Winter vs warm weather driving

[DucRider]

I said most EV's because a few use an actual heat pump to heat and cool the car but they must still have a resistance heater available for freezing weather.

The Clarity Electric is equipped with a heat pump, and it is a vast improvement over the Fit EV resistance only heater. At least in the "winter" we get in Coastal Oregon - less than half the range loss in all but the coldest conditions.

There are heat pump systems that work well below freezing, such as the gas injection system on the Prius Prime:
https://www2.greencarreports.com/ne...p-work-in-a-toyota-prius-prime-plug-in-hybrid

 

[David Towle]

I have no idea how any of that relates to the efficiency of the vehicle itself.

I have no idea how any of that relates to the efficiency of the vehicle itself.

An electric motor is upwards of 90% efficient.
A gas engine is 30% (this is in fact an extremely generous number). A hybrid (traditional or PHEV) recaptures some of the energy that would otherwise be wasted - but so does an EV!

Using the "efficiency" of the various ways electricity is produced while completely ignoring the "efficiency" of drilling, transporting, refining, transporting and dispensing gas?

If you have no idea how it relates maybe sit and think a bit.

No 40% is Honda's published figure for the Clarity engine.

I guess you just don't get that fossil fuels are still what is used to generate most of our electricity, so all the same inefficiencies (including drilling, transporting etc.) that are applicable to ICE powerplants also apply to the electricity used in motors too.

But our electricity system is getting better.

 

[ryd994]

Not at all, just the location of the inefficiency changes, unless you are charging all the time on your own renewable system like Kentucky Ken.

Just 17% of our power comes from renewables. The rest is fossil fuels and nuclear where the generation efficiency ranges from 30 to 60%. Not far off from the very good 40% Honda claims for our Clarity ICE. Its not easy to disobey the laws of thermodynamics.

But fortunately the renewable fraction is going up constantly!

https://afdc.energy.gov/fuels/electricity_production.html

I posted same words before, reposting:

1. As @DucRider said, transportation of fuel wastes also has waste and pollution. Electricity can be generated somewhere far away and transportation is almost lossless. Once the grid infrastructure built, they can run for years.

2. Car engine is far from efficient given weight and size constraints. A power plant can use all the heavy and huge devices to reduce pollution and improve efficiency. Do you really think the little engine in your car has higher chamber temperature and pressure and better cooling than a stationary power plant generator?

3. Car engine is rarely working at best efficiency point. It must work under various load and rpm. In real life, you won't hit the 40% efficiency Honda claimed, which is measured in lab.
In contrast, a power plant can control the generator to the best efficiency for the most of the time. The advertised efficiency is achievable.

4. Even EV does not reduce any pollution and has as horrible efficiency as a ICE, it is still favorable by moving all the pollution away from city center, the most populated places.

 

[ryd994]

If you have no idea how it relates maybe sit and think a bit.

No 40% is Honda's published figure for the Clarity engine.

I guess you just don't get that fossil fuels are still what is used to generate most of our electricity, so all the same inefficiencies (including drilling, transporting etc.) that are applicable to ICE powerplants also apply to the electricity used in motors too.

But our electricity system is getting better.

drilling, yes, it's the same crude oil.
transporting, no. For power plant, fuels arrive in oil tanker ships or oil pipes. For ICE car, fuel first arrive to a centralized warehouse, then distributed by tank trucks. There are so many gas stations around the city.

 

[DucRider]

If you have no idea how it relates maybe sit and think a bit.

No 40% is Honda's published figure for the Clarity engine.

I guess you just don't get that fossil fuels are still what is used to generate most of our electricity, so all the same inefficiencies (including drilling, transporting etc.) that are applicable to ICE powerplants also apply to the electricity used in motors too.

But our electricity system is getting better.

Fossil fuels are not used to generate most of my electricity. And this is true in many areas of the country.

And the 40% thermal ICE efficiency is still half that of the electric motor, but indeed more than the 30% I credited.

I'll stand by my statement that any vehicle is much more efficient using electricity than gas. The source of both fuels varies widely with a wide range of efficiencies in their production and distribution (with too many variables to be calculated by the consumer), but the vehicles themselves are easy to evaluate.

How many BTU's are used in the exploration, drilling, pumping, transporting, refining, transporting, and pumping a gallon of the gas you buy? Do you know the source of your gas? High quality from the Middle East? Shale oil with extraction costs high, efficiencies low, and yielding lower quality crude that take more energy to refine with lower yields? Is it refined at an newer more efficient refinery?
Add all those up and divide 45K (112K * 40%) by that total and the efficiency is? 5%? 15% 2%?

 

[David Towle]

Fossil fuels are not used to generate most of my electricity. And this is true in many areas of the country.

I'll stand by my statement that any vehicle is much more efficient using electricity than gas. ?

Lucky you! You are then in the same fortunate group as Kentucky Ken.

And I agree 100% with your efficiency statement, I just like to inform folks that EV powered cars are not quite as perfect as they think.

Here's a couple more interesting facts re efficiency, ryd994 thought there was no waste in fossil fuels getting to power plants, not true at all. First here's the fuel distribution for power plants, only 0.6% is oil, versus 35% natural gas for instance:
https://www.eia.gov/tools/faqs/faq.php?id=427&t=3

And here's an idea of how much natural gas is wasted:
https://www.forbes.com/sites/michae...stics-around-wasted-natural-gas/#23c0c6574775

Plus it also mentions that manure is 9% of our methane emissions!

The point of all these posts is energy is complicated, and its going to take a HUGE effort and many years for us and the world to get to the low emissions future everyone who bought a Clarity wants. I certainly wish more people felt the way we do.

 

[HagerHedgie]

I was seeing ranges in the mid to upper 30's when the temps were below freezing during the winter months (only used seat heater unless the windows needed to be defrosted). In the spring with no A/C use i was getting ranges in the high 50's and sometimes low 60's. To save some range I'm fine driving with the windows down in the 90 degree 100% humidity instead of using the A/C, but try telling that to my wife.

I haven’t notice near

After one year in all seasons and tracking every kW and mile, I can safely state that the AC set at Auto 72 to 74 F makes only a fraction of the range reduction that the resistance elements of the cabin heater and defroster make. Early on I tried not using the AC vs. using it and found only a 2 to 3 mile EV range reduction from mind 60s to low 60s.

So I use the AC whenever I need to but am still parsimonious with the heat since I precondition in a garage and most of my trips are short.

agreed; range loss with AC is less than I expected after experiencing what running the heat does. Plus I hate getting sweaty. Being cold is no big deal.

 

[HagerHedgie]

Huh What?
The BEV can be driven in Sport or Eco modes, which will "fine tune" it's efficiency. But that being said, any of the BEV modes will be more efficient than any mode you can choose with the PHEV. The pure electric drive train is inherently more efficient than that of the PHEV.
The PHEV is most efficient when the ICE is not utilized - any use of the ICE at all drops it's efficiency well below that of the BEV. Fine tune all you want - but running the ICE in it's most efficient mode is less than half as efficient as EV mode (PHEV or BEV).

In cold weather, especially below 20F, the battery loses A LOT of efficiency due to internal resistance. Combine that with climate control and burning gas isn’t such a bad deal. In my case this only applies for 1-2 months out of the year.
If you drive a lot of miles you’re burning fuel anyway.

 

[4sallypat]

Past 5 months, been getting over 50 miles per charge here in So Cal but now that A/C weather is upon us, I am using the open the windows to cool the car.

I wonder if the drag created with the windows open vs. windows closed for A/C use - which is worse on my miles per charge ???

 

[Robert_Alabama]

I get such little loss with A/C use with the fan setting low that I wouldn't be surprised if at best it is a push, and the A/C might even win. I'm guessing, but I don't think the A/C is hitting me for more than a couple of miles of range (again with low fan settings), thermostat set at about 69, and outside temps lower 80s.

 

[HagerHedgie]

I get such little loss with A/C use with the fan setting low that I wouldn't be surprised if at best it is a push, and the A/C might even win. I'm guessing, but I don't think the A/C is hitting me for more than a couple of miles of range (again with low fan settings), thermostat set at about 69, and outside temps lower 80s.

Agreed. The first few weeks when the weather warmed up here I was trying to avoid my AC use for the sake of efficiency but the difference was so small that lately I’ve just been turning on the air, staying comfortable and not sweating. I’m sure there’s some speed where the ac becomes more efficient than the windows I would imagine it’s in the 60s or 70s but that’s just a guess

 

[HagerHedgie]

Second winter we've gone through with our Clarity and warm temps are finally here again. I'm an enthusiast so I've stayed in EV most of the winter and kept the heat way down. Of course, that's gotten old. Some have mentioned that driving in hybrid mode in the winter is actually less expensive than EV because of the dramatic reduction in range coupled with the huge drain on the battery by having the heat on. My suggestion is to just drive in hybrid mode when the temp is below freezing so your can benefit from the waste heat created by the ICE. You will save money in multiple ways. In addition to lower fuel costs is the extended life of the battery by not having to charge so much in the winter time. Winter is very hard on the battery because you'll have to charge it a lot more for the same unit miles compared to the other seasons so you'll be more likely to deplete the battery on a regular basis. Also, it's a good idea to run the ICE regularly. A long term idle engine coupled with old gas is a recipe for an expensive system failure.

I wish Honda would have an “hv heat mode” that would just burn enough gas to heat the cabin(and the battery) and send all the torque to the generator. This would be perfect for people driving 80 miles a day like I do. Next winter I’m going to burn gas and stay warm. I’m sure I’ll still average 70mpgs.

 

[HagerHedgie]

I posted same words before, reposting:

1. As @DucRider said, transportation of fuel wastes also has waste and pollution. Electricity can be generated somewhere far away and transportation is almost lossless. Once the grid infrastructure built, they can run for years.

2. Car engine is far from efficient given weight and size constraints. A power plant can use all the heavy and huge devices to reduce pollution and improve efficiency. Do you really think the little engine in your car has higher chamber temperature and pressure and better cooling than a stationary power plant generator?

3. Car engine is rarely working at best efficiency point. It must work under various load and rpm. In real life, you won't hit the 40% efficiency Honda claimed, which is measured in lab.
In contrast, a power plant can control the generator to the best efficiency for the most of the time. The advertised efficiency is achievable.

4. Even EV does not reduce any pollution and has as horrible efficiency as a ICE, it is still favorable by moving all the pollution away from city center, the most populated places.

Energy transportation through the grid is anything but lossless. Losses range from 10% to over 60% depending on many factors. Transformers and length of the run are the biggest factors.
The clarity was designed so that when the ice is running it stays as close to the 40% as possible.
Don’t forget about energy expended in the manufacturing of the vehicle.

 

[The Gadgeteer]

Once the cabin is cooled down I am finding the AC even on minimal settings maintains the cabin comfortable without a noticeable range hit. Recycle vent mode makes all the difference.

 

[ryd994]

Energy transportation through the grid is anything but lossless. Losses range from 10% to over 60% depending on many factors. Transformers and length of the run are the biggest factors.
The clarity was designed so that when the ice is running it stays as close to the 40% as possible.
Don’t forget about energy expended in the manufacturing of the vehicle.

1. 40%? Citation needed. I see 5%: https://www.eia.gov/tools/faqs/faq.php?id=105&t=3[URL]https://www.eia.gov/tools/faqs/faq.php?id=105&t=3[/URL]
"The U.S. Energy Information Administration (EIA) estimates that electricity transmission and distribution (T&D) losses average about 5% of the electricity that is transmitted and distributed annually in the United States"
The wasted natural gas page you shared has nothing to do with production of gas. Those burnoff are byproduct of oil. They have to burned because we have too LITTLE, rather than too much need of natural gas. Nobody want's it, they only want the oil, and it's too dangerous to store the gas. What else can we do?

2. Again. Citation needed. Honda claimed the HV will have better efficiency, but never claimed it will always reach the optimal efficiency. The power plant generator will have better efficiency than car engine. I've explain why it should. Feel free to provide opposite evidence.

3. Sounds like gas car don't need manufacturing, and so don't engine oil .

 

[HagerHedgie]

1. 40%? Citation needed. I see 5%: https://www.eia.gov/tools/faqs/faq.php?id=105&t=3https://www.eia.gov/tools/faqs/faq.php?id=105&t=3
"The U.S. Energy Information Administration (EIA) estimates that electricity transmission and distribution (T&D) losses average about 5% of the electricity that is transmitted and distributed annually in the United States"
The wasted natural gas page you shared has nothing to do with production of gas. Those burnoff are byproduct of oil. They have to burned because we have too LITTLE, rather than too much need of natural gas. Nobody want's it, they only want the oil, and it's too dangerous to store the gas. What else can we do?

2. Again. Citation needed. Honda claimed the HV will have better efficiency, but never claimed it will always reach the optimal efficiency. The power plant generator will have better efficiency than car engine. I've explain why it should. Feel free to provide opposite evidence.

3. Sounds like gas car don't need manufacturing, and so don't engine oil .

https://www.energycentral.com/c/ec/grid-efficiency-opportunity-reduce-emissions
I was a bit misinformed. The grid is closer to 92% efficient on average. I was going off of memory and I must have lumped in production losses with my figure.
The thing that really made me decide to just run HV more in the cold was the range. My cold weather range is less than 1/2 my warm weather range. If you factor cabin heating in the situation the clarity’s ice might run closer to 60% efficient since the heat is used for something.
Don’t get me wrong, I’ll still use up most of my charge every day but I’m going to stay warm next winter. And if the heat is on so is my ice

 

[DucRider]

The electric motors will always, under all circumstances, be more energy efficient than the ICE.

Some weird morph has happened to what people are considering "efficiency" to be.
It may be more cost effective to run on gas for some people in some circumstances.
Power from the grid will usually produce less greenhouse gasses (well to wheels) than the ICE, depending on where you live, if that is your definition of "efficiency"

https://blog.ucsusa.org/dave-reichmuth/new-data-show-electric-vehicles-continue-to-get-cleaner

You can use the tool at fuel economy.gov to compare the Clarity BEV to an Accord Hybrid (47 mpg) to get a pretty close approximation to running from the grid or running the ICE.
https://www.fueleconomy.gov/feg/Find.do?action=sbs&id=40044&id=39918&#tab2
Under the Greenhouse Gas Emissions section, change it to show Tailpipe & Upstream GHG and note the total for the Accord
Click the Calculate Emissions link for the Clarity and put in you zip code to get the upstream number for the Clarity (tailpipe is of course zero)
The 47 mpg Accord Hybrid generates 227 g/mi (187 tailpipe + 40 upstream)
Where I live, charging from the grid is 100 g/mi
Denver is 270 g/mi (very coal heavy power mix)
Washington DC is 140
Atlanta is 180

 

[HagerHedgie]

The electric motors will always, under all circumstances, be more energy efficient than the ICE.

Some weird morph has happened to what people are considering "efficiency" to be.
It may be more cost effective to run on gas for some people in some circumstances.
Power from the grid will usually produce less greenhouse gasses (well to wheels) than the ICE, depending on where you live, if that is your definition of "efficiency"

https://blog.ucsusa.org/dave-reichmuth/new-data-show-electric-vehicles-continue-to-get-cleaner

You can use the tool at fuel economy.gov to compare the Clarity BEV to an Accord Hybrid (47 mpg) to get a pretty close approximation to running from the grid or running the ICE.
https://www.fueleconomy.gov/feg/Find.do?action=sbs&id=40044&id=39918&#tab2
Under the Greenhouse Gas Emissions section, change it to show Tailpipe & Upstream GHG and note the total for the Accord
Click the Calculate Emissions link for the Clarity and put in you zip code to get the upstream number for the Clarity (tailpipe is of course zero)
The 47 mpg Accord Hybrid generates 227 g/mi (187 tailpipe + 40 upstream)
Where I live, charging from the grid is 100 g/mi
Denver is 270 g/mi (very coal heavy power mix)
Washington DC is 140
Atlanta is 180

Thanks for the link. I enjoyed that information. I do think of efficiency in terms of the whole system. Of course the electric motor is much more efficient than the ice. It’s also a pleasure to drive. The beauty of this car is you get the best of both worlds. Gas still has certain advantages particularly in cold weather and in long distance driving. EV is generally cleaner and more luxurious. Of course those things vary from consumer to consumer based on personal driving habits and energy generation. I’m in MD so middle of the road as far as carbon emissions and electric cost. EV is cheaper for me until I turn on the heat in my car so I guess I’m a little biased. Before the clarity I’ve had two Prius so 40-50mpg is normal to me by now.

 

[Steve Caulfield]

I believe that is exactly what it will take.

As an aside, my EV range reached 40 this morning for the first time since our early Winter onset last year. Another item to add to my list of signs of Spring.

I'm with you, MNSteve. Here in Maine, the EV range only gets into the 40s when the temp gets back up to 50 or so. Finally saw the rated 47 mile range for EV mode when the temp topped 70 briefly. Oh, and don't get me started on the loss of "driver assists" when the ice covers that Honda emblem. There are still some cold weather bugs to fix. Must be nice to have one of these in the desert SW tho'.

 

[insightman]

Must be nice to have one of these in the desert SW tho'.

The HV battery doesn't like the heat in the desert SW, however.