H2 fuel cell or batteries?

[Richard230]

It looks like hydrogen fuel cell powered buses are not working out all that well for Canada: 

http://www.vancouversun.com/technology/Whistler+hydrogen+fuel+cell+program+jeopardy/9212028/story.html

[00049 (AKA SopFu)]

For a previous employer I was in charge of contracting for hydrogen fuel pilots, where the main item was always retrofitting fuel cells into lead acid fork trucks. Each of the pilots had a different way of getting hydrogen (ironically, tucking it in was the cheapest of the methods...but the location was right next to an Air Products plant), and one of them had a hydrogen bus (some methods of generating hydrogen require 100% or nothing, so you either burn off the excess...might as well pump it into a bus). The big benefit for forklifts is the ability to refuel in an instant and not have fumes in an indoor warehouse. I don't think H2 has any future in transportation since batteries are improving so rapidly.

At the time I figured the cheapest we could create H2 was around $9/gal of gasoline equivalent energy (at that was reforming natural gas at a large capacity plant). H2 is nice for speciality applications, but not a contender for consumer transportation fuel, IMO.

[ttxgpfan]

Elon Musk refers to fuel cells as "fool cells".  And that's enough for me.

[protomech]

I'm curious what their cost for hydrogen is, to get the running costs so high relative to diesel.

If hydrogen is reformed by grid electrolysis then it simply does not make sense. It costs more than diesel and in the general case will have similar or worse CO2 emissions. Canada may be a special case because they produce a very large amount of their power from hydro .. but elsewhere electrolysis is WORSE for CO2 than diesel.

It notes hydrogen fuel costs, at an average $2.28/km, are three times the cost of diesel, while maintenance costs $1 per kilometre, compared with 65 cents/km for diesel buses.

1 kg H2 is approximately equivalent to 0.81 gallons of diesel.

According to this study, hydrogen buses typically see 6.0 - 7.8 miles / diesel gallon equivalent.

This puts Whistler's fuel costs at approximately (6.0 to 7.8 miles / gal DGE) * (1 gal DGE / 0.81 kg H2) * ($2.28 CAD / km) * (1.6 km / mile) = $27 to $35 CAD per kg H2.

From http://hydrogen.energy.gov/pdfs/12024_h2_production_cost_natural_gas.pdf:

Using AEO 2009 prices for industrial natural gas as a production feedstock, the standard H2A case study for current forecourt hydrogen production via natural gas SMR estimates a dispensed hydrogen cost of $4.49/kg

Obviously this is a quick and flawed comparison. But purchasing units of transport fuel at $27-35 CAD when the roughly comparable "natural" costs are $4.49 USD seems suspect.

[oml]

Well here in Germany  we have the "problem" of too much wind energy on sunny days with lots of wind. We currently have days/weeks in the year were renewable energy is with about 70% the main provider of energy, but on other days it just 10-15%, forcing us to keep power-at-will stations like gas or coal (nuclear is getting extremely unimportent due to the fact its just not controllable enough). These numbers were achieved from 0-5% just ten years ago and its obvious it will just get "worse".
So we have to find a way to spend huge amounts of energy/power on demand and in response the first power-to-hydrogen-gas generators are going online, currently pumping the product directly into the natural gas grid (which has enough storage capacity for about 3/4 of a year, so the hope is that in the long run we can harvest enough energy in the summer to get through the winter with gas (with decentrealised fuel cells to get the warmth for free would be ideal)) but there are also experiments to use that as a car fuel.
(Hydrogen) gas seems to be the only realistic way to save the energy needed for seasonal differences (expect maybe thermal energy storage) and mobilising EV with it on the way wouldnt hurt that much (at least here in DE energy used for traffic is at about 15% of gross energy usage)

Therefore hydrogen generation through electrolysis does indeed make sense in certain situations - the inefficiency of about 20% is not a problem as we are talking about "waste"-conversion anyway - the problems are primarily the cost of building huge scale eletrolysis with minor workload (we are working on that   )

[protomech]

Round-trip efficiency for electrolysis (electrical energy -> electrolysis producing H2 -> fuel cell producing electrical energy) is around 40%, I think. Throwing away 60% of your energy is better than throwing away 100%, but it's not a great option.

Pumped hydro storage, battery storage, compressed air storage, thermal energy storage, kinetic energy storage are all better options as far as efficiency goes. Cost, power delivery, dispatchability are all considerations that will all drive the selection of energy recovery systems.

Personally I'd love to see V2G come online with EVs. Use the 60-80% range of my battery to handle minor grid fluctuations, keep the battery topped off for my selected departure point. It can potentially be a win for consumers (cheaper fuel) and a win for the power companies (cheaper energy storage in the form of customer-owned batteries).