Electricity, Heat Engine, Superheated Dry Steam, Coal-Fired Power Plant, Geothermal Power Plant and Waste-to-Energy Plant

Posted by PITHOCRATES - November 7th, 2012

Technology 101

(Originally published August 1, 2012)

Geothermal Power Plants and Waste-to-Energy Plants each produce less than Half of 1% of our Electricity

We produce the majority of our electricity with heat engines.  Where we boil water into steam to spin a turbine.  Or use the expanding gases of combustion to spin a turbine.  The primary heat engines we use are coal-fired power plants, natural gas-power plants and nuclear power plants.  The next big source of electricity generation is hydroelectric.  A renewable energy source.  In 2011 it produced less than 8% of our electricity.  These sources combined produce in excess of 95% of all electricity.  While renewable energy sources (other than hydroelectric) make up a very small percentage of the total.  Wind power comes in under 3%.  And solar comes in at less than 0.2% of the total.  So we are a very long way from abandoning coal, natural gas and nuclear power.

Two other renewable energy sources appear to hold promise.  Two heat engines.  One powered by geothermal energy in the earth.  The other by burning our garbage.  In a waste-to-energy plant.  These appear attractive.  Geothermal power appears to be as clean as it gets.  For this heat isn’t man-made.  It’s planet-made.  And it’s just there for the taking.  But the taking of it gets a little complicated.  As is burning our trash.  Not to mention the fact that few people want trash incinerators in their neighborhoods.  For these reasons they each provide a very small percentage of the total electric power we produce.  Both coming in at less than half of 1%.

So why steam?  Why is it that we make so much of our electrical power by boiling water?  Because of the different states of matter.  Matter can be a solid, liquid or a gas.  And generally passes from one state to another in that order.  Although there are exceptions.  Such as dry ice that skips the liquid phase.  It sublimates from a solid directly into a gas.  And goes from a gas to a solid by deposition.  Water, though, follows the general rule.  Ice melts into water at 32 degrees Fahrenheit (or 0 degrees Celsius).  Or water freezes into ice at the same temperature.  Water vaporizes into steam at 212 degrees Fahrenheit (or 100 degrees Celsius).  Or steam condenses into water at the same temperature.  These changes in the state of matter are easy to produce.  At temperatures that we can easily attain.  Water is readily available to vaporize into steam.  It’s safe and easy to handle.  Making it the liquid of choice in a heat engine.

Today’s Coal-Fired Power Plant pulverizes Coal into a Dust and Blows it into the Firebox

A given amount of water will increase about 1600 times in volume when converted to steam.  It’s this expansion that we put to work.  It’s what pushed pistons in steam engines.  It’s what drove steam locomotives.  And it’s what spins the turbines in our power plants.  The plumes of steam you see is not steam, though.  What you see is water droplets in the steam.  Steam itself is an invisible gas.  And the hotter and drier (no water) it is the better.  For water droplets in steam will pit and wear the blades on a steam turbine.  Which is why the firebox of a coal-fired plant reaches temperatures up to 3,000 degrees Fahrenheit (about 1,650 degrees Celsius).  To superheat the steam.  And to use this heat elsewhere in the power plant such as preheating water entering the boiler.  So it takes less energy to vaporize it.

To get a fire that hot isn’t easy.  And you don’t get it by shoveling coal into the fire box.  Today’s coal-fired power plant pulverizes coal into a dust and blows it into the firebox.  Because small particles can burn easier and more completely than large chunks of coal.  As one fan blows in fuel another blows in air.  To help the fire burn hot.  The better and finer the fuel the better it burns.  The better the fuel burns the hotter the fire.  And the drier the steam it makes.  Which can spin a turbine with a minimum of wear.

In a geothermal power plant we pipe steam out of the ground to spin a turbine.  If it’s hot enough.  Unfortunately, there aren’t a lot of geothermal wells that produce superheated dry steam.  Which limits how many of these plants we can build.  And the steam that the planet produces is not as clean as what man produces.  Steam out of the earth can contain a lot of contaminants.  Requiring additional equipment to process these contaminants out.  We can use cooler geothermal wells that produce wet steam but they require additional equipment to remove the water from the steam.  The earth may produce heat reliably but not water.  When we pipe this steam away the wells can run dry.  So these plants require condensers to condense the used steam back into water so we can pump it back to the well.  A typical plant may have several wells piped to a common plant.  Requiring a lot of piping both for steam and condensate.  You put all this together and a geothermal plant is an expensive plant.  And it is a plant that we can build in few places.  Which explains why geothermal power makes less than half of 1% of our electricity.

We generate approximately 87% of our Electricity from Coal, Natural Gas and Nuclear Power

So these are some the problems with geothermal.  Burning trash has even more problems.  The biggest problem is that trash is a terrible fuel.  We pulverize coal into a dust and blow into the firebox.  This allows a hot and uniform fire.  Trash on the other hand contains wet mattresses, wet bags of grass, car batteries, newspapers and everything else you’ve ever thrown away.  And if you ever lit a campfire or a BBQ you know some things burn better than other things.  And wet things just don’t burn at all.  So some of this fuel entering the furnace can act like throwing water on a hot fire.  Which makes it difficult to maintain a hot and uniform fire.  They load fuel on a long, sloping grate that enters the furnace.  Mechanical agitators shake the trash down this grate slowly.  As the trash approaches the fire it heats up and dries out as much as possible before entering the fire.  Still the fire burns unevenly.  They try to keep the temperature above 1,000 degrees Fahrenheit (about 538 degrees Celsius) .  But they’re not always successful.

They can improve the quality of the fuel by processing it first.  Tearing open bags with machinery so people can hand pick through the trash.  They will remove things that won’t burn.  Then send what will burn to a shredder.  Chopping it up into smaller pieces.  This can help make for a more uniform burn.  But it adds a lot of cost.  So these plants tend to be expensive.  And nowhere as efficient as a coal-fired power plant (or nuclear power plant) in boiling water into superheated dry steam.  Also, raw trash tends to stink.  And no one really knows what’s in it when it burns.  Making people nervous about what comes out of their smoke stacks.  You add all of these things up and you see why less than half of 1% of our electricity comes from burning our trash.

This is why we generate approximately 87% of our electricity from coal, natural gas and nuclear power.  Coal and nuclear power can make some of the hottest and driest steam.  But making a hot fire or bringing a nuclear reactor on line takes time.  A lot of time.  So we use these as baseload power plants.  They generate the supply that meets the minimum demand.  Power that we use at all times.  Day or night.  Winter or summer.  They run 24/7 all year long.  Natural gas plants add to the baseload.  And handle peak demands over the baseload.  Because they don’t boil water they can come on line very quickly to pickup spikes in electrical demand.  Hydroelectric power shares this attribute, too.  As long as there is enough water in the reservoir to bring another generator on line.  The other 5% (wind, solar, geothermal, trash incinerators, etc.) is more of a novelty than serious power generation.

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Electricity, Heat Engine, Superheated Dry Steam, Coal-Fired Power Plant, Geothermal Power Plant and Waste-to-Energy Plant

Posted by PITHOCRATES - August 1st, 2012

Technology 101

Geothermal Power Plants and Waste-to-Energy Plants each produce less than Half of 1% of our Electricity

We produce the majority of our electricity with heat engines.  Where we boil water into steam to spin a turbine.  Or use the expanding gases of combustion to spin a turbine.  The primary heat engines we use are coal-fired power plants, natural gas-power plants and nuclear power plants.  The next big source of electricity generation is hydroelectric.  A renewable energy source.  In 2011 it produced less than 8% of our electricity.  These sources combined produce in excess of 95% of all electricity.  While renewable energy sources (other than hydroelectric) make up a very small percentage of the total.  Wind power comes in under 3%.  And solar comes in at less than 0.2% of the total.  So we are a very long way from abandoning coal, natural gas and nuclear power.

Two other renewable energy sources appear to hold promise.  Two heat engines.  One powered by geothermal energy in the earth.  The other by burning our garbage.  In a waste-to-energy plant.  These appear attractive.  Geothermal power appears to be as clean as it gets.  For this heat isn’t man-made.  It’s planet-made.  And it’s just there for the taking.  But the taking of it gets a little complicated.  As is burning our trash.  Not to mention the fact that few people want trash incinerators in their neighborhoods.  For these reasons they each provide a very small percentage of the total electric power we produce.  Both coming in at less than half of 1%.

So why steam?  Why is it that we make so much of our electrical power by boiling water?  Because of the different states of matter.  Matter can be a solid, liquid or a gas.  And generally passes from one state to another in that order.  Although there are exceptions.  Such as dry ice that skips the liquid phase.  It sublimates from a solid directly into a gas.  And goes from a gas to a solid by deposition.  Water, though, follows the general rule.  Ice melts into water at 32 degrees Fahrenheit (or 0 degrees Celsius).  Or water freezes into ice at the same temperature.  Water vaporizes into steam at 212 degrees Fahrenheit (or 100 degrees Celsius).  Or steam condenses into water at the same temperature.  These changes in the state of matter are easy to produce.  At temperatures that we can easily attain.  Water is readily available to vaporize into steam.  It’s safe and easy to handle.  Making it the liquid of choice in a heat engine.

Today’s Coal-Fired Power Plant pulverizes Coal into a Dust and Blows it into the Firebox

A given amount of water will increase about 1600 times in volume when converted to steam.  It’s this expansion that we put to work.  It’s what pushed pistons in steam engines.  It’s what drove steam locomotives.  And it’s what spins the turbines in our power plants.  The plumes of steam you see is not steam, though.  What you see is water droplets in the steam.  Steam itself is an invisible gas.  And the hotter and drier (no water) it is the better.  For water droplets in steam will pit and wear the blades on a steam turbine.  Which is why the firebox of a coal-fired plant reaches temperatures up to 3,000 degrees Fahrenheit (about 1,650 degrees Celsius).  To superheat the steam.  And to use this heat elsewhere in the power plant such as preheating water entering the boiler.  So it takes less energy to vaporize it.

To get a fire that hot isn’t easy.  And you don’t get it by shoveling coal into the fire box.  Today’s coal-fired power plant pulverizes coal into a dust and blows it into the firebox.  Because small particles can burn easier and more completely than large chunks of coal.  As one fan blows in fuel another blows in air.  To help the fire burn hot.  The better and finer the fuel the better it burns.  The better the fuel burns the hotter the fire.  And the drier the steam it makes.  Which can spin a turbine with a minimum of wear.

In a geothermal power plant we pipe steam out of the ground to spin a turbine.  If it’s hot enough.  Unfortunately, there aren’t a lot of geothermal wells that produce superheated dry steam.  Which limits how many of these plants we can build.  And the steam that the planet produces is not as clean as what man produces.  Steam out of the earth can contain a lot of contaminants.  Requiring additional equipment to process these contaminants out.  We can use cooler geothermal wells that produce wet steam but they require additional equipment to remove the water from the steam.  The earth may produce heat reliably but not water.  When we pipe this steam away the wells can run dry.  So these plants require condensers to condense the used steam back into water so we can pump it back to the well.  A typical plant may have several wells piped to a common plant.  Requiring a lot of piping both for steam and condensate.  You put all this together and a geothermal plant is an expensive plant.  And it is a plant that we can build in few places.  Which explains why geothermal power makes less than half of 1% of our electricity.

We generate approximately 87% of our Electricity from Coal, Natural Gas and Nuclear Power

So these are some the problems with geothermal.  Burning trash has even more problems.  The biggest problem is that trash is a terrible fuel.  We pulverize coal into a dust and blow into the firebox.  This allows a hot and uniform fire.  Trash on the other hand contains wet mattresses, wet bags of grass, car batteries, newspapers and everything else you’ve ever thrown away.  And if you ever lit a campfire or a BBQ you know some things burn better than other things.  And wet things just don’t burn at all.  So some of this fuel entering the furnace can act like throwing water on a hot fire.  Which makes it difficult to maintain a hot and uniform fire.  They load fuel on a long, sloping grate that enters the furnace.  Mechanical agitators shake the trash down this grate slowly.  As the trash approaches the fire it heats up and dries out as much as possible before entering the fire.  Still the fire burns unevenly.  They try to keep the temperature above 1,000 degrees Fahrenheit (about 538 degrees Celsius) .  But they’re not always successful.

They can improve the quality of the fuel by processing it first.  Tearing open bags with machinery so people can hand pick through the trash.  They will remove things that won’t burn.  Then send what will burn to a shredder.  Chopping it up into smaller pieces.  This can help make for a more uniform burn.  But it adds a lot of cost.  So these plants tend to be expensive.  And nowhere as efficient as a coal-fired power plant (or nuclear power plant) in boiling water into superheated dry steam.  Also, raw trash tends to stink.  And no one really knows what’s in it when it burns.  Making people nervous about what comes out of their smoke stacks.  You add all of these things up and you see why less than half of 1% of our electricity comes from burning our trash.

This is why we generate approximately 87% of our electricity from coal, natural gas and nuclear power.  Coal and nuclear power can make some of the hottest and driest steam.  But making a hot fire or bringing a nuclear reactor on line takes time.  A lot of time.  So we use these as baseload power plants.  They generate the supply that meets the minimum demand.  Power that we use at all times.  Day or night.  Winter or summer.  They run 24/7 all year long.  Natural gas plants add to the baseload.  And handle peak demands over the baseload.  Because they don’t boil water they can come on line very quickly to pickup spikes in electrical demand.  Hydroelectric power shares this attribute, too.  As long as there is enough water in the reservoir to bring another generator on line.  The other 5% (wind, solar, geothermal, trash incinerators, etc.) is more of a novelty than serious power generation.

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Flint Tools, Levers, Wheels, Animal Power, Water Power, Wind Power, Steam Power, Electrical Power, Nuclear Power and Solar Power

Posted by PITHOCRATES - February 22nd, 2012

Technology 101

Man harnessed the Energy in Moving Water with a Water Wheel

When prehistoric man first chipped a piece of flint to make a sharp edge he learned something.  It made work easier.  And his life better.  This tool concentrated his energy into that sharp edge.  Increasing the amount of energy he could put to work.  Allowing him to skin an animal quickly and efficiently like never before.  Making better hides to protect him from the elements.  Yes, he said, this tool is good.  But in a somewhat less sophisticated manner of speech.

From that moment forward it has been man’s singular desire to improve on this first tool.  To find ways to concentrate energy and put it to work.  Levers allowed him to move heavier things.  Wheels allowed him to move heavier loads.  The block and tackle allowed him to lift or pull heavier weights.  Harnessing animals allowed him to do all of these things even better.  And we would use animal power for millennia.  Even today they still provide the primary source of power for some less developed countries.

But animals have their limitations.  They’re big, they eat, drink, pee and poop.  Which doesn’t make them an ideal source of power to turn a mill wheel.  A big wheel that grinds grain into flour.  It’s heavy.  But it doesn’t have to spin fast.  Just for long periods of time.  Then man had another moment like he did when he chipped a piece of flint.  He noticed in his environment that things moved.  The wind.  And the water in a river.  The wind could blow fast or slow.  Or not at all.  But the water flow was steady.  And reliable.  So man harnessed the energy in the moving water with a water wheel.  And connected it to his mill wheel via some belts and pulleys.  And where there was no water available he harnessed the less reliable wind.

The Steam Engine eliminated the Major Drawbacks of Water Power and Wind Power 

The water flowed day and night.  You didn’t have to feed it or clean up after it.  And a strong current had a lot of concentrated energy.  Which could do a lot of work.  Far more than a sharpened piece of flint.  Which was ideal for our first factories.  The water wheel shaft became a main drive shaft that drove other machines via belts and pulleys.  The main drive shaft ran the length of the factory.  Workers could operate machinery underneath it by engaging it to the main drive shaft through a belt and pulley.  Take a trip to the past and visit a working apple mill powered by a water wheel.  It’s fascinating.  And you’ll be able to enjoy some fresh donuts and hot cider.  During the harvest, of course.

While we built factories along rivers we used that other less reliable source of energy to cross oceans.  Wind power.  It wasn’t very reliable.  And it wasn’t very concentrated.  But it was the only way you could cross an ocean.  Which made it the best way to cross an ocean.  Sailors used everything on a sailing ship from the deck up to catch the wind and put it to work.  Masts, rigging and sails.  Which were costly.  Required a large crew.  And took up a lot of space and added a lot of weight.  Space and weight that displaced revenue-earning cargo.

The steam engine eliminated the major drawbacks of water power and wind power.  By replacing the water wheel with a steam engine we could build factories anywhere.  Not just on rivers.  And the steam engine let ships cross the oceans whenever they wanted to.  Even when the wind didn’t blow.  And more space was available for revenue-earning cargo.  When these ships reached land we transferred their cargoes to trains.  Pulled by steam locomotives.  That could carry this revenue-earning cargo across continents.   This was a huge step forward.  Boiling water by burning coal to make steam.  A highly concentrated energy source.  A little of it went a long way.  And did more work for us than ever.  Far more than a water wheel.  It increased the amount of work we could do so much that it kicked off the Industrial Revolution.

With Nuclear Power our Quest to find more Concentrated Forms of Energy came to an End 

We replaced coal with oil in our ships and locomotives.  Because it was easier to transport.  Store.  And didn’t need people to shovel it into a boiler.  Oil burners were more efficient.  We even used it to generate a new source of power.  Electrical power.  We used it to boil water at electrical generating plants to spin turbines that turned electrical generators.  We could run pipelines to feed these plants.  Making the electricity they generated even more efficient.  And reliable.  Soon diesel engines replaced the oil burners in ships and trains.  Allowed trucks and buses to run where the trains didn’t.  And gasoline allowed people to go anywhere the trains and buses didn’t go.

The modern economy ran on petroleum.  And electricity.  We even returned to the water wheel to generate electricity.  By building dams to build huge reservoirs of water at elevations.  Creating huge headwater forces.  Concentrating more energy in water.  Which we funneled down to the lower elevation.  Making it flow through high-speed water turbines connected to electrical generators.  That spun far faster than their water wheel ancestors.  Producing huge amounts of reliable electrical power.  We even came up with a more reliable means to create electrical power.  With an even more concentrated fuel.  Fissile material gave us nuclear power.  During the oil shocks of the Seventies the Japanese made a policy change to expand their use of nuclear power.  To insulate them from future oil supply shocks.  Which it did.  While in America the movie The China Syndrome came out around the time of the incident at Three Mile Island.  And killed nuclear power in America.  (But as a consolation prize we disproved the idea of Keynesian stimulus.  When the government created massive inflation with Keynesian policy.  Printing money.  Which raised prices without providing any new economic activity.  Causing instead high inflation and high unemployment.  What we call stagflation.  The Japanese got a big Keynesian lesson about a decade later.  When their massive asset bubble began to deflate giving them their Lost Decade.)

And with nuclear power that quest to find more ways to make better and more efficient use of concentrated energy from that first day we used a flint tool came to an end.  Global warming alarmists are killing sensible sources of energy that have given us the modern world.  Even animal rights activists are fighting against one of the cleanest sources of power we’ve ever used.  Water power.  Because damming rivers harms ecosystems in the rivers we dam.  Instead political pressures have turned the hands of time backwards by using less concentrated and less efficient sources of energy.  Wind power.  And solar power.  Requiring far greater infrastructure installations to capture far less amounts of energy from these sources.  Power plants using wind power and solar power will require acres of land for windmills and solar panels.  And it will take many of these power plants to produce what a single power plant using coal, oil, natural gas or fissile material can generate.  Making power more costly than it ever has been.  Despite wind and sunshine being free.  And when the great civilizations become bankrupt chasing bankrupt energy policies we will return to a simpler world.  A world where we don’t make and use power.  Or machinery.  Much like our flint-tool using ancestors.  Albeit with a more sophisticated way of expressing ourselves.

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