Mar 23 2018

Showdown – Hydrogen vs Battery

Right now fossil fuels are the king of transportation fuel. They are relatively inexpensive, energy dense, and highly convenient. Burning gasoline produces a lot of energy for acceleration, but the fuel is also relatively stable (it won’t just explode), and usable over a large temperature range. You can quickly fill up your car with gasoline, have a long range on one tank, and there are filling stations everywhere.

In many ways gasoline is an ideal fuel, which is why it has reigned supreme for a century. But gasoline isn’t perfect, and the downsides to fossil fuels are coming home to roost. Burning fossil fuels releases pollution that impacts quality of life and causes significant health problems and costs.  It also releases previously sequestered carbon into the atmosphere, which is building up and causing climate change.

Further, many of the countries that are a major source of crude oil are not exactly stable democracies. And finally, there is a finite supply of crude oil. It is still not clear what the total remaining reserves are, and the figures change whenever new sources are found and new technologies are developed to extract more oil from existing wells. But no matter what, there has to be finite supplies of oil that will run out eventually.

All of these downsides are why we seem to be living in a transition point away from fossil fuels in general, but especially for transportation. Every automaker seems to think that fossil fuel engines are on the way out, and the trend away from fossil fuel is pretty clear. The real question is – what technology will replace it?

At the moment it seems like the clear winner is battery technology. Twenty years ago battery powered cars simply did not have the features necessary to replace the fossil fuel automotive fleet. Despite claims that the electric car was killed by some sort of conspiracy, it was in fact killed by poor batteries providing a short range and long recharge time.

That is why the hydrogen fuel cell became popular as the likely successor of gasoline. “Here comes the hydrogen economy,” we were told, and there seemed to be a compelling case. Hydrogen fuel cells make electricity to run the car’s motor by burning hydrogen with oxygen. In this system hydrogen is not a source of energy, it is an energy storage medium. You store energy by splitting hydrogen from some molecule, like water. Then burn the hydrogen back with oxygen, making energy and water as the only waste product.

Hydrogen could also be shipped and piped like gasoline, and you could fill up your car in minutes like with gasoline. It all seemed very promising. In fact California funded a hydrogen infrastructure, trying to get ahead of the game by paving the way for hydrogen fuel cell cars.

But then a strange thing happened – all the prognosticators were wrong and the hydrogen economy never came. Technical hurdles proved to be much more difficult than anticipated. It turns out it is not easy to store large amounts of hydrogen in a stable way that won’t explode, but will release hydrogen quickly when needed, and not weigh too much to carry around in a car. Potential solutions were expensive and difficult to mass produce. Sure, platinum membranes help, but that does not put the fuel cells into a consumer price range.

While the industry was busy trying to work out the technical problems with hydrogen, battery technology continued its incremental improvements every year. The tortoise definitely won this race, with battery technology eventually getting to the point that the range and cost of all-electric cars were ready for prime time.

Now it seems like battery powered cars have definitely won. Every major car manufacturer is planning on releasing more and more electric cars, and fewer and fewer gasoline cars. Most manufacturers believe that by 2040 no (or very few) new fossil fuel cars will be made.

I was surprised, however, to read that these same car manufacturers still believe that hydrogen fuel cells will beat out battery technology. In a survey 78% of experts think hydrogen is still the future.

There are hydrogen fuel cell cars on the market. Hyundai is coming out with a fuel cell SUV called the Nexo. It boasts a range of 600 km (375 miles) on a full tank. It can also be filled in minutes, unlike recharging a battery. It will be expensive, probably in the range of $95,000.

So how do the two technologies compare head to head? Battery technology has several main advantages. While still relatively expensive, prices are coming down quickly as manufacturing scales up. It continues to benefit from steady incremental advances in every way. But perhaps more importantly, it is winning the infrastructure war. Not only can you charge your car at home, recharging stations are becoming very common.

The main downside is long recharge time. Even with a fast charger, it can take 30-40 minutes to fully recharge your car, which is not very convenient. Researchers are working on ways to swap out batteries, or swap out battery fluid, making a recharge as fast as filling a tank, but then that would reset the infrastructure war. You can’t do this at home, and we would be starting from scratch building stations that can provide this service.

Hydrogen also has several advantages. The biggest is the rapid refill. Hydrogen also currently has greater range. This advantage may eventually disappear, however. If hydrogen does not make some gains quickly, it may once again be left in the dust by the relentless advance of battery technology.

One interesting advantage is that hydrogen fuel cell technology may have many more uses outside of transportation – the promise of a full hydrogen economy. Fuel cells could power buildings, for example. So hydrogen power may prove more versatile, and its use in transportation may benefit from this, even if by itself it is not inherently better than battery technology.

Hydrogen has two big disadvantages, however. It is very expensive with current technology. But perhaps the fatal problem – it requires an infrastructure that simply does not exist. This is a classic chicken and egg problem – people won’t buy the cars until the infrastructure exists, and they won’t build the infrastructure until there is a demand. Battery-powered cars may simply be able to keep their hydrogen competitors down by keeping the technology from bootstrapping itself.

It will be an interesting technology war to watch over the next 30 years. Right now I give the edge to battery technology, but there could always be a disruptive breakthrough. A new fuel cell design with killer features could change the game.

It is also possible that we will end up with both. Some manufacturers are focusing on long-haul vehicles, like trucks, buses, and even trains, for hydrogen. Here the longer range is more of an advantage. Further, they can build a much more limited infrastructure, catered to the more predictable travel routes of these vehicles.

It seems like auto manufacturers are putting most of their resources in battery technology for now, but are hedging their bets by continuing to develop hydrogen fuel cells, which they think will be the long term winner. We’ll see. Either way, it’s a win-win. Either technology, or some combination of both, will be a huge advance over the dirty fossil fuel cars.

Who knows, maybe some third dark horse technology will win out. Perhaps we will be driving thorium powered cars (OK, I seriously doubt it, but the Fallout fan in me thinks the idea is cool).

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