The more Electric Cars people drive the greater the Stress on the Electric Grid

Posted by PITHOCRATES - April 16th, 2014

Week in Review

Have you ever noticed your lights dim when your air conditioner starts?  They do because when an electric motor starts there is a momentary short circuit across the windings.  Causing a great inrush of current as they start rotating.  Once they are rotating that inrush of current drops.  During that surge in current the voltage drops.  Because there is no resistance in a short circuit.  So there is no voltage across a short circuit.  And because everything in your house goes back to your electrical panel that momentary voltage drop affects everything in your house.  Including your lights.  The lower voltage reduces the lighting output.  Momentarily.  Once the air conditioning motor begins to rotate the short circuit goes away and the voltage returns to normal.

Air conditioners draw a lot of power.  And during hot summer days when everyone gets home from work they cause the occasional brownout.  As everybody turns on their air conditioners in the evening.  Stressing the electric grid.  Which is why our power bills rise in the summer months.  For this great rise in demand causes a corresponding rise in supply.  Costing the power companies more to meet that demand.  Which they pass on to us (see Electricity Price Surged to All-Time Record for March by Terence P. Jeffrey posted 4/16/2014 on cnsnews).

The average price for a kilowatthour (KWH) of electricity hit a March record of 13.5 cents, according data released yesterday by the Bureau of Labor Statistics. That was up about 5.5 percent from 12.8 cents per KWH in March 2013.

The price of electricity in the United States tends to rise in spring, peak in summer, and decline in fall. Last year, after the price of a KWH averaged 12.8 cents in March, it rose to an all-time high of 13.7 cents in June, July, August and September.

If the prevailing trend holds, the average price of a KWH would hit a new record this summer.

All-electric cars are more popular in California than in Minnesota.  Because there is little cold and snow in California.  And batteries don’t work so well in the cold.  AAA makes a lot of money jumping dead batteries during cold winter months.  So batteries don’t hold their charge as well in the winter.  Which is when an all-electric car requires more charge.  For the days are shorter.  Meaning that at least part of your daily commute will be in the dark and require headlights.  It is colder.  Requiring electric power for heating.  Windows fog and frost up.  Requiring electric power for defogging and defrosting.  It snows.  Requiring electric power to run windshield wipers.  Slippery roads slow traffic to a crawl.  Increasing the time spent with all of these things running during your commute.  So the all-electric car is more of a warm-weather car.  Where people who don’t live in sunny California may park their all-electric car during the worst of the winter months.  And use a gasoline-powered car instead.

As those on the left want everyone to drive all-electric cars they don’t say much about the stress that will add to the electric grid.  If everyone switched to an electric car in the summer it would be like adding a second air conditioner at every house.  Especially after work.  When everyone gets home and plugs in.  Causing an inrush of current for an hour or so as those discharged batters recharge.  A discharged battery is similar to an electric motor.  As it’s the current flow that recharges the battery cells.  There’s a high current at first.  Which falls as the battery charges.  So summer evenings will have a lot of brownouts during the summer months.  As the added electric load will greatly stress the electric grid during the evenings.  A demand that the power companies will have to supply.  At the same time they’re replacing coal-fired power plants with less reliable renewable forms of power generation.  Such as solar farms.  Which will be fast running out of sunshine as these cars plug in.

If people switch from gasoline to electric power in their cars en masse the average price for a kilowatt-hour will soar.  It’s simple economics.  Supply and demand.  The greater the demand the higher the price.  And there is little economies of scale in power production.  Because more power requires more fuel.  And the kicker is that even people who don’t drive will have to pay more on their electric bills when people switch from gasoline to electric cars.  And their gas bills if gas-fired turbines provide that peak power demand.  Raising the price of natural gas.  Making everyone pay more.  Whereas only drivers of gasoline-powered cars are impacted by the high cost of gasoline.

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Family Farms, Big City Factories, Fertility Rates and Federal Debt

Posted by PITHOCRATES - July 9th, 2013

History 101

The Mechanization of the Farm began a Migration from the Country to the Cities

Before the Industrial Revolution (1760-1830ish) if you worked you most probably farmed.  For most everyone from the dawn of civilization on the Nile, the Euphrates & Tigris, the Indus and the Yangtze farmed.  To produce food for the civilization for the good times.  And food surpluses for the bad times.  For having enough to eat was never a sure thing.  And surviving the winter was a challenge.

What early civilizations needed were a lot of people to work the land.  For large-scale farming could produce large harvests.  Enough to feed everyone during the good times.  During the winters.  And even the occasional drought.  But it could be a risky game to play.  Because a lot of people to work the land also meant a lot of mouths to feed.  Which meant everyone worked the fields.  Men.  Women.  And children.  Anyone who ate worked.  As they did on the family farm.  Which is why they had large families.  For the more children they had the more land they could work.  Allowing them to eat during the good times.  During the winters.  The occasional drought.  While having large food surpluses to sell.  Allowing them to build wealth.  Just like the landowners in the Old World.  The aristocracy.  Only instead of peasants working the land it was family.

But with the Industrial Revolution came change.  The steam engine mechanized farming.  Allowing fewer people to produce more.  Also, steam power allowed factories away from rivers.  As they no longer needed moving water to turn a waterwheel.  So factories filled our cities.  Creating a lot of jobs.  This and the mechanization of the farm requiring fewer hands to work the land began a migration.  Of people from the country.  To the cities.

The Migration from the Family Farm to the Big City got People used to Bigger Government and Taxes

The world modernized in the 1800s.  Food was never more plentiful.  Allowing more people to leave the farm.  And think about other things.  Like electrical engineering.  Nikola Tesla gave us AC electric power.  And the AC electric motor.  Changing manufacturing forever.  Those little spinning machines filled our factories.  And operated the machines in those factories.  Everything we ever made we made better and more efficiently thanks to the electric motor.  Allowing us to manufacture more than ever.  And manufacture more complex things.  Factories grew.  With many levels of manufacturing contained within.  Packing more people than ever in these factories.

The common perception of this industrial world is of sweatshops.  Child labor.  Soot and smoke casting a pall over overcrowded cities.  Where people packed into overcrowded housing.  Thanks to that migration from the family farm to the big city factories.  Which changed things.  Instead of people raising a large family on a large farm where there was plenty of room and plenty of food to eat these families were living in cramped apartments in the crowded city.  And they had to pay for the food they ate.  And the more mouths they had to feed the more money it took.  This was a big change.  Whereas on the farm a large family meant more food.  And more wealth.  In the city, though, more children meant less food for everyone else to eat.  And more poverty.

The growth of cities also caused another change.  When people lived on scattered farms they didn’t need any government services.  But in the crowded cities they did.  Homes had utilities.  And sanitation.  Cities also had streets.  Which the city needed to maintain.  Eventually there was street lighting.  And traffic signals.  Police departments.  Fire departments.  Schools.  And teachers.  All of these things cost money.  And we paid for them with taxes.  Getting people used to bigger government.  And bigger taxes.  Then the progressives entered government at the federal level.  Who wanted government to do at the federal level what it did at the local level.  Be mother to the people.  Instead of just doing those things the Constitution said it should do.

A Falling Fertility Rate forced the Government to go into ‘World War’ Debt just to pay for Social Security and Medicare

The fertility rate (the number of children a woman has during her child-bearing days) fell all during the 1800s.  As large families went from being wealth producers on the farm to poverty inducers in the cities.  While federal debt from the American Revolutionary War fell during the early 1800s.  The debt fell because there wasn’t a lot of federal spending.  So it wasn’t hard to retire that debt.  But that federal restraint didn’t last.  There was a spike in federal debt (as a percent of GDP) following American Civil War (1861-1865) as they had to borrow heavily to pay for that war.  But after the war the debt level did not fall back to pre-war levels.  A trend that would continue.  As we can see here.

Fertilty Rate versus Debt as Percent of GDP

There was another spike in federal debt following World War I (1917-1918).  But the debt level never fell back to pre-war levels.  Then the Great Depression and the New Deal (1930s) began another spike in Federal debt.  That World War II took to record highs.  And once again after the war the federal debt did not fall back to pre-war levels.  Then came President Reagan.  Who had the guts to call communism what it was.  A failed economic system that oppressed its people and was the greatest killer of the 20th century.  To push the Soviet Union into the ‘ash heap of history’ Reagan forced them to spend more than they could afford.  By ramping up defense spending to a level the Soviets couldn’t match.  Which ultimately won the Cold War (1947-1991, with Reagan delivering the knockout blow during his presidency (1981-1989) ).  But federal debt levels, once again, did not fall back to pre-war levels.  In fact, despite the peace dividend President Clinton inherited he still raised federal spending.  Just at a reduced rate than it was during the Cold War.  President Bush gave us Medicare Part D (drugs for seniors).  Then came 9/11.  And the War on Terror.  Then President Obama.  Who despite ending the Iraq War had the greatest budget deficits of any president.  As he spent more than any other president.  As he tried to transform the country into a European social democracy.  Sending out debt soaring to new heights.

FDR gave us Social Security in 1935.  At the tail-end of a long decline in the fertility rate.  Promising great benefits to future retirees.  Which LBJ added to during the Sixties with his Great Society.  During the post-war baby boom.  Perhaps assuming that increasing fertility rate would provide a lot of new taxpayers in the future when the weight of all these new government programs (FDR’s and LBJ’s) would be felt.  But then two things happened that they didn’t quite plan on.  The birth control pill and abortion created a baby bust following the baby boom.  Worse, thanks to modern medicine people were living longer into retirement.  Consuming more Social Security and Medicare benefits than anyone had ever imagined.  And just when the full force of those baby boomers was going to hit there were going to be fewer taxpayers around to pay for it.  Thanks to that baby bust.  More retirees paid for by fewer taxpayers.  A recipe for disaster.  Which is why debt soared towards World War II highs following the Cold War.  Even though there was no world war.  Because the cost of all those government benefits far exceeded the tax revenue.  Forcing the government to go into ‘world war’ debt just to pay for Social Security.  Medicare.  And everything else the federal government was providing so they could play mother to the American people.

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Coal Mines, Steam Engine, Electric Motor, Coal-Fired Power Plants, Water Pumps, Ventilation Fans, Strip Mining, Draglines and Coal Washing

Posted by PITHOCRATES - September 12th, 2012

Technology 101

The Steam Engine pumped Water from Mines allowing them to go Deeper as they followed Veins of Coal

Petroleum is the lifeblood of advanced economies.  It propels our airplanes, ships, trains, trucks, ambulances, air ambulances, fire trucks, cars, etc.  It moves everything.  Our sick and injured.  Our families.  Our food.  Our goods.  The raw materials that build the world we live in.  You would not recognize the world if we removed petroleum from it.  There would be no aviation.  No emergency vehicles that could respond in minutes.  No family car.  But we could still have ships and trains.  Because before petroleum there was coal.

Before the Industrial Revolution we used animals to move people and things.  We were using fuels for other things.  But not to move people and goods.  Until there was a problem getting that fuel.  The British were mining coal near the coast.  But there was a problem.  As the coal veins they mined moved under the sea they filled with water.  Limiting how far they could follow those veins.  They had a pump.  Driven by a crude steam engine.  But it just didn’t do the job very well.  Until a man came along and improved it.  James Watt.  Who improved that crude steam engine.  And changed the world.

The steam engine pumped water from coal mines allowing them to go deeper as they followed veins of coal.  But the steam engine had other uses.  They could power a drive shaft in a factory.  Allowing us to build factories anywhere.  Not just by moving water that drove a waterwheel.  And using a steam engine to move a train allowed us to connect these factories with other factories.  And to the stores in the cites that bought the things they built.  Steam-powered tractors replaced the horse and plow on the farm.  While steam locomotives brought coal from distant coal mines to our homes we burned for heat.  Coal was everywhere.  We had a coal-based economy.  And a coal-based life.  The more we used the more we had to mine.  Thanks to the coal-fired steam engine we could mine a lot of it.  And did.  It powered the Industrial Revolution.  And powers our modern economy today.  Because coal even powers the engines that replaced the steam engines in our factories.

The two largest Electrical Loads in a Coal Mine are the Water Pumps and the Ventilation Fans

We’ve replaced the steam engines in our factories with the electric motor.  Instead of having a main drive shaft through the factory and a system of belts and pulleys we put an electric motor at each workstation.  And connected it to the electric grid.  Greatly increasing our productivity.  And the electric power to drive these electric motors came predominantly from coal-fired power plants.  Coal has never been more important in the modern economy.  It provides about half of all electric power.  Followed by natural gas and nuclear power at about 20% each (though natural gas is on the rise).  Hydroelectric dams provide less than 10% of our electric power.  And everything else provides less than 5%.

Just as the steam engine made mining more efficient so did electric power.  Mines can go deeper because electric pumps can more efficiently pump water out of the mines.  And large fans can circulate the air underground so miners can breathe.  As well as disperse any buildups of methane gas or coal dust.  Before they can explode.  Which is one of the hazards of mining a flammable and, at times, explosive material.  The hazard is so real that you will not find ventilation fans inside the mine.  You’ll find water pumps deep in the mines.  But not the ventilation fans.  Because if there is a fire or an explosion underground they’ll need to protect those fans from damage so they will still be able to ventilate the mine.  For if the mine fills with smoke surviving a fire or an explosion will matter little if you cannot breathe.

The two largest electrical loads in a coal mine are the water pumps and the ventilation fans.  Mines consume enormous amounts of electric power.  And most of it goes to fighting the water seepage that will fill up a mine if not pumped out.  And making the mines habitable.  Electric power also runs the hoists that haul the coal to the surface.  Transports miners to and from the mines.  And runs the mining equipment in a confined space without any hazardous fumes.  As critical as this electric power is to survive working in such an unfriendly environment more times than not the power they use comes from a coal-fired power plant.  A plant they feed with the very coal they mine.  Because it’s dependable.  That electric power will always be there.

Coal will always let you Charge your Electric Car Overnight and Surf the Web in the Morning

But we just don’t mine coal underground.  We also dig it up from the surface.  With strip mining.  Most of the coal we use today comes from great strip mines out West.  Where they use mammoth machines called draglines to scrape away soil to get to the coal.  And then they scrape out the coal.  These machines are as big as ships and actually have crew quarters inside them.  They even name them like ships.  They operate kind of like a fishing rod with a few minor differences.  Instead of a rod there is a boom.  Instead of nylon fishing line there is a steel cable up to two inches in diameter.  And instead of a hook there is a bucket big enough to hold a 2-car garage.  The operator ‘throws’ the bucket out by running it out along the boom.  Then drops it in the dirt.  Then drags the bucket back.  The massive scale of the dragline requires an enormous amount of power.  And the power of choice?  Electric power.  Often produced by the very coal they mine.  Some of these machines have electric cables even bigger around than the cables that drag their buckets.  At voltages of 10,000 to 25,000 volts.  Drawing up to 2,000 amps.

These draglines can mine a lot of coal.  But it’s a lower-quality coal than some of our eastern coal.  Which has a higher energy content.  But eastern coal also has a higher sulfur content.  Which requires more costs to make it burn cleaner.  In fact, before any coal ships today we wash it to remove slate as well as other waste rock from the coal.  And it is in this waste rock where we find much of the sulfur.  So the washing makes the coal burn cleaner.  As well as raise the energy content for a given quantity of coal by removing the waste that doesn’t burn.  There are a few ways they do this.  But they all involve water.  Therefore, at the end of the process they have to dry the coal by spinning it in a large cylindrical centrifuge.  So a lot happens to coal between digging it out of the ground and loading it on a unit train (a train carrying only one type of cargo) bound to some power plant.  And chances are that it will go to a power plant.  For our coal-fired power plants buy about 80% or so of all coal mined.  So if you see a coal train it is probably en route to a coal-fired power plant.

Coal created the modern world.  And it powers it to this day.  From the first steam engines that dewatered mines to the coal-fired power plants that power the massive server farms that hold the content of the World Wide Web.  Yes, coal even powers the Internet.  As well as our electric cars.  For only coal will be able to meet the electric demand when everyone starts plugging their car into the electric grid overnight.  Because solar power doesn’t work at night.  And wind power is even less reliable.  For if it’s a still night you’ll have no charge to drive to work in the morning.  But if you plugged into coal you’ll always be able to charge your electric car overnight.  And surf the web in the morning.

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Internal Combustion Engine, Electric Motor, Fuel Economy, Emissions, Electric Range, Parallel Hybrid, Series Hybrid and Plug-In

Posted by PITHOCRATES - September 5th, 2012

Technology 101

We started the First Cars with a Hand Crank and Nearly Broke an Arm if the Hand Crank Kicked Back

The king of car engines is the internal combustion engine (ICE).  We tried other motors such as a steam engine.  But a steam engine is a heat engine.  Meaning it first has to get hot enough to boil water into steam.  Which meant any trip in a car took a little extra time to bring the boiler up to operating temperatures.  Boilers tend to be big and heavy.  And dangerous.  Should something happen and a dangerous level of steam pressure built up they could explode.  Despite those drawbacks, though, a steam engine-powered car took you places.  And as long as there was fuel for the firebox and water for the boiler you could keep driving.

Another engine we tried was the electric motor.  These didn’t have any of the drawbacks of a steam engine.  You didn’t have to wait for a boiler to get to operating temperatures before driving.  Nothing was in danger of exploding.  An electric motor was lighter than a cast-iron boiler.  And an electric motor could make a car zip along.  However, an electric motor requires continuous electricity to operate.  Provided by charged batteries.  Which didn’t last long.  And took hours to recharge.  Giving the electric car limited range.  And little convenience.  For the heavier it was and/or the faster you went the faster you drained those batteries.  Which could be a problem taking the family on vacation.  But they worked well in a forklift on a loading dock.  Because of the battery-power they produced no emissions so they’re safe to use indoors.  They had limited auxiliary systems to run (other than a horn and maybe a light).  And when they were running low on charge you rarely needed to drive more than 20 or 30 feet to a charging station.

The first ICE-powered cars took some manly strength to operate.  They didn’t have power brakes, power steering, automatic transmissions or starters.  We started the first ICE-powered cars with a hand crank.  That took a lot of strength to turn.  And if it backfired while starting the kick of the handle could easily break a wrist or an arm.  Putting a damper on any Sunday afternoon drive.  This limited the spread of the automobile.  They were complex machines that required some strength to operate.  And they could be very dangerous.  Then along came the electric starter.  Which was an electric motor that spun the ICE to life.  Making the car much safer to start.  Expanding the popularity of the automobile.  For there was no longer a good chance that you could break your arm trying to start it.  And through the years came all those accessories making it easier and more comfortable to drive.  Today automatic transmissions, power steering, power brakes, headlights, interior lights, power locks, power windows, powered seats, a fairly decent audio system, heat, air conditioning and more are standard on most cars.  All effortless powered by that internal combustion engine.

Current Battery Technology does not give the All-Electric Car a Great Range

The reason why an ICE can do all of this is because gasoline is a very concentrated energy source.  It doesn’t take a lot of it to go a long way.  And it can accelerate you up a hill.  It even has the energy to pass someone on a hill. It’s a fuel source we can take with us.  A small amount of it stores conveniently and safely in a gas tank slung underneath a car.  And when it’s empty it takes very little time to refill.  A ten minute stop at a gas station and you’re back on the road able to drive another 500 miles or so.  Even in the dark of night with headlights blazing.  While keeping toasty warm in the winter.  Or comfortably cool in the summer.  Things an electric battery just can’t do.  So why would we even want to trade one for the other?  In a word—emissions.

The internal combustion engine pollutes.  The more fuel a car burns the more it pollutes.  So to cut pollution you try to make cars burn less fuel.  You increase the fuel economy.  And you can do that in a couple of ways.  You can cut the weight of the vehicle.  And put in a smaller engine.  Because a smaller engine can power a lighter car.  But a smaller car carries fewer people comfortably.  And can carry less stuff.  A motor cycle gets very good fuel economy but you can’t take the family on a Sunday drive on one.  And you can’t pack up your things on a motorcycle when going off to college.  So the tradeoff between fuel economy and weight has consequences.

An electric car does not pollute.  At all.  (Though the power plant that charges its batteries does pollute.  A lot.)  But current battery technology does not give the all-electric car a great range.  Typically coming in at less than 75 miles per charge.  Which is great if you’re operating a forklift on a loading dock.  But it’s pretty bad if you’re actually driving on a road going someplace.  And hope to return.  The heavier the car is the shorter that driving range.  If you want to use your headlights, heater or air conditioner it’ll be shorter still.  On top of this short range recharging your battery isn’t like stopping at the gas station for 10 minutes.  No.  What one typically does is pray that he or she gets home.  Then plugs in.  And by morning the car would be fully charge for another 75 miles or so of driving.

To Maximize the Benefit of a Hybrid you’d want to Carry the Absolute Minimum of Batteries to Serve your Needs

So all-electric cars are clean but they won’t really take us places.  The ICE-powered car will take us places but it’s not really clean.  Enter the gas/electric hybrid.  Which combines the best of the all-electric car (clean) and the best of the ICE-powered car (range).  There are a few varieties.  The parallel hybrid has both an ICE and an electric motor connected to a transmission that powers the wheels.  The ICE also drives a small generator.  Batteries power the electric motor.  And a gas tank feeds the ICE.  The generator keeps the batteries charged.  The battery powers the electric motor to accelerate the car from a stop.  After a certain speed the small ICE takes over.  When the car needs to accelerate the electric motor assists the ICE.  The small ICE has excellent fuel economy thus reducing emissions.  The electric motor/battery provides the additional horsepower when needed to compensate for an undersized ICE.  And the gasoline-powered engine provides extended range.

In addition to the parallel hybrid there is the series hybrid.  It has the same parts but they are connected differently.  The series hybrid is more like a diesel-electric locomotive.  Gasoline feeds the ICE.  The ICE drives a generator.  The generator charges the batteries and/or drives the electric motor.  The electric motor drives a transmission that spins the wheels.  This car drives on batteries until the charge runs out and then switches over to the ICE.  For short commutes this provides excellent fuel economy.  For longer drives (well over 75 miles or so) it’s more like a standard ICE-powered car with a roundabout way of turning the wheels.

Then there’s the plug-in variety.  In addition to all of the above you can plug your car into a charger to further save on gasoline use and reduce emissions (produced by the car; not by the electric power plant).  Letting you recharge the battery overnight in a standard 120V outlet.  In a slightly shorter time with a 240 volt outlet.  And quicker still in a 480 volt outlet.  If your commute to and from work is 50 miles or less you can probably charge up at home and not have to carry a charger with you (to convert the AC power to the DC power of the batteries).  Saving even more weight.  But if you plan on charging on the road you’ll need to carry a charger with you.  Adding additional weight.  Which will, of course, reduce your battery range.  Also, you can adjust the number of batteries to match your typical daily commute.  The shorter your commute the less charge you need to store.  Which lets you get by on fewer batteries.  Greatly reducing the weight of the car (and extending your battery range).  A gallon of gas weighs about 7 pounds and can take a car 30 miles or more.  You would need about 1,000 pounds of batteries to provide a similar range.  So range doesn’t come cheap.  To maximize the benefit of a hybrid you’d want to carry the absolute minimum of batteries to serve your needs.  Knowing that if you got a new job with a longer commute you could rely on the ICE in your hybrid to get you to work and back home safe again.

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Windmills, Waterwheels, Steam Engine, Electric Power, Coal, Heat Engine, Steam Turbine, Generator and Coal-Fired Power Plant

Posted by PITHOCRATES - July 11th, 2012

Technology 101

By burning Coal to Boil Water into Steam to Move a Piston we could Build a Factory Anywhere

We created advanced civilization by harnessing energy.  And converting this energy into working power.  Our first efforts were biological.  Feeding and caring for large animals made these animals strong.  Their physiology converted food and water into strong muscles and bones.  Allowing them to pull heavy loads.  From plowing.  To heavy transportation.  To use in construction.  Of course the problem with animals is that they’re living things.  They eat and drink.  And poop and pee.  Causing a lot of pollution in and around people.  Inviting disease.

As civilization advanced we needed more energy.  And we found it in wind and water.  We built windmills and waterwheels.  To capture the energy in moving wind and moving water.  And converted this into rotational motion.  Giving us a cleaner power source than working animals.  Power that didn’t have to rest or eat.  And could run indefinitely as long as the wind blew and the water flowed.  Using belts, pulleys, cogs and gears we transferred this rotational power to a variety of work stations.  Of course the problem with wind and water is that you needed to be near wind and water.  Wind was more widely available but less reliable.  Water was more reliable but less widely available.  Each had their limitations.

The steam engine changed everything.  By burning a fuel (typically coal) to boil water into steam to move a piston we could build a factory anywhere.  Away from rivers.  And even in areas that had little wind.  The reciprocating motion of the piston turned a wheel to convert it into rotational motion.  Using belts, pulleys, cogs and gears we transferred this rotational power to a variety of work stations.  This carried us through the Industrial Revolution.  Then we came up with something better.  The electric motor.  Instead of transferring rotational motion to a workstation we put an electric motor at the work station.  And powered it with electricity.  Using electric power to produce rotational motion at the workstation.  Electricity and the electric motor changed the world just as the steam engine had changed the world earlier.  Today the two have come together.

You can tell a Power Plant uses a Scrubber by the White Steam puffing out of a Smokestack

Coal has a lot of energy in it.  When we burn it this energy is transformed into heat.  Hot heat.  For coal burns hot.  The modern coal-fired power plant is a heat engine.  It uses the heat from burning coal to boil water into steam.  And as steam expands it creates great pressure.  We can use this pressure to push a piston.  Or turn a steam turbine.  A rotational device with fins.  As the steam pushes on these fins the turbine turns.  Converting the high pressure of the steam into rotational motion.  We then couple this rotational motion of the steam turbine to a generator.  Which spins the generator to produce electricity.

Coal-fired power plants are hungry plants.  A large plant burns about 1,000 tons of coal an hour.  Or about 30,000 pounds a minute.  That’s a lot of coal.  We typically deliver coal to these plants in bulk.  Via Great Lakes freighters.  River barges.  Or unit trains.  Trains made up of nothing but coal hopper cars.  These feed coal to the power plants.  They unload and conveyor systems take this coal and create big piles.  You can see conveyors rising up from these piles of coal.  These conveyors transport this coal to silos or bunkers.  Further conveyor systems transfer the coal from these silos to the plant.  Where it is smashed and pulverized into a dust.  And then it’s blown into the firebox, mixed with hot air and ignited.  Creating enormous amounts of heat to boil an enormous amount of water.  Creating the steam to turn a turbine.

Of course, with combustion there are products left over.  Sulfur impurities in the coal create sulfur dioxide.  And as the coal burns it leaves behind ash.  A heavy ash that falls to the bottom of the firebox.  Bottom ash.  And a lighter ash that is swept away with the flue gases.  Fly ash.  Filters catch the fly ash.  And scrubbers use chemistry to remove the sulfur dioxide from the flue gases.  By using a lime slurry.  The flue gases rise through a falling mist of lime slurry.  They chemically react and create calcium sulfate.  Or Gypsum.  The same stuff we use to make drywall out of.  You can tell a power plant uses a scrubby by the white steam puffing out of a smokestack.  If you see great plumes puffing out of a smokestack there’s little pollution entering the atmosphere.  A smokestack that isn’t puffing out a plume of white steam is probably spewing pollution into the atmosphere.

Coal is a Highly Concentrated Source of Energy making Coal King when it comes to Electricity

When the steam exits the turbines it enters a condenser.  Which cools it and lowers its temperature and pressure.  Turning the steam back into water.  It’s treated then sent back to the boiler.  However, getting the water back into the boiler is easier said than done.  The coal heats the water into a high pressure steam.  So high that it’s hard for anything to enter the boiler.  So this requires a very powerful pump to overcome that pressure.  In fact, this pump is the biggest pump in the plant.  Powered by electric power.  Or steam.  Sucking some 2-3 percent of the power the plant generates.

Coupled to the steam turbine is a power plant’s purpose.  Generators.  Everything in a power plant serves but one purpose.  To spin these generators.  And when they spin they generate a lot of power.  Producing some 40,000 amps at 10,000 to 30,000 volts at a typical large plant.  Multiplying current by power and you get some 1,200 MW of power.  Which can feed a lot of homes with 100 amp, 240 volt services.  Some 50,000 with every last amp used in their service.  Or more than twice this number under typical loads.  Add a few boilers (and turbine and generator sets) and one plant can power every house and business across large geographic areas in a state.  Something no solar array or wind farm can do.  Which is why about half of all electricity produced in the U.S. is generated by coal-fired power plants.

Coal is a highly concentrated source of energy.  A little of it goes a long way.  And a lot of it produces enormous amounts of electric power.  Making coal king when it comes to electricity.  There is nothing that can match the economics and the logistics of using coal.  Thanks to fracking, though, natural gas is coming down in price.  It can burn cleaner.  And perhaps its greatest advantage over coal is that we can bring a gas-fired plant on line in a fraction amount of the time it takes to bring a coal-fired plant on line.  For coal-fired plants are heat engines that boil water into steam to spin turbines.  Whereas gas-fired plants use the products of combustion to spin their turbines.  Utilities typically use a combination of coal-fired and gas-fired plants.  The coal-fired plants run all of the time and provide the base load.  When demand peaks (when everyone turns on their air conditioners in the evening) the gas-fired plants are brought on line to meet this peak demand.

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