Hot and Cold Weather reduce Range of Electric Cars

Posted by PITHOCRATES - March 22nd, 2014

Week in Review

AAA makes a lot of money during cold winters.  Because when the temperatures plummet a lot of batteries won’t start their cars.  A low cost service call for AAA.  For all it requires is about 5 minutes of time on site and a pair of jumper cables.  Connect the cables to the dead battery.  Give the AAA vehicle a little gas to increase alternator output and the car with the dead battery will start up like it’s a summer’s day.  And as soon as it does the driver can drive home.  She doesn’t have to wait for the battery to charge.  For it will trickle charge on the drive home.  While the car’s alternator will provide all the electric power needed to run the defroster blower on the windshield, the electric defroster on the rear window, the headlights, the turn signals, the stop lights, the radio, whatever.  Once the car starts gasoline will do the rest by providing the rotational motion that spins the alternator.  None of this could happen, though, with an all-electric car (see Electric car range fluctuates in extreme weather, reports AAA by Richard Read posted 3/21/2014 on The Christian Science Monitor).

We’ve known for some time that battery range in electric vehicles can fluctuate in response to temperature. However, studies and simulations have produced varying estimates of how much range owners can expect to lose…

To carry out its tests, AAA used a 2014 Ford Focus Electric Vehicle, a 2012 Mitsubishi iMIEV, and a 2013 Nissan Leaf…

When tested at the moderate temperature of 75 degrees Fahrenheit, AAA says the three vehicles averaged 105 miles per charge. After the thermostat was cranked up to 95 degrees, however, that range plummeted to just 69 miles.

The batteries performed even worse in cold weather. When the vehicles were tested at 20 degrees Fahrenheit, they averaged just 43 miles — a 57 percent reduction in range.

Imagine yourself driving home in a February blizzard after work.  With a 30 minute drive home on the expressway.  Which is crawling along at a slow speed due to the bad weather.  Your normal 30 minute drive home turns into an hour.  As you inch along in heavy traffic.  With your wipers running.  Your heat on.  Your headlights on.  Your windshield defroster blower running.  Your rear window defroster on.  And your stop lights blinking on and off as you ride your brake in stop and go traffic.  All of these things just sucking the charge out of your battery.  Imagine all of that and tell me which kind of car would you rather be in.  An all-electric car that has only 43 miles of charge in it?  Or a gasoline-powered car that can sit in that traffic for 3 hours (or longer) before getting you home with everything running while keeping you toasty warm inside?

If you don’t want to wait for a tow truck standing next to your all-electric car in that blizzard to tow you home after it runs out of charge in that stop and go traffic I’m guessing you’ll probably choose the gasoline-powered car.  Which is why few people are buying these all-electric cars.  People don’t want a car that can only be driven in nice weather when there is little traffic on the road to slow your way home.  That’s why they choose gasoline-powered cars.  Because it will drive in anything and will always get you home as long as there is gasoline in the tank.

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Car Companies making more Electric Cars that people will not Buy

Posted by PITHOCRATES - March 9th, 2014

Week in Review

Auto makers are caving in to green paranoia.  Fooling themselves that electric cars are worth the investment (see Geneva Motor Show: Electric cars no longer the exception? by Theo Leggett posted 3/6/2014 on BBC News Business).

The Porsche Panamera S is quite a car. Sleek, powerful and aerodynamic, it’s capable of 167mph.

But that’s not all. The version on display here in Geneva is also able to travel for about 20 miles on nothing but battery power.

It is, of course, a hybrid. It has an electric motor sitting alongside a 3-litre petrol engine. It is fast, powerful and remarkably economical. Porsche claims it can drive for 91 miles on a single gallon of petrol.

Wow.  A whole 20 miles on battery.  A Ford Taurus with a full tank of gas will take you 522 miles on the expressway.  With heat or air conditioning.  In snow or rain.  Night or day.  That’s what the internal combustion engine gives you.  The ability to get into your car and drive.  Whenever.  Without worrying if you have enough charge in the battery.  Or whether you can risk running the heat or use the headlights when you’re running low on charge.   All you need is gasoline.  And when you’re low on gasoline you just have to spend about 10 minutes or so at a convenient gas station to refill your tank.  Something no battery can do.  For the fastest chargers (i.e., the highest voltage chargers) still require more than a half hour for a useful charge.

Now, under pressure from regulators around the world, carmakers have been working hard to reduce emissions and fuel consumption. So hybrids have become decidedly mainstream…

“There’s no doubt in our mind that it’s coming and it’s coming quickly and there is legislation supporting this in many cities.

“You can drive into London and pay zero congestion charge, for example. There are taxation incentives in the UK, but also in the US and Asia as well…

“We know our customers now,” he says, “and we remain totally convinced that electric cars have a strong, strong place in the market…”

Yet although sales of electric vehicles are growing rapidly, they remain a tiny fraction of the global total. For the moment, the internal combustion engine remains king.

The only thing causing electric cars to become mainstream is the coercion of government.  Legislation.  The only way you can make an electric car more attractive than a gasoline-powered car.  Also, just to get people to buy electric cars requires massive government subsidies.  No.  Hamburgers, fries and Coke are mainstream.  Because you don’t have to subsidize them or coerce people to buy them.  In fact they are so mainstream that some in government use legislation to try and stop people from buying them.

The internal combustion engine is king and will remain king until you can drive an electric car as carefree as a gasoline-powered car.  Until the electric car makers can give us the range and the ability to use our heaters and lights without sweating profusely as we sit in gridlock during a blizzard worrying whether we’ll ever make it home people just aren’t going to buy an electric car.  Because people want to know they will make it home safely.  And right now nothing does that better than the internal combustion engine.

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Engine Block Heaters and Battery Heaters

Posted by PITHOCRATES - February 19th, 2014

Technology 101

As Matter loses Heat it shrinks from a Gas to a Liquid to a Solid

There is no such thing as cold.  Cold is simply the absence of heat.  Which is a real thing.  Heat.  It’s a form of energy.  Warm things have a lot of energy.  Cold things have less energy.  The Kelvin scale is a measurement of temperature.  Like degrees used when measuring temperature in Celsius or Fahrenheit.  Where 32 degrees Fahrenheit equals 0 degrees Celsius.  And 0 degrees Celsius equals 273.15 kelvin.  Not ‘degrees’ kelvin.  Just kelvin.

When something cools it loses heat energy.  The molecular activity slows down.  Steam has a lot of molecular activity.  At 212 degrees Fahrenheit (100 degrees Celsius or 373.15 kelvin) the molecular activity decreases enough (i.e., loses energy) that steam changes to water.  At 32 degrees Fahrenheit (0 degrees Celsius or 273.15 kelvin) the molecular activity decreases enough (i.e., loses energy) that water turns into ice.

The more heat matter loses the less molecules move around.  At absolute zero (0 kelvin) there is no heat at all.  And no molecular movement.  Making 0 kelvin the ‘coldest’ anything can be.  For 0 kelvin represents the absence of all heat.  As matter loses heat it shrinks.  Gases become liquid.  And liquids becomes solid.  (Water, however, is an exception to that rule.  When water turns into ice it expands.  And cracks our roadways.)  They become less fluid.  Or more viscous.  Cold butter is harder to spread on a roll than warm butter.  Because warm butter has more heat energy than cold butter.  So warm butter is less viscous than cold butter.

Vehicles in Sub-Freezing Temperatures can Start Easily if Equipped with an Engine Block Heater

In a car’s internal combustion engine an air-fuel mixture enters the cylinder.  As the piston comes up it compresses this mixture.  And raises its temperature.  When the piston reaches the top the air-fuel mixture is at its maximum pressure and temperature.  The spark plug then provides an ignition source to cause combustion.  (A diesel engine operates at such a high compression that the temperature rise is so great the air-fuel mixture will combust without an ignition source).  Driving the piston down and creating rotational energy via the crank shaft.

For this to happen a lot of things have to work together.  You need energy to spin the engine before the combustion process.  You need lubrication to allow the engine components to move without causing wear and tear.  And you need the air-fuel mixture to reach a temperature to burn cleanly and to extract as much energy from combustion as possible.  None of which works well in very cold temperatures.

Vehicles operating in sub-freezing temperatures need a little help.  Manufacturers equip many vehicles sold for these regions with engine block heaters.  These are heating elements in the engine core.  You’ll know a vehicle has one when you see an electrical cord coming out of the engine compartment.  When these engines aren’t running they ‘plug in’ to an electrical outlet.  A timer will cycle these heaters on and off.  Keeping the engine block warmer than the subfreezing temperatures.

The Internal Combustion Engine is Ideal for use in Cold Temperatures

At subfreezing temperatures engine oil because more viscous.  And more like tar.  This does not flow well through the engine.  So until it warms up the engine operates basically without any lubrication.  In ‘normal’ temperatures the oil heats up quickly and flows through the engine before there’s any damage.  At subfreezing temperatures oil needs a little help when starting.  So the oil sump is heated.  Like an engine block heater.  So when someone tries to start the engine the oil is more like oil and less like tar.

Of course, for any of this to help start an engine you have to be able to turn the engine over first.  And to do that you need a charged battery.  But even a charged battery needs help in sub-freezing temperatures.  For in these temperatures there is little molecular action in the battery.  And without molecular activity there will be little current available to power the engine’s starter.  So there are heaters for batteries, too.  Electric blankets or pads that sit under or wrap around a battery.  To warm the battery to let the chemicals inside move around more freely.  So they can produce the electric power it needs to turn an engine over on a cold day.

Once an engine block, the engine oil and battery are sufficiently warmed by external electric power the engine can start.  Once it warms up it can operate like it can at less frigid temperatures.  The engine alternator powers the electrical systems on the vehicle.  And recharges the battery.  The engine coolant heats up and provides heat for the passenger compartment.  And defrosts the windows.  Once the engine is warm it can shut down and start again an hour or so later with ease.  Making it ideal for use in cold temperatures.  Unlike an electric car.  For the colder it gets the less energy its batteries will have.  Making it a risky endeavor to drive to the store in the Midwest or the Northeast during a winter such as this.  Something people should think about before buying an all-electric car.

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Melting Snow and Ice

Posted by PITHOCRATES - February 5th, 2014

Technology 101

When Temperatures fall below Freezing Liquid Water turns into Solid Water

You know what the best thing about water is?  You don’t have to shovel it.  Well, that, and its life-giving properties.  Let’s face it.  We couldn’t survive without the stuff.  We couldn’t grow food.  We even couldn’t live without drinking water.  So perhaps its life-giving properties is the best thing about water.  But a close second would be that thing about not having to shovel it.

When it rains water soaks into our green areas.  It runs off driveways and sidewalks into green areas.  And into streets.  Where it runs off into a storm drainage system.  Which takes it to a river or lake.  The rain lets our gardens grow.  And any excess water conveniently just goes away.  We may have a puddle or two to slosh through.  But even those go away without us having to do anything.  Water is nice that way.  As long as the temperature is above its freezing point.

When the temperature falls below the freezing point of water bad things start to happen.  Liquid water turns into solid water.  And hangs around for awhile.  Accumulating.  On our driveways, sidewalks, porches and roads.  It’s pretty much everywhere we don’t want it to be.  Making it difficult to walk.  And drive.  We slip and fall a lot in it.  The sun may melt it a little during the day.  Creating puddles of water where the snow once was. But when the sun sets those puddles freeze.  And become even more slippery.  Making solid water more dangerous than liquid water.  So a big part of making it through winters in northern climes, then, is transforming solid water back into the liquid form.

Even though Bourbon melts Ice Cubes Bourbon would be a Poor Choice to melt Snow and Ice

All material can be in three different stages.  It can be a solid.  A liquid.  Or a gas.  What determines the phase of this material depends on a couple of things.  Mostly temperature and pressure.  And the chemical properties of the material.  At ambient temperature and pressure material typically exists stably in one phase.  Water, for example, is stable in the liquid phase on an 80-degree summer day.  Allowing us to swim in it.  While on a freezing February day it is stable in the solid phase.  Which is why we hold the Winter Olympics in February.  The cold temperatures give us the best solid water conditions.

If we raise the temperature of water we can turn it from a liquid to a gas.  We could also do this by lowering the ambient air pressure.  Such as putting it into a vacuum.  For a liquid remains a liquid as long as the vapor pressure (the tendency for particles to escape from the liquid they’re in) of the liquid is less than the ambient air pressure.  If we lower the ambient air pressure below the vapor pressure of the liquid we can lower the boiling point of that liquid.  This is why different liquids have different boiling points.  They have different vapor pressures.  Oxygen has a very high vapor pressure and requires a high pressure and cold temperature to keep oxygen in a liquid phase.

When we take ice cubes out of the freezer and add them to a glass of bourbon they melt.  Because the ambient temperature outside of the freezer is above the freezing point of water.  So the solid water changes its phase from solid to liquid.  It would follow, then, that pouring bourbon on snow and ice would help melt it.  Of course we don’t do that.  For wasting bourbon like that would be criminal.  Not to mention costly.  Even if you used the cheap stuff.  Making bourbon a poor choice for melting snow and ice.

Salt dissolves into a Brine Solution that lowers the Melting Point of Snow and Ice

We see that a material will change its phase at different temperatures and pressures.  Which is good to know.  But it doesn’t help us to melt snow and ice during winter.  For we can’t lower the atmospheric air pressure to lower the boiling and melting points of water.  And we can’t raise the ambient temperature above the melting point of water.  If we could our winters would probably be a lot more comfortable than they are now.  So because when we can’t change the air pressure or temperature of the ambient environment the snow and ice is in we do something else.  We use chemistry to lower the melting point of snow and ice.  And the most common chemical we use is salt.

To melt snow and ice salt needs heat and moisture.  The moisture comes from the snow and ice.  Or from the humidity in the air.  The heat comes from the warmth of the earth or air.  Heated by the sun.  It also comes from the friction between tires and the road.  When salt comes into contract with water and heat it dissolves into a brine solution.  And this brine solution has a much lower melting point than water.  Which in turn lowers the melting point of the snow and ice it comes into contact with.  Allowing it to be in the liquid phase at temperatures below freezing temperatures.  Melting that snow and ice so it can run off like rain water.

The warmer it is when it snows the quicker salt will melt that snow.  While the colder it is the longer it takes to melt.  If it gets too cold (around 15 degrees Fahrenheit) salt proves to be ineffective.  In temperatures below 15 degrees Fahrenheit other chemicals work better.  Such as calcium chloride.  But calcium chloride is more costly than sodium chloride (salt).  Ambient temperatures, time of day, sunny or cloudy, wind, etc., all determine the chemical to use.  And the amount of chemical to use.  They consider all of these factors (and more) before sending those ‘salt’ trucks out on the roads.  Allowing us to drive in the worst of winters just as we drive in the best of summers.  It may take more time.  And there may be a little more cussing.  But we still go to work, take our kids to school, go shopping, etc., when it snows.  Thanks to chemicals.  Chemistry.  And the people that put those chemicals and that chemistry to work.

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Manufacturers are Lowering Prices on Electric Cars to get us to Buy Cars we don’t Want

Posted by PITHOCRATES - December 8th, 2013

Week in Review

The government and those on the left may want us to all drive electric cars.  But you know who doesn’t?  Pretty much all of us (see Mitsubishi iMiev is now the cheapest electric car by Eric Evarts posted 12/5/2013 on Consumer Reports).

The biggest improvement electric cars need is in the price. And the latest electric-car maker to make that improvement is Mitsubishi, which just slashed the price of its golf-cartlike iMiev by more than 20 percent, to $23,845. That’s a $6,130 price drop from $29,975. (Toyota recently lowered the price on the Prius Plug-In.)

In addition, Mitsubishi has added some standard features, such as front heated seats, CHAdeMO DC quick charge port, rear door speakers, leather steering wheel trim, passenger-side vanity mirror, fog lights, and aluminum wheels. While these standard features sweeten the deal, they do underscore just how barebones the car was previously.

The iMiev is still eligible for a $7,500 federal electric vehicle tax credit that brings the price down to $16,345, or less where other state and local credits are available. Even at that reduced price, it still a lot of money for a car that feels like little more than an enclosed golf cart. The appeal lies solely in providing attainable access into the world of pure-electric cars. At this price, it becomes more feasible as a second, occasional-use car. (Visit our alternative fuel hub for more on electric cars and hybrids…)

The i-MiEV feels tiny, tinny, and slow, with clumsy handling and a bumpy ride. And its short cruising range—barely 60 miles in our tests—keeps you on a tight leash. Charging times are long, spanning between 6 and 7 hours for a full charge using 240-voltage.

The Spartan interior is cramped and unappealing, with seating limited to four people. Finally, the car’s small size and slow responses make you feel vulnerable sharing the road with “real” cars.

So to own an electric car you have to pay a fortune to get little.  You can’t drive further than 30 miles from your house.  And you must play ‘Russian roulette’ when you share the road with real cars.  As well as trucks.  You should never drive around a down railroad crossing gate.  Because in a car-train accident the car will always lose.  Just as in an electric car-anything-else accident the electric car will always lose.  Give me a big heavy 4-door sedan any day.  It’s big, it takes up space and pollutes the air (a quote taken loosely from the 1980 movie Serial).  But most of all it has space to survive in should you ever get into a non-train accident.

Any car that a manufacturer has to sell at a loss even with massive government subsidies is a car they shouldn’t be selling.  And it’s especially a car the government shouldn’t be subsidizing.  Especially when pretty much all of us prefer a car that’s big, takes up space and pollutes the air.  And will let you drive further than 30 miles from home.  While getting you home again.  Even if you get stuck in rush hour traffic.  In the middle of a blizzard.  When it’s dark outside.  Things that are not a problem when you have gasoline in the gas tank.

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Triple Expansion Steam Engine

Posted by PITHOCRATES - November 6th, 2013

Technology 101

Pressure and Temperature have a Direct Relationship while Pressure and Volume have an Inverse Relationship

For much of human existence we used our own muscles to push things.  Which limited the work we could do.  Early river transport were barges of low capacity that we pushed along with a pole.  We’d stand on the barge and place the pole into the water and into the river bed.  Then push the pole away from us.  To get the boat to move in the other direction.

In more developed areas we may have cleared a pathway alongside the river.  And pulled our boats with animal power.  Of course, none of this helped us cross an ocean.  Only sail did that.  Where we captured the wind in sails.  And the wind pushed our ships across the oceans.  Then we started to understand our environment more.  And noticed relationships between physical properties.  Such as the ideal gas law equation:

Pressure = (n X R X Temperature)/Volume

In a gas pressure is determined my multiplying together ‘n’ and ‘R’ and temperature then dividing this number by volume.  Where ‘n’ is the amount of moles of the gas.  And ‘R’ is the constant 8.3145 m3·Pa/(mol·K).  For our purposes you can ignore ‘n’ and ‘R’.  It’s the relationship between pressure, temperature and volume that we want to focus on.  Which we can see in the ideal gas law equation.  Pressure and temperature have a direct relationship.  That is, if one rises so does the other.  If one falls so does the other.  While pressure and volume have an inverse relationship.  If volume decreases pressure increases.  If volume increases pressure decreases.  These properties prove to be very useful.  Especially if we want to push things.

Once the Piston traveled its Full Stroke on a Locomotive the Spent Steam vented into the Atmosphere 

So what gas can produce a high pressure that we can make relatively easy?  Steam.  Which we can make simply by boiling water.  And if we can harness this steam in a fixed vessel the pressure will rise to become strong enough to push things for us.  Operating a boiler was a risky profession, though.  As a lot of boiler operators died when the steam they were producing rose beyond safe levels.  Causing the boiler to explode like a bomb.

Early locomotives would burn coal or wood to boil water into steam.  The steam pressure was so great that it would push a piston while at the same time moving a connecting rod connected to the locomotive’s wheel.  Once the piston traveled its full stroke the spent steam vented into the atmosphere.  Allowing the pressure of that steam to dissipate safely into the air.  Of course doing this required the locomotive to stop at water towers along the way to keep taking on fresh water to boil into steam. 

Not all steam engines vented their used steam (after it expanded and gave up its energy) into the atmosphere.  Most condensed the low-pressure, low-temperature steam back into water.  Piping it (i.e., the condensate) back to the boiler to boil again into steam.  By recycling the used steam back into water eliminated the need to have water available to feed into the boiler.  Reducing non-revenue weight in steam ships.  And making more room available for fuel to travel greater distances.  Or to carry more revenue-producing cargo.

The Triple Expansion Steam Engine reduced the Expansion and Temperature Drop in each Cylinder

Pressure pushes the pistons in the steam engine.  And by the ideal gas law equation we see that the higher the temperature the higher the pressure.  As well as the corollary.  The lower the temperature the lower the pressure.  And one other thing.  As the volume increases the temperature falls.  So as the pressure in the steam pushes the piston the volume inside the cylinder increases.  Which lowers the temperature of the steam.  And the temperature of the piston and cylinder walls.  So when fresh steam from the boiler flows into this cylinder the cooler temperature of the piston and cylinder walls will cool the temperature of the steam.  Condensing some of it.  Reducing the pressure of the steam.  Which will push the piston with less force.  Reducing the efficiency of the engine.

There was a way to improve the efficiency of the steam engine.  By reducing the temperature drop during expansion (i.e., when it moves the piston).  They did this by raising the temperature of the steam.  And breaking down the expansion phase into multiple parts.  Such as in the triple expansion steam engine.  Where steam from the boiler entered the first cylinder.  Which is the smallest cylinder.  After it pushed the piston the spent steam still had a lot of energy in it looking to expand further.  Which it did in the second cylinder.  As the exhaust port of the first cylinder is piped into the intake port of the second cylinder.

The second cylinder is bigger than the first cylinder.  For the steam entering this cylinder is a lower-pressure and lower-temperature steam than that entering the first cylinder.  And needs a larger area to push against to match the down-stroke force on the first piston.  After it pushes this piston there is still energy left in that steam looking to expand.  Which it did in the third and largest cylinder.  After it pushed the third piston this low-pressure and low-temperature steam flowed into the condenser.  Where cooling removed what energy (i.e., temperature above the boiling point of water) was left in it.  Turning it back into water again.  Which was then pumped back to the boiler.  To be boiled into steam again.

By restricting the amount of expansion in each cylinder the triple expansion steam engine reduced the amount the temperature fell in each cylinder.  Allowing more of the heat go into pushing the piston.  And less of it go into raising the temperature of the piston and cylinder walls.  Greatly increasing the efficiency of the engine.  Making it the dominant maritime engine during the era of steam.

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Green Energy Policies raise the Cost of Heating this Winter in the UK

Posted by PITHOCRATES - October 19th, 2013

Week in Review

You can either fight ‘manmade’ global warming or you can have low energy prices.  But you can’t have both (see British Gas to raise prices by 9.2% posted 10/17/2013 on BBC News Business).

British Gas is to increase prices for domestic customers, with a dual-fuel bill going up by 9.2% from 23 November.

The increase, which will affect nearly eight million households in the UK, includes an 8.4% rise in gas prices and a 10.4% increase in electricity prices.

The company said it “understands the frustration” of prices rising faster than incomes. The average annual household bill will go up by £123 [$198.89]…

The company said that the cost of buying energy on the global markets, delivering gas and electricity to customers’ homes, and the government’s “green” levies, were all factors in the decision to put up prices.

With a focus on renewables we bring fewer fossil fuels to market.  Coal, oil and natural gas.  And with the war against clean nuclear power we’re shutting down our reactors.  So instead we focus on the more costly wind and solar power.  Because it takes a lot more costly infrastructure to capture the ‘free’ energy from the sun and the wind.  So much that the taxpayer has to subsidize them.  To bring us that ‘free’ energy.  When the sun is shining and the wind is blowing, that is.  Which brings us to that costly distribution system.

People can put solar arrays on their home to use that ‘free’ solar power during sunny days.  But what about cloudy days?  And night?  Wind farms can generate ‘free’ wind power when the winds are blowing right.  But what about when they are not blowing right?  Either too fast?  Too slow?  Or not at all?  What then?  Fossil fuels.  That’s what.

Baseload power (typically coal that takes hours to bring on line) is a funny thing.  To be cost effective power plants run at full capacity 24/7.  When demand rises they can bring on some ‘peaker’ units (typically gas that are quick to bring on line) to add additional capacity.  So power companies have to maintain baseload power even if the people aren’t buying any to be available when solar and wind aren’t.  And if all the homes disconnected from the grid and ran on solar power during the day the power companies would still have to keep them physically connected to the grid.  So these homes can use their power at night.

This is why energy prices are rising.  Revenue at power companies are falling due to that ‘free’ wind and solar power while their expenses are not.  And because they are selling to fewer customers they have to charge them more to cover their expenses.

Affordable energy for the people lies with fossil fuels.  Not renewables.  Governments have to choose.  All the people.  Or their liberal base.  Less costly power from fossil fuels.  Or more costly power from renewables.  It’s that easy.  For you can fight ‘manmade’ global warming or you can have low energy prices.  You just can’t have both.

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Another Electric Car bursts into Flames

Posted by PITHOCRATES - October 5th, 2013

Week in Review

One thing we learned from Breaking Bad was to respect the chemistry.  And that’s what batteries are.  Chemistry.  The kind of chemistry that’s a little on the dangerous side.  Unlike gasoline.  Which we can store relatively safely in tanks under our cars.  Where little chemistry goes on inside our gas tanks.  To use that gasoline to power our cars we have to do a couple of things.  We have to aerosolize it.  Combine it with oxygen.  Compress it.  Then ignite it.  Then and only then does it release its incredible energy.  Producing great heat in the engine.  But not the gas tank.  Which needs no cooling system.  It’s a little different in an electric car.

In a battery the chemistry is all local.  It produces electricity—and heat—where the chemicals are stored.  In the battery.  One of the problems with electric cars is their limited range.  And you fix this problem with bigger and more powerful batteries.  That can produce a lot of electricity—and heat—as they charge or power the car.  Making battery cooling a requirement for safe battery use.  To keep those chemicals under control.  But sometimes these chemical reactions go out of control.  Causing fires as cars re-charge in their garages.  Causing fires that grounded the new Boeing 787 Dreamliner.  And this (see Hot Wheels! Tape of Tesla Fire Has Stock Tanking by Dan Berman, Hot Stock Minute, posted 10/3/2013 on Yahoo! Finance).

Tape of a Tesla (TSLA) on fire is giving new meaning to the term “hot wheels.” The video was shot on Tuesday after a Model S sedan went up in flames…

In an e-mail sent to The New York Times, Tesla spokeswoman Elizabeth Jarvis-Shean wrote that the fire was caused by the “direct impact of a large metallic object to one of the 16 modules within the Model S battery pack.” The e-mail went on to say, “Because each module within the battery pack is, by design, isolated by fire barriers to limit any potential damage, the fire in the battery pack was contained to a small section in the front of the vehicle.”

Contained to a small section?  It looks like the fire engulfed the whole car.  All because of some metal debris thrown up from the roadway.  Of course, a way to protect against something like this in the future is to add a metal shield that can take a direct hit without damage.  Adding a thick piece of metal under the car, though, adds weight.  Which, of course, reduces range.

This is a problem with electric cars.  Improving safety results in a reduction in range.  Because it adds weight.  It adds weight, too, with gasoline-powered cars.  But one full tank of gas can hold a lot more energy that all the batteries can on an electric car.  And when you run out of gas all you have to do is stop at a conveniently located gas station and fill up.  Which takes about 10 minutes or so.  Unlike a recharge of an electric car.  Which can take anywhere between a half hour (with a high-voltage fast charger) to overnight in the garage plugged into a standard outlet.  Which is why electric cars are more of a novelty.  Those who have them typically have other more reliable cars for their main driving needs.  For though gasoline-powered cars catch fire, too, when they’re not on fire you know you’re going to get home.

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Tesla to expand Charging Network which may lead to the Success and then Failure of the All-Electric Car

Posted by PITHOCRATES - June 1st, 2013

Week in Review

There’s nothing like hitting the open road.  And just driving wherever your car takes you.  Because for some it’s the journey.  Not the destination.  For America has a special love affair with their cars.  They are symbolic of the liberty our Founding Fathers gave us.  The freedom to go anywhere.  All you need is a tank full of gas.  And a gas station or two along the way.  Which is something the all-electric car just can’t do.  But it’s not for a lack of trying (see Tesla tripling supercharger network for LA to NY trip by Chris Isidore posted 5/31/2013 on CNNMoney).

Musk said that the expansion of the network of superchargers, which allow the company’s cars to be recharged in about an hour, will cover most major metropolitan areas in the United States and southern Canada. While owners can charge the car using ordinary electrical current at home overnight, the supercharging stations are important for relieving drivers’ anxiety about running out of power and being stranded on long journeys.

“It is very important to address this issue of long-distance travel,” he said. “When people buy a car, they’re also buying a sense of freedom, the ability to go anywhere they want and not feel fettered.”

I don’t know about you but waiting an hour to recharge while on a road trip kind of defeats the purpose of hitting the open road.  Driving.  An hour doesn’t seem like a long time.  But the next time you go to a gas station stay there for an hour and see how it really feels.

At a speed limit of 70 MPH that’s like adding an additional 70 miles to your trip every time you stop to charge.  Or more.  For what happens if all the chargers are in use and there is a line of Tesla cars waiting for a charger when you arrive at one of these charging stations?  Because you’re not the only person driving a Tesla?  What then?  Whenever you pulled into a gas station with every pump in use you never had to wait 2 or 3 hours for your chance to spend an hour fueling your car.  But the success of all-electric cars could very well do this.  If enough people are driving them.  Well, the success would be short-lived.  For after the first hour-plus wait for a charge people will no doubt sell their all-electric cars.  And buy something gasoline-powered instead.

And here’s another thought.  Some horrific storms just blew through the Midwest.  Causing some huge power outages.  Right along some major interstate arteries passing through the state.  What do you do then?  When you need a charge and there is no electric power available?  Chances are that you’d have enough gasoline to get you to a gas station that didn’t lose its power.  But if there is only a charger every 80-100 miles you’re going to need a tow to the next charging station.  Making it harder and harder to enjoy your journey.  While your gasoline-powered companions mock you as they continue on enjoying their journey.

Someone should think long and hard about these things before pouring so much money into a charging infrastructure.  For that infrastructure will only work if they have few cars using it.  In fact, the success of the Tesla could very well lead to the failure of the all-electric car market.  When the reality of the charging problems of the all-electric car become apparent to all-electric car owners.  Who simply won’t want to spend a large part of their day waiting for a charge.  Or a tow truck.

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Phase Transition, Expansion Valve, Evaporator, Compressor, Condenser and Air Conditioning

Posted by PITHOCRATES - April 3rd, 2013

Technology 101

We can use Volume, Pressure and Temperature to change Water from a Liquid to a Gas and back Again

Liquids and gasses can do a lot of work for us.  If we can control three variables.  Volume.  Pressure.  And temperature.  For example, internal combustion engines work best when hot.  But excessive heat levels can damage the engine.  So we use a special anti-freeze/anti-boil liquid in the cooling system.  A pump circulates this liquid through the engine where it absorbs some of the excess heat of combustion that isn’t used in pushing the piston.  After leaving the engine it flows through a radiator.  Air blows across tubes in the radiator cooling this liquid.  Ejecting some of the heat of combustion into the atmosphere.  Lowering the temperature of the cooling liquid so it can flow through the engine again and absorb more heat.

Our first cars used alcohol in the winter for a lower freezing point.  So this liquid didn’t freeze in the engine and crack the block.  Letting the coolant flow out.  And with no cooling available the excessive heat levels would damage the engine.  In the summer time we used plain water in the cooling system.  And kept the cooling system sealed and under high pressure to prevent the water from boiling into steam.  But the high pressure often caused a hose or a radiator cap to fail.  Releasing the pressure.  And letting the cooling water boil out leaving the engine unsafe to operate.

If this happened on a hot summer’s day and you got a tow to a gas station you may have sat there waiting for them to complete the repairs.  Sipping on a cool bottle of soda from a refrigerated soda machine.  Soon drops of water would condense onto your cold bottle.  The cold bottle cooled the water in gas form (the humidity in the air) and turned it back into a liquid.  So in these examples we see how we were able to use pressure to keep water a liquid.  And how removing heat from water as a gas changed it back into a liquid.  This phase transition of a material has some very useful applications.

The High-Pressure Refrigerant Liquid from the Condenser loses Pressure going through the Expansion Valve

The phase transition between a liquid and a gas are particularly useful.  Because we can move liquids and gases in pipes and tubing.  Which allows us to take advantage of evaporation (going from a liquid to a gas) in one area.  While taking advantage of condensation (going from a gas to a liquid) in another area.  By changing pressure and volume we can absorb heat during evaporation.  And release heat during condensation.  Allowing us to absorb heat inside a building with evaporation.  And release that heat outdoors with condensation.  All we need are a few additional components and we have air conditioning.  An expansion valve.  An evaporator.  A compressor.  A condenser.  A couple of fans.  And some miscellaneous control components.

We install the expansion valve and the evaporator inside our house.  Often installed inside the furnace.  And the compressor and the condenser outside of the house.  We interconnect the indoor and the outdoor units with tubing.  Inside this tubing is a refrigerant.  Which is a substance that transitions from liquid to a gas and back again at relatively low temperatures.  As the refrigerant moves from the evaporator to the condenser it is a gas.  As it moves from the condenser to the evaporator it is a liquid.  The transition between these stages occurs at the evaporator and the condenser.

The refrigerant leaves the condenser as a liquid under high pressure.  As it passes through the expansion valve the pressure drops.  By restricting the flow of the liquid refrigerant.  Think of a faucet at a kitchen sink.  If you open it all the way the water flowing in and the water flowing out are almost equal.  But if we just open the faucet a little we get only a small trickle of water out of the faucet.  And a pressure drop across the valve.  With the full force of city water pressure pushing to get out of the faucet.  And a low pressure trickle coming out of the faucet.

As the Warm Air blows across the Evaporator Coil any Humidity in the Air will condense on the Coil

As the liquid leaves the expansion valve at a lower pressure it enters the evaporator coil.  A fan blows the warm air inside of the house through the evaporator coil.  The heat in this air raises the temperature of the refrigerant.  And because of the lower pressure this heat readily boils the liquid into a gas.  That is, it evaporates.  Absorbing heat from the warm air as it does.  Cooling the air.  Which the fan blows throughout the ductwork of the house.

As the gas leaves the evaporator it travels through a tube to the condenser unit outside.  And enters a compressor.  Where an electric motor spins a crankshaft.  Attached to the crankshaft are two pistons.  As a piston moves down it pulls low pressure gas into the cylinder.  As the piston moves up it compresses this gas into a higher pressure.  As the pressure rises it applies more pressure on the spring holding the discharge valve closed.  When the pressure is great enough it forces open the valve.  And sends the high-pressure gas to the condenser coil.  Where a fan blows air through it lowering the temperature of the high pressure gas enough to return it to a liquid.  As it does it releases heat from the refrigerant into the atmosphere.  Cooling the refrigerant.  As the liquid leaves the condenser it flows to the expansion valve to repeat the cycle.  Over and over again until the temperature inside the house falls below the setting on the thermostat.  Shutting the system down.  Until the temperature rises high enough to turn it back on.  A window air conditioner works the same way.  Only they package all of the components together into one unit.

There is one other liquid in an air conditioning system.  Water.  As the warm air blows across the evaporator coil any humidity in the air will condense on the coil.  Like on a cold bottle of soda on a hot summer day.  As this water condenses on the evaporator coil is eventually drips off into a pan with a drain line.  If the evaporator is in the furnace this line will likely run to a sewer.  If the evaporator is in the attic this line will run to the exterior of the house.  Perhaps draining into a gutter.  If it’s a window unit this line runs to the exterior side of the unit.  These simple components working together give us a cool and dehumidified house to live in.  No matter how hot and humid it gets outside.

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