RegGuheert wrote:Let Reg complete the thought

LOL!

evnow wrote:BTW, what is the well-to-wheel Carbon gm/mile for this FCEV vs Leaf (or for that matter RAV4EV)?

Some figures to start:

Tuscon FCEV is rated at 2 kg H2 / 100 mi

RAV4-EV: 44 kWh / 100 mi

LEAF: 30 kWh / 100 mi

So now you just need to figure out how many emissions are in each kWh of electricity or kg of H2.

Other figures if someone else wants to do the math:

The grid in California is around 400 lbs CO2 / MWh [1]

The CEC says that natural gas is around 13.446 lbs CO2 / therm [2]

A therm is around 29.3 kWh of energy [3]

Reforming H2 from natural gas is around 70% efficient [4]

A kg of H2 holds around 33.3 kWh of energy [5]

Compression of one kg of H2 to 700 bar takes about 3 kWh (9%) [6]

Using that data:

RAV4-EV: 0.44 kWh/mi * 0.4 lbs CO2 / kWh = 0.176 lbs CO2 / mi

LEAF: 0.3 kWh/mi * 0.4 lbs CO2 / kWh = 0.12 lbs CO2 / mi

1 therm natural gas * 70% reforming efficiency * 91% compression efficiency = 63.7% overall efficiency or 18.7 kWh worth of H2 per therm

18.7 kWh / 33.3 kWh / kg = 0.56 kg H2 per therm natural gas or 1.78 therms per kg.

1.78 therms * 13.446 = 24 lbs CO2 / kg

Tuscon FCEV: 0.02 kg H2 / mi * 24 lbs CO2 / kg = 0.48 lbs CO2 / mi

Did I make a mistake or is the Tuscon FCEV 3 times worse than the RAV4-EV in terms of CO2 emissions per mile?

[1]

http://www.pge.com/includes/docs/pdfs/s ... _sheet.pdf[2]

http://www.pge.com/about/environment/ca ... ions.shtml[3]

http://en.wikipedia.org/wiki/Therm[4]

http://en.wikipedia.org/wiki/Steam_reforming[5]

http://www.hydrogen.energy.gov/pdfs/901 ... ession.pdf