GRA wrote:I'm in general agreement with the above advantages and advantages, and having used gas, diesel, propane and battery forklifts (and pallet jacks), I'd say that for multi-shift operations FCEVs win hands-down - you just don't have the down time to charge, especially when the shifts overlap and both of them are using the same equipment.
I agree in the case where shifts overlap into the break times. Otherwise, it seems that a one-hour quick charge could be accomplished during two 30-minute breaks each shift.
The drawback to charging only during breaks is that it creates very high peak electricity usage, which can drive costs up significantly. The question is whether it can drive costs up to H2 fuel cell cost levels
GRA wrote:Assuming H2 tanks can be swapped like propane can, the on-site costs are essentially zero.
That assumption is almost certainly wrong. If you can support it with some reference, feel free. Plug Power ONLY discusses refueling, NOT swapping.
No, H2 fuel cells for forklifts are refueled using specialized refueling equipment. As I learned from my discussion with a friend
, this equipment is extremely expensive. In that case, a four-station filling system for Plug Power fuel cells cost $3.5M. This is a huge drawback for fuel cells, which will limit their use to larger sites.
GRA wrote:Re efficiency, current fuel cells are apparently about 60% efficient.
You may be right here, but that would only be true in the very latest units from Plug Power, which only recently started shipping
timesunion wrote:Plug Power says it has created a new, more efficient fuel cell for its fork lift customers that the company says will reduce the need for refueling.
timesunion wrote:"This new GenDrive model stores more fuel on-board than earlier models, increasing run-time by 56 percent and reducing a customer's overall fueling time by more than 30 percent," the company said in a statement. "The first customer orders for these GenDrive units are scheduled to ship at the beginning of the third quarter of 2018."
I've read elsewhere that they increased the capacity of the storage tanks by about 10%, so that means the efficiency of the fuel cell must have increased by about 42%. Plug Power "plugs" this as reducing the number of refuelings from three per day to only two. This is an interesting claim, as it implies that there is value in saving those extra three minutes each day. In fact, Plug Power claims those three minutes have extremely high value:
timesunion wrote:"For a typical customer with more than 90 Class 2 vehicles, this translates to a projected productivity savings in excess of $400,000 over five years," Plug Power said.
I seriously doubt any company can translate that time savings into anywhere near that big of a dollar savings. I also doubt the third refueling is a big deal to any company which operates three shifts.
But it *does* indicate that Plug Power likely has a runtime benefit over Flux Power, at least for the time being. In the long run, Li-ion batteries will win out over fuel cells in terms of runtime. How do I know this? Simple: if we agree that fuel cells are 60% efficient today, then they can only ever realize a 38% efficiency boost before they reach their theoretical limit of 83%. OTOH, Li-ion batteries are a long way from reaching theoretical capacities. Many are expecting that solid-electrolyte Li-based batteries are capable of 1000 Wh/kg
or even more. Since solid-electrolyte lithium batteries will have lower efficiency than their Li-ion counterparts, there will be a real tradeoff between capacity and efficiency. In any case, it should not be long before Li-ion batteries are capable of providing two full shifts of energy before needing a recharge, which will meet the needs of all but the most demanding warehouses.
GRA wrote:The fuel cell's components can apparently be refurbished, while battery packs that aren't very new will quickly pull new cells down to the level of the old cells. From what I've read, fuel cell stack lifetimes are currently considerably longer than batteries.
While all of that may be true, there is a lot more to fuel cells than just the life of the stack. We know that Plug Power has had some problems with the reliability of their units
. Perhaps that is why they have recently redesigned their units for better servicability
Fuel Cell Works wrote:These new units are designed with Plug Power’s proven ProGen hydrogen fuel cell engine technology which delivers increased efficiency and higher reliability. The new units include several significant enhancements such as larger fuel tanks for increased runtime (approximately 10%) and wireless communication capabilities for operations data and effective fleet management. With a new design that is focused on ease of service for both field technicians and customers, Plug Power also improved the product serviceability, reducing the time and effort required to work on the units.
It will be interesting to see how these new units stand up when compared with Li-ion batteries.
GRA wrote:I suspect at the moment it depends on your operating requirements as to which is cheaper, and there's not as yet any universal "best" answer for now.
As I stated above:
RegGuheert wrote: I suspect each will have clear benefits over the other depending on the customer situation.
Overall, it seems that fossil fuels now have a home in high-demand materials handling applications.