Is the Future of EVs Lithium Batteries or Hydrogen Powered Fuel Cells?
Blog written by Bill Pollock, General Manager
There is a big push by many to make the days of the internal combustion engine-based vehicles limited. In part this is driven by the marketplace, but the primary driver is government subsidies, tax credits and mandates. When it’s finally gone what type of electric vehicle will take its place? I’ve been asked many times what the difference is between an EV vehicle powered by lithium-ion batteries (BEV) and one powered by hydrogen fuel cells (FCEV). What are the advantages and disadvantages of one over the other and is one better than the other? A great deal of research and investment has gone into both technologies, and both are being considered as future replacements for cars powered by an internal combustion engine. There are many factors driving the decision, but in the end, once government subsidies dry up, it will likely be cost considerations that make one technology win out over the other. A marketplace battle between electric vehicle and gas driven vehicles is nothing new. Most people don’t know that around 1900, at the dawn of powered transport, nearly 40 percent of all cars in the United States were electric cars. Back in that era gas engines were noisy and smelly and very hard to start with a hand crank. Those features were especially disliked by women drivers. Electric cars were quiet and easy to start and had no smelly exhaust. In the cities of the time, where automobiles were more common, electric cars were popular. Back then the batteries used were lead acid batteries. Original lead acid battery technology had been introduced in 1859 and the technology was mature. The first production electric cars went on the market as early as 1884. The range achieved, however, was limited and infrastructure to support charging electric cars wasn’t there. There were few charging stations, making it difficult to keep an electric car charged. In most cases the owner had to leave their batteries overnight at a dealer for recharge. Henry Ford had partnered with Thomas Edison to explore opportunities for low-cost electric cars. But the introduction of the electric car starter in 1912, eliminating the need for a crank, and the Model T in 1914, reducing the cost of a car, proved to be too much to overcome. A new model T was sold at about one third of the cost of an electric vehicle and gas stations were becoming more common. It was possible to refuel gasoline cars when taking longer trips. Cheap gasoline and continued improvement in functions of the internal combustion engine won the day. Battery powered cars became obsolete and gasoline powered vehicles won round one against the EV.
Hydrogen powered vehicles don’t have the same kind of history. Although hydrogen was introduced as a fuel by the 1900s, it was used primarily in experimental vehicles and typically to fuel an internal combustion engine. The first fuel cell, hydrogen powered vehicle, was built in 1966 by General Motors but only used for research and never sold to the public. It wasn’t until 1994 that Mazda introduced the Miata, a hydrogen powered fuel cell car, to the public. Since then, many other manufacturers have introduced hydrogen powered fuel cell cars. But these have never gone mainstream, in part because of cost and in part because of the limited availability of hydrogen refueling stations.
We are finally reaching a turning point for electric vehicles. While there are many improvements being made in technology, especially in more cost effective and more efficient batteries as well as improved fuel cell technology, the strongest driver is still government tax credits and subsidies. The result of driving technology by government edict does not always provide the best results. Today the cost of operating electric cars is touted by many , especially the politicians, as a big advantage over their gas fuel counterparts. Presently EVs are subsidized by government grants, typically in the form of tax credits. In some states they are exempt from sales tax. No one has yet imposed road taxes on their use. As EVs become a larger portion of the vehicles driven, states will need to find way to fun roads used by the EV owners and will begin to impose road use taxes. This will impact the cost of operating an EV and make the per mile cost less attractive. But we are going in the direction of the EV, so let’s look at the similarities, differences, advantages and disadvantages of those powered by batteries and those powered by hydrogen fuel cells.
Both the fuel cell electric vehicle (FCEV) and the battery electric vehicle (BEV) are being subsidized and are improving. Both reduce carbon emissions by powering an electric motor. The difference is that one gets the electric energy from a battery and the other from a hydrogen powered fuel cell. Many people believe that the future lies with the BEV because of the lower initial cost of the vehicle. But in many cases the decision on which to use may be based on factors other than initial cost. If we do a comparison of the two vehicle types, there are many factors that an end user should consider. In addition to the cost of the vehicle, there is energy density which impacts the weight of the vehicle, driving range, time to refuel, cost of fuel, and the availability of fueling stations. Each of these will have an economic impact. There are also more than one type of fuel cell and many types of batteries which will have impact vehicles as the technologies evolve. Both the BEV and the FCEV will need maintenance and there is a life of batteries and the cost of replacement to consider compared to the cost of maintenance of the fuel cell.
Energy density is a significant factor. Some of the best lithium batteries have a specific energy density of about 250 Watt hours/kg. Hydrogen has a specific energy density of 40,000 Watt hours/kg. even considering the weight of the hydrogen tanks, the FCEV provides over a hundred times more energy per kg. and this allows much greater distances before refueling. Additionally, FCEVs can go much further on a single refueling. Since batteries add weight to a vehicle, and this means adding more batteries reduces the range as well as the efficiency of the vehicle. In addition to the time and effort to refuel, this makes BEVs less efficient for longer travel. FCEVs are much more efficient for longer trips. Long trips and larger vehicles favor an FCEV.
Refuel time can be a factor for many vehicles. A FCEV can refuel in five minutes or less, much like a gasoline vehicle. BEVs can take three or four hours to charge depending on the type of charger being used. But FCEVs cannot be charged at home in the same way that BEVs can. The need for faster fueling favors the FCEV.
EV batteries have a typical expected live of 100,000 miles. This is a function of how many charging cycles they go thorough. Fuel cell stacks have a life equivalent to about 150,000 miles, but much less if used in traffic or for short distance driving. Small vehicles and those driving short distances favor a BEV.
The cost of producing hydrogen is presently more expensive than charging battery, so energy costs are higher for the FCEV than for the BEV. There are many more charging stations available to BEV users than there are hydrogen fueling stations to be used by the FCEV owner. Home-owners and those driving mostly short distances favor the BEV. The initial cost of a FCEV car may be as much as twice the cost of a BEV. But research and new developments are improving that. Additionally, as the size of the vehicle increases the cost ratio gets lower. Private users and small cars will continue as BEVs.
Considering all the factors listed it becomes apparent, that for the near future, personal EVs and small commercial vehicles will be BEVs. As the size of the vehicle increase, or the distance to be traveled, speed to refuel, or the cost of down time become an important factor, it become more attractive to use a FCEV. Hydrogen presently costs roughly the same price per unit of energy as diesel fuel. For long haul trucks, busses or other industrial applications FCEVs are more competitive and provide the best options. But BEVs are still expensive. For the near-term, at least the next five to eight years, gasoline powered vehicles will be less expensive to buy than a BEV. For now, gas powered cars are still the most attractive for the average car owner.
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