omenti

fc-evs

The other day I was out walking around noon looking at the trees.  Some took a lot of damage from the harsh Winter, but almost all have enough leaf area to catch most of the light striking their habit.  The average maple around here this time of year is averaging 20 or 30 watts.

 

To do any sort of work you need access to energy in a useable form.  Most of the energy we use, and all of the important energy, comes from the Sun.  In its original form it is intermittent and ephemeral. Energy storage is a requirement for life.  Green plants figured that out and we wouldn't be here without them.  They are machines that use photosynthesis to turn sunlight into storable forms of energy.  Mostly carbohydrates - basic fuels.  

 

The first part of the industrial revolution was fueled by coal giving easy access to millions of years worth of stored plant energy.  Chemical energy was turned into heat which was turned into mechanical energy.  The cost of power dropped dramatically and power levels steadily increased creating a revolution, but the work you did had to be close to close to the coal burning engine. In the last 1800s a radical change was introduced - the generation of electricity at industrial scales.  Now the mechanical energy from the steam engine was transformed into electrical energy which was transmitted great distances to an electric motor which turned the electrical energy back into mechanical energy or into light.¹

 

Electric light was the killer application early on, although remotely located motors were also desirable.  An electric grid grew and spread through the country, but it couldn't go everywhere.  Mobility is a serious problem.

 

One solution for portable electric power was the chemical battery.  They turn stored chemical energy into electricity and come in two flavors - primary and secondary.  

 

Primary batteries are not rechargeable.  The best AA cells provide can provide about 1.4 watt-hours of energy.  Three of them would supply about eighty percent of the energy an iPhone stores in a charge - you might be able to make it through a day on a set.  They retail for about a dollar each, so you're looking at about a thousand dollars a year to power your cellphone with them.  About $700 per kWh ..   5,000 times the average residential electric rate..   OK for low drain devices like smoke detectors and infrequently used flashlights, but the modern smartphone wouldn't be possible without a different type of battery.

 

Secondary batteries are rechargeable.  They tend to cost more initially and have lower performance for a given chemistry, but the total energy cost is dramatically less for applications like mobile phones and cars ...  we'd still be hand starting cars if only primary batteries existed.  One of the reasons why the Bio-Lite stove has been accepted in parts of the developing world is that it generates enough electricity to charge mobilephones.

 

We've talked about the efficiency of an electric vehicle in the past three posts. Automotive grade batteries are still expensive - a 40 kWh battery that would give 100 to 120 miles of range is roughly $20,000 and needs to be replaced after 1,000 to 2,000 charging cycles.²  Gasoline and diesel fuel have much greater energy densities and the initial costs associated with storing them is very low.  Electricity may be cheaper over the length of a car's life, but don't expect widespread use without price reductions and range improvements. You might solve part of the problem if you could quickly charge the battery.  What if the energy could be stored like gasoline -- as a fuel?

 

Enter the fuel cell.

 

Fuel cells turn a fuel like hydrogen or a hydrocarbon into electricity directly.  There are a variety of types, but the most interesting for automotive use combine hydrogen with oxygen in the air poducting electricity directly along with water as a waste product.  In theory it sounds ideal.  If you can somehow store hydrogen in a car, you should be able to refuel quickly rather than slowly recharge and still use the 80%+ efficiency of an electric drive train.  

 

Unfortunately there are problems that need to be solved.  When he was Secretary of Energy, Steven  Chu was interviewed by Technology Review:

 

Technology Review: It used to be thought, five to eight years ago, that hydrogen was the great answer for the future of transportation. The mood has shifted. What have we learned from this?

Steven Chu: I think, well, among some people it hasn’t really shifted. I think there was great enthusiasm in some quarters, but I always was somewhat skeptical of it because, right now, the way we get hydrogen primarily is from reforming [natural] gas. That’s not an ideal source of hydrogen. You’re giving away some of the energy content of natural gas, which is a very valuable fuel. So that’s one problem. The other problem is, if it’s for transportation, we don’t have a good storage mechanism yet. Compressed hydrogen is the best mechanism [but it requires] a large volume. We haven’t figured out how to store it with high density. What else? The fuel cells aren’t there yet, and the distribution infrastructure isn’t there yet. So you have four things that have to happen all at once. And so it always looked like it was going to be [a technology for] the distant future. In order to get significant deployment, you need four significant technological breakthroughs. That makes it unlikely.

… If you need four miracles, that’s unlikely: saints only need three miracles.

 

Politics being what they are have thrown more money into fuel cell R&D and a few refueling stations have appeared in California and Washington DC, but the miracle level problems remain.

 

The best automotive fuel cells top out at about 60% efficiency (lower for most operating conditions).  That means the overall efficiency of the fuel cell plus the power train of a fuel cell electric car is under 50% - much better than the 25% of the average internal combustion car, but much lower the 80% of a plug-in electric car.

 

Now to find a hydrogen mine...  after all, it is the most common element in the universe.  Sadly molecular hydrogen is very rare on earth.  You probably made it using electrolysis in science class when you were in school, but the process is very energy intensive and too expensive unless you have a very inexpensive supply of electricity.  Industrial hydrogen is usually produced from natural gas and carbon dioxide is given off in the process.

 

Gaseous hydrogen at atmospheric pressure has a very low density and needs to be compressed or liquified if you want to drive more than out of your driveway.  It takes energy to compress and liquify hydrogen and both of these denser forms have their own storage issues.  If the hydrogen is produced from natural gas it is possible to do the conversion near or at a filling station, but the infrastructure costs are high (a few million dollars per filling station).  You could use electrolysis powered by electricity produced off peak by renewables like wind energy and have a much more environmentally friendly fuel, but the process is inefficient. ³

 

 

Finally the price of fuel cells is still very high - Toyota has announced a car will be produced late this year, but these will probably be money losing expensive leases.  Early on fuel cell electrics won't attract the well heeled green crowd as their green house gas footprint is larger than a plug-in electric.  While it is possible to refuel one in five minutes, that won't matter if the nearest filling station is 1,000 miles away.  California is spending a lot of money to make a drive between San Diego and Sacramento possible, but don't expect a rapid build-out nationwide.  

 

There is enthusiasm among some of the major car companies - they see themselves as being able to own and control fuel cell production.  The major oil/natural gas companies like the idea as they see this as an infrastructure they can build.  Some researchers like it as there are some interesting and difficult problems to solve.

 

Electrified power trains are inevitable.  It will go slowly at first - micro and mild hybrids may be standard in ten years and small car niches will start to grow in five.  Eventually we'll see an automotive grade metal-air secondary battery and, if it is cheap enough, the internal combustion car becomes a niche vehicle.  It seems very unlikely fuel cells will change the pattern. 

 

But it can be said the battery powered pure electric also has challenges, perhaps miracle level in the short term, too.  Range anxiety means the user experience of a car is different for most people.  While battery EVs are on a path to a wider spread existance sooner than fuel cell EVs, neither will be a major force in ten years.  Beyond that something will happen, but these are very complex and challenging systems interacting with other systems including politics and locations other than the US and Europe.  

 

There are many more questions than answers.

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¹ I'm ignoring water power  ..  it was very important throughout the revolution.  It is just gravitational potential energy being converted to mechanical energy.

² Battery costs are dropping and should be about a third of this by 2020.  Also there is residual value in a battery that is no longer useful in a car -- they'll be used by utilities to storage energy in the grid.

³ The chart from a talk by Ulf Bossel a few years ago.

 

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Recipe corner..

 

Just a tip this time.  Soon we'll be seeing high quality fresh fruit. Dry some of it.  I cut it into slices (except for blueberries) and spread onto non-stick baking pans.  Pop them in a cool over (125°F) with the door slightly ajar to permit steam to escape.  Drying times depend on fruit moisture content and slice thickness, but allow at three hours for most fruits.  Seal them in airtight containers and you'll have fruit later on in the season for a fraction the price of commercial fruit.  Last year I dried about 20 pounds of the blueberries I picked along with cherries, cranberries, peaches and apples.  All were excellent.  

Ferrets love dried cranberries.

 

 

moving beyond cup holders, color and monthly payments

Stripped to the basics a vehicle is just a device that moves by converting stored energy into mechanical energy.  In the early days of the automobile it wasn't clear what the stored energy would be and how it would be converted.  Experimenters worked with steam engines, a wide variety of two and four cycle internal combustion engines, compressed air and electric motors.  There were engineering and usage hints from horse drawn wagons and carriages as well as the bicycle, but infrastructure ranged from poor to nonexistent.  There was something of a race to see what would be good enough to begin to define and infrastructure and it was up to the users to invent and evolve usage patterns.

 

By 1900 three of the main contenders were the internal combustion engine, the steam engine and the electric motor.  All were expensive and limited, but new designs were changing and improving rapidly.  By 1910 the gasoline engine had matured to the point where it was more efficient, cheaper to manufacture and less temperamental than the steam engine.  The electric car had seen considerable use in large cities where its short range wasn't a big issue, but it faded as trip lengths increased, electric starters appeared on gasoline powered cars making them easier to use and the price of gasoline cars dropped.  

 

By the time the Ford Model T arrived it was clear the future was going to be a gasoline fueled internal combustion engine.  The innovation that came with the Model T was a dramatic price reduction made possible by standardization and a soup to nuts scale assembly line.  Suddenly cars were available to the middle class and the supporting infrastructure from  oil refineries to better roads grew sprouted up.  So many people had mobility that the distances between where we lived, worked, shopped and played adjusted to fit the hour or so a day we were willing to devote to travel. 

 

Human and family size, road widths, parking spaces and a few other factors fixed the size of the personal car.  The cars of the 1950s are functionally not that different from those of today and most of them are built using materials and construction techniques that have slowly evolved.

 

The efficiency of moving a person around has roughly doubled and cars are now much safer, reliable, easier to use and comfortable.  About a billion cars are currently on the road and the developed world is now near or at saturation.  There are issues with pollution and global warming and petroleum is becoming more expensive to mine.  The question is where do we go from here?  What will cars in the US and Europe look like in the next thirty years and what about the next billion that will go into emerging economies?  

 

We need to look at usage models, efficiency and then drill in a bit deeper to get a little insight.  Kilowatt-hours of energy used per 100 miles of travel is a common metric used to compare transportation modes.¹  Colleen has to provide about 3.3 kWh/100 miles to ride her bike, but her old pickup only gets about 15 miles per gallon so she's using about 225 kWh/100 miles when she's driving.²   The average new American car uses about 147 kWh in 100 miles - a major improvement over the old truck if you're paying three or four dollars a gallon for gasoline.  But there is room for improvement.

 

65 kWH/100 mile gasoline power cars are available, but are not popular as they're considered too small for most buyers and we're not seeing increases in the price of gasoline at the moment.  Moving much lower than that with an internal combustion engine is expensive and moving the average family car to that level will be difficult.  The low hanging fruit has been harvested so improvements in conventional cars will be incremental.  

 

Pure electrics, on the other hand, represent a major efficiency improvement.  The Tesla Model S needs 35 kWh to travel 100 miles and the BMW i3 just 28 when run as a pure electric.  (perhaps a tad optimistic numbers as there is weather variation, but consider these will improve over time) But two major issues prevent wide-spread adoption.

 

Cost prevents an electric car with "good enough" range from being affordable.  Automotive grade battery packs are in the $400 to $700 per kilowatt-hour range these days  The price is dropping rapidly and many believe it will be in the $150 to $200/kWh range in five years bringing a 100 mile range battery pack for midsize cars down to $7k or less.  The cost saving moving from an advanced internal combustion engine coupled with a sophisticated 8 or 9 speed automatic transmission to a simple electric motor with a one or two speed transmission would be close to that figure.  A competitively priced 100 mile range electric without subsidies.  Two car families may find this attractive.  The other niche that would only have a modestly higher price than a normal car might be the 200 mile range family car.  Tesla and General Motors are both talking about the "reasonably priced" 200 mile goal within three or four years.  Tesla may be very conservative with their battery factory plans.

 

The issue weight.  Current automotive grade lithium batteries store about 150 watt-hours per kilogram while gasoline has an energy density of about 12,800 wh/kg - about 85 times higher.  Batteries are very heavy - probably at least 1,100 pounds in a Tesla Model S.  Improvements are being made the rate of about five percent per year, but lithium batteries are limited to about twice their current energy density.  This isn't quite the problem cost is at the moment, but major improvement will require new chemistries and ultimately may erase the advantage of gasoline.  A large amount of research is going into metal air batteries which promise energy densities that, adjusted for power train efficiency, are roughly equivalent to that of gasoline.³

 

From today's vantage point it looks like cost neutral 100 mile range compacts will be available in five years time.  There are numerous advantages to electrics including  lower long term maintenance costs and energy costs that may make them very attractive.⁴

 

Current electric vehicles are basically a conventional car with a power train transplant. We can, and will, move beyond that and real innovation is possible.  Batteries can be distributed around the car and the motor may become several small motors closer to the wheels.  It may be possible to build lighter vehicles with equivalent or better crash performance and, without the constraint of large radiators a massive engine better aerodynamics are possible.  

 

If you are willing to consider new niches there are some interesting possibilities.  Many European cities and suburbs have speed limits of 40 km/h (25 mph) or less..  While most Americans would consider a 25 mph speed limit a burden,  it would make bicycles more practical and open up niches for very different vehicles.  A back of the envelope shows a two passenger 1,100 pound, 100 mile range electric car is possible without resorting to exotic materials.  The battery pack could be about 10 kWh making the total cost very low.   And there are even ways to manufacture it without resorting to a billion dollar factory. 

 

Very small electric cars may be the first practical self driving platform.  They would probably be confined to small areas that could be well mapped with embedded naviation aids.  Driver controls could be eliminated reducing cost and making it easier to improve crash protection.  It would probably make more sense to have a city or company own the cars - they would be a bridge between mass transit and a private car or taxi.  There are a number of problems to work out and even discover, so trials are necessary.  Google appears to be moving down that path and there are indications several other companies are doing the same thing.⁵

 

We're witnessing an exciting time.  The advent of new materials, improving batteries, very different production techniques with different scaling characteristics, networked vehicles and self driving technologies.  These changes are arriving along with middle class growth in emerging nations and new cities where moving people, pollution and efficiency are issues.  

 

The automobile gave us suburbs - perhaps we'll see major change in what a city is.

  

I've run over my hour and haven't touched many issues. Automotive electrification may well become universal in the next decade for example.  Beyond the car it makes sense to talk about energy storage - something fundamental to energy use and a very hot topic these days.  My guess is Musk is at least as interested in it as he is in the electric car.   

++++

addition

 

Jheri asked a question in the comments that I should comment on in the main body:

How much extra should you spend if greenhouse gases are important to you? I think I know that they aren't a good carbon investment.

While I think government stimulus makes sense to encourage battery development, buying a electric car only to be green is a poor use of money.  There are much cheaper ways to keep more greenhouse gases from the atmosphere using the price differential.  That said there are other reasons for buying one, although I'm waiting a few years myself.

The question often comes up about how clean the electric source is. No emissions means nothing from plug to wheel and people are often interested in power plant to wheel.  If the power comes from a green source you're in good shape, but grid power is a mixture and you have to look at the mix.  The worst cases in the US are the Intermountain West and North Central which have a heavy reliance on coal.  For every kWh of fuel burned you get about 0.3 to 0.35 kWh of electricity at your plug and then you need to factor in the charger.  For the bad areas you are close to or just a little worse than breaking even given similar cars.  Everyone else emits less.  But it is important to note an internal combustion engine emits far more than just carbon dioxide and keeping that out of your local environment is a good thing.  Particulates from fossil fuel power plants in North America are better managed than those from a car.

The bottom line is get an electric car if the other features are important to you and lower your greenhouse gas emissions from other areas in your life for much less money.

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¹ You could use any distance or unit of energy.  In the US we tend to think in terms of a gallon of gasoline, but that is about 33.7 kWh.  Megajoules are commonly used as an unit of energy at the scale of a car, but we'll stick with kWh.   

The simple conversion is 3370/mpg = kWh/100 miles.  

² More detail here, but note her bike has a comfortable upright riding position that happens to be common on European commuter bikes.  This position and the large amount of frontal area she presents because she is tall gives her a somewhat lower efficiency than a smaller rider in a tucked position on a bike with higher pressure tires. A road bike is probably closer to 2.5 kWh/100 miles.

³ Progress has been very slow.  It is fairly easy to make a single use metal air battery, but there are serious problems when the battery is rechargeable.  Even if one was announced tomorrow it would probably take five to seven years from lab to production.

There has been some progress with an aluminum-air battery that is not rechargeable.  The idea is to install it in a car where the main battery is lithium and only use it for long trips. It would store enough energy for about 2,000 miles and would be swapped for a rebuilt battery when it expired.  The economics aren't practical yet, but the approach is under active investigation.

⁴ There is almost no brake wear as the motor is used as a generator to move about half of the energy used to slow the car back into the battery.  The motor has one moving part, very low vibration and no complex pollution system.  It is possible that a drive train could go a half million miles with only tiny amounts of regular maintenance - a bit of oil on the bearings every year or so.  Tires would be the other item and, at around eight or ten years, the battery pack would be replaced with one that is much less expensive with a higher energy density.  The car would get better with age.  Most car dealers make much of their profit in the repair shop, so this will be a major issue.

A 33 mpg car can go 100 miles on three gallons of gasoline - $9 to $12 at current prices. A similar electric needs about 30 kWh.  If you charge at night some utilities are offering power for around ten cents per kWh ..  so $3 for the same distance.  

⁵ Google is getting the lion's share of publicity because they have been issuing a lot of press releases.  Most of the other companies known to be working on this are not in the habit of pre-announcement at Google's level.

 

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Recipe Corner

 

Avocado's are inexpensive these days.  This is a modification of an old Bittman recipe.

 

Avocado and Peanut Salad

 

Ingredients

 

° 1/3 cup rice vinegar

° 50 g white cane sugar

° pinch of salt

° 2 tbl freshly grated ginger root

° 2 medium avocados pitted and sliced

° 1/4 to 1/2 cup salted roasted peanuts chopped 

 

Technique

 

° make a dressing by heating the vinegar, sugar, salt and 2 tbl water in a small pan over medium heat.  Cook until the sugar dissolves 

° add the ginger and cook until the dressing thickens (about five minutes)

° remove from heat, cool, cover and chill for at least an hour

° arrange the avocado slices on a plates, drizzle with the dressing and sprinkle on the peanuts.

 

 

 

car power - where does it go?

Colleen and I spent a fair amount of time trying to understand how to talk about energy issues.  1,000 miles per gallon on a bicycle gets attention as does telling someone for every four gallons of gasoline they use only one moves the car and the other three are mostly used to heat the air.  The notion that energy can't be created or destroyed, but can change form leads is the basis of how work is done.  Chemical energy in gasoline is converted to mechanical energy and heat when you drive a car.  The sums all work out, but some forms of energy - like the heat from an engine - are difficult for us to use, so we tend to think of them as waste.

 

We also learned that people tend to think in terms of power - the rate at which energy is used.  You buy some amount of energy,  ten gallons of gasoline for example, but how you drive determines how quickly the tank is emptied.  You eat a meal but it lasts for less time if you're running a marathon rather than watching tv.  We associate power with activity and we can control activity.

 

To understand what it takes to make a car more efficient and where new forms of power may first become practical, it is useful to build a simple model of the power use.  A bit of physics 101 is used to build this model, but I'll try to talk about the  results in the main body of the post and reference two sheets that describe what goes into the model for those that want deeper detail.

1

2

  

The energy that goes into your car is used to do roughly five kinds of work. An easy way to build the model is to use consider power rather than energy and to consider each of the terms separately as most are independent.  Calculating total energy use is simple - at the end, when the model is complete,  just integrate over time.

 

power is used to:

 

speed up and slow down

overcome air resistance

deal with the inefficiency of the power train (mostly waste heat)

overcome rolling resistance

run the car's heater, air conditioner and electronics

 

You accelerate your car to speed increasing the its kinetic energy.  To slow down the brakes are used to turn the kinetic energy into heat (equation 1).  When it is moving the car must overcome air resistance.  You can think of this as causing the air to move and swirl.  The exact calculation of this is difficult, but you can get a good enough estimate by looking at the kinetic energy the air receives and knowing how aerodynamic the car is. (equation 2 - an earlier post had a more detailed explanation)

 

The simplest model of a car's power use is the sum of these two terms (equation 3).  There are more terms to consider, but this much usually dominates and there are some interesting observations that can be made.  The power used goes as the cube of velocity - driving fast demands a lot of power.  Stop and go low speed driving is dominated by the first term and high speed highway driving by the second.  The first term has distance associated with it - the average distance between braking events.  Using this it is possible calculate a special distance below which the stop and go term is more important and above which the highway driving term dominates (equation 4).

 

The most important characteristics for stop and go driving are made clear in equation 1 - low mass and low velocity.   At highway speeds the dominant term is velocity.  Note that mass isn't a concern.  Once you get something like a two ton car up to speed you are  no longer accelerating and are only moving swirling the air away.¹

 

 

Why not plug in a few numbers to get a sense of what's going on at this point?  The special distance that is the boundary between stop and go and highway driving is about 1,150 meters for an average family car.²  That goes up with mass, so a heavy SUV will be longer.  Being able to shut off the engine when the car stopped is useful and regenerative braking, which recovers some of the energy that would normally go into waste heat during braking, can be very useful.

 

At higher speeds without having to constantly speed up and slow down you have two main options.  Make the car slip through the air more efficiently by reducing its frontal area and/or its drag coefficient, and lowering your speed.  Making the car slipperier is difficult if you want a car that people will buy.  Frontal areas don't change much within a category of car and drag coefficients are usually in the 0.25 to 0.35 range.  Moving much lower than 0.20 dictates a shape many people find too strange.  

 

To get some realistic numbers for power we need to consider the efficiency of the power train.  The average efficiency of an internal combustion engine power train is about 25%.  An electric vehicle can be over 80% efficient.  Using equation 3 and factoring in the power train efficiency (the first equation on the second page - I forgot to number it) we find a family car with average aerodynamics moving at 70 mph (about 110 km/h) uses about 80 kilowatts of power.  An electric vehicle with similar aerodynamics would use about 25 kw.  For a sanity check note that a gallon of gasoline has about 33 kilowatt-hours of energy.  If you run the car at speed for an hour you use 80 kWh of energy and travel 70 miles.  This is about 2.5 gallons of gasoline in 70 miles or 28 mpg.. not too bad for such a simple model.

 

If you dropped your speed by half to 35 mph your power use would be reduced by a factor of eight and the total time it would take you to make the trip would double.  This turns out to not be quite the real world case as internal combustion engines have very narrow ranges where they operate at peak efficiency. It is necessary to have a transmission with multiple gears that cover a wide range of speeds. Some cars have eight or nine speed transmissions and some have moved to continuously variable transmissions.⁴  Most cars are designed to be most efficient at constant speeds in the 45 to 60 mph range. Exceeding that by much requires a lot of power to break through the air and the engine is usually out of its most efficient operating range.  

 

If you've ever tried to ride a bike with too little air pressure in the tires, you've thought about rolling resistance.  Equation 5 shows resistance increases with the car's mass and velocity.  For an average family car with is about 4,500 watts at 70 mph so the total power needed to cruise at this speed is a bit less than 85 kW.⁵  Keeping your tires inflated to their maximum safe pressure is important for your fuel economy and the car's safety.  Under-inflation can double the rolling resistance dropping your fuel economy by about five percent and reducing your safety.

 

Finally power is needed to heat and cool the car and run the car's electronics.  An IC car gets heat "free" as a bit of waste heat from the engine is diverted into the passenger area.  Air conditioning is a load that can add a few kilowatts to the requirement depending on temperature and passenger space.⁶  Electronic loads like entertainment systems, computers, gps, and lights are another load that vary a lot from vehicle to vehicle - one or two kW is common.

 

I'm already over time and should probably detail where exactly electrics will begin to dominate in yet another post, but some of the basics hopefully are now a bit more clear.  Electrics are fundamentally more efficient, but batteries are expensive and heavy.  To do the calculus you need to look at use cases and ponder technology curves.  Also there is a hard limit increasing the effiency of an IC engine.  Doubling the efficiency is extremely unlikely, so improvments have to come from radical and departure in design and use.  At this point there are cost and social issues that make big improvements difficult.  

 

but ...  the first two terms of the model dominate.  You can optimize a vehicle for the highway or for stop and go use, but if you want both there is compromise.  Acceptable design for the job we want a car to do (safety, moving stuff, style,..) require further compromise. If you just move yourself over short distances you can't beat a bicycle using yourself as a power source.

 

To be continued...

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¹ This is a overly simplistic model at this point!  The rolling resistance and other terms have a velocity dependent component, but we're staying simple at this point.

² mass = 1,500 kg, C_d = 0.33, frontal area = 3 m²

³ Here C_d is assumed to be 0.33 and frontal area 3 m² as before, Efficiency is 0.25.

⁴ Electric motors have much different power curves than internal combustion engines, some getting by without a multi-speed transmission and others just using two or three speeds.  This is much less expensive and lower the weight of the power train dramatically.

⁵ Cr = 0.01, mass = 1,500 kg and velocity is 31 m/s (70 mph).  Sorry for the ugly switching of units .. most people who read this are more comfortable with miles per hour and such.

⁶ Opening windows at high speeds increases a car's drag coefficient.  The break-even varies from car to car, but above 45 mph it is usually more efficient have the windows up and use the AC.  Of course it is even more efficient to leave the windows up and not use the AC, but ...

 

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Recipe corner ..

 

Not much really other than go out and get some fresh produce and try grilling it with a bit of olive oil.  There are grilling baskets that can be useful for the small stuff.  Grilled peppers are a revelation that can be used in many dishes.  Even carrots are amazing.

The Maillard reaction rules.

 

 

change with be electrified but it will trickle out over a long time

Bob and I would sometimes get in a family car and drive to the top of Gore Hill just to see if we could coast back down the hill to the river.  It was a bit tricky with his dad's old Chevy working better than our family Falcon.  The Chevy was a bit more aerodynamic.  To minimize rolling resistance you would pump the tire pressure up to as much as you thought you could get away with.  Cheap retreaded snow tires in cool weather worked much better than Summer tires.  Early Sunday mornings with little or no traffic and a day with no headwind (strong winds from the West were cheating too).  Turn onto the on-ramp, scan for traffic and the police, clutch-in, shift to neutral and turn the engine off.  

 

We made it twice, but there must have been thirty or forty attempts.  Pure fun.  There was also the ride to Choteau.  It took you through a bit real prairie, a Hutterite colony, fields of hops,  and brought you close to the edge of the Bob Marshall Wildness (know to locals as 'The Bob').  The draw, of course, was Choteau's first traffic light and driving the sixty or so miles from Great Falls to find the next red light was a quintessentially teenage activity in the day.

 

A few decades ago a central coming of age event for many teens in the US was getting a driver's license.  The family car, if you could borrow it, represented  freedom.  Kids with their own cars had status.  Training for the car culture.   As danah and many others have documented, teens were allowed a greater freedom of place and there were places to go.¹  Local malls, parks, even mindless joyrides with friends.

 

While there was real freedom for teens and  families on vacation, the current reality of driving is different.  Cars with over four hundred horsepower and the ability to reach sixty miles per hour in under five seconds are shown driving in fantasy regions that don't exist for most of us. Driving has become a burden and millennials appear to be coming to grips with reality more rapidly than their elders.

 

In the early days of the automobile driving was hallenging to the point of adventure.  Roads were terrible and breakdowns were common.  Mobility was greatly improved and there was the prospect of a changed life.  Madison Avenue figured out how to romanticize the potential with Ned Jordan and the Jordan Motor Company.   Folklore has it that he saw a beautiful woman racing her horse by the train on a trip through Wyoming. He asked the conductor where they were and heard: Oh, somewhere west of Laramie. He penned an ad for the Jordan Playboy which was published in The Saturday Evening Post. I seen it cited as a watershed moment for associating a product with romance rather than the product itself.

... the text of the ad (if it is difficult to read)

Somewhere west of Laramie there’s a broncho-busting, steer-roping girl who knows what I’m talking about. 

 

She can tell what a sassy pony, that’s a cross between greased lightning and the place where it hits, can do with eleven hundred pounds of steel and action when he’s going high, wide and handsome.

The truth is--the Playboy was built for her.

Built for the lass whose face is brown with the sun when the day is done of revel and romp and race.

She loves the cross of the wild and the tame.

There’s a savor of links about that car--of laughter and lilt and light--a hint of old loves--and saddle and quirt.  It’s a brawny thing--yet a graceful thing for the sweep o’ the Avenue.

Step into the Playboy when the hour grows dull with things gone dead and stale.

Then start for the land of real living with the spirit of the lass who rides, lean and rangy, into the red horizon of a Wyoming twilight.

 

That brings us to today.

 

There has been a lot of speculation on the future of cars with speculation on electric power being made necessary by global warming along with advanced like driverless vehicles.  But change comes slowly to the automobile industry - especially when there are new technologies, usage patterns and even notions on what is romantic.

 

Tesla may seem to be at the forefront, but I would suggest they are just making a large and spendy American car.  A very nice car, but an incremental improvement on what the current state of the art.   It isn't particularly green unless you  have a very green power source - wind, solar, hydro, or nuclear.  It may be a beautiful ride that can take you a few hundred miles between charges, but it is nearly two and a half tons of vehicle and physics tells you a automobile's usage pattern is not efficient if you are moving a lot of mass around.²  Of course the tailpipe emissions of an electric are a big plus and a certain status attached, but this is not an innovation.³

 

Currently there are about a billion cars on the road. In areas where usage is close to saturation there is  a great deal of resistance to change even though the need for change seems clear. Infrastructure is expensive to change, new manufacturing processes are difficult to scale, regulations are difficult to adjust and, perhaps most of all, people have a deeply routed idea of what a car is.

 

Change seems much more likely in the next billion cars that will mostly go into the developing world.  There are also some interesting niches where automobiles have reached their limits and have lost much of their practicality - dense urban areas.

 

Google recently announced a new prototype of their self-driving car.  Previously they've modified existing family cars and have driven them mostly in suburban environments.  There are several important points.  The areas where this can be used are tightly constrained - it has a 40 km/h speed limit, about 25 miles per hour.  That means passenger crash protection is much cheaper and lighter.  The car can be very light - perhaps 500kg or so in final form.  This, combined with its top speed and a reasonable range means you could get away with less than ten horsepower. It is a plug-in electric.  At this weight in common urban driving patterns the battery could be  small and the drive train would probably be less expensive than a conventional high efficiency internal combustion engine.  Maintenance of a pure electric vechile  is much lower than that of a conventional car and lifetimes can be much longer.  Finally the self-driving only nature of the car means, combined with a dense urban area, means it is practical to go to a car sharing ownership model.  It is likely companies or local governments will own and maintain the vehicles.⁴  You'll just buy the transport you need.  Think of it as a more efficient and less expensive taxi.

 

Google loves to show off their exploratory work and it the publicity appears to be part of building and maintaining their mystique.  They're hunting for new businesses that will take them beyond peak growth in search and ad revenue.  There are many possibilities and they're throwing a lot of darts at the wall.  This is one of those darts. It seems reasonable to me that we could see small sized electric self navigating cars in a few urban and even suburban environments in the next three or four years.  Moving to the North American notion of what an automobile's job is happens to be much more complicated and will wait much longer.  

 

There will be a lot of competition in this area as a dozen other companies have projects investigating the same space.  The megacity car for developing countries is likely to be the growth path for automobile companies - you've know some of the names, but it also seems likely there will be major players that aren't building cars at this point and may not exist yet. The history of technology suggests that the people who work on technologies that eventually become major innovations rarely are those who dominate the innovation stage.

 

I've burned up my hour without saying much about the efficiency of electric versus internal combustion power trains, how mass and aerodynamics get involved and why physics may dictate where change first appears.  Fodder for the next post.

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¹ Much has been written on the increase in the structure of teenage lives.  It is a core theme in danah boyd's new book  It's Complicated, which is a must read for anyone interested in the sociology of computer mediated communications.

² If you really want to optimize your carbon emissions there are many other uses for your money than buying an electric car given the cost differential.  Better to reduce your driving and flying, insulate your home, and so on.

³ Tesla is working on two potential innovations.  One is breaking the dealer-based car sales model in the US and the other is the widespread use of stationary batteries to augment a slightly smarter grid and allow a much greater penetration of intermittent alternative energy sources.  

⁴ I have problems with the term 'sharing economy' and only use it to give a general idea of how this might happen.  Many models will probably be tried and there is a good chance the best model for New York City would be very different from Madrid or Shanghai.   Rather than write something on 'sharing economy' I'll link to a piece by Susie Cagle... I'm roughly in her camp.

 

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 Recipe Corner

 

To own a dish you need to make it a lot - perhaps dozens of times so you can understand how it works as ingredients change in taste and freshness as well as discovering some new tricks.  One of the dishes I love is an afghan lentil soup that tried to equal that of a few restaurants.  I like it better than any of the restaurants now.  

 

The key ingredient is the dried sour plums.  You can find them in major cities like NYC, but I use Fastachi in Boston as a reliable mailorder supplier.  Dried sour plums are one of those revelatory ingredients that can kick off some interesting experiments.

 

 Afghan Red Lentil Soup with Sour Plums

 

Ingredients

° 4 tbl  extra virgin olive oil

° 2 medium-large yellow onions minced (it is a bit different and also good with red onions)

° 6 large garlic cloves minced

° 6  cups water (may need to add more)

° 2 cups red lentils (cleaned!)

° 1/2 tsp red pepper

° 1 tsp turmeric

° 16 dried sour plums - a good source is Fastachi  

° non-iodized sea salt to taste, after freshly ground black pepper to taste

Technique

° saute onions and garlic in olive oil until the onions are golden

° add water, plums, spices and salt and bring to boil

° cut heat to medium and add lentils and stir

° cut heat a bit more and cover

° cook 40-45 minutes - stir regularly and add water as necessary

° puree it and season to taste (it can take a lot of black pepper and it is important to note that black pepper ages quickly)

° serve with a warm, crusty bread.  The soup does improve with time.