Just took my PIP for a Road Trip to Prius Hippy Heaven!

True, but you are doing a lot of averaging across various energy sources in order to get that 100 KWh number for electricity. For example the ~10 yr old CCNG plant in San Jose is about 60% efficient. Transmission losses are probably about 5% to the local area (smaller than the national average of 7%). Therefore, working backwards from 33.7 kwh per gallon equivalent, that is about 60 kwh. ((33.7/.95)/.6) Still need to account for drilling and transport of NG. That is where most of my power comes from.

Second. It seems your 40 kwh for crude to the pump is optimistic. You are using 83% (33.7/.83). However, the DOE says that just the refining step is about 83% efficient. Thus you still need to add in the energy cost of drilling, pumping and distribution of the oil...or exclude its equivalent on the electricity side.

Third. Solar, wind, nuclear and hydro, for example all have varying "efficiency numbers" which have no correlation to each other or typical coal/NG plants. In order to do a fair comparison, for each, you'd have to do an energy balance, not look at efficiency numbers. For example a nuclear plant might have a thermal efficiency of 45%. But this is a meaningless number in this comparison because it is telling us the thermodynamic Carnot efficiency which is how much of the theoretical heat from each fission reaction gets converted into electricity. We don't really care one wit about this (in this context). We only care how much other energy it cost us to get any useful energy back out.

A more easily understood example might be wind or solar. It doesn't matter if a wind turbine only captures 1% of the wind flowing by. What really counts is how much energy did it take to build, install and maintain the turbine vs how much energy did it produce before EOL. I have no idea what those numbers are. But for solar PV we do know. A solar PV panel might last for 20-25 years and we know (roughly) that they pay back in 5 years the energy required to build and install them. Using 20 years as their lifetime (assume some maintenance and/or inverter replacement) that means for each 20 kwh produced is costs us 5 kwh. That means 80% efficiency of energy invested. Way above the average you are using. And, yes, solar is a small part of the national total.

But hydro, wind, solar and nuclear all have similar large efficiencies in terms of energy returned for energy invested.

Mike

 

100kWh is from all sources, weighted by kWh they generate.

Toyota didn't design PiP for San Jose. They designed it for global since Prius is sold around the world.

I think there are a lot more room for electricity generation efficiency for improvement. I look forward to it because, so then plugin hybrids can be tuned for it with respect to the upstream efficiency/emission.

PiP is the only plugin hybrid that I know that was designed with upstream in mind. The others like Ford Energi and Volt just cared about EV speed or range.

 

Still, I think your numbers are way off...100 kwh too high for average electric and 40 kwh too low for gas. The 40 kwh for gas just doesn't make sense...it is only taking into account the refining step, IMO.

60 KWh for CCNG is probably the "best" that number can be. Oh, except for nuclear and hydro. That means that to get the US average at 100 coal needs to be well over 100, perhaps 140 or 150. This just doesn't make sense.

Mike

 

Look at the values CAFE use to calculate Petroleum-equivalency factor (PEF).

Tg = U.S. average fossil-fuel electricity generation efficiency = 0.328
Tt = U.S. average electricity transmission efficiency = 0.924
Tp = Petroleum refining and distribution efficiency = 0.830
C = Watt-hours of energy per gallon of gasoline conversion factor = 33,705 Wh/gal

From that, we get:

40.6 kWh to refine and distribute for a gallon of gas.
111.2 kWh to generate and transmit a gallon equivalent electricity.

 

Something wrong with that picture. I find myself going into a slow burn over parking, more often than I'd like. If some party would include in their platform a pledge to outlaw pay parking, I'd be onboard.

Just starting with the low hanging fruit: why the heck to you have to pay for parking at a hospital? I mean besides lining someone's pocket.

 

The problem is that you are using 32.8% efficiency for fossil fuels and using that for all electricity. You can only use that for a portion of the whole electricity mix. Nuclear and hydro for example are fairly large and not included. Wind and solar are small but also not included. And as I said before, for these the "efficiency" values (the thermodynamic Carnot efficiency) don't apply. What does apply is energy in vs energy out. For large scale hydro, for example, there is virtually zero energy in since all big dams are already built. For nuclear it is primarily the cost of fuel enrichment.

Your numbers do not include the energy cost for drilling and transporting oil (nor for mining of coal or drilling for NG).

Bottom line (for me) is that coal + NG is about 2/3rds of US generation. The other 1/3 has (comparatively) near zero energy required for the fuel (nuclear excepted, but it is small). So the more realistic numbers are more like 75-80 kwh for electricity and 40 for oil. Coal (as bad as it is) and NG (much better) require much less energy to get to the power plant than oil to get to the refinery. 100% of coal and NG are domestic while, on the margin, 100% of oil comes from distant countries...tilting the numbers even more, besides the geo-political issues.

My records show that I get about 130-175 MPGe on electric, depending on the time of year and 50-55 mpg on gas. Not 100% fair since most EV is at slower speeds...but far above the ratio needed for EV to be a clear winner based on the national energy mix.

Mike

 

I think we both can agree that if adding more battery to the point of dragging down the gas MPG and the electric efficiency, would be the worse case scenario for a plugin hybrid.

Once that line is crossed, the point of plugging in becomes counter productive (perhaps the exception of geo-politic but still a debate between it and the environment).

The important things is, with the PiP, gas is setup to use for high speed long distance drives whereas electricity is setup for short trip lower speed driving. This is the only way the efficiency of both fuels is raised with synergy.

I think what you've accomplished cannot be done with either a pure EV nor a regular hybrid. An EV won't get 130-175 MPGe all year round and a regular Prius won't get 50-55 MPG with all those short trips you have.

 

Untill we get much lighter batteries and much larger battery capacity we are kind of stuck.
Lots of different batteries in the works using nano tech and different materials, hopefully things will pan out in the testing modes.

I'm like Sergeant Schultz......I know nothing!!!!!