Thank goodness the need for the GREET measurement is being eliminated. With CO2 regulation dead and buried in Congress - we can get back to the vital issues of producing domestic energy. Thanks in part to the OBama OMB.

So based on this PHEV tax credits should be adjusted by states electricity generation carbon intensity.

This selected interpretation of this work should be clarified. PHEV charging on the US grid portfolio is nearly identical, or worse, in term of in-use CO2 compared to the equivalent HEV - ORNL (http://www.greencarcongress.com/2008/03/ornl-study-expl.html). PHEVs may decrease net CO2 emissions in France and Sweden, but not in the States. PHEVs will save big $$$ for any new car buyer...especially for those of use with 6kW of PV on our roof. I'll be driving for free...better than free due to the income and state tax rebates.',;

FCV use 10-90% less greenhouse gas? Well at least it's a tight little range.

@Hess,

All power plants are much more efficient at turning carbon into kilowatts than a typical ICE. The closer a PHEV becomes to a BEV in its actual usage, the better its GHG advantage over any vehicle that burns chemicals.

I think you all are missing a few important points.

Most striking is that EV's won't substantially reduce CO2 emissions in the U.S. since 50% of our electricity comes from coal (thanks Sierra Club) and 20% from natural gas, especially since natural gas is the marginal fuel of choice as detailed in the study.

It's a shame they didn't include all-electric EV's in the study, but we can tease out the results by comparing the different battery sizes.

The flat and sometimes inverted slopes of the line between the 10 mile and 40 mile PHEV shows that the reduction in CO2 is proportional to the fuel savings and overall the extra battery doesn't really help.

Focusing on the rectangular shape showing the U.S. average mix, a few interesting observations jump out:

1) Gasoline, diesel and E85/corn were all about flat, with the larger battery only producing slightly less CO2.

2) For H2/FC/natural gas, H2/FC/biomass and E85/biomass, the larger battery causes much more CO2 production (sharp curve).

3) Electrolysis is a relatively efficient way to produce H2.

The conclusion? Absent a huge shift in electrical power production, fuel efficiency and biomass (into H2 or E85) are the only effective way of reducing CO2.

The problem is that even though gas and coal can be converted into electricity more efficiently than an ICE, losses on the way to the wheels turn it into a little better than a wash.

Also, until the marginal power source is replaced, using clean power to charge the batteries won't change the equation, because that clean power could alternatively be pumped into the grid to reduce natural gas usage.

-Mercy

FC distributed electrolysis - H2...that sounds like photovoltaic electrolysis at your home. I do not believe that compares favorably to photovoltaic recharging of BEV.

Mercy,

For H2/FC/natural gas, H2/FC/biomass and E85/biomass, the larger battery causes much more CO2 production (sharp curve).

If you have a larger battery you use less biofuel, so more is available for generating electricity, which lowers the CO2 emissions for power generation.

The conclusion? Absent a huge shift in electrical power production, fuel efficiency and biomass (into H2 or E85) are the only effective way of reducing CO2.

Therefore, I do not share this conclusion, since it doesn't take this shift into account but relies upon a constant grid mix.

This research suggests that biofuels are better than electricity, which is incompatible with the findings of this study.

You can not ignore the fact that biomass not used as biofuel is available for electricity generation.

Actually, the suggestion of this research that biofuels are better than electricity is incompatible with the findings of this study.

You can not ignore the fact that biomass not used as biofuel is available for electricity generation.

Yes I can. First it is not a fact. Second, you need to read chapter two of this LCA. Biomass generated electricity would be base load like nuclear and not be be a marginal source of electricity to charge batteries.

Hauling heavy batteries around is a marginal, at best, way to reduce the environmental impact of oil. Mercy nailed this aspect.

I will pile it on. BEV are MAI and PHEV are DOA. Nobody will buy them. Ya, folks here talk a lot but it is hard to beat a good compact car like a Corolla.

Of course none of this matters because the effect of the .000038 man-made CO2 in our atmosphere is statistically ZERO.