SageBrush wrote:It is said by optimists that electrolysis efficiency will reach 80%, and fuel cells will reach 70% efficiency in the future.
With a theoretical efficiency of about 83%, I'll guess that the 70% number is about right. Water electrolysis could top out at or above 100% given that the theoretical efficiency is around 120%.
SageBrush wrote:I'll wager good money that cell batteries will drop to $50 a kWh for the manufacturer, energy density will double, and charging speeds average over 200 kW long before the hoped for H2 improvements.
I think you are correct on all counts. But here is the rub: Many of the near-term improvements in batteries will be achieved by moving to a solid electrolyte. That change will increase energy density and safety and reduce cost. Unfortunately, it will also reduce the efficiency.
Instead of the 98+% round-trip energy efficiency which is achieved in the battery in your Tesla Model 3, battery efficiency could drop to somewhere between 60% and 90%.
So we will get back to the thesis that GRA has always held: People will choose convenience over efficiency any day. If we lower the round-trip energy efficiency of batteries to 80% and increase the round-trip energy efficiency of hydrogen to 60% or 70%, what will people choose for their vehicles?
I suspect there will be different preferences for different people:
- For someone like me who produces electricity on my roof and can charge at home, I will continue to prefer a battery-electric vehicle since the fuel is pre-paid and charging at home is more convenient than stopping for fuel. I will also prefer a Li-ion battery over a solid-state battery given the higher efficiency since that means I get more "miles per panel" from the investment on my roof.
- For others living in single-family homes, I suspect they will also prefer BEVs over H2 FCVs based on the convenience factor.
- For people like GRA who rent, I suspect the convenience of H2 FCVs *may* win out.
But even if the efficiency numbers do end up that close, then cost will end up being the deciding factor. Since I don't see the fuel or vehicle cost of H2 FCVs ever getting close to that of BEVs (again, there is NO crossover point), I suspect that even many without their own homes will choose BEVs, pushing for better charging infrastructure to make that option viable.
As always, time will tell.