Hydrogen Cars vs Electric Cars

With gas prices being so high, alternative fuel vehicles have become a popular topic. Two of the types of vehicles that tend to get a lot of press are the hydrogen fuel cell powered vehicles and electric powered vehicles. Both are lauded as the way of the future

But which of these two options are really has the better chance of being the car your children drive.

Let’s look at hydrogen fuel cells first. When burned in an engine, the only emissions giving off is water, so a hydrogen powered vehicle is a zero emission vehicle. Hydrogen is also a better fuel than gasoline, it actually has the highest energy content per unit of weight of any known fuel.

Hydrogen is also a very abundant element. While current methods for making hydrogen are done by using fossil fuels, such as natural gas, coal, and oil, American wouldn’t be dependent on foreign oil anymore. Also, hydrogen can be extracted from water, and we all know there’s a lot of water on this planet.

However, hydrogen is not without its share of drawbacks. Probably the biggest problem right now is that it would require an entire new infrastructure. While gas stations could be outfitted with hydrogen fueling stations that would take years. Also, the technology to store hydrogen efficiently is still not ready for prime time.

Then there’s the electric car. Electric cars can also be considered zero emission vehicles since they give off no emission when running. However, electric cars do require power from the electric grid, which does give off emissions. As the electric grid gets cleaner, though, so do electric cars, and electric powered cars are substantially less polluting than gasoline powered cars due to the fact that power plants are far cleaner and more efficient than an internal combustion engine in a vehicle.

The technology for mainstream electric cars is also not quite ready for all the major manufacturers to stop making gasoline powered cars, but it’s much closer than hydrogen currently is. The challenge with electric cars right now is the batteries. The batteries are both expensive and current models, like the Tesla Roadster, have a range of only 250 miles – great for commuting, but not so good for road trips. The other problem is the length of time these vehicles take to charge. It’s not simply a matter stopping at your local power station and plugging in for five minutes and leaving. A typical charging cycle for current prototypes is 4-5 hours – again, fine if you’re commuting, but impossible for a road trip. While technology is being developed to make charging your vehicle as quick as quick as filling up with gas, it has a ways to go before it’s ready, just like hydrogen fuel cells.

Fleets of electric cars will certainly be hitting the roads sooner hydrogen fuel cell cars, but which one ultimately ends up being the vehicle of choice for drivers remains to be seen as both have plenty of challenges to overcome before people will readily give up their cheap gas powered cars in favor of these alternatives.

Fuel Cell vs Batteries

Until new batteries that can provide much higher energy densities without compromising safety are discovered, fuel cells will continue to outperform today’s heavy and large storage batteries. On the other hand, it is less expensive to build electric cars with batteries than with fuel cells.

Today’s batteries are less expensive than fuel cells, but their energy density is insufficient, and their weight and size are too high to provide the required driving range. The final outcome of the battery-versus-fuel cell race cannot be predicted. All that is obvious right now is that there are substantial developments in both fields.

In the area of fuel cells, reliability and availability have much improved. Recent U.S. military experience with phosphoric acid fuel cells found that the mean time between failure (MTBF) was almost 1,800 h and the availability was 67%. This is comparable with the MTBF service intervals for diesel generators. These fuel cells also favorably compare with the service interval needed for a typical gas turbine generation set. Still, much more development is required to obtain a commercially viable product. Today, the typical fuel cell system still requires servicing every 3–4 days to replace its scrubber packs.

The early electric cars used the old lead–acid batteries. Today’s hybrids are provided with more robust nickel–metal units. The EVs of the future are likely to be provided with lithium–iron batteries, found in today’s laptops and cell phones. Much work remains to be done in this area to increase safety and life span (to 100,000 mi of driving), while reducing their cost. Nissan and Mitsubishi are both making major investments in building lithium-ion battery mass production plants.

New battery developments include the ultracapacitor hybrid barium titanate powder design (EEStors). These devices can absorb and release charges much faster than electrochemical batteries. They weigh less, and some projections suggest that in electric cars they might provide 500 mi of travel at a cost of $9 in electricity. But these are only the projections of researchers.

Another direction of battery development involves high temperature and larger units. NGK Insulators, Ltd., in Japan uses sodium–sulfur batteries operating at 427°C (800°F) that are able to deliver 1 mW for 7 hours from a battery unit. The size of these units is about the size of a bus. Such units could be used at electric filling stations that are not connected to the grid.