June 11, 2008. Toyota president with PHEV Prius. Congress to meet.

[bac]

Originally Posted by thecoook

I think oil prices and the freemarket solutions to it are doing more/faster than anything Congress could put together.

Totally agreed .... as long as we can keep the government out of the "free market", there is a chance. However, I just don't see that happening given our history.

... Brad

[Scruge]

Originally Posted by Earthling

I don't have the exact figures, but you are way off with that statement.

You're right its not 20%. I used thermodynamics approximation for thermal engine efficiency.

Sub critical Nuclear, NG and coal plants are in the 30-35% range .
Some of the newer super critical coal plants are approx 40% with a few experimental coal coming in at 50%

[Godiva]

Originally Posted by Scruge

I guess EV will mean higher electric bills and brown outs.

btw.. running a car off the power grid isn't very efficient, conversion and transmission losses suck.

No. It won't.

Most cars will be charged overnight. Electricity production is steady 24 horus a day. The electricity generated at night goes largely unused. So charging cars at night doesn't add much to demand but does efficiently use all that is produced.

And....I like the paint job.

[jhinton]

Originally Posted by Scruge

Assuming the power plant is burning oil, coal or natural gas to run its external combustion engine (steam, thermal engine) to turn the generator I would say it is working with the same inefficiency as the ICE 20%. Plus the power plant has the additional losses from transformation and transmission which can be as high as 20-30%.. so you wind up with total efficiencies of 15% before you've even charged your battery. Now factor your EV's charging/discharging and motor losses of 30+%. The way I see it your over all efficiency is down to 10-12% running off the power grid.

Your efficiency numbers for power plants are WAY off. The latest in Combined-Cycle technology are the GE 7H and GE 9H. These are 400MW and 520 MW respectively and both achieve 60% efficiency. I worked on this program during it's development from 2000 to 2002 and the first commercial plant came online in 2007. GE Energy - H System™ Combined Cycle Gas Turbine

I've also worked on the GE 7FA, 9FA, 7FB, and 9FB programs which achieve 56% to 58% efficient These powerplants first came on line in the mid 80's and were developed in the late 70's to early 80's. This is not new technology and is quite representative of the typical powerplant.

You can read up of these at: GE Energy - F Class

[hill]

Originally Posted by Scruge

hmmm..
Ethanol demand is contributing to higher food prices.

I guess EV will mean higher electric bills and brown outs.

btw.. running a car off the power grid isn't very efficient, conversion and transmission losses suck.

You're presuming photo cels can't pick up the slack. And that the U.S. will always remain more ignorant than the European community, that benefits so much from the technology, so much that they even buy up product from the paltry U.S. market. What an irony ... the amount of jobs that are exploading in the photo cel biz overseas ... and other high tech power businesses as well ... yet here in the U.S. ? We are NOT experiencing high tech power industry growth. We're still stuck with the mentality that says, "better not plug in that car, or we'll all brown out". Makes me want to cry.

BTW, you CAN recharge "off peak" ~ during the night time, you know. Lots of other novel ideas out there as well. But pooh poohing via brown outs? Maybe I should just be greatfull the natural gas industry didn't come up with that excuse, when electric ovens / stoves ramped up many decades ago. After all, a big ol' electric oven will use more power than a charger.

[Scruge]

Geeezzz, I was only making an observation. You guys are a tough croud.

Fact 1. The US consumes 388,000,000 gallons of gasoline per day or put another way 14,200,000,000 KWH which equals 5,188,306,000,000 KWH per year. I used 36.6KWh per gallon of regular unleaded, at unity conversion

Fact 2. The US in 2003 consumed 3,883,000,000,000 KWH of electricity for the whole year.

If we assume power plants are 2x more efficient at converting fuel to electricity than ICE, then demand for cars should be half the current level. Resulting in cars only needing to suck an additional 2,600,000,000,000 KWH per year, off a system that's only putting out 3,883,000,000,000 KWH per year

Which means a 67% increase and you must also pick a readily available fuel to feed it.
That doesn't look like an easy task to me. .

I see nothing wrong with EV, but it looks to me like we need to reinforce our current power generation infrastructure before embracing EV as a cure all.
I certainly don't want to be sitting in the dark, without A/C and transportation.

To others.. from what I've been able to find, the newer high efficiency plants still represent a small fraction of the total.

[urs70]

Here's a comparison provided by Tesla motors for electric vs other cars for efficiency.

Tesla Motors - well-to-wheel

May be they are biased but the no.s look plausible.

Originally Posted by Scruge

Which means a 67% increase and you must also pick a readily available fuel to feed it.
That doesn't look like an easy task to me. .

I once read a report suggesting 80% of the current no. of vehicles can be run by electricity without any increase in capacity if they are charged during off-peak hours.
But no matter what the real-life no.s are, the change is going to take a long time. If 10% vehicles are plug-in by 2020 I think they can be considered really successful. The power companies are already rooting for plug-in vehicles. They will have plenty of time for adapting.

[jhinton]

Originally Posted by Scruge

Geeezzz, I was only making an observation. You guys are a tough croud.

You will find a lot of engineering / scientific types here at PriusChat. We tend to dislike guesses and estimates and instead prefer your line of reasoning be backed up with verifiable references.

Originally Posted by Scruge

Fact 1. The US consumes 388,000,000 gallons of gasoline per day or put another way 14,200,000,000 KWH which equals 5,188,306,000,000 KWH per year. I used 36.6KWh per gallon of regular unleaded, at unity conversion

Fact 2. The US in 2003 consumed 3,883,000,000,000 KWH of electricity for the whole year.

You can't just convert the energy in gasoline KW's due to the differences in efficiencies for gasoline and electric vehicles. The telsa link above is a good summary of these differences.

If you will notice, even though electric power generation has a rather poor efficiency from source to plug (52%) the vehicle itself is so much more efficient (~3x as efficient) that the overall energy use per km is ~ 1/2 that of the most efficient gasoline vehicle.

Originally Posted by Scruge

If we assume power plants are 2x more efficient at converting fuel to electricity than ICE, then demand for cars should be half the current level. Resulting in cars only needing to suck an additional 2,600,000,000,000 KWH per year, off a system that's only putting out 3,883,000,000,000 KWH per year.

Which means a 67% increase and you must also pick a readily available fuel to feed it. That doesn't look like an easy task to me.

Yes, you will need more fuel, but not necessarily more infrastructure. The US electric grid is set up to handle the highest peak loads. The base load is usually supplied by Coal and Nuclear plants while peaks are handled by natural gas IGT's, and hydro. The peak loads happen infrequently and during the day do to industrial and A/C use. Electric vehicles would plug in at night, when the grid use is low. This would be done by placing the vehicles on a timer to start charging about mid-night. The details of this can be found in the DOE Pacific Northwest National Lab's paper titled: IMPACTS ASSESSMENT OF PLUG-IN HYBRID VEHICLES ON ELECTRIC UTILITIES AND REGIONAL U.S. POWER GRIDS. In this paper the lab concludes that the current electrical grid could handle 84% of our personal transportation needs or 73% of total Light-Duty Vehicle use.
http://www.pnl.gov/energy/eed/etd/pd...s_combined.pdf

Originally Posted by Scruge

To others.. from what I've been able to find, the newer high efficiency plants still represent a small fraction of the total.

You are correct that there are many older and less efficient power plants still in use in the US. One of the coal-fired power plants I toured while interviewing with Southern Power had (4) 250MW and (1) 900 MW steam turbines. The oldest of the 250MW turbines came on line in the 50's and have been in use ever since. Coal-fired plants are also less efficient that the IGT's I talked about above. Coal-fired plants are between 38% - 48% efficient.
Fossil fuel power plant - Wikipedia, the free encyclopedia

[drees]

Originally Posted by Godiva

Electricity production is steady 24 horus a day. The electricity generated at night goes largely unused.

No, it's not. Just because a plant has 500MW of capacity, does not mean that it has to burn 500MW worth of fuel 24 hours a day.

While some excess is generated all the time to account for peaks, power generation definitely varies depending on the current load.

Certain types of plants are slower to react to changes in demand, so those types of plants tend to be used for baseload (along with the cheapest to operate plants), with quicker reacting and more expensive plants (like natural gas) used for peak loads.

Here in California, the power mix is about 50% natural gas, 20% nuclear, 10% hydro, 10% coal and 10% renewable.

[Scruge]

Interesting you picked on the 20% efficiency I used for power plants, which btw had a nice margin of safety.
However the feasibility report provided uses every thing including ICE generators to help meet only 65-75% of the potential demand for a 12 hour car charging period. The report isn't even sure how to enforce designated charging hours. It then talks about an elaborate method to transfer the demand around the country at given times of the day. Reminiscent of the rolling blackouts? Talk about a stretch.

The report only addresses generating capacities and doesn't touch on delivery/distribution, grid stress or battery disposal.
Like, what is the impact of everyone plugging a 3 - 5 KW charger into their household wiring. I certainly don't have an outlet in my house capable.
What about apartments and condos?
In some areas a single 30kva transformer serves 4 homes. Can it handle the additional 12-20kw load?
With the additional demand on the grid won't MTBF decrease?
What's the life expectancy of the batteries and where will they be disposed?.

What does this mean?
When compared with an HEV such as the Prius, the economics of the PHEV are not favorable at high electricity prices and marginally favorable at lower electricity prices. This conclusion could change if electric utilities offered reduced electric rates for large blocks of electricity purchased off-peak (and possibly increased them on-peak).

Originally Posted by jhinton

You can't just convert the energy in gasoline KW's due to the differences in efficiencies for gasoline and electric vehicles. The telsa link above is a good summary of these differences.

I wasn't able to find any stats on the amount of work preformed by the 388,000,000 gallons of gasoline consumed daily. We are talking about plug-in EV so I thought it would be appropriate to convert to equivalent electrical power. One can debate whether its all needed and its effective use. I already reduced it by half via power plant conversion. There are a lot of other factors that affect efficiency, cargo, size, shape, weight, speed, safety and reliability, just to name a few. Plus one can debate miles/KW verses HP/KW

Originally Posted by urs70

Here's a comparison provided by Tesla motors for electric vs other cars for efficiency.

As for Tesla, I couldn't find the EPA doc they cited for their MPG conversion. From the looks of their glossy, they can go 220 miles on approximately $4.40 worth of energy. (220 miles @ 2 cents/mile) Sounds like a freight train commercial, "we can move 1 ton 423 miles on 1 gallon of diesel". Tesla must use those very efficient Chinese air compressor motors, (5hp on only 100 watts of power)


Again my comments are meant only to stimulate thought beyond the dazzle.