My thoughts on BEV, FCEV, and PHEV

[brad850csi]

BEV

I'm guessing that we won't see battery capacities for normal passenger vehicles get much above ~100kWh simply due to the weight of the battery based on current technology. Maybe ~125kWh will happen for larger SUVs such as the X7/GLS/Escalade, but I don't see battery capacities increasing too much more than they already are for smaller vehicles such as the Kona, i4, e-tron, etc. which have 60-95kWh batteries. The Model 3 75kWh battery apparently weighs 478kg, so a 125kWh battery will be around 800kg - quite a bit of weight for any normal sized car. In addition to that, VAG, Tesla, and others are pushing faster and faster charging so I think that outright capacity will become less of an issue for more and more people.

That said, I've done a few drives here in NZ that I couldn't have completed in an electric car due to the sparseness of the population in some areas. I understand this is also a concern for large parts of the USA and I'm sure many other countries around the world too. For the moment, in NZ, the infrastructure wouldn't be good enough for me to replace my M6 with any BEV for the types of drives I like to do every few months. I think plenty of people will have similar use cases which could limit the practicality of BEVs around the world, especially in more remote regions or in countries where electricity is more expensive and petrol/diesel is relatively cheap.

Another issue with BEVs is that many people don't have off street or garage parking. For everyone that does a normal commute that can plug their car in each night, they'll get 160km/100miles of charging overnight which will be ample. But if you can't charge easily at home then availability of rapid chargers becomes more important. At the moment I think we are in a bit of a chicken and egg situation. You need more BEV owners that require fast chargers for the infrastructure to be invested in, but those same people are reluctant to buy a BEV until they know they can rely on the infrastructure being available. At the moment, in areas with insufficient fast chargers available, you might need to wait in line for a charger to become available, before you then spend another 45-60 minutes for the actual charge. That might be acceptable if you're going to a shopping mall for a day, but not so much if you're going on a long trip and just wanted to stop for lunch charge up. However, over time, as BEVs are able to charge faster and faster and with (hopefully) the infrastructure keeping pace or ahead of the game, this should become less of a problem.

FCEV

While Hydrogen appeals to me much more than BEVs, I think that the energy cost to manufacture H2, storage issues both in the car and in a tank at a filling station, and so on are problems that have no easy solution. And there isn't enough interest in resolving those problems when BEVs will be good enough for almost all situations.

PHEV

I believe these will die soon. The added complexity of having both the electric motor plus batteries and the combustion engine plus its supporting hardware in the same vehicle will always penalize with weight and size. And these will become unnecessary with the increase in battery capacity and recharging speed. Having said that, my very niche dream would be to replace my M6 with an M8 that has a DCT gearbox sending power to the rear only with an i8 front axle . I do wonder if a niche will develop for AWD vehicles because it may be lighter/cheaper to install an electric motor and some batteries instead of an additional driveshaft and differential. This was the case with the NSX, 918 and I'm fairly sure I remember a Citroen or Peugeot SUV that was front wheel drive with a small electric motor at the back. But, once charging becomes more convenient and more accepted amongst consumers, these will go away except perhaps a few high end vehicles that use the AWD setup I describe.

[RM7]

The problem with hydrogen isn't just creation. It's also storage and transportation which take a huge amount of energy and infrastructure - extremely high pressure holding tanks, trucking it everywhere, etc.

[Efthreeoh]

My opinion is the best solution is an electo-diesel (or other combustion technology) hybrid drive train. The most efficient conversion of stored energy to vehicular motive force is using an electric drivetrain. Modern EVs have proven that. The problem is the storage capacity of batteries even with advanced tech. The batteries are slow to recharge and the fastest recharge technology requires massive current flow and cooling of the hardware to make it possible. This means the charging hardware is expensive to build, maintain, and must be operated by a trained technician. There are limits to physics, especially when economics are in the mix.

A drive train that combines a very efficient conversion of the stored energy in petroleum fuel to electricity to power an electric drive can be efficient. Locomotives, ships and submarines have been use this technology for 70 years. It needs to be adapted to automotive use of course, since automobiles have different drive cycles than trains and ships. This means that fast storage of peak energy is needed, battery or capacitors.

Back in the late 1970s and early 1980's many automotive companies were investing R&D into increasing the efficiency of ICE. I remember Ford was investing in a ceramic engine, the idea being a ceramic block and head would allow the engine to run at an elevated temperature that created a higher energy extraction from the combustion process. Ford dropped the research mainly because the cost to bring such new technology to the market wasn't worth the investment and acceptability of such radical technology by the market was nonexistent. An example: TRW's development of the parallel hybrid drivetrain in the early 1970's. The Big Three had no interest in developing it for production because it wasn't economically viable at that time and the American market was not tolerable to such an aberration of the standardized ICE/transmission design.

Now with better acceptance of alternative technologies (i.e. hybrid, BEV, etc.) I think the market is more tolerable to accepting different designs. Yet, I think the R&D on vastly improving carbon fuel burning efficiency is a non-starter in the current political climate.

[yco]

The charging problem will be solved when they figure out how to charge moving vehicles wirelessly.

[overcoil]

I think internal combustion engines will dominate for the next few hundred years. ICE will continue due to the weight of batteries. We are probably coming close to the limits of what physics allows us so civility and continual finessing of design will be the future advances.

Maybe we'll see engines that do not need glycol coolants, maybe not even lubricating oil, and efficiencies like 80 - 100 mpg will be common. I also think we won't need passive safety systems like crush zones because cameras and advances in processing will have cars talking to one another. So, cars will be smaller and the space that is now a three lane highway will allow seven or more cars abreast.

[chassis]

US Market:

I think diesel and hydrogen in the US for passenger vehicles is dead technology.

Near term: continued engine downsizing with direct injection gasoline ICE+turbo+CVT solutions

Medium term: growing use of electric passenger vehicles, initial stages of short-route electric commercial vehicles. Gasoline ICE for passenger vehicles and diesel for long- and medium-route commercial vehicles still in the market.

Longer term: growing use of electric passenger vehicles, growing use of short and medium route electric commercial vehicles. Gasoline ICE for passenger vehicles and diesel for long-route commercial vehicles still in the market.

[overcoil]

Originally Posted by Efthreeoh

Back in the late 1970s and early 1980's many automotive companies were investing R&D into increasing the efficiency of ICE. I remember Ford was investing in a ceramic engine, the idea being a ceramic block and head would allow the engine to run at an elevated temperature that created a higher energy extraction from the combustion process. Ford dropped the research mainly because the cost to bring such new technology to the market wasn't worth the investment and acceptability of such radical technology by the market was nonexistent.

I remember talk of ceramic piston liners. Though ceramic bearings, not sure when they were first utilized, have been hugely successful.

[Efthreeoh]

Originally Posted by JamesNoBrakes

The problem with hydrogen isn't just creation. It's also storage and transportation which take a huge amount of energy and infrastructure - extremely high pressure holding tanks, trucking it everywhere, etc.

I have concerns with the exhaust. Water vapor. Icy streets in the northern climates...

[danniexi]

Originally Posted by Efthreeoh

My opinion is the best solution is an electo-diesel (or other combustion technology) hybrid drive train. The most efficient conversion of stored energy to vehicular motive force is using an electric drivetrain. Modern EVs have proven that. The problem is the storage capacity of batteries even with advanced tech. The batteries are slow to recharge and the fastest recharge technology requires massive current flow and cooling of the hardware to make it possible. This means the charging hardware is expensive to build, maintain, and must be operated by a trained technician. There are limits to physics, especially when economics are in the mix.

A drive train that combines a very efficient conversion of the stored energy in petroleum fuel to electricity to power an electric drive can be efficient. Locomotives, ships and submarines have been use this technology for 70 years. It needs to be adapted to automotive use of course, since automobiles have different drive cycles than trains and ships. This means that fast storage of peak energy is needed, battery or capacitors.

it’s been done but hasn’t been wildly successful.

[JohnnyCanuck]

brad850csi two principle issues come to mind from your post.

The first is that there are no peer reviewed academic studies that demonstrate that BEVs provide any environmental benefit. Lithium mining and battery production/disposal are the issues most referred to, but those aren't the complete picture. So much of the world's electricity is generated by burning fossil fuels (esp. coal) generating GHGs. In the US 67% of electrical generation produces GHGs. Then you have other environmental damage caused by mining/drilling/fracking for those fuels (and the GHGs from those activities). And, that doesn't measure the environmental damage done building and operating non-GHG sources of electricity (habitat damage, etc).

The second point is, like you, I think there is huge potential in fuel cell technology. Your point is well taken that commercial hydrogen production itself generates significant GHGs and has a high energy cost. However, I think researchers are at the point of breakthrough. Localized GHG-free hydrogen production is feasible and foreseeable. What's required is investment and infrastructure.