Roadtrek demonstrates WATT Fuel Cell Technology

[john61ct]

Direct generation from propane, no combustion

https://youtu.be/naQk7RrWUdI

[Dtrombley]

I've had my eye on Watt Fuel Cells for several months. They recently shipped their first batch of Imperium Fuel Cells to Hymer, a Canadian RV manufacturer/conglomorate. Hymer is starting to incorporate the fuel cells into their RV lines. I emailed Watt to find out about acquiring one for our boat. The response was, "Availability will be through selected distributors sometime in late 2019." For now, that's all I can add to this discussion.

[sparrowhawk1]

So what's the bottom line? How much propane needs to be burned to get 1 amp hour?
Or how many amp hours for one pound of propane?

[SV DestinyAscen]

Originally Posted by sparrowhawk1

So what's the bottom line? How much propane needs to be burned to get 1 amp hour?
Or how many amp hours for one pound of propane?

https://www.wattfuelcell.com/portabl...watt-imperium/



I'm not really sure what's the competitive advantage over the much more adopted, lighter & mature EFOY methanol fuel cells?

https://www.efoy-comfort.com/technical-data

The EFOY units are time tested and routinely used on the Class 6.5 little boats.

[Dtrombley]

For the EFOY units, is methanol readily available? Can the M5 or M10 fuel cartridges be easily refilled?

[Paul Elliott]

Originally Posted by SV DestinyAscen

https://www.wattfuelcell.com/portabl...watt-imperium/

I think these guys are being overoptimistic when comparing their propane fuel-cell to a diesel generator. On their website they claim that their fuel cell uses 20 gallons of propane, where a diesel generator requires 55 gallons of diesel fuel to deliver the same energy. They are assuming a 40A alternator and a apparently a high-consumption diesel.

If I look at my fairly typical setup, with a 45hp Yanmar and an 80A alternator, I can get roughly 60A continuous (once the alternator gets hot) and burn about 0.3 gallons per hour (transmission in neutral). Assuming a battery voltage of 12.5V, this means I burn about 5 gallons of diesel fuel in 16.7 hours, generating 10kWh. These are rough numbers, but reasonably close.

Their fuel cell consumes 0.34 gph and delivers 500W. To get 10kWh would require 6.8 gallons of propane and take 20 hours.

If I didn't already have an engine I could see the benefit. Yes, noise and engine wear are an issue, but not enough of one for me to want to add the fuel cell.

[SV DestinyAscen]

Originally Posted by Dtrombley

For the EFOY units, is methanol readily available? Can the M5 or M10 fuel cartridges be easily refilled?

The cartridges are not refillable - but are readily available at least in most of Europe and a quick search shows availability in the US.

It isn't for everyone - but the EFOY unit weighs significantly less than the propane fuel cell, the methanol is stored in a plastic container and doesn't compete with your cooking propane system... is a lot easier to safely storage/integrate into a boat.

The EFOY units aren't for everyone - but they're reliable and they're another option for folks who don't have/or don't want to run the diesel (and can't/won't opt for solar/hydro/wind gen).

[john61ct]

The key USP here is ready worldwide availability of LPG.

If it requires a very pure propane then that goes away, often butane is in the mix.

And yes, KWH produced per pound compared to traditionally fuelling a genny will be important, but perhaps not that critical for many.

[Colin A]

Originally Posted by SV DestinyAscen

https://www.wattfuelcell.com/portabl...watt-imperium/



I'm not really sure what's the competitive advantage over the much more adopted, lighter & mature EFOY methanol fuel cells?

https://www.efoy-comfort.com/technical-data

The EFOY units are time tested and routinely used on the Class 6.5 little boats.

Well your getting almost 5x the output in a package only about 3 times as heavy. Also many boats already have propane systems installed. Then you have the ease of fuel access. You also seem to have better energy density (installed cubic space of both unit and fuel) for the Watt.



For me the 500 watts makes it interesting. That's quite a bit of power for a short run to charge the battery.

[Matt Johnson]

Originally Posted by Paul Elliott

Their fuel cell consumes 0.34 gph and delivers 500W. To get 10kWh would require 6.8 gallons of propane and take 20 hours.

It's 0.34 lb/hr not gallons. So, it will make about 30kWh from a 20 lb tank.

Matt

[john61ct]

So about 25 "fillups" of a 100AH LFP bank.

Not bad at all IMO, last bottle I filled was ~$8, so 30¢ for fuel, not counting amortization of the gear.

And given only used to make up for poor solar conditions, that might be once a quarter in nice weather conditions.

[tanglewood]

Originally Posted by Paul Elliott

I think these guys are being overoptimistic when comparing their propane fuel-cell to a diesel generator. On their website they claim that their fuel cell uses 20 gallons of propane, where a diesel generator requires 55 gallons of diesel fuel to deliver the same energy. They are assuming a 40A alternator and a apparently a high-consumption diesel.

If I look at my fairly typical setup, with a 45hp Yanmar and an 80A alternator, I can get roughly 60A continuous (once the alternator gets hot) and burn about 0.3 gallons per hour (transmission in neutral). Assuming a battery voltage of 12.5V, this means I burn about 5 gallons of diesel fuel in 16.7 hours, generating 10kWh. These are rough numbers, but reasonably close.

Their fuel cell consumes 0.34 gph and delivers 500W. To get 10kWh would require 6.8 gallons of propane and take 20 hours.

If I didn't already have an engine I could see the benefit. Yes, noise and engine wear are an issue, but not enough of one for me to want to add the fuel cell.

Interesting figures, even with the propane usage corrected from gph to lbs/hr. To add to the mix, the rule of thumb for a diesel generator is 1 gal to produce 10kwh. So from a fuel perspective, 1/5 the consumption of running your main, and about 1/2 (in gallons) the propane fuel cell.


To me, greater dependence on propane is a killer, just as is bringing any other type of fuel on board. The only reason I tolerate propane is because when used for cooking alone, the tanks last a very long time. If I had the schlep off to find propane every few weeks for power generation, it would get old really fast, especially when I already have a lot of diesel on board.


But that of course assumes you have a generator, and descent chargers to load it up and recharge quickly.

[Matt Johnson]

Yup! Finding propane fill every few months is pain enough... having to do it monthly would be a killer.

We have 600 watts of solar and a D400 wind gen. This past month, if we weren’t plugged into shore power, we wouldn’t have been able to keep up with our daily load here in the Azores. It’s grey, rainy and pretty much windless. We’ve had similar conditions both in Belize and in the Bahamas in the past.

Based on what I’ve seen coming in via renewables, I’d get a little less than a month on a 20lb tank to cover our deficit.

And, if it’s going to be rarely used, why not save the money and go with a Honda 2000.

Really, I’m guessing the liveaboard full time cruiser is not the market they are targeting.

Matt

[john61ct]

No, in fact for now the prototype beta stage, exclusive to the Hymer / RoadTrek RVs.

My offroad trailer carries 80-100 gallons of LPG anyway, hence my interest.

I agree much more limited niche in fulltime cruising boats.

But for those off-grid only a few weeks at a time, in regions where propane is easy and cheap,

leaves only the safety issues.

Personally I would value the near-silence and lack of CO production.

[Matt Johnson]

I get the near silence, but if it's supplemental to solar, the times you'd need the gen is when it's cloudy/rainy and not a time I'd be hanging out in a lounge chair next to an RV anyway.

Matt