Category Archives: Automotive

7% of new US vehicles were EVs in 2023. Expect slow growth in 2024.

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About 7% of new US car and truck sales in 2023 were electric, 1.2 million vehicles. Of these, about 55% were Teslas. These numbers make sense based on US manufacturing and driving habits, so I don’t expect fast sales growth in 2024.

Currently home owners are the only major group of private drivers that save on fuel cost from owning an EVs. Home owners pay relatively little for electricity, about 11¢ per kWh, and they can generally charge their EVs conveniently, at home, overnight. Charging is more expensive and inconvenient for apartment dwellers. As a result, in 2023, some 95% of US EV sales went to home owners. Over 2 to 3 years they could hope to recover in gasoline savings the $7000 more that their EVs cost compared to petrol-powered vehicles, but they still have to drive a fair amount. A full charge of 80kWh EV at home will cost about $8.80 at current rates. This will power about 250 miles at a cost of 3.5¢/mile = $8.80/250.

Home, level 2 Chargers will cost about $1500 including the electrician cost.

The cost of gasoline is about 16.5¢/mile = $3.80/gal/ 23mi/gal) suggesting that you save 13¢ per mile by owning an EV. In order to recover the extra $7000 cost of the car in two years, you’d have to drive 27,000 miles per year, or 74 miles per day. To recover the difference in three years, you must drive 50 miles per day or 18,000 miles per year. This is more than most people drive.

EVs also offer reduced maintenance, but customers can balance this against the inconvenience of long charge times and spotty availability of chargers. My sense is that the fraction of Americans who benefit and drive 50-75 miles per day is about 7%. This fraction will increase as EVs get cheaper, but families that can benefit already own an EV.

The average Tesla costs today about $3000 more than the equivalent petrol car, but that still makes it relatively expensive, and it seems that the price differential was intentionally set to match sales to Tesla’s production capacity. Tesla could make EVs cheaper than petrol cars and still make a profit on each, but if they did this, they would have too much demand. Other US auto makers are mostly lose money on EVs and are unmotivated to lower prices. Based on this, my sense is that it is unlikely that sales will be much higher in 2024 than the 1.2 million sold in 2023.

The Chinese have plenty of new EVs, and they are eager to export. Their car market is currently about 50% EV, with companies like BYD selling EVs for as little as $12,000. The Chinese government subsidizes production and powers their EVs with cheap electricity by burning coal. These cars do not seem very good, compared to Tesla, but at this price they would flood the market if allowed to compete. The US government has kept them out with tariffs and with complaints about slave labor. Trump has promised a yet higher tariff, 100% on Chinese cars, if elected. The intent is to preserve US jobs and manufacturing. This is one of those situations where tariffs are good, IMHO.

Toyota Prius, the most popular hybrid.

Hybrids are a third option, cheaper than EVs, high mpg than normal engines. Though they are sometimes touted as a transition to EVs, to me they’ seem to suit a completely different demographic: those who don’t own their own home and drive a lot. Toyota makes the most popular hybrids in the US. They cost about $4000 more than the equivalent petrol car, $30,000 for a Prius vs $26,000 for a Corolla. When using a Prius in the city, you’ll get about 50 mpg, spending 7.5¢ per mile ($3.80/gal / 50 mpg = 7.5¢). This implies a gas savings of about 9¢ per mile vs an ordinary Corolla. Based on this, you have to drive about 27,000 miles per year in the city to recover the cost difference in two years. That’s a lot, and your performance is typically worse with a hybrid: you have a heavier car with a small engine. Maintenance cost is also higher with a hybrid than with an EV: you still need oil changes, fluid changes, belts, etc. and the mpg advantage vanishes on the highway. A hard driving home owner is better off with an EV, IMHO, an apartment dweller with a hybrid. Hybrids also should make sense for taxis and local-haul trucks. I can imagine hybrid sales rising in 2024, perhaps as high as 15% of vehicle sales. What we’re all waiting for is more near-shore manufacturing (or mandates), and this is not likely in 2024.

Robert Buxbaum April 28, 2024

BYD is not first world competition for Tesla

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In Q4 2023, BYD became the world’s largest electric vehicle (EV) manufacturer, passing Tesla in world wide sales. They mostly sell in China, and claim to make a profit while selling cars for about half the price of a Tesla. They also make robots, trucks, busses, smart phones, and batteries — including blade batteries that Tesla uses for a variant in its Berlin facility. They are a darling of the wall-street experts, in part because Warren Buffett is an investor. BYD cars look to be about as nice as Tesla’s at least from the outside and sell (In China) for a fraction of the price. The experts are convinced enough to write glowing articles, but I suspect that the experts have not invested, nor bought BYD products. — What do I know?

BYD truck. It looks good on the outside. Is it competition?

Part of the BYD charm is that it is considered socially progressive, while Tesla is seen as run by a dictatorial villain. A Delaware judge who concluded that Musk did non deserve the majority of his salary, and confiscated it. There are no such claims against BYD. BYD also has far more models than Tesla, 41 by my count, compared to Tesla’s 4. The experts seem to believe that all BYD has to do is bring their low-cost cars west, and they will own the market. My sense is that, if that was all they needed, they’d have done it already. I strongly suspect the low cost cars that are the majority of BYD’s sales are low quality versions — too low to sell in the US. Here are some numbers.

Total number of vehicles made 2023:
Tesla: ~1,800,000
BYD: ~3,020,000 (1,570,000 BEV)

Employees 2023: Vehicles / Employee 2023:
Tesla: ~140,000 Tesla: 12.86
BYD: ~631,500 BYD: 5.03

Gross Revenue 2023: Gross revenue per vehicle:
Tesla: ~$96.8B Tesla: $53,900
BYD: ~ $85B BYD: $28,100

Net Profit 2023: Profit per employee: Profit per vehicle:
Tesla: ~$9.5B (9.7%). Tesla: $67,857. Tesla: $5,280.
BYD: ~$3.5B (4.1%). BYD: $5,542. BYD: $1,160

Market share based on sales in western countries 2023:
Tesla: US: 4%, EU: 2.6%
BYD: US: 0%, EU: 0.1%

The most telling comparison, in my opinion, is BYD’s tiny market share in western countries. Their cars sell for 1/2 what Tesla’s sell for. If their low-cost cars were as good as Tesla’s, there is no way their market penetration would be so low. My sense is that the average BYD vehicle is lacking in something. Maybe they’re underpowered, or poorly constructed, unsafe, or unreliable: suitable only for China, India, or other poor markets. I suspect that the cars BYD sells in Europe are made on a separate line. Even so, customers say that BYD cars feel “cheap.” BYD charges more for these cars in Europe than Tesla charges for its top sellers, suggesting that these vehicles are of a different, better design. Even so, the low numbers suggest that BYD does not turn a profit on the sales. I suspect they do it for PR.

Both cars look sporty. Why doesn’t the BYD sell?

Another observation is that BYD produces 5.03 vehicles per worker, per year. That’s half as many as Tesla workers produce per worker-year. It’s also about half of Ford’s Rouge plant (Detroit) worker production in the 1930s. That Ford plant was vertically integrated starting with raw materials and outputting finished cars. This low output per worker suggests that BYD is built on low wage, low skill production, or equally damning, that none of these models are really mass-produced.

A first world market favors a polished product that your mechanic is somewhat familiar with. That favors Tesla as it has significant market penetration, and a network of mechanics. Also, Tesla has built up a network of fast charge stations and reliable service providers. BYD has no particular charging infrastructure and virtually no service network. Charging price and experience is a key decider among first world customers. No American will tolerate slow charging in the snow at a high price — especially if they must travel to a charger without being sure the charger will be working when they get there. Tesla has figured out how to make charging less painful, and that’s worth a lot.

Tesla might fail, but if so I don’t think it will be because of BYD success. Months ago the experts assured us that cybertruck would be deadly a failure. I disagree, but it might be. I don’t think BYDs will be better. Government subsidies have ended in many states and countries (Germany, California…) putting a dent in Tesla sales, and they are having manufacturing difficulties, particularly with batteries. These seem fix-able, but might not be. I see relatively little first world competition in the US EV market from legacy auto companies. Maybe they know to avoid EVs. They currently make decent products, IC and EV, but lose money on every EV. They treat EVs as a passing fad. If they are right, Tesla and BYD will fail. If they are wrong, Tesla will do fine, and they may not be able to make up their lost place in the market. As for BYD, given their low production numbers, they will need some 3 million new workers and many new factories. I don’t think they can find them, nor raise the money for the factories.

Most of the data here was taken from @NicklasNilsso14. All of the opinions are mine.

Robert Buxbaum February 18, 2024.

Cybertruck an almost certain success

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Leading up to the Cybertruck launch 4 weeks ago, the expert opinion was that it was a failure. Morgan Stanley, here dubbed it as one, as did Rolling Stone here. Without having driven the vehicle, the experts at Motor trend, here, declared it was worse than you thought, “a novelty” car. I’d like to differ. The experts point out that the design is fundamentally different from what we’ve made for years. They claim it’s ugly, undesirable, and hard to build. Ford’s F-150 trucks are the standard, the top selling vehicle in the US, and Cybertruck looks nothing like an F-150. I suspect that, because of the differences, the Cybertruck can hardly fail to be a success in both profit and market share.

Cybertruck pulls a flat-bed trailer at Starbase.

Start with profit. Profit is the main measure of company success. High profit is achieved by selling significant numbers at a significant profit margin. Any decent profit is a success. This vehicle could trail the F-150 sales forever and Musk could be the stupidest human on the planet, so long as Tesla sells at a profit, and does so legally, the company will succeed. Tesla already has some 2 million pre-orders, and so far they show no immediate sign of leaving despite the current price of about $80,000. Unless you think they are all lying or that Musk has horribly mispriced the product, he should make a very decent profit. My guess is he’s priced to make over $10,000 per vehicle, or $20B on 2 million vehicles. Meanwhile, no other eV company seems to be making a profit.

The largest competing electric pickup company is Rivian. They sold 16,000 electric trucks in Q3 2023, but the profit margin is -100%. This is to say, they lose $1 for every $1 worth of sales –and that’s unsustainable. Despite claims to the contrary, a money-losing business is a failure. The other main competitors are losing too. Ford is reported to lose about $50,00 per eV. According to Automotive News, here, last week, Ford decided to cut production of its electric F-150, the Lightning, by 50%. This makes sense, but provides Cybertruck a market fairly clear of US e-competition.

2024 BYD, Chinese pickup truck

Perhaps the most serious competitor is BYD, a Chinese company backed by the communist government, and Warren Buffet. They are entering the US market this month with a new pickup. It might be profitable, but BYD is relatively immune to profitability. The Chinese want dominance of the eV market and are willing to lose money for years until they get it. Fortunately for Tesla, the BYD truck looks like Rivian’s. Tesla’s trucks should exceed them in range, towing, and safety. BYD, it seems, is aiming for a lower price point and a different market, Rivian’s.

A video, here, shows the skin of a Cybertruck is bulletproof to 9mm, shotgun, and 45 caliber machine gun fire. Experts scoff at the significance of bulletproof skin — good for folks working among Mexican drug lords, or politicians, or Israelis. Tesla is aiming currently for a more upscale customer, someone who might buy a Hummer or an F-250. This is more usable and cheaper.

Don’t try this with other trucks.

Another way Cybertruck could fail is through criminal activity. Musk could be caught paying off politicians or cheating on taxes or if the trucks fail their safety tests. So far, Cybertruck seems to meet Federal Motor Vehicle Safety Standards by a good margin. In a video comparison, here, it appears to take front end collisions as well as an F-150, and appears better in side collisions.

This leaves production difficulty. This could prevent the cybertruck from being a big success, and the experts have all harped on this. The vehicle body is a proprietary stainless steel, 0.07″ thick. Admittedly it’s is hard to form, but Tesla seems to manage it. VIN number records indicate that Tesla had delivered 448 cybertrucks as Friday last week, many of them to showrooms, but some to customers. Drone surveys of the Gigafactory lot show that about 19 are made per day. That’s a lot more than you’d see if assembly was by hand. Assuming a typical learning curve, it’s reasonable to expect some 600 will be delivered by December 31, and that production should reach 6000 per month in mid 2024. At that rate, they’ll be making and selling at the same rate as Rivian or Ford, and making real money doing it. The stainless body might even be a plus, deterring copycat competition. Other pluses are the add-ons, like the base-camp tent option, a battery extension, a ramp, and (it’s claimed) some degree of sea worthiness. Add-ons add profit and deter direct copying (for a time).

Basecamp, tent option.

So why do I think the experts are so wrong? My sense is that these people are experts because of long experience at other companies — the competitors. They know what was tried, and that innovation failed. They know that their companies chose not to make anything like a Cybertruck, and not to provide the add-ons. They know that the big boys avoid “novelty cars” and add-ons. There is an affinity among experts for consensus and sure success, the success that comes from Chinese companies, government support and international banking. If the Cybertruck success is an insult to them and their expertise. Nonetheless, if Cybertruck succeeds, they will push their companies towards a more angular design plus add-ons. And they will claim cybertruck is no way novel, but that government support is needed to copy it.

Robert Buxbaum, December 25, 2023.

Solving the evening solar power problem

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Solar power is only available during the day, and people need power at night too. As a result, the people of a town will either need a lot of storage, or a back-up electric generator for use at night and on cloudy days. These are expensive, and use gasoline (generally) and they are hard to maintain for an individual. Central generated alternate power is cheaper, but the wires have to be maintained. As a result, solar power is duck curve, or canon curve power. It never frees you from hydrocarbons and power companies, and it usually saves no money or energy.

People need power at twilight and dawn too, and sunlight barely generates any power during these hours, and sometimes clouds appear and disappear suddenly while folks expect uniform power to their lights. The mismatch between supply and demand means that your backup generator, must run on and off suddenly. It’s difficult for small, home generators, but impossible for big central generators. In order to have full power by evening, the big generators need to run through the day. The result is that, for most situations, there is no value to solar power.

Installed solar power has not decreased the amount of generation needed, just changed when it is needed.

Power leveling through storage will address this problem, but it’s hardly done. Elon Musk has suggested that the city should pay people to use a home battery power leveler, a “power wall” or an unused electric car to provide electricity at night, twilight, and on cloudy days. It’s a legitimate idea, but no city has agreed, to date. In Europe, some locations have proposed having a central station that generates hydrogen from solar power during the day using electrolysis. This hydrogen can drive trucks or boats, especially if it is used to make hythane. One can also store massive power by water pumping or air compression.

Scottsbluff Neb. solar farm damaged by hail, 6/23.

In most locations, storage is not available, so solar power has virtually no value. I suspect that, at the very least, in these locations, the price per kWh should be significantly lower at noon on a sunny day (1/2 as expensive or less). The will cause people to charge their eVs at noon, and not at midnight. Adjusted prices will cause folks to do heavy manufacturing at noon and not at midnight. We have the technology for this, but not the political will, so far. Politicians find it easier to demand solar, overcharge people (and industry) and pretend to save the environment.

Robert Buxbaum Aug 8, 2023

Hydrogenation, how we’ve already entered the hydrogen economy

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The hydrogen economy is generally thought to come in some distant future, where your car (and perhaps your home) runs on hydrogen, and the hydrogen, presumably, is made by clean nuclear or renewable solar or wind power. This is understood to be better than the current state of things where your car runs on dirty gasoline, and your home runs on coal or gas, except when the sun is shining bright and the wind is blowing hard. Our homes and cars can not run on solar or wind alone, although solar cells have become quite cheap, because solar power is only available in the daytime, basically for 6 hours, from about 9AM to 3PM. Hydrogen has been proposed as a good way to store solar and wind energy that you can’t use, but it’s not easy to store hydrogen — or is it? I’d like to suggest that, to a decent extent, we already store green hydrogen and use it to run our trucks. We store this hydrogen in the form of Diesel fuel, so you don’t realize it’s hydrogen.

Much of the oil in the United States these days comes from tar sands and shale. It doesn’t flow well at room temperature, and is too heavy and gooey for normal use. We could distill this crude oil and use only the light parts, but that would involve throwing away a huge majority of the oil. Instead we steam reform it to gasoline, ethylene and other products. The reaction is something like this, presuming an input feed of naphtha, C10H8:

C10H8 + 2 H2O –> C7H8 + C2H4 + CO2.

The C2H4 component is ethylene. We use it to make plastics. The C7H8 is called toluene. It is a component of high octane gasoline (octane rating about 114). The inventor of the process, Eugene Jules Houdry claimed to have won WWII for the allies because his secret process (Houdryflow catalytic cracking) allowed high production of lots of gasoline of very high octane, giving US and British planes and trucks higher mpg than the Germans or Japanese had. It was a great money maker, but companies can make even more by adding hydrogen.

Schematic of the hydrocracking process, from the US energy information agency

Over the last 2-3 decades, refineries have been adding catalytic hydrogenation processes. These convert high octane aromatic products, like toluene to low -octane diesel and jet fuel. These products sell for more. Aromatic toluene is exposed to hydrogen at about 500°C and 300 psi (20 bar) to produce heptane, an excellent diesel fuel with about 7% more energy content than toluene per gallon.

C7H8 + 4H2 –> C7H16.

Diesel fuel sell for about 20% more than gasoline per gallon, in part because of the higher energy content, and because Diesel engines are more efficient than gas engines. What’s more, toluene expands as it’s converted to heptane. One gallon of toluene converts to 1.16 gallons of heptane. As a result hydrogenation adds about 40% to the sales price per molecule. Refineries have found that they can make significant money this way if they can buy cheap hydrogen. Over the last few years, several refineries in Norway and Texas (high sun and wind areas) have added hydrogenators along with electrolysis units to produce the cheap hydrogen when no one needs the unwanted electricity generated when supply exceeds demand. Here is an analysis of the thermodynamics of this type of hydrogen generation.

Robert Buxbaum, May 11, 2023

A clever range extender for EVs

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Electric vehicles work well for short trips between places where you can charge with cheap electricity. Typically that’s trips from home to a nearby place of work, and to local shopping malls and theaters with low-cost charge spots. If you drive this way, you’ll pay about 3.2¢/mile for home electricity, instead of about 17¢/mile for gasoline transport (e.g. 24 mpg with $4/gallon gas). Using an EV also saves on oil changes, transmission, air filters, belts, etc., and a lot of general complexity. Battery prices are still high, but much lower than they were even a few years ago.

The 10 kW Aquarius Engine is remarkably small and light, about 10kg (22 lb).

EVs are less attractive for long trips, especially in the cold. Your battery must provide the heat, as there is no waste heat from the engine. Expect to have to recharge every 200 -250 miles, or perhaps twice in the middle of a long trip. Each charge will take a half-hour or more, and fast charging on the road isn’t low cost. Expect to pay about 15¢/mile, nearly as much as for gasoline. See my full comparison of the economics here.

One obvious solution is to have two cars: a short commuter and an EV. Another solution is a hybrid. The Toyota’s Prius and the Chevy Volt were cutting edge in their day, but people don’t seem to want them. These older hybrids provided quick fill-ups, essentially infinite range, and about double the gas milage of a standard automobile, 30-45 mpg. The problem is you have even more complexity and maintenance than with even a gas automobile.

Aquarius liner engine as a range extender

I recently saw a small, simple, super-efficient (they say) gas engine called Aquarius. It provides 9.5 kW electric output and weighs only 22 lbs (10 kg), see picture above. A Tesla S uses about 16 kW during highway driving, implying that this engine will more than double the highway range of a Tesla S at minimal extra weight and complexity. It also removes the fear of being stranded on the highway, far from the nearest charge-station.

The energy efficiency is 34%, far higher than that for normal automobile engines, but fairly typical of floating piston linear engines. The high efficiency of these engines is partly due to the lack of tapper valves, risers, crank-shaft, and partially due to the fact that the engine always runs at its maximum power. This is very close to the maximum efficiency point. Most car engines are over sized (200 hp or so) and thus must run at a small fraction of their maximum power. This hurts the efficiency, as I discuss here. The Aquarius Engine makes electricity by the back-forth motion of its aligner rods moving past magnetic stator coils. Slots in the piston rod and in the side of the cylinder operate as sliding valves, like in a steam engine. First versions of the Aquarius Engine ran on hydrogen, but the inventors claim it can also run on gasoline, and presumably hythane, my favorite fuel, a mix of hydrogen and natural gas.

At the moment shown, slit valves in the piston rod are open to both cylinder chambers. The explosion at left will vent to the exhaust at left and out the manifold at top. The sliding valve is currently sending fresh air into the cylinder at right, but will soon send it into both cylinders to help scavenge exhaust and provide for the next cycle; engine speed and impression are determined by the mass of the piston.

A video is available to show the basic operation (see it here). The drawing at right is from that video, modified by me. Air is drawn into the engine through a sliding valve at the middle of the cylinder. The valve opens and closes depending on where the piston is. At the instant shown in the picture, the valve is open to the right. Air enters that chambered is likely exiting through slits in the hollow piston rod. It leaves through the manifold t the top, pushing exhaust along with it. When the piston will have moved enough, both the slits and the intake will close. The continued piston motion (inertially driven) will compress the air for firing. After firing, the piston will move left, generating electricity, and eventually opening the slit-valve in the piston to allow the exhaust to leave. When it moves a little further the intake will open.

The use of side-opening exhaust valves is a novelty of the “Skinner UniFlow” double-acting, piston steam engines, seen on the Badger steamship on Lake Michigan. It’s one of my favorite steam engine designs. Normally you want a piston that is much thicker than the one in the drawing. This option is mentioned in the patent, but not shown in the drawing.

Aquarius is not the only company with a free-piston range extender. Toyota built a free-piston extender of similar power and weight; it was more complex but got higher efficiency. It has variable compression though, and looks like a polluter. (the same problems might affect the Aquarius) They dropped the project in 2014. Deutsch Aerospace has a two headed version that’s more powerful, but long and heavier: 56kg and 35kW. Lotus has a crank-piston engine, also 56kg, 35kW; it’s more complex and may have service life issues, but it’s compact and relatively light, and it probably won’t pollute. Finally, Mazda is thinking of bringing back its Wankel rotary engine as a range extender. Any of these might win in the marketplace, but I like the Aquarius engine for its combination of light weight, compact size, and simplicity.

This is not to say that Aquarius motors is a good investment. Aquarius automotive went public on the Toronto exchange in December, 2021, AQUA.TA. The company has no profits to date, and the only chance of them making a profit resides in them getting a good licensing deal from an established company. The major car companies have shown no interest so far, though they clearly need something like this. Their plug in hybrids currently use standard-size, 4 stroke engines: 110-150 kW, 100-150 kg, complex, and low efficiency. Consumers have not been impressed. Tesla autos could benefit from this engine, but Musk shows no interest either.

Robert Buxbaum May 5, 2022. I have no stock in Aquarius motors, nor have I received any benefits from them, or any auto company.

Lithium Battery prices fell 98%, solar prices fell more.

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Most people have heard of Moor’s law, the law that computing power keeps doubling every two years, with the price remaining the same, but the same law is observed with other tech products, notably lithium ion batteries and solar cells.

By my calculation the price of lithium ion batteries has fallen 98% so far, at a rate of 12.5% per year. That’s a remarkable drop given that the chemistry has hardly changed. The size has dropped too; it’s nowhere near as much as the price but enough to make batteries a reasonable choice for powering automobiles, scooters, and power tools. Batteries still lack the range and fast charging for some applications, but even there the low cost means that hybrids become attractive, combining for cars and truck, the long range of gas with a reduced cost per mile. The rate of decrease suggests that prices will be below $100 per kWh by 2025. That’s an $8000 cost for a battery powered car with 300 miles of range.

As for where the electricity comes from, the price of electricity is going up and becoming less reliable. In part that’s because of regulations on coal and nuclear power and the inherent problems with large-scale wind and solar. But decentralized solar may turn out to be a winner. Solar prices have fallen 99.6% since 1976. Even though the rate of decrease is slower, about an 8% drop in price per year, there is a sense that solar power has entered the mainstream. Combined with cheap, home batteries, it may soon make sense to power your home and car by solar cells on the house; there isn’t enough area on a car to quite power it.

Robert Buxbaum, September 27, 2021

Automobile power 2021: Batteries vs gasoline and hydrogen

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It’s been a while since I did an assessment of hydrogen and batteries for automobile propulsion, and while some basics have not changed, the price and durability of batteries has improved, the price of gasoline has doubled, and the first commercial fuel cell cars have appeared in the USA. The net result (see details below) is that I find the cost of ownership for a gasoline and a battery car is now about the same, depending on usage and location, and that hydrogen, while still more pricey, is close to being a practical option.

EV Chargers. They look so much cooler than gasoline hoses, and the price per mile is about the same.

Lithium battery costs are now about $150/kwh. That’s $10,000 for a 70 kWh battery. That’s about 1/5 the price of a Tesla Model 3. The reliability that Tesla claims is 200,000 miles or more, but that’s with slow charging. For mostly fast charging, Car and Driver’s expectation is 120,000 miles. That’s just about the average life-span of a car these days.

The cost of the battery and possible replacement adds to the cost of the vehicle, but electricity is far cheaper than gasoline, per mile. The price of gasoline has doubled to, currently, $3.50 per gallon. A typical car will get about 24 mpg, and that means a current operation cost of 14.6¢/mile. That’s about $1,460/year for someone who drives 10,000 miles per year. I’ll add about $150 for oil and filter changes, and figure that operating a gas-powered car engine costs about $1,610 per year.

If you charge at home, your electricity costs, on average, 14¢/kWh. This is a bargain compared to gasoline since electricity is made from coal and nuclear, mostly, and is subsidized while gasoline is taxed. At level 2 charging stations, where most people charge, electricity costs about 50¢/kWh. This is three times the cost of home electricity, but it still translates to only about $32 for a fill-up that take 3 hours. According to “Inside EVs”, in moderate temperatures, a Tesla Model 3 uses 14.59 kWh/100 km with range-efficient driving. This translates to 11.7¢ per mile, or $1170/year, assuming 10,000 miles of moderate temperature driving. If you live in moderate climates: Californian, Texas or Florida, an electric car is cheaper to operate than a gasoline car. In cold weather gasoline power still makes sense since a battery-electric car uses battery power for heat, while a gasoline powered car uses waste heat from the engine.

Battery cars are still somewhat of more expensive than the equivalent gasoline car, but not that much. In a sense you can add $400/year for the extra cost of the Tesla above, but that just raises the effective operating cost to about $1,570/year, about the same as for the gasoline car. On the other hand, many folks drive less than 50 miles per day and can charge at home each night. This saves most of the electric cost. In sum, I find that EVs have hit a tipping point, and Tesla lead the way.

Now to consider hydrogen. When most people think hydrogen, they think H2 fuel, and a PEM fuel cell car. The problem here is that hydrogen is expensive, and PEM FCs aren’t particularly efficient. Hydrogen costs about $10/kg at a typical fueling station and, with PEM, that 1 kg of hydrogen takes you only about 25 miles. The net result is that the combination hydrogen + PEM results in a driving cost of about 40¢/mile, or about three times the price of gasoline. But Toyota has proposed two better options. The fist is a PEM hybrid, the hydrogen Prius. It’s for the commuter who drives less than about 40 miles per day. It has a 10kWh battery, far cheaper than the Tesla above, but enough for the daily commute. He or she would use charge at home at night, and use hydrogen fuel only when going on longer trips. If there are few long trips, you come out way ahead.

Toyota 2021 Mirai, hydrogen powered vehicle

Toyota also claims to have a hydrogen powered Corolla or debut in 2023. This car will have a standard engine, and I would expect (hope) will drive also — preferably — on hythane, a mix of hydrogen and methane. Hythane is much cheaper per volume, and more energy dense, see my analysis. While Toyota has not said that their Corolla would run on hythane, it is supposed to have an internal combustion engine, and that suggests that hythane will work in it.

A more advanced option for Toyota or any other car/truck manufacturer would be to design to use solid oxide fuel cells, SOFCs, either with hydrogen or hythane. SOFCs are significantly more efficient than PEM, and they are capable of burning hythane, and to some extent natural gas too. Hythane is not particularly available, but it could be. Any station that currently sells natural gas could sell hythane. As for delivery to the station, natural gas lines already exist underground, and the station would just blend in hydrogen, produced at the station by electrolysis, or delivered. Hythane can also be made locally from sewer gas methane, and wind-power hydrogen. Yet another SOFC option is to start with natural gas and convert some of the natural gas to hydrogen on-board using left-over heat from the SOFC. I’ve a patent for this process.

Speaking of supply network, I should mention the brown outs we’ve been having in Detroit. Electric cars are part of the stress to the electric grid, but I believe that, with intelligent charging (and discharging) the concern is more than manageable. The driver who goes 10,000 miles per year only adds about 2,350 kWh/year of extra electric demand. This is a small fraction of the demand of a typical home, 12,154 kWh/year.It’s manageable. Then again, hythane adds no demand to the electric grid and the charge time is quicker — virtually instantaneous.

Robert Buxbaum, September 3, 2021

A useful chart, added September 20, 2021. Battery prices are likely to keep falling.

Adding H2 to an engine improves mpg, lowers pollution.

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I month ago, I wrote to endorse hythane, a mix of natural gas (methane) and 20-40% hydrogen. This mix is ideal for mobile use in solid oxide fuel cell vehicles, and not bad with normal IC engines. I’d now like to write about the advantages of an on-broad hydrogen generator to allow adjustable composition fuel mixes.

A problem you may have noticed with normal car engines is that a high hp engine will get lower miles per gallon, especially when you’re driving slow. That seems very strange; why should a bigger engine use more gas than a dinky engine, and why should you get lower mpg when you drive slow. The drag force on a vehicle is proportional to speed squared. You’d expect better milage at low speeds– something that textbooks claim you will see, counter to experience.

Behind these two problems are issues of fuel combustion range and pollution. You can solve both issues with hydrogen. With normal gasoline or Diesel engines, you get more or less the same amount of air per engine rotation at all rpm speeds, but the amount of air is much higher for big engines. There is a relatively small range of fuel-air mixes that will burn, and an even smaller range that will burn at low pollution. You have to add at least the minimal fuel per rotation to allow the engine to fire. For most driving that’s the amount the carburetor delivers. Because of gearing, your rpm is about the same at all speeds, you use almost the same rate of fuel at all speeds, with more fuel used in big engines. A gas engine can run lean, but normally speaking it doesn’t run at all any leaner than about 1.6 times the stoichiometric air-to-fuel mix. This is called a lambda of 1.6. Adding hydrogen extends the possible lambda range, as shown below for a natural gas – fired engine.

Engine efficiency when fueled with natural gas plus hydrogen as a function of hydrogen amount and lambda, the ratio of air to stoichiometric air.

The more hydrogen in the mix the wider the range, and the less pollution generally. Pure hydrogen burns at ten times stoichiometric air, a lambda of ten. There is no measurable pollution there, because there is no carbon to form CO, and temperature is so low that you don’t form NOx. But the energy output per rotation is low (there is not much energy in a volume of hydrogen) and hydrogen is more expensive than gasoline or natural gas on an energy basis. Using just a little hydrogen to run an engine at low load may make sense, but the ideal mix of hydrogen and ng fuel will change depending on engine load. At high load, you probably want to use no hydrogen in the mix.

As it happens virtually all of most people’s driving is at low load. The only time when you use the full horse-power is when you accelerate on a highway. An ideal operation for a methane-fueled car would add hydrogen to the carburetor intake at about 1/10 stoichiometric when the car idles, turning down the hydrogen mix as the load increases. REB Research makes hydrogen generators based on methanol reforming, but we’ve yet to fit one to a car. Other people have shown that adding hydrogen does improve mpg.

Carburetor Image from a course “Farm Power”. See link here. Adding hydrogen means you could use less gas.

Adding hydrogen plus excess air means there is less pollution. There is virtually no CO at idle because there is virtually no carbon, and even at load because combustion is more efficient. The extra air means that combustion is cooler, and thus you get no NOx or unburned HCs, even without a catalytic converter. Hydrogen is found to improve combustion speed and extent. A month ago, I’d applied for a grant to develop a hydrogen generator particularly suited to methane engines. Sorry to say, the DoT rejected my proposal.

Robert Buxbaum June 24, 2021

The solar powered automobile

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The typical car has about 60 ft2 of exposed, non glass surface area, of which perhaps 2/3 is exposed to the sun at any time. If you covered the car with high-quality solar cells, the surfaces in the sun would generate about 15W per square foot. That’s about 600W or 0.8 horsepower. While there is no-one would would like to drive a 0.8 hp car, there is a lot to be said for a battery powered electric car that draws 6000 Wh of charge every sunny day — 6kWh per day– moving or parked — especially if you use the car every day, but don’t use it for long trips.

Owners of the Tesla sedans claim you can get 2.5 to 3 miles/kWhr for average driving suggesting that if one were to coat a sedan with solar cells, one day in the sun would generate 15 to 20 miles worth of cost-free driving power. This is a big convenience for those who only drive 15 to 20 miles each day, to work and back. As an example, my business is only 3 miles from home. That’s enough for the lightyear one, pictured below. The range would be higher for a car with a lighter battery pack, and some very light solar cars that have been proposed.

Lightyear one solar boosted plug in electric vehicle.

Solar power also provides a nice security blanket boost for those who are afraid of running out of charge on the highway, or far from home. If a driver gets worried during the day, he or she could stop at a restaurant, or park in the sun, and get enough charge to go a few miles, especially if you stick to country roads. Unlike gas-powered cars, where mpg is highest on the highway, electric vehicles get more miles per kWh at low speeds. It seems to me that there is a place for the added comfort and convenience of solar.

Robert Buxbaum, May 21, 2021