Electric Vehicles on the horizon? Do your homework

[Shotgun]

I asked an expert at a public meeting about electric cars:

3. I then asked if the cars are charging at night how can solar be included.
He got flustered at that time and said that was a question for an engineer(I happen to be an engineer)

We always run into trouble when we try to apply old thinking to new problems, and "experts" never seem to want to upset the old way of doing things. Having panels to directly charge the cars would turn your logical logic train on its head. I'd like to use solar to charge my car at work from solar panels that are keeping the southern sun from baking my car to an early death, and then driving it home to use the extra energy to partially power my house.

Sure, I would probably only have about 2kW of panels available at a parking space, but it is 8 hours at a minimum. According to this link it requires 0.346kWh to travel 1 mile. That 8 hours would get me a little more than 46 miles. When I have a daily drive, it is about 10 miles each way.

Average Electric Car kWh Per Mile [Results From 231 EVs]

Find the average electric car kWh per 100 miles, along with the best and the worst. Plus see the costs, savings and how you can go greener.

ecocostsavings.com

 

[ErichKeane]

We always run into trouble when we try to apply old thinking to new problems, and "experts" never seem to want to upset the old way of doing things. Having panels to directly charge the cars would turn your logical logic train on its head. I'd like to use solar to charge my car at work from solar panels that are keeping the southern sun from baking my car to an early death, and then driving it home to use the extra energy to partially power my house.

Sure, I would probably only have about 2kW of panels available at a parking space, but it is 8 hours at a minimum. According to this link it requires 0.346kWh to travel 1 mile. That 8 hours would get me a little more than 46 miles. When I have a daily drive, it is about 10 miles each way.

Average Electric Car kWh Per Mile [Results From 231 EVs]

Find the average electric car kWh per 100 miles, along with the best and the worst. Plus see the costs, savings and how you can go greener.

ecocostsavings.com

FWIW, my EV gets ~4.1 miles/stored KWh (and it is a mid-sized EV), so that is either out of date, or including some level of conversion.

Another thing, having solar power 'stored' in some method is completely plausable to cover night-time-use as well. The nice part about solar is the 'cost' (after initial install) of the power is 'free', so even less-effective ways of power storage are back on the menu! I know that some traditional power grids use water-pumped-up-hill as a method, and others boil sodium/some other chemical, so those are presumably somewhat efficient.

Finally, an automotive ICE is quite inefficient compared to power-plants (thanks to the economies of scale), even running on the same fuel. So a power plant running on coal/oil isn't ideal, but is at least efficient enough to make up for the conversions plus some.

 

[Superburban]

I asked an expert at a public meeting about electric cars:

1. I asked about the stiffness of the grid and the ability to handle the peak loads from the charging.
He stated that the cars would charge at night when demand is low
2. Then I asked If over 50% of the US power is generated by coal and natural gas what specifically are the environmental benefits.
He stated that new wind and solar would be available to handle the peak
3. I then asked if the cars are charging at night how can solar be included.
He got flustered at that time and said that was a question for an engineer(I happen to be an engineer)

In engineering we perform mass and energy balances to determine the efficiency of a system, weather it be mechanical, electrical or chemical. A quick look at losses inherent in going from chemical combustion to steam to electrical, then transmission losses back to chemical(charging the batteries)then to electrical then mechanical(turning the wheels on the car) and you are hard pressed to say the electrical car "system" is more efficient than internal combustion engines. And if you add in the mining and refining of the rare earths and metals mentioned earlier, we are essentially pushing the environmental nightmare on third world countries, which in my opinion is unconscionable.

I would love to know what percentage of the electric from the grid is used to cool the batteries while it charges. My Pacifica hybrid has one heck of a fan going on the hot days, to cool things down. Even when driving on a hot day, the fan runs for several minutes after I park, to cool the batteries back down.

Charge at night? only residential ones with off peak rates, otherwise most will be charged when needed. Look at all these charging stations this new infastructure bill claims to be adding. No one can look at that and say they will only be used at night.

 

[Janderso]

I asked an expert at a public meeting about electric cars:

1. I asked about the stiffness of the grid and the ability to handle the peak loads from the charging.
He stated that the cars would charge at night when demand is low
2. Then I asked If over 50% of the US power is generated by coal and natural gas what specifically are the environmental benefits.
He stated that new wind and solar would be available to handle the peak
3. I then asked if the cars are charging at night how can solar be included.
He got flustered at that time and said that was a question for an engineer(I happen to be an engineer)

In engineering we perform mass and energy balances to determine the efficiency of a system, weather it be mechanical, electrical or chemical. A quick look at losses inherent in going from chemical combustion to steam to electrical, then transmission losses back to chemical(charging the batteries)then to electrical then mechanical(turning the wheels on the car) and you are hard pressed to say the electrical car "system" is more efficient than internal combustion engines. And if you add in the mining and refining of the rare earths and metals mentioned earlier, we are essentially pushing the environmental nightmare on third world countries, which in my opinion is unconscionable.

5t,
Your conversation with the "expert" is comical.
I agree with your opinions.

 

[Janderso]

The scientist Neil Degrasse Tyson released this rather silly interview. He says after all the fossil fuel used to produce and charge an EV, the EV is still a better choice?

 

[ErichKeane]

The scientist Neil Degrasse Tyson released this rather silly interview. He says after all the fossil fuel used to produce and charge an EV, the EV is still a better choice?

Yep, its counter-intuitive perhaps, but an ICE car tends to be ~20%[0], up to ~35% [1] for a very specific diesel engine. Gas turbine engines (like can be used in power plants!) are about double that. So as long as the conversions/storage of the power is better than half, it ends up being net-positive. Additionally, not enough can be said about the fact that incremental gains in 1 location (that is, an update to a power plant) are much easier/cheaper/more effective than trying to improve every engine in town.

[0] https://en.wikipedia.org/wiki/Internal_combustion_engine#Energy_efficiency
[1] https://en.wikipedia.org/wiki/Engine_efficiency#Internal_combustion_engines
[2] https://en.wikipedia.org/wiki/Engine_efficiency#Gas_turbine

 

[ericc]

Erich, that is correct.

It reminds me of this old man harassing me at a party. One of the faculty at a local university seemed to get it in his head that I was uneducated, so he called an old man over and asked him to make a fool out of me discussing thermodynamics. The first thing the old man asserted was that electric vehicles all ran off fossil fuel and were no more efficient than burning it directly due to all the steps. You hear this argument a lot on the Internet. I told him that you can get insane efficiencies with innovative combined cycle plants that you cannot get from the otto cycle. He demanded, how good? I said, how about 105%. He said that violates the first law of thermodynamics. Then, I said, how about 85%. He said that violates the second law of thermodynamics, which is Carnot's Law. I told him that Carnot's Law tells nothing about the efficiency of a complete process. It only tells about the maximum amount of energy that can be extracted from a theoretical heat engine based on the temperature difference between inlet and outlet. I then told him about a steam plant running near Bakersfield. I think a lot of you can see what's coming. One of the operators in a heavy oil field needed some steam for their enhanced oil recovery process. The price was kind of high, even for "low quality" steam. "Low quality" means low superheat temperature, and this steam is useless for power generation. It does, however, contain a lot of energy. So, this operator started generating higher quality steam, and ran it through a power plant to generate electricity. The waste heat (lost energy) of such a cycle was low quality steam, which is just what they needed for their oilfield operation. It turned out that the power they generated from the energy released in the transition from high to low quality steam more than paid for the operation, so that's where the greater than 100% number comes from. Then, I asked the old man whether this cycle could be used in an internal combustion engine for road transportation applications. His eyes went wide and he didn't answer. He ended up running to the faculty guy who sent him, and asked him where he found this creep. Get him away from me. Ha ha, that's the last time I got an invitation. Later I found out that he wasn't really faculty, he was more of a visiting or adjunct.

 

[f350ca]

Lets see, solar panels operate at about 20 watt / square foot. A full sized truck is about 6 feet wide and 20 feet long, 120 square feet, 2.4 kw max. If it takes a 19.2 kw charger all night to bring up a battery you might make it out of the parking lot by the end of a sunny week.

Greg

 

[ErichKeane]

Lets see, solar panels operate at about 20 watt / square foot. A full sized truck is about 6 feet wide and 20 feet long, 120 square feet, 2.4 kw max. If it takes a 19.2 kw charger all night to bring up a battery you might make it out of the parking lot by the end of a sunny week.

Greg

That assumes the truck is starting from 0% when parking. Most people don't use a full tank of gas (or charge!) every day.

One additionally 'interesting' thing: My employer put solar panels up in the parking lot creating 'covered' parking for a large section. They get a surprising amount of energy from them (in Oregon no less!), but the 'covered parking' bit is also a huge advantage. You end up saving a bunch of power having to warm up the car in the winter to melt ice, and a bunch from having to cool off the car when getting into it in the summer!

That said, even panels on the top of a car/truck wouldn't need to be a 100% solution. Each source of power is to augment the grid, not replace it.

 

[martik777]

Erich, that is correct.

It reminds me of this old man harassing me at a party. One of the faculty at a local university seemed to get it in his head that I was uneducated, so he called an old man over and asked him to make a fool out of me discussing thermodynamics. The first thing the old man asserted was that electric vehicles all ran off fossil fuel and were no more efficient than burning it directly due to all the steps. You hear this argument a lot on the Internet. I told him that you can get insane efficiencies with innovative combined cycle plants that you cannot get from the otto cycle. He demanded, how good? I said, how about 105%. He said that violates the first law of thermodynamics. Then, I said, how about 85%. He said that violates the second law of thermodynamics, which is Carnot's Law. I told him that Carnot's Law tells nothing about the efficiency of a complete process. It only tells about the maximum amount of energy that can be extracted from a theoretical heat engine based on the temperature difference between inlet and outlet. I then told him about a steam plant running near Bakersfield. I think a lot of you can see what's coming. One of the operators in a heavy oil field needed some steam for their enhanced oil recovery process. The price was kind of high, even for "low quality" steam. "Low quality" means low superheat temperature, and this steam is useless for power generation. It does, however, contain a lot of energy. So, this operator started generating higher quality steam, and ran it through a power plant to generate electricity. The waste heat (lost energy) of such a cycle was low quality steam, which is just what they needed for their oilfield operation. It turned out that the power they generated from the energy released in the transition from high to low quality steam more than paid for the operation, so that's where the greater than 100% number comes from. Then, I asked the old man whether this cycle could be used in an internal combustion engine for road transportation applications. His eyes went wide and he didn't answer. He ended up running to the faculty guy who sent him, and asked him where he found this creep. Get him away from me. Ha ha, that's the last time I got an invitation. Later I found out that he wasn't really faculty, he was more of a visiting or adjunct.

Reminds me of my fav scene in Good Will Hunting: