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Thoughts on Producing and Delivering Enough Energy to "Go Electric"

gizmoboy

Member
Jul 2, 2015
700
38
Rancho Palos Verdes, CA
I was wondering if anyone else had read Jean-Louis Gassee's MondayNote post about the VW scandal and the challenges he sees in generating and delivering enough power for a meaningful move to EVs.

He's pessimistic about the ability of electric to match the energy density of petrol, and I'm curious if those who know the science better than I can see the flaws in his argument. If it holds up, I'd be pessimistic about a large-scale move to EVs as well.
 

jdw

Supporting Member
Jun 1, 2015
695
1,332
Vancouver
The first thing that jumps out at me is that there is no adjustment for efficiency. A gas vehicle uses somewhere around 20% of the energy in a tank of gas to actually move the vehicle - the rest is used to produce heat and noise or is wasted in idle time. An electric vehicle is closer to 60-80% efficiency.

You can get an idea of this from the "equivalent MPG" stat in the Remote S app which is usually around 120-130 "MPG".

Alternatively, I use 18kWh to drive 60 miles, which would take 3 gallons of gasoline in a typical ICE vehicle. 18kWh is 64800000 Joules; 3 gallons of gas is 395280000 joules or over 6 times the total energy usage. Adjusting for city driving, electric vehicles are probably one tenth of the total energy usage of an ICE vehicle.
 

nwdiver

Well-Known Member
Feb 17, 2013
7,946
10,306
United States
WOW... there are so many things wrong with that hit-piece it's hard to know where to begin.

- Why convert gasoline in to Joules? kWh are far easier... Ah... with joules you have to use scary scientific notation...
- As mentioned above... EVs use >60% less energy than ICE.
- <10% of charging is done under the 'gas station' paradigm; The other 90% is done at home @ <20kW.
- Even for an ICE... 20gallons per week is not the average US consumption...

I couldn't help but think of this scene while I was struggling to get to the end of the article...

 
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jdw

Supporting Member
Jun 1, 2015
695
1,332
Vancouver
Second thing that jumped out at me was the assumption that gasoline is a naturally occurring resource. It takes a lot of inefficient energy consumption to find, extract, transport, refine and transport gasoline to the pump. If that energy was used to produce electricity at the efficiency level of a typical power plant, it would probably be sufficient in itself to power a very large number of electric vehicles.
 
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MichFin

Member
May 8, 2015
303
61
Detroit, MI
Almost all electric car charging happens at night when electricity production is usually idle. That's why I get 1/2 price electric rates with my off peak charging. I read a study 5 years ago that if all cars in Israel would switch electric it would only require an 8% increase in grid capacity.
 

nwdiver

Well-Known Member
Feb 17, 2013
7,946
10,306
United States
He's pessimistic about the ability of electric to match the energy density of petrol, and I'm curious if those who know the science better than I can see the flaws in his argument. If it holds up, I'd be pessimistic about a large-scale move to EVs as well.

So here are the salient 'elevator points'...

- The US currently uses 270B gallons of petroleum products per year.
- For simplicity converting that to electric reduces that energy by 2/3 to ~90B gallons equivalent.
- 90B x 35kWh = 3150 TWh/yr
- Current US electrical consumption is ~4000TWh/yr

How much area to generate 7500TWh/yr from solar alone?

- A 10MW solar farm can generate 25GWh/yr and occupies 0.04 square miles.
- You would need 300k 10MW farms occupying 12k square miles.
- For scale there are 3500 square miles of golf courses in the US and 61k square miles of paved surface.

The numbers aren't nearly as overwhelming when you don't use Joules..... probably why he used Joules :wink:
 
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AudubonB

One can NOT induce accuracy with precision!
Mar 24, 2013
8,132
27,367
Thanks for the elevatadata ;)

And now to make them even more crunchable and usable: how many square miles in parking lots.....and why cannot most of them be dual-purposed, with solar panels above them?
 

nwdiver

Well-Known Member
Feb 17, 2013
7,946
10,306
United States
Thanks for the elevatadata ;)

And now to make them even more crunchable and usable: how many square miles in parking lots.....and why cannot most of them be dual-purposed, with solar panels above them?

The number of parking spaces is actually harder to nail down than you would think... estimates range from ~800M - 3B. You would need to cover ~3B parking spaces with solar PV so that might work...

IMO the 'pithiest' retort would be 'We need ~3x as much space for Solar as we use for golf' and yes, mostly on roof tops and parking canopies.
 
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ecarfan

Well-Known Member
Sep 21, 2013
19,222
13,872
West Vancouver, British Columbia
And now to make them even more crunchable and usable: how many square miles in parking lots.....and why cannot most of them be dual-purposed, with solar panels above them?
And as Elon pointed out in the Tesla Energy launch presentation earlier this year, most of the solar energy power generation we need to add to move the grid onto renewable energy can be added to existing building roofs, very little unused land is needed.
 

cpa

Active Member
May 17, 2014
3,101
3,975
Central Valley
Diver,

would we not be able to redirect some of the electricity used to refine, extract, etc. etc. petroleum towards charging all the BEVs out there? It would seem to me that amount would not be an insignificant amount.

It was not clear whether your calculations factored this in or not. Regardless, certainly not as overwhelming as implied in the story.
 

nwdiver

Well-Known Member
Feb 17, 2013
7,946
10,306
United States
Diver,

would we not be able to redirect some of the electricity used to refine, extract, etc. etc. petroleum towards charging all the BEVs out there? It would seem to me that amount would not be an insignificant amount.

Actually a relatively small amount of electricity is used for refining... <300w/gal if I recall correctly. ~7kWh/gal ENERGY is used but most of that is Nat gas.


Regardless, certainly not as overwhelming as implied in the story.

LOL That's an understatement... Quote from the article;
[FONT=monday_text_egyptian_webRg]
'Even if we dedicated the entire Earth’s surface to solar energy collection and conversion, either photovoltaic or photosynthetic, electronics or plants, we couldn’t possibly match our consumption.'[/FONT]
 
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snort

Member
Jun 27, 2015
164
74
Seattle, WA
He's not trying to factor in local generation, such as rooftop solar. Using a fairly bad-case scenario: a Seattle based 20kw nameplate system generates an average of about 20kwh per day in the winter. (About 80kwh in the summer.) This takes less than 1400 square feet: e.g. 40*35, a fairly typical small American suburban rooftop. 20kwh can move a model S about 60 miles; the Leaf is better and we can assume that will be true of the model III as well. That's all most people need most days. No impact to the grid AT ALL.

of course this is an average--a long stream of dreary days will leave you wanting. adding a battery to the system (whether it's a local system like the PowerWall or net metering on the grid, pretending that the power companies do the right thing) costs about 25% efficiency loss. If you can only charge your car at night, you'll need to use something like this. But it still gets the job done. local batteries don't impact the grid at all (in fact they'll probably reduce the load). Grid attached storage, co-located with substations, or anywhere that's convenient, can achieve something similar. The power companies should do this anyway.

Workplaces and highrise apartments are more of a problem. A typical tall apartment building has less than 40,000 square feet. fewer than 30 cars at this level. Apartment dwellers tend to use more transit than suburbanites, so this may be good enough. A car parked under a 10x20 solar panel on a Seattle winter day adds less than 3kw--less than 10 miles--if they're under there the whole time the sun is up. This is borderline adequate during the summer, not in the winter. But, the factory rooftop can also be used. If the factory produces more than it needs, it can charge cars. Electricity is fungible. Lots of factories do their own generation--solar, wind, etc., already. No reason to imagine that that won't expand.

(an interesting bit of history: In the early days of the power grid, many of the big factories, especially steel mills, which produce a lot of excess heat, added generators to capture this and sell it. It cost them next to nothing to generate, so they wound up undercutting the electric utilities...who fought back by convincing most legislatures to ban the practice. Most of these laws, preventing what is today called co-generation, are still on the books. Even if the steel mills were still in the US, which most are not, it would only contribute a few percent to the grid if it were legal. Moreover, modern mills produce a lot less waste heat, even if they haven't been sold to the far east for short term profits by their owners.)

Gassee's conspicuous omission of Tesla's gigafactory and the expansion implied by that tells us that he's either more ignorant than his history would suggest, or he's got an anti-ev agenda for some reason.

--Snortybartfast
 

jerry33

(S85-3/2/13 traded in) X LR: F2611##-3/27/20
Mar 8, 2012
19,709
22,706
Texas
He's not trying to factor in local generation, such as rooftop solar. Using a fairly bad-case scenario: a Seattle based 20kw nameplate system generates an average of about 20kwh per day in the winter. (About 80kwh in the summer.) This takes less than 1400 square feet: e.g. 40*35, a fairly typical small American suburban rooftop.

The fly in this ointment is that almost all roofs are pitched, so only half or less of the 1400 sq.ft. is available for solar panels. I'd love to have them on my roof (1800 sq.ft house), but so far the best they can do is about 40% of my energy use. A high month (means A/C at 21C 30-40C outside, plus two EVs) is $170. Average is more like $110. I doubt you can get a system for $50 a month, and I'd still have an electric bill. So I use the 100% renewable energy plan.
 

nwdiver

Well-Known Member
Feb 17, 2013
7,946
10,306
United States
The fly in this ointment is that almost all roofs are pitched, so only half or less of the 1400 sq.ft. is available for solar panels. I'd love to have them on my roof (1800 sq.ft house), but so far the best they can do is about 40% of my energy use. A high month (means A/C at 21C 30-40C outside, plus two EVs) is $170. Average is more like $110. I doubt you can get a system for $50 a month, and I'd still have an electric bill. So I use the 100% renewable energy plan.

Where in TX are you located Jerry? DIY systems aren't too difficult and the cost is now ~$1.2w ($0.84/w after FTC). If you shopped around a bit you might even be able to build a nice 8kW system for ~$8k ($5600 after FTC). 8kW in TX depending on location would generate ~14000kWh/yr.
 

snort

Member
Jun 27, 2015
164
74
Seattle, WA
The fly in this ointment is that almost all roofs are pitched, so only half or less of the 1400 sq.ft. is available for solar panels. I'd love to have them on my roof (1800 sq.ft house), but so far the best they can do is about 40% of my energy use. A high month (means A/C at 21C 30-40C outside, plus two EVs) is $170. Average is more like $110. I doubt you can get a system for $50 a month, and I'd still have an electric bill. So I use the 100% renewable energy plan.

900 sqft can give you about 13kw nameplate. In Dallas, this can do about 68 kwh/day in July, 39 in December. Ample for your car, which was the subject of the essay. The good news is that solar is at its best exactly when AC is most needed. electricity is fungible. Anything you do to reduce the burden on the grid is to the good.

Today, a lot of roofs are not pitched optimally for solar. we should not imagine that the way things are is the only way things can ever be, as Gassee is doing. Houses don't last forever and new ones are being built every day. Eventually, most will change.
--Snorty
 

Saghost

Well-Known Member
Oct 9, 2013
8,217
7,008
Delaware
I was wondering if anyone else had read Jean-Louis Gassee's MondayNote post about the VW scandal and the challenges he sees in generating and delivering enough power for a meaningful move to EVs.

He's pessimistic about the ability of electric to match the energy density of petrol, and I'm curious if those who know the science better than I can see the flaws in his argument. If it holds up, I'd be pessimistic about a large-scale move to EVs as well.

As a couple of folks have mentioned, the analysis he did is fundamentally flawed, being based on replicating the energy content in the gas tank and some random assumptions about how often people refuel.

I actually took my own stab at this problem some months back, based on the best metrics I could assemble for cars on the road and miles driven as well as statistics for the US power grid, with links for where I got the data included. I've been over it a couple times, but I don't guarantee I don't have a mistake in here somewhere, or an odd assumption.

I based it on the assumption that every car in the US was suddenly replaced with a RWD Model S...
Walter

It's not a problem, once you look at the big picture. Let's pull together the facts and do a little math... :)


Over here, the US used 136.78 billion gallons of gas in 2014.


If you look at this, the total US grid electricity production for 2014 was 14.78 Quads of electricity.


These two looked at together show that US drivers drove about 2.98 trillion miles in 2014.


Incidentally, that suggests 21.8 mpg overall average (2.98 trillion miles/136.78 billion gallons.)


A quad of electricity is a quadrillion BTUs - at 3412.14 BTUs per kWh, it is about 293 GWh per quad.


For the sake of this exercise, I'll assume that all those 2.98 trillion miles are suddenly being driven by RWD 85 kWh Model Ss. Not only is this a more viable car for most people than the others, it's also one of the least efficient pure EVs in the current market (due to the weight and performance gearing) - so it should give a conservative answer.


Over here, the EPA rates that car at 38 kWh per 100 miles including charging losses.


2.98 trillion miles at 38 kWh per 100 miles gives 1.132 PWh - 1.1 trillion kWh. That's a huge total, right?


But here's the perspective on that - it's only 3.86 quads. In the electricity chart I gave you above, we spent 4.79 quads (1.4 PWh) on residential electricity usage alone in 2014.


With that perspective and considering that the current grid experiences a 2:1 ratio of consumption from the middle of the afternoon to the middle of the night, it should be clear that the grid as a whole should be fine.


There could be local cases where residential neighborhoods that were already near the edge might need some improvement in the infrastructure, but it should be minimal and localized - and the variable nature of EV charging could help a lot...


If the cars involved are indeed Model Ss, with always on net connectivity and extensive software, there's no reason they can't be tied to the power company directly through the web. What if the power company gave you a 20% discount on all your charging power in exchange for the right to choose exactly when and how fast you charge, with a guarantee that they'd always give you a battery charged to your charging target before you leave in the morning?


That sort of deal would be a no-brainer for me, and I'd think most of us - but the power company would probably come out ahead on it as well. If they have a bunch of cars charging, they can ramp the rates up and down or suspend/initiate charging a lot faster than they can spin up most types of standby power to respond to load changes - and the distributed nature of the load would let them balance the response across transmission lines too.


The next step, vehicle to grid (V2G) where they could actually use a little power from you battery to meet the demand, requires a lot more infrastructure and control and may not happen, but just the flexibility to shape what would become ~21% of their overall usage would be a huge boon and might save them (and hopefully thereafter you) money on meeting spinning reserve requirements if the system for adjusting the charging is robust enough to convince regulators.


Of course, there aren't 216.8 million Model Ss to drive those 2.98 trillion miles, and there won't be for some time. We certainly have the ability to build enough car bodies, and I believe that with all the other things we use them for, we probably have enough capacity to build the power electronics and the drive motors. The problem is batteries...


Tesla sees this coming, and that's why they are building the Gigafactory. If you look here, you'll see that Tesla is hoping to build 35 Gwh of batteries at the Gigafactory in 2020 and every year thereafter. That's more than the entire industry produced in 2013 - and still a drop in the bucket for total conversion.


Those 216.8 million Model Ss up above need 18.4 TWh of capacity - 526 years of production at 35 GWh per year. Even if they were 216.8 million Leafs instead, they'd still need nearly 5 TWh - two orders of magnitude more than the Gigafactory can produce.


After spending a while trying to digest this chart, I think it's telling me that in 2014 we introduced about 16.8 million new cars into the fleet. (Which means the average car lasts 12.9 years in service somewhere.) If we were building only EVs, we'd need 1.4 TWh of production (or, eventually, recycling of batteries from old EVs) for Model Ss or 370 GWh for Leafs - between 11 and 40 times the planned Gigafactory capacity.


Lithium is fairly plentiful, and "mining" it is both relatively easy and not horrible for the environment (mostly achieved by concentrating salts from ground water, especially geothermal type deep underground water,) but we're going to need to do a whole lot of it, even though the Model S battery only has about 20 pounds of Lithium in the ~1200 pound pack.
 
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Theshadows

Active Member
Apr 20, 2013
1,977
298
PA
For a very very conservative figure. Each 1kw of PV installed will get you 3000 miles in a Model S per year.

This is at 40 deg north latitude. 50 deg north you would need about 1.1kw, 30 deg, 0.9kw.
 

bluetinc

Member
May 11, 2009
760
176
MD
Gizmoboy,

That's quite a convoluted comparison that he generated. Here is a more strait forward way to look into the future. Lets look at a pathological case and say we could change all passenger miles driven in the US to EV miles today. Feel free to change the number to ones you like, I'm using easy numbers to calculate, and discounting charging and transmission losses.

Average energy per mile .250kWh
Average miles driven per year in the US 14,000
Average number of cars on the road in the US 200,000,000

That means each car will use (in one year) .250 kWh/mi * 14,000mi/yr = 3,500 kWh/yr
And for the year, for the US: 3,500 kWh/yr * 200,000,000 cars = 700,000,000,000 kWh/yr

About 4,000,000,000,000 kWh/yr of electricity were produced in 2014 in the US

That means that you (might, worst case) need to produce 4,700,000,000,000 kWh of electricity over the next year, or about 20% more than we did last year. That's not bad, it's a pathological case that doesn't take into account that it will take us 20 years to even attempt to get there, that most charging will happen in off hours which are easier for the utilities to deal with, or that the change over to solar that is picking up.

Oh, and just a quick thought on solar since we are looking at these numbers. That energy you need to drive for a year (3,500 kWh/yr) can be produced where I am (MD) with a 2 kW solar system, small by today's standards. That system takes up about 10x10 rooftop area (100 square feet), which is about the area of roof just above where the car is parked.

Peter



Used these site for rough numbers:
How Many Miles Do Americans Drive Per Year?
What is U.S. electricity generation by energy source? - FAQ - U.S. Energy Information Administration (EIA)
 
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jerry33

(S85-3/2/13 traded in) X LR: F2611##-3/27/20
Mar 8, 2012
19,709
22,706
Texas
Where in TX are you located Jerry? DIY systems aren't too difficult and the cost is now ~$1.2w ($0.84/w after FTC). If you shopped around a bit you might even be able to build a nice 8kW system for ~$8k ($5600 after FTC). 8kW in TX depending on location would generate ~14000kWh/yr.

DFW.

However, I'm a firm believer in not giving a screwdriver to a software guy (or a code patch to a hardware guy), plus I'm not good on ladders. No way would I be able to convince myself that I could successfully do a DIY solar installation. The last quote I received was in the $30K area a few months ago. Solar City came up with an excuse that they wouldn't do any roof that was steeper than 23 degrees (mine is 25).
 

jerry33

(S85-3/2/13 traded in) X LR: F2611##-3/27/20
Mar 8, 2012
19,709
22,706
Texas
Average energy per mile .250kWh
Average miles driven per year in the US 14,000
Average number of cars on the road in the US 200,000,000

That means each car will use (in one year) .250 kWh/mi * 14,000mi/yr = 3,500 kWh/yr

The 250 is about right for me (248 actual), but I'd suggest a better average is 350 kWh/mi for the majority of Tesla drivers (The Model 3 may bring this down to closer to 250, but that's speculation at this point).

I'd suggest that the average Tesla driver puts on more than 14,000 miles a year. My average has been 1850/month 22,200/year. As EVs get more range, people will likely switch from planes to EVs for the majority of vacation trips (that don't involve crossing a large body of water). I suggest this will happen because between the airline deregulation and all the security checks, air travel has become a worse experience than bus travel--unless of course you fly your own plane, then it's a far better experience.

Actual energy used is 14.3 MW for 57,600 miles. This doesn't include metre to charger losses or pre-warming.

About 50% of the driving is has been for trips.

So I think the target generation should be somewhat higher than your projection (the main premise of "it will be a long time before the extra generation is needed" is correct).
 

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