More Shockingly Good News from Shale Gas

[RedylC94]

Right. Assuming (I realize these are only rough estimates.) Indigo's 80% electric motor efficiency is correct and 50 mpg's 80% plug-to-motor efficiency is correct, and optimistically assuming 40% fuel-to-plug efficiency of power plant and distribution, 80%×80%×40%= about 26%. Power plants do have the big advantage of being able to burn cheaper fuel.

Overall thermal losses through coolant and directly from exposed engine surfaces include a mixture of heat from two sources: 1)friction, which shows up as heat; and 2) heating of cylinder walls by hot combustion gases, which reduces cylinder pressure during the power stroke, which reduces torque, which reduces efficiency. Even if engine designers could miraculously eliminate friction and heat loss in the cylinder, an engine would still be far below 100% efficiency, because of the basic thermodynamics of heat engines---not to mention part-load throttling losses of SI engines.

[50 mpg by 2012]

Average US coal fired power generation fleet efficiency was about 33% back about 2008 and some of the very old (70+ years) were down in the 22~25% range ... and best of breed was 36% ... iirc.

Emissions abatement upgrades on these coal powered systems could increase parasitic losses by 2% to 20% depending on facility design, equipment condition, and fuel source (quality/cleanliness).

There was suppose to be a new best of breed pilot coal plant startup in the US some time in 2012 with an efficiency in the range of 45~55%. I have not followed up on the status of that effort.

[I read somewhere the average coal fired coal plant in China was about 40% ... for several reasons ... predominately because most are newer with the latest technologies.]

NG power plant (turbines) are said to be in the 50~55% range. However, something I have seen little discussion of ... like coal ... all NG is NOT created equal. Some requires cleaning before use. I don't have a clue about the economics associated with this.

As for electricity delivery efficiency ... prior exchanges suggest about a 7~12% loss from the generator to point of use, at least one step up and three step down transformers plus transmission line losses.

And we still have not discussed losses from the hole in the ground to flame ...

fwiw ...

[PaleMelanesian]

To compare EV against gas-powered cars, you have to include all the drilling, shipping, refining, and delivery inefficiencies in the petro industry.

[Right Lane Cruiser]

Originally Posted by 50 mpg by 2012

On of the major losses in EVs is all the electrical and chemical/thermal losses from the power input power plug to motor terminals.

My best guess is about 80% efficient input plug to motor (charging plus discharging). IF anyone has a better number ... please share.

My LEAF is holding steady at around 71.4% for that measure, though that is on 110V and I've read that it should be more efficient on 220V charging (more like 77% or so). Other vehicles may have more efficient chargers onboard.

[CRT1]

I've seen reports that have done the well-to-wheels analysis and put EVs at ~30% and PHEV at ~50% the carbon footprint of similarly sized gas-only car, IIRC. This using a mix of energy for the elec generation (coal, nat gas, diesel, renewables, etc) that was roughly average for the US. Even at all-coal, the EV was still only about 50% the carbon footprint.

[50 mpg by 2012]

Even at all-coal, the EV was still only about 50% the carbon footprint.

IIRC, WXMAN's GREET analysis "well/hole-to-wheel" did not support that. In fact, I believe the results showed PEV using average US electrical power mix was a wash with a Passat diesel.

My LEAF is holding steady at around 71.4% for that measure, though that is on 110V and I've read that it should be more efficient on 220V charging (more like 77% or so).

Maybe ... lower I^2R losses at 220 VAC and lower current demand?

[CRT1]

Originally Posted by 50 mpg by 2012

In fact, I believe the results showed PEV using average US electrical power mix was a wash with a Passat diesel

A Passat Diesel is about 50% the carbon footprint of an average car its size (40 MPG, vs 20 MPG IIRC), so you are in fact confirming my recollection +/- 5ish%.

The numbers I quoted do not mean that PHEVs and EVs are the ONLY solution. Like anything there is no sliver bullet, there is and will be a mix of technologies that will carry the day. High efficiency diesels are totally awesome. I suspect that there is a lot of runway left with straight-gas engines also, like the 1L Ecoboost. PHEVs are awesome also. Pure EVs for the right person are spectacular . . .

[RedylC94]

Originally Posted by Right Lane Cruiser

My LEAF is holding steady at around 71.4% for that [input plug to motor] measure, though that is on 110V and I've read that it should be more efficient on 220V charging (more like 77% or so). Other vehicles may have more efficient chargers onboard.

How much of your 25.8% loss is in the charger, how much in battery, and in wiring, etc.? Does the OEM display reveal specifically how much energy reaches the motor? They probably could make the 120VAC charger more efficient by putting more money and weight into it, but engineering requires a lot of compromises.

[50 mpg by 2012]

Originally Posted by CRT1

Like anything there is no sliver bullet, there is and will be a mix of technologies that will carry the day. High efficiency diesels are totally awesome. I suspect that there is a lot of runway left with straight-gas engines also, like the 1L Ecoboost. PHEVs are awesome also. Pure EVs for the right person are spectacular . . .

Agreed, there will be an evolutionary phasing of technology solutions.

Diesel is probably the quickest and most cost effective near term solution ... an "interim bridge" if you will.

One for the imagination to play with ...

Start with Ford's new 1 Liter EcoBoost. Then, translate those inovations to a small displacement diesel ... how much could be gained??

Interesting possibilities to consider ... with a little dreaming and innovation.

Delphi, Bosch, Riccardo, and others are all doing interesting work toward achieving <95 gCO2/km fleet average by 2020 ... about 58/66 mpg(US) for gasoline and diesel respectively.

And we should know by August if the EU commits to the 2020 <95 gCO2/km fleet average.

The same time frame the US decides on committing to 44 mpg fleet average (about 135 gCO2/km) for 2025 CAFE.

Originally Posted by RedylC94

How much of your 25.8% loss is in the charger, how much in battery, and in wiring, etc.? Does the OEM display reveal specifically how much energy reaches the motor? They probably could make the 120VAC charger more efficient by putting more money and weight into it, but engineering requires a lot of compromises.

My best guess is that 1/2 the loss is battery chemistry and thermal. The other half is fairly evenly split between charging and discharging (powering the drive motors).

I am not certain about battery loss differences between RAPID and SLOW charging. More data is needed.

[basjoos]

Originally Posted by Indigo

An aspect of the big picture that is often overlooked is the cattle industry. In addition to deforestation, cattle farming creates a vast amount of methane (which is actually a lot worse than CO2). The government seriously needs to stop subsidizing beef.

The methane produced by the cattle industry replaces the methane that used to be produced by the vast herds of bison that used to populate the Great Plains before the white man shot them to near extinction in their effort to get rid of the American Indian's "commissary". Today's cattle population is roughly equivalent to the population of bison prior to the slaughter.