Drought in the west, electric cars, catch-22

[Kev Williams]

So the West, which I'm in, is in a severe drought. Not sure about California but there's only been like 3 days the past month in the SLC area where the temp didn't reach at least 95°, several days over 100°--

I read where California's PG&E is going to start cutting power, partly as wildfire prevention but I'm supposing AC usage isn't helping (I had 2 power outages during one 104° day last week)--and so Tesla has warned their customers to get those cars charged up before PG&D starts cutting power. And I suppose all electric-car owners are planning doing the same-?

So, questions: is mass-car charging going to help overload their power grid? (catch-22 #1),
-and-
If people's electricity is out and they can't charge their cars, then what? -- use gasoline burning generators to charge them? (catch-22 #2)

Just pondering :) - I have no idea what's going to happen, but I WILL say this drought is scaring the hell outta ME...

[Doug Garson]

Hmmmm, wonder how many gas stations will be pumping gas when the power is out? Sounds like a good time to have your car charging station connected to a battery bank fed by solar panels on your roof.

[Brian Elfert]

I am pretty sure at least one local gas station has a standby generator. One day I was getting gas and there was a loud noise like a generator running coming from one part of the building. I noticed what looked like an exhaust stack coming out of the wall. If it wasn't a generator it had to be some sort of engine.

The only way a generator like that really makes financial sense is if they hope to sell a lot of fuel and convenience store items during a prolonged power outage. The power rarely goes out here unless a massive storm comes through and takes out power for huge swathes of customers. I have lived in my house for over six years now and have had less than 20 minutes total of power outages in that time. I installed a standby generator shortly after moving in since my well needs power to have water. Glad I only spent about $3,000 on my generator install since the power is so reliable.

[Alex Zeller]

Not all solar panels work if not connected to a grid. The car's battery pack could act like a grid but I'm not up to speed as EVs aren't very popular around here. What will have to happen is charging stations will have to be located near high tension power lines. They don't have to worry about trees and such shorting them out and causing a fire. Wouldn't that be funny. You have to drive your car to a charger, wait an hour, then drive it home so you can plug it into your house for power during a black out vs firing up your generator.

[Keith Outten]

I think I read somewhere that the Governor of California was telling people to cut their air conditioning off at night. If this is true there must already be a shortage or power on the grid. Charging automobiles at night may be another drain that can't be supported, surely the news will be adding some light ot the situation by this evening.

Looks like the green states are going to suffer the most. FWIW California has San Onofre Nuclear Power Station that probably could be repaired....fire that bad boy up or sleep in the heat :)
We replaced all of the Steam Generators in our nuclear plants here in Virginia several years ago, it was a total success.

[Malcolm McLeod]

Texas was in a drought from ~1998 to 2014 (meteorologically speaking) IIRC. And it was not even our worst. We managed to deal with it.

I watched our drinking water supply lake go from ~275,000 acre-feet to ~nothing, fed by a trickle in creek, fed by temporary pumps pulling from the Red River 70-odd miles away. Lost ALL my landscaping and I have zero right to whine about it - compared to others, I had it EASY! In 2010, a co-worker was 2 weeks late arriving to a job site, since he was a volunteer fireman trying to save 1/2 the houses in E.TX. In 2011, we had some 180,000 acres around Possum Kingdom, and 1300-odd homes destroyed by drought-inspired fire - and not even a Fed Emergency Declaration. We managed. Proudly.

Hang in there! I'll bet y'all will manage too.

(The EV owners may need to move...??)

[Jim Koepke]

I read where California's PG&E is going to start cutting power, partly as wildfire prevention but I'm supposing AC usage isn't helping

The utility market in California changed drastically from deregulation. Before this, utilities were allowed a fixed percentage return on investment. This meant the cost of providing service had an amount tacked on and that became the total collected from the rate payers.

Line items like tree trimming and insulator washing were profitable.

After the change they were 'extra costs.'

That is a very simple way of explaining the problem with electric distribution in California. There are other factors. Basically to avoid the cost of paying damages for fires caused by trees in power lines or insulators arcing, the power is shut off during dry windy periods.

jtk

[Mike Henderson]

Right now, California has excess power during the day because of all the solar installed. So as far as charging electric vehicles, that's the time to do it. If you have "time of day" rates, it's also the cheapest time to charge your car. Less expensive than at night - which used to be the cheapest.

Mike

[Peter Kelly]

SSo, questions: is mass-car charging going to help overload their power grid?No. If an EV's computers sense a significant drop below what it considers normal voltage during charging, it backs off the current draw until things stabilise. Also, most EV's trickle charging on a 120v 20a outlet typically only draw around 12a, certainly less than a home's worth of air conditioners and refrigerators on a hot day.

[Peter Kelly]

Looks like the green states are going to suffer the most. FWIW California has San Onofre Nuclear Power Station that probably could be repaired....fire that bad boy up or sleep in the heat :)
We replaced all of the Steam Generators in our nuclear plants here in Virginia several years ago, it was a total success.An ageing light-water reactor located directly on the Pacific coast in a heavy seismic zone worked out great in Japan, what could possibly go wrong in Southern California?

[Mike Henderson]

No. If an EV's computers sense a significant drop below what it considers normal voltage during charging, it backs off the current draw until things stabilize. Also, most EV's trickle charging on a 120v 20a outlet typically only draw around 12a, certainly less than a home's worth of air conditioners and refrigerators on a hot day.

You really can't charge an EV on a 120V outlet - it would take forever. Most manufacturers recommend a NEMA 14-50 outlet (240 volts, 50 amps). The car will only draw 80% of the rated current, so 40 amps. So if you have a car with a 75 KWhr battery and it's half empty, it will take you about 4 hours to charge it, while drawing 40 amps.

Given the same situation, with a 120 volt outlet rated at 15 amps, the car will draw 12 amps. It will take about 26 hours to fill the battery given the same starting point.

So you can charge your EV during the sunlight hours without any problems in California, providing you do it on a high capacity outlet. California has so much solar and wind that they used to pay other states to take their excess power during the daylight hours.

Mike

[Doug Garson]

Mike, not sure the numbers support your point that you can't really charge an ev on 120 Volt power. The average range on an ev is about 180 miles while the average daily drive in the US is only about 25 miles, so on average you only need to top up the battery about 14% daily. Using your number of 26 hours to fill a battery, topping it up 14% would take under 4 hours using 120Volt power.

[Doug Garson]

Not all solar panels work if not connected to a grid. The car's battery pack could act like a grid but I'm not up to speed as EVs aren't very popular around here. What will have to happen is charging stations will have to be located near high tension power lines. They don't have to worry about trees and such shorting them out and causing a fire. Wouldn't that be funny. You have to drive your car to a charger, wait an hour, then drive it home so you can plug it into your house for power during a black out vs firing up your generator.
Not sure I understand why charging stations would have to be located near high tension power lines, can you explain why? Currently I think charging stations are located where they are convenient to EV owners just as gas stations are located where they are convenient to ICE car owners.

[Alex Zeller]

Not sure I understand why charging stations would have to be located near high tension power lines, can you explain why? Currently I think charging stations are located where they are convenient to EV owners just as gas stations are located where they are convenient to ICE car owners.

The problem in California (at least one of them) is the risk of winds damaging the power lines. For example branch falls on one, shorts it out, catches fire, then falls to the ground. California has done back flips to try and prove most of these large fires are the fault of the power company. High tension lines don't have that risk since they are up higher and trees and brush and kept clear of them. When power is shut off it's the local lines. By having charging stations that aren't likely to get shut off it would reduce the fear of "what happens if I can't charge my car"? There's plenty of solar in California but not every person has it. When the grid is shut off due to fire risk solar panels are shut off from feeding the grid as well.

[Stan Calow]

A few years ago I saw a presentation at a professional conference in which it was mentioned that 25% of the electricity generated in California was used to pump water. Thats the real Catch 22.

[Peter Kelly]

Mike, not sure the numbers support your point that you can't really charge an ev on 120 Volt power. The average range on an ev is about 180 miles while the average daily drive in the US is only about 25 miles, so on average you only need to top up the battery about 14% daily. Using your number of 26 hours to fill a battery, topping it up 14% would take under 4 hours using 120Volt power.120v L1 charging gives you about 2 miles per hour of charge so yeah, one overnight charge and you're within that 25 mile range. Installing an a dedicated 240V 40A circuit plus a basic ESVE can get expensive pretty quickly so most EV owners make do with 120V trickle charging and occasional trips to the local L2 or Supercharger. None of this would cause the grid in California to catastrophically fail.

[Doug Garson]

The problem in California (at least one of them) is the risk of winds damaging the power lines. For example branch falls on one, shorts it out, catches fire, then falls to the ground. California has done back flips to try and prove most of these large fires are the fault of the power company. High tension lines don't have that risk since they are up higher and trees and brush and kept clear of them. When power is shut off it's the local lines. By having charging stations that aren't likely to get shut off it would reduce the fear of "what happens if I can't charge my car"? There's plenty of solar in California but not every person has it. When the grid is shut off due to fire risk solar panels are shut off from feeding the grid as well.
Agree the risk is branches falling on power lines causing fires, the solution is not moving the car chargers to the high tension lines (which are also at risk if proper tree trimming is not done) but trimming the trees. I was in Berkley a few years ago and our trip was affected by the power outages. I was amazed to see street after street with power lines running thru the trees which had obviously not been trimmed for decades. A better solution is to run the power lines underground, you don't see overhead gas and water lines, why power?

[Peter Kelly]

Because it's insanely expensive?

[Doug Garson]

Because it's insanely expensive?
Agree in some areas that may be true but once you have trenched for gas, sewer and water, how much more to also bury power? All the utilities in my area are underground, granted the soil here is mainly sand so digging is easy. If they had buried the lines decades ago when the neighborhoods were developed, I suspect the premium would not have been that great, doing it now would be expensive but so is the cost of power outages and fires caused by overhead lines.

[mike stenson]

A few years ago I saw a presentation at a professional conference in which it was mentioned that 25% of the electricity generated in California was used to pump water. Thats the real Catch 22.

Water will be the bigger problem in the west.

[Malcolm McLeod]

Agree the risk is branches falling on power lines causing fires, the solution is not moving the car chargers to the high tension lines (which are also at risk if proper tree trimming is not done) but trimming the trees. I was in Berkley a few years ago and our trip was affected by the power outages. I was amazed to see street after street with power lines running thru the trees which had obviously not been trimmed for decades. A better solution is to run the power lines underground, you don't see overhead gas and water lines, why power?


Because it's insanely expensive?

As we drift off topic....
From memory, but on a typical 70kV branch circuit I recall cost for overhead is ~$300,000/mile; cost for underground is ~$1,500,000/mile. I may have the specific $$ numbers off a bit, certainly depends on location, but 5X difference has been a rule of thumb for years.

And that is just for install; repairs, upgrades, and expansions only add to it. Forever. About the only benefit is that underground is less prone to damage.

Like so many things, we do 'it' cuz it's cheaper. No idea what % of the bill is generation vs delivery, but who wants their electric rate to jump up to support this?

By the way, who else has these problems of power line induced fires? I know the media has questionable focus at times, but I don't recall ever hearing of this anywhere but CA? East TX has tall trees, power lines, wind, and drought.... but not fires from the mix. At least not that I see reported. Edit: I found one reported in TX in 2011 - way south of me (Bastrop County), so perhaps why I didn't see a report.

[Brian Elfert]

Underground power definitely fails a lot less often, but repairs can be expensive when it does fail. My parents had an animal chew through one phase of their underground feed years ago. The utility had to replace the wire all the way from the transformer to the house. The city I live in has required underground utilities for new installations since the late 1970s. It is nice not having many power poles.

I have seen utilities here in Minnesota cut very wide swathes around power lines. In one case they removed all trees and vegetation at least 50 feet out on either side of the line. It was jarring to see how wide a gash they cut through the forest, but it has to be done to provide reliable power.

[Bill Dufour]

In California they do allow them to trim trees back that far, too ugly. If you live in a historic house would it be prohibited to convert to under ground wires?
Bill D

[Mike Henderson]

Mike, not sure the numbers support your point that you can't really charge an ev on 120 Volt power. The average range on an ev is about 180 miles while the average daily drive in the US is only about 25 miles, so on average you only need to top up the battery about 14% daily. Using your number of 26 hours to fill a battery, topping it up 14% would take under 4 hours using 120Volt power.

Sure, if you can get by with a fairly small charge, 120V charging is fine. However, my calculations were that it would take 26 hours to fill the battery HALF WAY. I assumed that you wouldn't run your battery all the way down before charging it again. So, using your numbers, 14% would take a bit less than 8 hours, not four. Your 14% was of the full capacity of an average battery, good for 180 miles. At half charge you'd be putting 90 miles into the battery and my calculations were that it would take 26 hours to do that. 25 miles is about 28% of 90 miles. 28% of 26 hours is 7.26 hours.

I wasn't working on miles, but on KWh. We are assuming 75 KWh is equal to 180 miles for these calculations.

To fully charge a 75KWh battery at 120V, 12 amps would take about 52 hours. Probably longer because you have some losses to heat while doing the charge.

I put in a 240V 50 amp outlet in my garage and it wasn't that expensive. Most of the EVs now have portable charging devices so you don't need a permanent charging device in your garage. I don't really want a charging device in my garage. It doesn't charge faster than the portable charger plugged into a 50 amp outlet, and when I go to sell the car, I'd have to remove the charging device so that the new owner can use it. With a portable charging device, I just leave it in the trunk.

Mike

[Alex LaZella]

I have an electric car. Nobody would charge an electric car on 120v. 120 is much less efficient as well. I think I was told it is only 80% efficient to use that low of a voltage to charge your car. For you nit-pickers, I may be wrong on the number but it is absolutely not efficient. As far as a "charger", you do not need a charger the car has the charger internally. All you need is an outlet to plug a charging cable into your vehicle. For the people who don't want to believe, feel free to google "how long to charge my tesla on 120v" you will find times listed in days.

thanks

[Mike Henderson]

The other point is that the thing that wears a battery out is the number of charge cycles, not the number of miles driven. The best approach to battery charging is to treat your car just like an ICE car - only "fill up the tank" when it gets down to some level you feel comfortable with. I generally fill up my ICE car with gas when I get down to about half tank. I'd do the same with an EV. And that makes charging with 120 volts a very long affair.

Mike

[Doug Garson]

I have an electric car. Nobody would charge an electric car on 120v. 120 is much less efficient as well. I think I was told it is only 80% efficient to use that low of a voltage to charge your car. For you nit-pickers, I may be wrong on the number but it is absolutely not efficient. As far as a "charger", you do not need a charger the car has the charger internally. All you need is an outlet to plug a charging cable into your vehicle. For the people who don't want to believe, feel free to google "how long to charge my tesla on 120v" you will find times listed in days.

thanks

Technically you are correct because nobody has 120V power, :rolleyes: standard power in North America is 110 V or 220 V. However Tesla appears to disagree with what I think you meant. In response to the question "can you charge a Tesla on 110 V?" Tesla responded "Yes. An adapter for a 110 volt outlet (NEMA 5-15) is included as standard equipment with all new Tesla cars. This provides approximately two to four miles of range per hour of charge depending on the car."
So an overnight charge of say 12 hours would give you 24 to 48 miles of range which, depending on your daily drive might be all you need for your daily commute.

Getting back to the original question, it is ironic that those who choose to reduce their carbon footprint by buying an EV may be more inconvenienced by a drought likely caused by climate change than those who didn't. Another question is would PG&E need to cut power to avoid wildfires if they had not prioritized profit over maintenance for decades drought or no drought?

[Mike Henderson]

Technically you are correct because nobody has 120V power, :rolleyes: standard power in North America is 110 V or 220 V. However Tesla appears to disagree with what I think you meant. In response to the question "can you charge a Tesla on 110 V?" Tesla responded "Yes. An adapter for a 110 volt outlet (NEMA 5-15) is included as standard equipment with all new Tesla cars. This provides approximately two to four miles of range per hour of charge depending on the car."
So an overnight charge of say 12 hours would give you 24 to 48 miles of range which, depending on your daily drive might be all you need for your daily commute.

Getting back to the original question, it is ironic that those who choose to reduce their carbon footprint by buying an EV may be more inconvenienced by a drought likely caused by climate change than those who didn't. Another question is would PG&E need to cut power to avoid wildfires if they had not prioritized profit over maintenance for decades drought or no drought?

I think if you check you'll find that 110 volts and 220 volts are not the standard power in the USA. A lot of people use those terms to mean the low voltage and the high voltage brought into a residence but the standard is not 110/220.

My checking says that the standard in the US and Canada is 120 volts +/- 6%, giving 114V to 126V. (and 240 volts +/- 6%, 228V to 252V). Wikipedia has an entry about this here (https://en.wikipedia.org/wiki/Mains_electricity).

Mike

[Doug Garson]

OOPS, :( my bad.

[Dan Friedrichs]

I have an electric car. Nobody would charge an electric car on 120v. 120 is much less efficient as well. I think I was told it is only 80% efficient to use that low of a voltage to charge your car. For you nit-pickers, I may be wrong on the number but it is absolutely not efficient.

I'm curious where you heard this. I don't think it's correct. It certainly takes more time at 120V, but is not less efficient.

[Bill Dufour]

I read that the time to charge from 20% to 80%. is the same as from 80% to 100% assuming equal power input from the plug. It becomes harder to add more power as the back EMF in the battery increases.
I have not heard of any makers doing it but you can draw 50 amps from a 50 amp outlet for two hours and 59 minutes then drop down to 75% load for the continuous load portion.
Bill D

[Zachary Hoyt]

Our grid power here is generally 117 volts and change. I don't know how typical this is.

[Alex LaZella]

I'm curious where you heard this. I don't think it's correct. It certainly takes more time at 120V, but is not less efficient.

sorry, it's true. a quick google search backed that up. Feel free to google it. I quickly saw several EV sites and an article in car and driver based on their charging of a test car.


Yes Tesla and all EV's that I am aware of can be plugged into 120V and mathematically that could indeed add a pittance of range overnight which might mathematically work for your daily drive. Of course, how you drive might make that alleged 24-48 miles of range only work out to 12. The temperature outside might cut the range, (too hot or too cold) running the heat absolutely cuts the range etc. The "range" is a mythical number. you need to drive your car and see what range you get in a variety of conditions and then keep that in the back of your mind. My Wife consistently gets about 25% less range than I do. EV's absolutely suck in places with cold winter.

Bill, yes the first 80% is quick and easy the last 20% takes a long time. If you have a Tesla the superchargers can get you up to 80% nice and fast and with their range that is usually enough. Non Teslas can use the DC fast chargers that can be found though they are not as common as supercharagers.

I love all the people that have never used EV's arguing about how great it is to charge them and use them. Get one and try it. It is a choice and they are not for everyone or everything. I am on my third EV and am happy with it but I happily have 4 "regular" cars that I wouldn't get rid of to save my life. As to their being a green option, try googling how they get the materials to make the batteries, or what happens to all of the left over batteries. If I recall I think the batteries will still have like 75% capacity when they are considered useless for vehicles any longer. There have been all sorts of neat ideas on how to use the "bad" batteries but I don't know if any of them have ever come to fruition. "green" is more of virtue signaling in the first world while we rape the third world.

[Alex Zeller]

I would think somebody will take the old batteries and make something like Tesla's power wall. Who cares if the capacity is 70% of what it once had or if they only last 1/2 the life span of what a new battery would. 99% of the houses they would be installed in space isn't a huge issue. The batteries are basically free making the cost only a fraction of what one with new batteries would cost.

As far as EVs go I really think the government should be pushing for plug in hybrids to offer more range. Toyota's Rav4 only has about 40 miles. That's 20 miles each way which would mean burning gas for a lot of commuters. A range of 100 miles would get most people to work and back on battery power alone. If it has the software to allow it to power a house you could actually use the gas engine like a generator if the power goes out.

[Jason Roehl]

I would think somebody will take the old batteries and make something like Tesla's power wall. Who cares if the capacity is 70% of what it once had or if they only last 1/2 the life span of what a new battery would. 99% of the houses they would be installed in space isn't a huge issue. The batteries are basically free making the cost only a fraction of what one with new batteries would cost.

As far as EVs go I really think the government should be pushing for plug in hybrids to offer more range. Toyota's Rav4 only has about 40 miles. That's 20 miles each way which would mean burning gas for a lot of commuters. A range of 100 miles would get most people to work and back on battery power alone. If it has the software to allow it to power a house you could actually use the gas engine like a generator if the power goes out.

The new Ford F-150 Lightning (all-electric) has whole-home power as one of the options.

[Dan Friedrichs]

sorry, it's true. a quick google search backed that up. Feel free to google it. I quickly saw several EV sites and an article in car and driver based on their charging of a test car.

Interesting. It sounds like a certain fixed overhead wattage is used by the car, even when parked. Charging at a very low current (regardless of 120V or 240V) results in that overhead being a larger portion of the available power, so "efficiency" is less, as less power goes into the battery.

It seems more accurate to say this is a side-effect of charging at low currents, though, as the same would be true if you were charging at 240V, 7A.

[Mike Henderson]

If it has the software to allow it to power a house you could actually use the gas engine like a generator if the power goes out.

Most hybrid vehicles have pretty small batteries, maybe 10KWh. And the generator on the car isn't that big. I found specifications for the Ford F-150 hybrid that said the generator is 7.2KW. So for long term use, the vehicle would act like a 7KW portable generator. You could power some of your house but probably not all of it.

I think a better approach is not to tie your car into your home electrical system - like a backup generator - but to just have a couple of 120 volt and 240 volt outlets on the vehicle that you could run extension cards from. That way, you could keep your refrigerator and a few other things running.

Installing a transfer switch - which you would have to do if you wanted to connect your car to your household electrical system - is expensive. Unless you have a lot of power problems, I'd be happy to run a few long extension cords.

Mike

[Kev Williams]

Sure, if you can get by with a fairly small charge, 120V charging is fine. However, my calculations were that it would take 26 hours to fill the battery HALF WAY. I assumed that you wouldn't run your battery all the way down before charging it again. So, using your numbers, 14% would take a bit less than 8 hours, not four. Your 14% was of the full capacity of an average battery, good for 180 miles. At half charge you'd be putting 90 miles into the battery and my calculations were that it would take 26 hours to do that. 25 miles is about 28% of 90 miles. 28% of 26 hours is 7.26 hours.

I wasn't working on miles, but on KWh. We are assuming 75 KWh is equal to 180 miles for these calculations.

To fully charge a 75KWh battery at 120V, 12 amps would take about 52 hours. Probably longer because you have some losses to heat while doing the charge.

I put in a 240V 50 amp outlet in my garage and it wasn't that expensive. Most of the EVs now have portable charging devices so you don't need a permanent charging device in your garage. I don't really want a charging device in my garage. It doesn't charge faster than the portable charger plugged into a 50 amp outlet, and when I go to sell the car, I'd have to remove the charging device so that the new owner can use it. With a portable charging device, I just leave it in the trunk.

Mike
75 THOUSAND watts? Just checking if their may be a decimal point missing? :)

My home/business burns thru about 6500 kilowatt hours a month, my EP light bill just a few $ shy of $600... 6500 / 30 days = 217 Kw hours a day - 75kW works out to around 8 hours of my power usage, which seems like a ton! Do these electric cars & batteries really eat that much power?

[Mike Henderson]

75 THOUSAND watts? Just checking if there may be a decimal point missing? :)

My home/business burns thru about 6500 kilowatt hours a month, my EP light bill just a few $ shy of $600... 6500 / 30 days = 217 Kw hours a day - 75kW works out to around 8 hours of my power usage, which seems like a ton! Do these electric cars & batteries really eat that much power?

That's kilowatt HOURS. So one way of looking at it is that the battery will supply one kilowatt for 75 hours, or 75 kilowatts for one hour. There are probably restrictions on the output.

But, yes, 75 thousand watt hours. A car is pretty heavy. As far as pricing from your electrical supplier, a KWh probably cost between $0.10 and $0.30. So to fully charge a 75KWh battery you'd pay between $7.50 and $22.50. That's not too bad compared to the price of gas. Most of the time your battery won't be completely empty so a "fill up" will be less than that.

Your electricity is pretty cheap, looks like about 9 cents per kilowatt hour. A lot less expensive than what I pay.

Mike

[Lee DeRaud]

75 THOUSAND watts? Just checking if their may be a decimal point missing? :)Look at it this way: 75kW is right around 100HP. That 75kWh battery can give you 100HP for an hour*, or 25HP for 4 hours. At 80MPH, that 4 hours is just about the range of a Tesla. Given that the EPA figures a gallon of gasoline contains the equivalent of ~34kWh of energy, that 75kWh is about 2.2 gallons of gasoline and you just went 320 miles on it.

(* Or 1000HP for 6 minutes. I'm gonna need ten or so miles of straight road, a good helmet, and a change of underwear... :) )

[Mike Henderson]

Look at it this way: 75kW is right around 100HP. That 75kWh battery can give you 100HP for an hour*, or 25HP for 4 hours. At 80MPH, that 4 hours is just about the range of a Tesla. Given that the EPA figures a gallon of gasoline contains the equivalent of ~34kWh of energy, that 75kWh is about 2.2 gallons of gasoline and you just went 320 miles on it.

(* Or 1000HP for 6 minutes. I'm gonna need ten or so miles of straight road, a good helmet, and a change of underwear... :) )

To add to what Lee said, the reason you don't get that kind of great mileage from gasoline is that an internal combustion engine is very inefficient - a lot of the energy in gasoline just goes into heat. The electric motors on an EV are MUCH more efficient so you get a lot more miles from the same energy equivalent.

Mike

[Doug Garson]

Yeah, most people don't realize a typical internal combustion engine is only around 25% efficient compared to an electric motor which could be in the 90% range. So, not only is the engine producing CO2 but 75% of the energy in the fuel is just heating the planet.

[Rod Sheridan]

Yeah, most people don't realize a typical internal combustion engine is only around 25% efficient compared to an electric motor which could be in the 90% range. So, not only is the engine producing CO2 but 75% of the energy in the fuel is just heating the planet.

Doug, 25% is pretty good.

Big engines are about a 1/1/1 energy balance (without co-generation) which gives 1 unit of work, 1 unit of heat rejection out the exhaust and 1 unit out the water jacket (radiator),….Rod

[Kev Williams]

So, just read where Tesla "S" batteries run 375 'nominal' volts, and that a Model S P90DL at full-on accel is putting down 400kW, which calculates out around 500hp and 1067 amps... My house/business is ran off 200 amp service... boggles the mind...

[Alex Zeller]

People are going to learn that drag racing is going to be a thing of the past. Draining the batteries too fast is bad for them. It also produces a lot of heat and drains them quickly.

[Bill Dufour]

I liked slotcars as a kid. The cable car slot in San Francisco looks like a full size slot car track
Bill D

[Doug Garson]

Here's a video on an idea I previously thought was impractical, battery swapping in EVs. The Chinese have developed an automated system that can swap the battery in less time than a gas fill up. Really neat idea for swapping batteries in electric scooters also. https://www.youtube.com/watch?v=2-xWYScsvts

[Brian Elfert]

Electric car battery swapping is not new. The Tesla model S has/had the ability for battery swaps. There was a battery swap station built that I believe is now closed. Tesla even did a big press event where they swapped a battery in a car.