Tuesday, October 1, 2013

HYDROGEN: The Practical Electric Car

Hydrogen has been heralded for decades as the logical fossil-fuel replacement for our transportation needs. Yet whenever the topic crops up in conversation, I often encounter two misconceptions: that hydrogen is burned in an internal combustion engine and the technology isn’t ready for prime time.
A HYDROGEN CAR IS AN ELECTRIC CAR. It’s that simple. Yes, you can convert an existing gasoline-powered car to burn hydrogen but this is far from the optimum solution. Any car with an electric motor, including a Tesla, could swap its battery for a hydrogen fuel cell. Nothing else is needed. A hydrogen fuel cell produces electricity and the car’s motor doesn’t care where that electricity comes from. No hydrogen is being burned—indeed, no fuel of any kind is being burned. Hydrogen combines with oxygen from the air, inside the fuel cell, and is converted to electricity, clean water and heat. Electricity powers the motor, heat is used in the vehicle’s heating system and water vapor is released from the tailpipe. Hydrogen fuel cell electric vehicles (FCEV s) are near-silent and emit zero pollution. Think of hydrogen as portable electricity.
So if a hydrogen car is an electric vehicle, why not just use a battery?
This is a controversial question and there’s no straightforward answer. Storing enough electricity to move a vehicle and its passengers for hundreds of miles is a challenge. In support of the battery argument, more energy is lost when converting electricity to hydrogen and back again than is lost in charging/discharging a lithium-ion battery—no dispute on the science behind this. Score a point for batteries.
However, car batteries are heavy (a half ton for a Tesla Model S battery) and far more expensive than a fuel cell. Their enormous weight negates any advantage gained over hydrogen in energy conversion and cripples their range-per-charge. It gets worse. Batteries are orders of magnitude slower to refuel than gasoline or hydrogen cars. A practical replacement for fossil fuel needs to meet customer expectations for price, range and time spent at the filling station. Hydrogen comfortably achieves all three, batteries clearly do not.
Let’s leave the battery versus fuel cell debate and examine two other common concerns: safety and availability/technology status.
Lithium-ion batteries, gasoline, liquid natural gas (LNG) and hydrogen are all potentially dangerous. All can, and are, being used to power vehicles. All are approved for use throughout the world. There really is nothing more to be said.
As of writing, several major automotive manufacturers have FCEV s ready for mass production. The barrier holding them back is a lack of hydrogen filling stations. These are not experimental or concept vehicles and no technical problems need to be solved before assembly lines can roll. FCEV s have the same range, refueling time and running costs as gasoline-powered cars. The only difference; hydrogen cars are silent and don’t emit toxins into the atmosphere. Living in a city like Los Angeles, clean air is something I can only dream about.
So now we come to the big hydrogen “gotcha”. Where is it going to come from?
The most common element in the universe, hydrogen is almost always found on earth as part of a molecule such as water (H2O). Splitting water to produce hydrogen takes energy and that energy needs to come from somewhere. This is hydrogen’s only weakness—one that can’t and shouldn’t be denied. Although arguments can be made for generating the element from fossil fuels, hydrogen really comes into its own when made from a sustainable source. This is where companies like HyGen Industries can help. Developer of the world’s first solar hydrogen refueling station, HyGen’s model is to buy sustainable electricity from the power companies (yes, you can do that) and create hydrogen on demand at the fuel station. No trucks are needed to deliver the hydrogen which means no massive storage tanks.
So far so good, but this “gotcha” isn’t done yet. There isn’t enough sustainable energy being produced today to power all the cars on the road. This statement is fact but it’s also correct to say that enough sustainable energy is being produced to support a meaningful roll-out of hydrogen vehicles. Once FCEVs get into the hands of customers, the demand for sustainable energy will increase. At this point, more clean-energy generators will come online and we’ll start to see technological breakthroughs. It seems like every day, I read an article about new and promising advances in solar, bio, wind and tidal. Remember when computers used to be the size of a room? Demand continually spurred advances until devices, far more powerful than those vacuum tube giants, could fit in our pockets.
Having spent many years in the semiconductor industry, it is easy to see PEM fuel cell technology following the same evolutionary path. Instead of $/MIPS (million instructions per second), fuel cells are measured in $/kW (kilowatt) but a similar cost-reduction curve is to be expected.
Several European countries are forging ahead and developing a hydrogen infrastructure. This term conjures up visions of new pipelines crisscrossing the nation with a budget to rival the national debt. But the reality is far less intimidating. Companies like HyGen propose installing equipment at existing stations to make hydrogen on site. The infrastructure (electricity and water) already exists. As FCEV s begin to proliferate, more equipment gets installed. Stations make a profit dispensing hydrogen—cars need fuel—funding will come from the private sector. Gasoline and hydrogen will continue to be dispensed from the same facilities as long as gasoline cars remain on the roads.
Here in the California, Governor Brown has just signed Assembly Bill 8 into law. $2B AB 8 focuses on FCEV s, mandating a minimum of 100 hydrogen fueling stations. This piece of legislation provides certainty to auto manufacturers that a hydrogen infrastructure will be in place to support vehicle deployment. Something’s in the air this time (apart from carbon dioxide). The combination of government and auto industry leadership is just what’s needed to trigger change. Let’s hope that hydrogen’s time has finally come.