Listing only areas where fuel-cell technology is progressing paints a rosy picture, but completely misses the big picture. The big picture is that fuel cells are deficient as a transportation fuel in many areas. Until all, or nearly all, of those deficiencies are overcome, fuel-cell vehicles will have little to no chance of taking market share from BEVs. But several of these deficiencies CANNOT be overcome. Let's try to list these many areas of deficiency:GRA wrote:Yes, fuel cell mass production will be the key to their costs making the next major step down, which is exactly where the companies which are producing FCEVs are devoting much of their R&D - Toyota certainly is. Other R&D areas are reducing or eliminating Pt and increasing both power density and longevity. So far, every succeeding generation of FCEVs deployed has seen these last three areas improve by 50% or more (about 100% for power density) compared to the immediately preceding generation. Those curves will start to flatten soon, if they haven't already.RegGuheert wrote:That's a completely different story than fuel cells, which no one has yet learned how to mass produce.
- Because of the chemical reactions required to hydrolyze and recombine the water, the round-trip energy efficiency is low: below 50%. This compares with current Li-ion battery round-trip energy efficiency of 98%. The impact is that H2 FCVs require more than twice as much renewable electricity generation as BEVs.
- H2 FCVs cannot be refueled at home inexpensively. In addition to the over 2-to-1 increase in generation required, H2 FCVs require complex, unreliable equipment costing in the 100s of thousands of dollars. This compares with BEVs, which can be cheaply and efficiently refueled at home using reliable, off-the-shelf equipment which costs about $1000 installed. This single fact will virtually eliminate demand for H2 FCVs for homeowners.
- H2 is extremely expensive to make using hydrolysis, resulting in the cost of H2 fuel exceeding US$9.00/kg. This cost is nowhere near being competitive and has to compete with BEV fuel costs which are near the cost of purchasing less than half as much electricity as an H2 FCV requires per mile. In other words, there will never be a crossover for fuel costs.
- H2 FCV refueling infrastructure is nearly non-existent while most BEV refueling infrastructure equates to simple grid extensions.
- According to Toyota, the technology does not yet exist to mass-produce fuel cells.
- Fuel cells are very expensive to manufacture. On top of that, the DOE reports that per-kW manufacturing costs for fuel cells are not coming down:
OTOH, costs of batteries are coming down faster than government projections.
- H2 FCVs do not offer the performance of BEVs. It seems likely that even low-end BEVs will have higher performance than high-end FCVs. The exception could be the application of H2 fuel cells as a range extender for a BEV.
- The range of BEVs has now surpassed that of H2 FCVs. This gap in range capability is likely to only increase as time goes on due to the difficulty of carrying additional H2 fuel.
- H2 fuel is carried on-board at very high pressure. In addition, H2 tends to make the its container brittle over time, particularly when stored at high pressure. Massive explosions are possible when a high-pressure containment vessel is damaged in an accident.
- H2 fuel has the widest range of flammability of any gas. While it dissipates rapidly in the atmosphere once released, there is a potential for ignition until it does dissipate. Indoor leaks or releases could be very dangerous.
- Electrolysis of water consumes fresh water. That could pose a real problem in many areas of the fresh water is a very limited resource.
I used to believe that H2 would find some applications as a vehicle fuel, and it HAS made some inroads in forklifts, but Li-ion battery technology has advanced so rapidly in the recent past that it seems unlikely that H2 can compete in more than obscure short-term storage applications such as transportation. That would leave H2 to possibly serve in the role of providing long-term energy storage (beyond a week or so) because it can offer efficiencies over batteries in terms of resource consumption over BEVs in those roles. GRA has provided an article about H2 in this application immediately above this post. It will be interesting to see if this approach has long-term merit. I have to wonder if any form of long-term storage will ultimately be too costly in terms of overall resource consumption to make it unattractive except in locations far from the equator. Countries like Germany may not have sufficient renewable resources to feed their economies without massive improvements in energy efficiency. Unfortunately, fuel cells fall on the wrong side of the efficiency equation.
There are some here who have imagined that if/when H2 is used for long-term storage applications that it will then become a cheap form of vehicle fuel. There is a major problem with this idea: H2 is an INEFFICIENT vehicle fuel, so fewer renewable resources and infrastructure will be required to fuel a BEV fleet than an H2 FCV fleet. The only exception may be in very cold temperatures in which a heat pump does not offer better efficiencies than a resistive heater. But even then H2 FCVs only approach the efficiency of BEVs seasonally. During the other months, H2 FCVs will waste H2 that could otherwise be stored for wintertime heating applications.
It seems quite clear that batteries will be used to address the vast majority of short-term energy storage that will be required in the future, including for transportation.