What I don't understand about EVs is that you have four wheels; why are those four wheels not turning generators? You use the battery to get the wheels turning, and then one would think that at the RPMs at which the wheels are turning, you could generate enough electricity to recharge the battery and keep the vehicle moving.
You are describing a perpetual motion machine. So far, no one has gotten one to work. Energy is neither created or destroyed, but there are losses to other forms ( heat, for one). Regenerate braking charges the battery as you describe, but not that much. Buddha
I am sorry is this sounds rude, but life does not work that way. The energy going into an electric motor, even under no external load, is more than the same motor will generate if used as a generator. I am not an expert in the way electric motors work, but the input is consumed in generating a magnetic field strong enough to induce the rotor to turn. You should be able to reap some of the energy if you could harvest the energy while the car is coasting to a stop, but the act of doing so would act as a brake on the forward movement of the vehicle and would be significantly less than the energy taken to maintain the vehicle's forward motion.
If your idea was practical, then we would only have to build some sufficiently large generators and then plug them into themselves to get free energy in perpetuity. I know that some will see this as mansplaining, but I am (after all, a man) and have a reasonably good history of explaining things, so I can't help myself. I can bore even the most enthusiastic supplicant to tears in just a matter of a few minutes when I get on a roll in my chosen field of expertise. I have stories.
You aren't that far off. They do use "regenerative braking" to capture the kinetic energy from braking and convert it into the electrical power that charges the vehicle’s high voltage battery. This can be very useful in hybrid gas/electric vehicles to keep the battery charged. [https://www.tiresplus.com/blog/brakes/what-is-regenerative-braking-in-electric-vehicles/]
Electric vehicles already do this! It's called "regenerative braking". Which is a fancy way of saying "turn those electric motors powering the wheels into generators, slowing the car down." Works great!
Only works well enough to keep the car going forever if you happen to always be going downhill. I heard a story once of a mine in ... scotland? ... Anyway, it was an open pit mine up on a hill. So they made all their dump trucks into EV's, and they'd charge going down the hill while full to ore processing, and have plenty of juice in their batteries for going back up the hill empty. Worked great, never had to buy fuel. But that's a bit of a special case.
Judy is talking about using achieved momentum to generate electricity, but remember energy conversion is never straight across; there is loss due to friction and many other variables. Hybrid vehicles do that to a degree, by using braking and gas engine downshifting to spin a generator, but it's never going to equal the power needed to move a car & everything in it as it goes down the road. At least not with current technology-also maybe further down the road. And they make more sense than an all-electric car. Way back in the dusty, dim past, Mother Earth News sold plans to build your own hybrid. CC
I was taught in college that the best motors and generators are 90% efficient. The 10% loss is mostly heat which has to be shed to protect the motor or generator. So when you have a hybrid car you burn gas to drive a 90% efficient generator which in turn drives a 90% efficient motor so 81% of the engine's output propels the car. Regenerative braking works best in stop and go traffic, on the highway with the cruise control set there is no braking for regeneration and aerodynamic drag becomes much more of a factor as drag quadruples when velocity doubles.
Aircraft have been using starter-generators since after WWII, it saves weight and precious space under the cowling. Al_in_Ottawa
Thanks, everybody. I didn't understand the physics/engineering that was going on. So, to my way of thinking, it's still a R&D project in the application they want to use it in.
I wonder how long it takes those six panels to charge the battery. I had thirty-seven on my roof for whole house electricity. The access, which was not a lot, went into the grid and I was lamely compensated for it. I rarely ran the a/c. There was no heat mode on the air handler and no tv on all day long or ever. Most homes on Maui don't have heat except for Upcountry.
I have 19 panels up and so far this year have produced 1 MWh. Net export is 524 kWh. Just getting started with it. It will be interesting to see how it does when the sun starts getting towards peak.
I have lived with no connection to the electrical grid with solar panels, batteries, and a backup generator for the last 14 years. None of that stuff is free. I pay my electric bill in large amounts when I have to replace batteries (so far, on schedule for every ten years). Not sure it saves me any money at all, but I will never have a utility company screwing with my thermostat (ain't got one, anyway). So far my uptime is much higher than the neighbors who are connected to the grid, but we are in a remote area, so I suspect it takes a little longer to get them back on than those in the burbs. Sure hope I never have to get an electric vehicle, because I doubt I would want to buy enough infrastructure to charge it. Of course, the knuckleheads in charge would like to eliminate my ability to buy propane and gasoline, the fuel for my backup power sources. As Old NFO always says,...sigh.
Electric Vehicles - When you absolutely, positively, have to get to work...sometime this week...as long as the sun is shining...or something.
ReplyDeleteDon't forget the hammer and sickle.
ReplyDeleteDipshit earthmuffin ecotards would be first in line to buy one.
ReplyDeleteWhat I don't understand about EVs is that you have four wheels; why are those four wheels not turning generators? You use the battery to get the wheels turning, and then one would think that at the RPMs at which the wheels are turning, you could generate enough electricity to recharge the battery and keep the vehicle moving.
ReplyDeleteHuh?
DeleteYou are describing a perpetual motion machine. So far, no one has gotten one to work. Energy is neither created or destroyed, but there are losses to other forms ( heat, for one). Regenerate braking charges the battery as you describe, but not that much.
DeleteBuddha
I am sorry is this sounds rude, but life does not work that way. The energy going into an electric motor, even under no external load, is more than the same motor will generate if used as a generator. I am not an expert in the way electric motors work, but the input is consumed in generating a magnetic field strong enough to induce the rotor to turn. You should be able to reap some of the energy if you could harvest the energy while the car is coasting to a stop, but the act of doing so would act as a brake on the forward movement of the vehicle and would be significantly less than the energy taken to maintain the vehicle's forward motion.
DeleteIf your idea was practical, then we would only have to build some sufficiently large generators and then plug them into themselves to get free energy in perpetuity. I know that some will see this as mansplaining, but I am (after all, a man) and have a reasonably good history of explaining things, so I can't help myself. I can bore even the most enthusiastic supplicant to tears in just a matter of a few minutes when I get on a roll in my chosen field of expertise. I have stories.
You aren't that far off. They do use "regenerative braking" to capture the kinetic energy from braking and convert it into the electrical power that charges the vehicle’s high voltage battery. This can be very useful in hybrid gas/electric vehicles to keep the battery charged.
Delete[https://www.tiresplus.com/blog/brakes/what-is-regenerative-braking-in-electric-vehicles/]
Electric vehicles already do this! It's called "regenerative braking". Which is a fancy way of saying "turn those electric motors powering the wheels into generators, slowing the car down." Works great!
DeleteOnly works well enough to keep the car going forever if you happen to always be going downhill. I heard a story once of a mine in ... scotland? ... Anyway, it was an open pit mine up on a hill. So they made all their dump trucks into EV's, and they'd charge going down the hill while full to ore processing, and have plenty of juice in their batteries for going back up the hill empty. Worked great, never had to buy fuel. But that's a bit of a special case.
-John Gilmore
Judy is talking about using achieved momentum to generate electricity, but remember energy conversion is never straight across; there is loss due to friction and many other variables.
DeleteHybrid vehicles do that to a degree, by using braking and gas engine downshifting to spin a generator, but it's never going to equal the power needed to move a car & everything in it as it goes down the road.
At least not with current technology-also maybe further down the road.
And they make more sense than an all-electric car. Way back in the dusty, dim past, Mother Earth News sold plans to build your own hybrid.
CC
I was taught in college that the best motors and generators are 90% efficient. The 10% loss is mostly heat which has to be shed to protect the motor or generator. So when you have a hybrid car you burn gas to drive a 90% efficient generator which in turn drives a 90% efficient motor so 81% of the engine's output propels the car.
DeleteRegenerative braking works best in stop and go traffic, on the highway with the cruise control set there is no braking for regeneration and aerodynamic drag becomes much more of a factor as drag quadruples when velocity doubles.
Aircraft have been using starter-generators since after WWII, it saves weight and precious space under the cowling.
Al_in_Ottawa
Thanks, everybody. I didn't understand the physics/engineering that was going on. So, to my way of thinking, it's still a R&D project in the application they want to use it in.
DeleteI wonder how long it takes those six panels to charge the battery. I had thirty-seven on my roof for whole house electricity. The access, which was not a lot, went into the grid and I was lamely compensated for it. I rarely ran the a/c. There was no heat mode on the air handler and no tv on all day long or ever. Most homes on Maui don't have heat except for Upcountry.
ReplyDeleteThose look like 150W or maybe 200W panels, and are a popgun compared to what that car uses.
DeleteI have 19 panels up and so far this year have produced 1 MWh. Net export is 524 kWh. Just getting started with it. It will be interesting to see how it does when the sun starts getting towards peak.
DeleteSarcasm?
ReplyDeleteIn about a year, they will be able to drive to the grocery store.
ReplyDeleteWhy not just put large wheels on the rear and small wheels on the front. That way the vehicle is going downhill all the time!
ReplyDeleteI love it. Cartoon Physics at its best.
DeleteI have lived with no connection to the electrical grid with solar panels, batteries, and a backup generator for the last 14 years. None of that stuff is free. I pay my electric bill in large amounts when I have to replace batteries (so far, on schedule for every ten years). Not sure it saves me any money at all, but I will never have a utility company screwing with my thermostat (ain't got one, anyway). So far my uptime is much higher than the neighbors who are connected to the grid, but we are in a remote area, so I suspect it takes a little longer to get them back on than those in the burbs. Sure hope I never have to get an electric vehicle, because I doubt I would want to buy enough infrastructure to charge it. Of course, the knuckleheads in charge would like to eliminate my ability to buy propane and gasoline, the fuel for my backup power sources. As Old NFO always says,...sigh.
ReplyDeleteInstead of towing around a parking place for SUVs, why not a wind generator on the roof.
ReplyDeletesarc/ for those who need it
Now he just needs a wind turbine on the hood and he's all set!
ReplyDelete? I thought that the must have accessory would be a bicycle.
ReplyDelete