to build a distribution network, and make it so the highly pressurized hydrogen doesn't set your car on fire. This is a massive task. Think how long it took from the emergence of the internal combustion engine in the 1890s, to being reasonably certain of finding a gas station wherever you happened to be driving: decades, even as automobile use exploded.