Nuclear Power is Green but Governments prefer Wind Power because its More Costly

Posted by PITHOCRATES - November 30th, 2013

Week in Review

To save the world from global warming we have to go to a low-carbon energy economy.  Say goodbye to coal.  And hello to solar.  And wind (see Energy firm RWE npower axes £4bn UK windfarm amid political uncertainty by Terry Macalister posted 11/25/2013 on The Telegraph).

Britain’s green ambitions have been dealt a blow as a big six energy company has pulled the plug on one of the world’s largest offshore windfarms, with the political storm enveloping the industry threatening the multibillion-pound investments needed to meet emissions targets and head off a looming capacity crunch.

Weeks after warning that the government was treating environmental subsidies as a “political football”, the German-owned RWE npower is pulling out of the £4bn Atlantic Array project in the Bristol Channel because the economics do not stack up.

The move comes as figures show that energy firms reaped a 77% increase in profits per customer last year, due to bill increases that the big six say are partly due to government green levies…

The Renewable Energy Association (REA), which lobbies for more low-carbon power, said government infighting over subsidies was causing deep uncertainty in the industry…

“We need assurances from George Osborne in the autumn statement about where we stand,” said a spokesman for the REA. “Nick Clegg says one thing about the green levies, Michael Fallon [the energy minister] another…”

RWE indicated that the government might have to raise green subsidies – and thus increase bills or the burden on the taxpayer – after admitting that technical difficulties had pushed the price up so far that it could not be justified under the current subsidy regime.

But RWE has already pulled out of a £350m nuclear-power project, is selling its DEA North Sea oil business and last week disposed of part of its UK gas and electricity supply arm. Developers have been warning for some time that they would need more subsidies from the government if ministers were to realise low-carbon energy targets.

RWE was in partnership to build that nuclear project.  Which cost in total £696m.  Or 17% of the cost of the £4bn Atlantic Array project in the Bristol Channel.  Which they say will power one million homes.  Of course, that would be only when the wind is blowing.  But not blowing too fast.  For there is a small window for safe wind speeds these turbines can generate power at.  Giving them a low capacity factor (the amount of power they could produce over a period of time at full nameplate capacity and the actual power they produced over that period).  About 30% in Britain.  Whereas nuclear power is about 90%.  Which is why we use it for baseload power.  Because it’s always there.  Even when the wind is blowing too slow.  Or too fast.  So that Atlantic Array wasn’t going to provide reliable power for a million homes.  In fact, on a calm day it will provide no power to any home.  Which begs the question why spend £4bn for unreliable power when you can spend £696m for reliable power?

Worse, wind power requires government subsidies.  So much that companies won’t build wind farms unless they get government subsidies.  Something you don’t need to build a nuclear power plant.  And to rub salt in an open wound those subsidies are paid for with levies on the family utility bill.  Or higher taxes.  Forcing these families to get by on less.  While these green energy firms are seeing rising profits.  Because of the money the government takes from the households and gives to the green energy firms in the form of subsidies.  Which begs another question.  Why charge the British people so much more for clean energy when they can get it for far less from nuclear power?  At 17% of the cost for the Atlantic Array project?

When it comes down to it renewable energy is crony capitalism at its worst.  Huge transfers of money from the private sector to the public sector.  Where they turn around and give to their friends in green energy companies in the form of lucrative contracts and fat subsidies.  After taking some off the top for their expenses, of course.  If it wasn’t they’d be building less costly and more reliable nuclear power plants to be green.  Instead of building these green elephants all over the place.

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After Fukushima Meltdown shuts down Nuclear Power Industry Japan turns to Solar Power

Posted by PITHOCRATES - November 10th, 2013

Week in Review

Japan shows how easy it is to go green after the Fukushima Nuclear Power Plant meltdown.  Nuclear power is unsafe.  Coal-fired power plants are too dirty.  So what to do?  Why, go solar, of course (see Kyocera launches 70-megawatt solar plant, largest in Japan by Tim Hornyak posted 11/8/2013 on CNET).

Smartphone maker Kyocera recently launched the Kagoshima Nanatsujima Mega Solar Power Plant, a 70-megawatt facility that can generate enough electricity to power about 22,000 homes.

The move comes as Japan struggles with energy sources as nuclear power plants were shut down after meltdowns hit Tokyo Electric Power Co.’s Fukushima plant in 2011.

Set on Kagoshima Bay, the sprawling Nanatsujima plant commands sweeping views of Sakurajima, an active stratovolcano that soars to 3,665 feet.

It has 290,000 solar panels and takes up about 314 acres, roughly three times the total area of Vatican City.

Wow, 70 megawatts.  Sounds big, doesn’t it?  With 290,000 solar panels on 314 acres.  An installed capacity of 0.22 megawatts per acre.  It must have cost a fortune to build.  And they built it on a bay.  At sea level.  In the shadow of an active volcano.  It would be a shame if that volcano erupts and covers those solar panels in a layer of ash.  Or if another typhoon hits Japan.  An earthquake.  Or a storm surge.  For if any of these things happen those 22,000 homes will lose their electric power.

So how does this compare to the Fukushima Daiichi Nuclear Power Plant?  Well, that plant sits on 860 acres.  And has an installed capacity of 4700 megawatts.  Or the installed capacity of 67 Kagoshima Nanatsujima Mega Solar Power Plants.  And an installed capacity of 5.47 megawatts per acre.  Which is perhaps why they built this on the bay.  Because it is such an inefficient use of real estate in a nation that has one of the highest population densities that they put it on the water.  To save the land for something that has value. 

We used the term ‘installed capacity’ for a reason.  That reason being the capacity factor.  Which is the actual amount of power produced over a given amount of time divided by the maximum amount of power that could have been produced (i.e., the installed capacity).  Nuclear plants can produce power day or night.  Covered in volcanic ash or not.  On a sunny day or when it’s pouring rain.  Which is why a nuclear power plant has a much higher capacity factor (about 90%) than a solar plant (about 15%).  So the actual power people consume from the Kagoshima Nanatsujima Mega Solar Power Plant will be far less than its 70 megawatts of installed capacity.

So in other words, solar power is not a replacement for nuclear power.  Or any other baseload power such as coal-fired power plants.  Power demand will far exceed power supply.  Leading to higher costs as they try to ration electric power.  And a lot of power outages.  Some longer than others.  Especially when powerful typhoons and/or storm surges blow in.  As they often do in the Pacific Ocean.

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A Renewable Boom means more Expensive and Less Reliable Electric Power

Posted by PITHOCRATES - October 20th, 2013

Week in Review

The news on our green energy initiatives sounds good.  We’re importing less oil.  And adding more and more wind power.  If you’re a proponent of green energy you no doubt are pleased by this news.  But if you understand energy and economics it’s a different story.  You’ll think the country is moving in the wrong direction.  Ultimately raising our energy costs.  Without making much of an impact on carbon emissions.  And just because we are exporting gasoline doesn’t mean we’re on the road to being energy self-sufficient (see The Renewable Boom by Bryan Walsh posted 10/11/2013 on Time).

Earlier this year, the U.S. became a net exporter of oil distillates, and the International Energy Agency projects that the U.S. could be almost energy self-sufficient in net terms by 2035.

This is not necessarily a good thing.  Being a net exporter of oil distillates.  It means that US supply exceeds US demand at the current market price.  That’s an important point.  The current market price.  The US has been in an anemic economic recovery—though some would say we’re still in a recession—since President Obama assumed office.  During bad economic times people lose their jobs.  Those who haven’t are worried about losing theirs.  And they worry about the uncertainty, too, about the cost of Obamacare.  So people are driving less.  And they are spending less.  Because they have less.  And worry about how much money they’ll need under Obamacare.  So they’re not taking the family on a cross-country vacation.  Some are even spending their vacation in the backyard.  The so called ‘staycation’.  No doubt the 10 million or so who disappeared from the labor force since President Obama assumed office aren’t driving much these days.  So because of this US demand for gasoline is down.  And, hence, prices.   Even though gasoline prices are still high and consuming an ever larger part of our reduced median family income (also down since President assumed office), gasoline prices are higher elsewhere.  Which is why refineries are exporting their oil distillates.  To meet that higher demand that has raised the market price.

But the biggest source of new electricity in the U.S. last year wasn’t a fossil fuel. It was the humble wind. More than 13 gigawatts of new wind potential were added to the grid in 2012, accounting for 43% of all new generation capacity. Total wind-power capacity exceeded 60 gigawatts by the end of 2012—enough to power 15 million homes when the breeze is blowing.

These numbers do sound big for wind.  Like it’s easy sailing for wind power to replace coal.  But is it?  Let’s look at the big picture.  In 2011 the total nameplate capacity of all electric power generation was 1,153.149 gigawatts.  So that 13 gigawatts though sounding like a lot of power it is only 1.127% of the total nameplate capacity.  Small enough to be rounding error.  In other words, that 13 gigawatts is such a small amount of power that it won’t even be seen by the electric grid.  But it gets even worse.

We used the term ‘nameplate capacity’ for a reason.  This is the amount of power that this unit is capable of producing.  Not what it actually produces.  In fact, we have a measure comparing the power generation possible to the ‘actual’ power generation.  The capacity factor.  Which measures power production over a period of time and divides it by the total amount of power that the unit could have produced (i.e., its nameplate value).  Coal has a higher capacity factor than wind because coal can produce electric power in all wind conditions.  While wind power cannot.  If the winds are too strong the wind turbines lock down to protect themselves.  If the wind is blowing too slowly they won’t produce any electric power.

The typical capacity factor for coal is 62.3%.  Meaning that over half of the installed capacity is generating power.  Some generators may be down for maintenance.  Or a generator may be shut down due to weak demand.  The typical capacity factor for wind power is 30%.  Meaning that the installed capacity produces no power 70% of the time.  And it’s not because turbines are down for maintenance.  It’s because of the intermittent wind.

So coal has twice the capacity that wind has.  Does this mean we need twice the installed capacity of wind to match coal?  No.  Because if you tripled the number of wind turbines in a wind farm they will still produce no power if the wind isn’t blowing.  In this respect you can say coal has a capacity factor of 100%.  For if they want more power from a coal-fired power plant they can bring another generator on line.  Even if the wind isn’t blowing.

You could say wind power is like parsley on a plate in a restaurant.  It’s just a garnishment.  It makes our electric power production look more environmentally friendly but it just adds cost and often times we just throw it away.  For if coal provides all our power needs when the wind isn’t blowing and the wind then starts blowing you have a surplus of power that you can’t sell.  You can’t shut down the coal-fired power plant because the wind turbines don’t produce enough to replace it.  You can’t shut down the wind turbines because it defeats the purpose of having them.  So you just throw away the surplus power.  And charge people more for their electric power to cover this waste.  Like a restaurant charges more for its menu items to cover the cost of the parsley the people throw away.

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Wind Turbines versus a Coal-Fired Power Plant

Posted by PITHOCRATES - August 26th, 2013

Economics 101

The Diameter of a 6 Megawatt 3-Blade Rotor is Greater than two 747-400s parked Wingtip to Wingtip

One of the largest coal-fired power plants in the world is in Macon, Georgia.  Plant Scherer.  Whose furnaces consume some 31,000 tons of coal a day.  Producing 3,500 megawatts of electric power.  Enough to power three good sized American cities.  A few million households.

One of the largest offshore wind turbines available on the market is 6 megawatt.  Which is huge.  One blade can be as long as 250 feet.  A typical 3-blade rotor can have a diameter of just over 500 feet.  To get a feel of this magnitude the wingspan of the world’s most common jumbo jet, the Boeing 747-400, is about 211 feet.  Which means one blade of a 6 megawatt wind turbine is longer than the wingspan of a Boeing 747-400.  And the diameter of a 3-blade rotor is greater than two 747-400s parked wingtip to wingtip.

A 6 megawatt wind turbine requires a tower of about 300 feet tall.  So the blades can spin without hitting the ground.  Which is about the same height of a 20 story building.  And if it’s an offshore turbine you can add another 2 stories or so for the tower below the surface of the water.  So these things are big.  And tall.  Some of the largest manmade machines built.  And some of the most costly.  It takes a huge investment to install a 6 megawatt wind turbine.  That can only produce 0.171% of the electric power that Plant Scherer can produce.

There is a Small Window of Wind Velocities that we can use to Generate Electric Power with Wind Turbines

So how many 6 megawatt turbines does it take to match the power output of Plant Scherer?  Well, to match the nameplate capacity you’ll need about 584 turbines.  If we install these offshore in a line that line would extend some 56 miles.  About an hour’s drive time at 55 mph.  Which is a very long line of very large and very costly wind turbines.

We said ‘nameplate capacity’ for a reason.  If 584 wind turbines were spinning in the right kind of wind they could match the output of Plant Scherer.  And what is the right kind of wind?  Not too slow.  And not too fast.  These turbines have gear boxes to speed up the rotational speed of the rotors.  And they vary the pitch of the blades on the rotors.  So the turbine can keep a constant rotational input to the electric generator.  If the wind is blowing slower than optimum the blades can catch more air to spin faster.  If the wind is blowing pretty strong the blades will turn to catch less air to spin slower.

In other words, there is a small window of wind velocities that we can use to generate electric power with wind turbines.  Too slow or no wind at all they produce no power.  If the wind is too great the blades turn parallel to the wind.  So the wind blows across the blades without turning them.  They also have brakes to lock down the rotors in very high winds to prevent any damage.  So if a storm blows through 584 offshore turbines they’ll produce no electric power.  Which means they can’t replace a Plant Scherer.  They can only operate with a Plant Scherer in backup.  To provide power then the winds just aren’t right.

The more Wind Turbines we install the more Costly our Electric Power Gets

Now back to that nameplate capacity.  This is the amount of power a power plant could produce.  It doesn’t mean what it will produce.  The capacity factor divides actual power produced over a period of time with the maximum amount of power that could have been produced.  A coal-fired power plant has a higher capacity factor than a wind turbine.  Because they can produce electricity pretty much whenever we want them to.  While a wind turbine can only produce electricity when the winds are blowing not too slow and not too fast.

So, if the winds aren’t blowing, or if they’re blowing too strongly, it is as if those wind turbines aren’t there.  Which means something else must be there.  Something more reliable.  Something that isn’t weather-dependent.  Such as a Plant Scherer.  In other words, even if we installed 584 turbines to match the output of Plant Scherer we could never get rid of Plant Scherer.  Because there will be times when those windmills will produce no power.  Requiring Plant Scherer to produce power as if we never had installed those wind turbines.  And because it takes time to bring a coal-fired power plant on line it has to keep burning coal even when the wind turbines are providing power.  So it can be ready to provide power when the windmills stop spinning.

Wind may be free but 584 wind turbines cost a fortune to install.  And this investment is in addition to the cost of building, maintaining and operating a coal-fired power plant like Plant Scherer.  All of which the consumer has to pay for.  Either in their electric bill (adding a surcharge for ‘clean energy investments’).  Or in higher taxes (property tax, income tax, etc.) that pays for renewable energy grants and subsidies.  Which means the more wind turbines we build the poorer we get.  Because we have duplicate power generation capacity when a single power plant could have sufficed.

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Solar Power grows at 76% Annual Growth but you wouldn’t know it by the Power it Adds to the Grid

Posted by PITHOCRATES - March 16th, 2013

Week in Review

The government subsidized solar power industry is growing like gangbusters.  Thanks to all those government subsidies.  For it appears if it weren’t for that there would be no solar power industry.  Except in space.  Where it is the best choice.  But here on earth?  It just doesn’t work that well (see U.S. Solar Market Grew 76% in 2012 by Ucilia Wang posted 3/14/2013 on Forbes).

Imagine 16 million solar panels blanketing large pieces of land and covering roofs of homes and businesses. That was the number installed in the United States in 2012, when 3.3 gigawatts of the solar equipment materialized to representing a 76% annual growth.

Cumulatively, the country had about 7.2 gigawatts of solar generation capacity from solar panels by the end of 2012, according to a report by GTM Research the Solar Energy Industries Association. That capacity doesn’t mean consumers could tap that much power from solar power projects. The amount of production depends on whether the sun is up and unobstructed by clouds.

So how much useable power do we get from that installed 7.2 gigawatts?  Well, to determine that we must look at the capacity factor.  Which is the ratio of actual power to potential power over a period of time.  According to the Carnegie Mellon Electricity Industry Center they calculated the capacity factor for a solar array in Arizona.  A pretty sunny place.  They found the capacity factor to be 19%.  So if we use that we can calculate the useable power from that installed 7.2 gigawatts.  Which comes to approximately 1.4 gigawatts (0.19 X 7.2 gigawatts).  Now, assuming a house with a 200-amp, 240-volt service uses about 30 amps on average over a period of time that 1.4 gigawatts could power maybe 190,000 homes.  Of course, this power can only go to the grid when the sun is shining.  And in Arizona that means the air conditioners are running at maximum capacity.  So if we assume these houses are consuming 100 amps on average when the sun is shining this 1.4 gigawatts may only power 57,000 homes.

The U.S. is one of the fast-growing solar energy markets in the world, thanks in part to the generous federal tax benefits, loans and grants to support solar technology development and deployment. On top of that, over half of the states require their utilities to sell an increasing amount of renewable electricity.

The declining prices for solar panels in recent years have helped to make them more attractive. The fall — 28% for wholesale silicon solar panel prices — came largely as a result of a global oversupply of solar panels and a fierce competition. While project developers and consumers benefit from the lower prices, dozens of manufacturers have filed for bankruptcy or needed financial rescues to stay alive.

According to the U.S. Census there were 132,312,404 housing units in 2011.  So that massive investment in government subsidized solar power can at best in the southern United States (where it is very sunny) power only 0.043% of the houses in the country.  While providing no power for our businesses or institutions.  Or our street lighting.  Which, of course, it can’t.  As the streetlights only come on when solar power doesn’t work.  When it’s dark.  Because the sun isn’t shining.

Which explains why solar power is so heavily subsidized by government.  Because it is so bad an alternative to coal-fired power plants that no private investors will provide the financing for these boondoggles.  Which is typical for any government investment.  For if there were any value in it private investors would be pouring money into it.  But they’re not.  Because solar power is a bad investment.  For it is such a poor producer of energy.  It has its applications.  Such as in space.  Where it is a cheaper alternative than running power lines to the International Space Station from a coal-fired power plant on earth.  But back on terra firma we are far better off running power lines from coal-fired power plants than from solar arrays.  Because coal is good.  Coal is right.  Coal works.  All of the time.  Even when the sun isn’t shining.

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Wind Power Expansion Reliant on Market Forces now so there probably won’t be Much More of It

Posted by PITHOCRATES - November 17th, 2012

Week in Review

The wind power market is slowing down.  Not that there was ever a wind power market.  The only way wind power has grown has been with massive taxpayer subsidies.  But as economies wallow in stagnant economic growth those subsidies are starting to dry up.  And with it the expansion of wind power in nations across the world (see Wind Power Market to Slow on EU, U.S., China Hurdles, Lobby Says by Alex Morales posted 11/14/2012 on Bloomberg).

Wind farm growth is set to slow as limits on capacity in China’s grid, falling carbon prices in Europe and a lack of direction in U.S. government policy hamper demand in major markets, the Global Wind Energy Council said.

Turbine capacity of 586,729 megawatts will be installed by 2020, from 237,699 megawatts in 2011, the Brussels-based lobby said today in an e-mailed report co-authored by environmental campaigner Greenpeace. They see annual investment of 45 billion euros ($57 billion) in 2020, down from 50 billion euros in 2011. The figure is equivalent to annual capacity growth of less than 11 percent, down from 28 percent for the 15 years through 2011…

Chinese growth in the past few years has outstripped the ability of the country’s power grid to absorb new generating capacity. In the U.S., the industry has been hobbled by the government’s failure to extend a tax credit that expires at the end of this year, and in Europe carbon prices this year have reached all-time lows, reducing the incentive to cut emissions.

The report took as its central scenario a “new policies” pathway outlined by the Paris-based International Energy Agency. Using that scenario, Greenpeace and GWEC said installations in China, slowing because of constraints in the power grid, will climb more than 180 percent to 179,498 megawatts in 2020.

Wind capacity in the 27-nation European Union will rise 120 percent to 207,246 megawatts, and North America will gain 130 percent to 121,238 megawatts. African installations will surge fivefold to 5,372 megawatts, Latin America almost triple, and Indian installations double, according to the scenario.

Let’s look at some of these numbers.  And note the units.  Annual investment in wind power is falling to $57 billion a year.  For what?  To bring installed wind turbine capacity up to 586,729 megawatts worldwide.  That’s a lot of money for not a lot of power.  As a percentage of total installed capacity that comes to about 11% for North America, 25% for China and 27% of the EU.  Sounds like it will make a difference.  And it will.  But not in a good way.

The power wind power is replacing is basically coal-fired power plants.  Which are on all of the time.  Having capacity factors reaching and exceeding 90%.  Meaning that over a given period of time 90% or more of that installed capacity will be on line producing useable electric power.  Why?  Because coal will burn all of the time.  Something wind can’t do.  Blow all of the time.  And when it blows it doesn’t always blow at the right wind speed.  Which is why the capacity factor for wind power is much lower.  About 25%.  So if you convert the wind power to equivalent coal power the installed wind turbine capacities fall.  From 121,238 megawatts in North America to about 30.3 megawatts (or about 2.7% of the total installed capacity).  From 179,498 megawatts in China to about 44.8 megawatts (or about 6.2% of total installed capacity).  And from 207,246 megawatts to about 51.8 megawatts in the EU (or about 6.8% of the total installed capacity).  Which is a lot less power for the investment.

This is why wind power is not economically viable.  And can only exist with taxpayer subsidies.  And adding a tax to the more reliable and more plentiful power sources.  Such as coal.  As in carbon prices coal-fired power plants have to pay.  A cost that they add to our electric bills.  And why are carbon prices falling in Europe?  Because the economy is so poor that there is a low demand for electric power.  In part due to the EU’s green policies that hinder economic growth.  By raising the cost of doing business.

So what will green energy do for us?  It will raise the cost of our electric power.  And make that electric power less reliable.  Making rolling blackouts a common occurrence.  Even though we’re paying more for electric power.  That is what green energy will do for us.

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The Government provides more Solar Power Subsidies to Encourage Bad Investments into Solar Power

Posted by PITHOCRATES - October 14th, 2012

Week in Review

When it comes to electric power the smart money is on coal.  So of course our government chooses solar (see US gov’t sets aside 285,000 acres for solar, wind development posted 10/12/2012 on EDI).

The US government has finalized a plan to encourage new solar-energy projects on federal lands in several western states. The area covered by the new agreement is 285,000 acres, consisting of seventeen “solar energy zones.” considered to be the best locations for solar development…

The Obama administration has authorized the development of 10,000 megawatts of solar, wind and geothermal projects. These would provide enough energy to power more than 3.5 million homes, said Salazar. According to Salazar, solar and wind energy production has doubled since Obama took office.

You know what the federal government doesn’t have to encourage?  The building of coal-fired power plants.  In fact, the demand for the electric power a coal-fired power plant produces is so great that the government has to increase the cost of building and operating them to discourage people from building them.  Why?  To please President Obama’s liberal, environmental base.  Which includes a lot of wealthy donors.  The environmentalists don’t like coal or the cheap and reliable electric power it produces.  So they attack coal.  And encourage government to subsidize solar power.  Because solar power is not cheap or reliable like the electric power produced by coal-fired power plants.  Which is why no one will build a solar power plant without massive government subsidies.

Power plants have capacity factors.  Which we calculate by dividing actual power produced by the maximum possible power a power plant can produce over a period of time.  A typical capacity factor for a coal-fired plant is approximately 90%.  Because all you need is fuel.  Unlike a solar power plant.  Which has a capacity factor of approximately 20%.  The reason why it’s so much lower than a coal-fired power plant is that solar power plants turn off every evening at dusk and turn back on at dawn.  Something you don’t have to do with coal.  Because you can burn coal all day long.  Even at night.  Which is when we use electric power the most.  To light our homes.  To run our air conditioners after work.  To power our televisions we watch after dinner.

So 10,000 megawatts is not likely to power 3.5 million homes.  Especially at night.  Unless they build a very expensive energy storage system to store the electric power they make during the day to use at night.  As long as no one needs any electric power during the day.  As you can see solar power is not what the government thinks it is.  It’s a novelty at best.  That is very, very expensive despite sunlight being free.  Why is it so expensive?  Because that 285,000 acres needs to be covered with solar panels.  And for this power to be useful at night there’s that aforementioned energy storage system.  All of this to provide what a coal-fired power plant can produce with about 30% the installed capacity of the solar power plant.  Which makes the logical and rational choice coal.  Not solar.  Yet our government chooses solar over coal.  Which tells us what?  Our government is neither logical nor rational.

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Ontario to add Solar Power Plant to Electric Grid that will Power up to 180 Homes

Posted by PITHOCRATES - September 1st, 2012

Week in Review

Ontario is going green.  They’re shutting down parts of one of the largest coal-fired power plants in North America.  Nanticoke Generating Station.  Refitting this plant to burn natural gas and biomass.  But the ‘feeling good’ doesn’t end there.  They are also installing solar power plants.  To feel even better about their part in saving the planet (see Canadian Solar sells solar power plant for $48 million posted 8/27/2012 on EDI).

Canadian Solar Inc. has sold a utility-scale solar power plant to Stonepeak Infrastructure Partners for approximately $48 million. Canadian Solar was the developer, EPC and construction financier for the project. The solar power plant can provide enough renewable energy to power more than 1,200 homes in eastern Ontario near the town of Napanee.

Assuming each house has an electric service of 100 amps at 240 volts that comes to about 28.8 megawatts.  With a capacity factor (actual power output divided by nameplate rating over a period of time) of 15% for solar power that plant will produce only about 4.32 megawatts of useable power.  Which reduces the number of homes it will be able to power from 1,200 to 180.  For no matter how many solar modules you install in a power plant none of them will produce power when the sun doesn’t shine.  Such as during the night.  On cloudy days.  Rainy days.  Snowy days.  Or days with lots of birds pooping on the solar modules.

Now compare that to the Nanticoke Generating Station in Nanticoke, Ontario.  A coal-fired power plant that could produce 3,964 megawatts with all of its units fired.  With a capacity factor of about 90% for coal (they only shut down for periodic maintenance) that comes to 3,324.6 megawatts of useful, dependable power.  Power that will always be there to light your home.  Cook your food.  Run your air conditioner.  And power any of your home medical devices.

The 4.32 megawatts of solar power is but 0.13% of what the Nanticoke Generating Station can provide.  To match the useable output of the Nanticoke Generating Station you would need to build an additional 769 of these solar power plants.  Costing another $36.9 billion.  To equal the output of three Nanticoke Generating Stations would cost over $1 trillion.  Making solar power not an alternative to coal but a deep hole to throw money into.  Which is a strange thing to do just to feel good.

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Hydroelectric Dams can’t make Electricity if it doesn’t Rain

Posted by PITHOCRATES - July 21st, 2012

Week in Review

Some people like to think that renewable energy is the energy of the future.  And that it will be free and abundant.  But with today’s technology it is none of these things.  It is just too unreliable.  And has such low capacity factors (CF).  The CF is a rating we calculate by dividing actual power produced by the amount possible under ideal conditions over a period of time.  Solar panels have a CF of about 20% because there are nights and cloudy days.  Wind farms have a CF of about 30% because there are times the wind doesn’t blow.  Big hydroelectric dams have a CF of about 50%  because there are times when it doesn’t rain (see Erratic monsoon clouds hydro power generation by Sadananda Mohapatra posted 7/18/2012 on the Business Standard).

Hydro power generation in the state may decline over the next couple of weeks due to erratic and deficient monsoon…

Daily generation from seven hydro power plants in the state reached up to 722 MW this week, up from 210 MW in early June. However, as the monsoon rainfall has been below normal so far, power managers feel this could hurt generation in coming days.

“All reservoirs, except Burla, have water levels below or at par with (MDDL) Minimum Draw Down Level. The generations had gone up on expectation of better rainfall, but it has to come down as rainfall has not been satisfactory,” said a senior official of state-run power trader Gridco…

Even though hydro power generation does not contribute significantly to meet the state’s power demand, cash-strapped Gridco depends on it heavily due to its low cost and easier availability. This summer, thermal units operating in the state had to shut down operations frequently due to technical glitch or coal supply problems, compelling the power trader to look for other sources such as captive power plants.

Fossil fuel-fired plants may not be as clean as the renewable energies but they are more reliable.  With capacity factors in excess of 90%.  As long as they aren’t broke.  Or run out of fuel.  Things we can minimize with proper maintenance.  And a sound energy policy.  One that encourages the extraction of fossil fuels from the ground.  Even with this though these plants can go off line because they only have a CF of about 90%.  And sometimes that 10% happens.

Of the renewable energies hydroelectric is the one with the most commercial potential.  A mix of coal and hydro can go a long way in meeting a nation’s energy needs.  One that normally works in India.  When the rains cooperate.  Which they sometimes don’t.  Which limits their capacity factor.  For if the water in the reservoir isn’t high enough it can’t spin those water turbines fast enough.  Or long enough.  And if it falls too low it may not even be able to enter the water inlets that feed those water turbines.  A prolonged dry spell could shut a hydro dam down completely.  Something you never have to worry about with coal.

Renewable energy can help.  But it just can’t replace fossil fuel-generated electric power.  For nothing is more reliable.  Which is a comforting fact when you head home after a tiring day at work.  Knowing that the electricity-provided creature comforts you so enjoy will be there waiting for you.  Thanks in large part to coal.  With the occasional assist from hydroelectric power.

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Silicon, Semiconductor, LED, Photon, Photovoltaic Effect, Photocell, Solar Panel, Converter, Battery and Solar Power Plant

Posted by PITHOCRATES - July 4th, 2012

Technology 101

A Photocell basically works like a Light Emitting Diode (LED) in Reverse

Solar power is based on the same technology that that gave us the electronic world.  Silicon.  That special material in the periodic table that has four electrons in its valence (i.e., outer most) shell.  And four holes that can accept an electron.  Allowing it to form a perfect silicon crystal.  When these silicon atoms come together their four valence electrons form covalent bonds with the holes in neighboring silicon atoms.  These silicon atoms share their valence electrons so that each silicon atom now has a full valence shell of eight electrons (with four of their own electrons and four shared electrons).  Making that perfect crystal structure.  Which is pretty much useless in the world of semiconductors.  Because you need free electrons to conduct electricity.

When we add impurities (called ‘doping’) to silicon is where the magic starts.  If we add a little bit of an element with five electrons in its valence shell we introduce free electrons into the silicon crystal.  Giving it a negative charge.  If we instead add a little bit of an element with 3 electrons in its valence shell we introduce extra holes looking for an electron to fill it.  Giving it a positive charge.  When we bring the positive (P) and the negative (N) materials together they from a P-N junction.  The free electrons cross the junction to fill the nearby holes.  Creating a neutrally charged depletion zone between the P and the N material.  This is a diode.  If we apply a forward biased voltage (positive battery terminal to the P side and the negative battery terminal to the N side) across this junction current will flow.  Like charges repel each other.  The negative charge pushes the free electrons on the N side of the junction towards the junction.  And the positive charge pushes the holes on the P side of the junction towards the junction.  Where they meet.  With free electrons filling available holes causing current to flow.  A reverse bias does the reverse.  Pulls the holes and electrons away from the junction so they can’t combine and cause current to flow.

It takes energy to move an electron out of its ‘hole’.  And when an electron combines with a hole it emits energy.  Typically this energy is not in a visible wavelength so we see nothing.  However, with the proper use of materials we can shift this wave length into the visible spectrum.  So we can see light.  Or photons.  This is the principle behind the light emitting diode.  Or LED.  An electric current through a P-N junction causes electrons to leave their holes and then recombine with holes.  And when they recombine they give off a photon in the visible spectrum of light.  Which is what we see.  A photocell basically works the other way.  Instead of using voltage and current to create photons we use photons from the sun to create voltage and current.

A Solar Array that could Produce 12,000 Watts under Ideal Conditions may only Produce 2,400 Watts in Reality

When we use the sun to bump electrons free from their shells we call this the photovoltaic (PV) effect.  This produces a small direct current (DC) at a low voltage.  A PV cell (or solar cell) then is basically a battery when hit with sunlight.  Electric power is the product of voltage and current.  So a small DC current and a low voltage won’t power much.  So like batteries in a flashlight we have to connect solar cells together to increase the available power.  So we connect solar cells into modules and modules into arrays.  Or what we commonly call solar panels.  Small panels can power small loads.  Like emergency telephones along the highway that are rarely used.  To channel buoys that can charge a battery during the day to power a light at night.  And, of course, the electronics on our spacecraft.  Where PV cells are very useful as there are no utility lines that run into space.

These work well for small loads.  Especially DC loads.  But it gets a little complicated for AC loads.  The kind we have in our homes.  A typical 1,000 square foot home may have a 100 amp electric service at 240 volts.  Let’s assume that at any given time there could be as much as half of that service (50 amps) in use at any one time.  That’s 12,000 watts.  Assuming a solar panel array generates about 10 watts per square foot that means this house would need approximately 1,200 square feet of solar panels (such as a 60 foot by 20 foot array or a 40 foot by 30 foot array).  But it’s not quite that simple.

The sun doesn’t shine all of the time.  The capacity factor (the percentage of actual power produced divided by the total possible it could produce under the ideal conditions) is only about 15-20%.  Meaning that a 1,200 square foot solar array that could produce 12,000 watts under ideal conditions may only produce 2,400 watts (at a 20% capacity factor).  Dividing this by 120 volts gives you 20 amps.  Or approximately the size of a single circuit in your electrical panel.  Which won’t power a lot.  And it sure won’t turn on your air conditioner.  Which means you’re probably not going to be able to disconnect from the electric grid by adding solar panels to your house.  You may reduce the amount of electric power you buy from your utility but it will come at a pretty steep cost.

Solar Power Plants can be Costly to Build and Maintain even if the Fuel is Free 

Everything in your house that uses electricity either plugs into a standard 120V electrical outlet, a special purpose 240V outlet (such as an electric stove) or is hard-wired to a 240V circuit (such as your central air conditioner).  All of these circuits go back to your electrical panel.  Which is wired to a 240V AC electrical service.  A lot of electronic devices actually operate on DC power but even these still plug into an AC outlet.  Inside these devices there is a power supply that converts the AC power into DC power.  So you’ll need to convert all that DC power generated by solar panels into useable AC power with a converter.  Which is costly.  And reduces the efficiency of the solar panels.  Because when you convert energy you always end up with less than you started with.  The electronics in the converters will heat up and dissipate some of that generated electric power as heat.  If you want to use any of this power when the sun isn’t shining you’ll need a battery to store that energy.  Another costly device.  Another place to lose some of that generated electric power.  And something else to fail.

We typically build large scale solar power plants in the middle of nowhere so there is nothing to shade these solar panel arrays.  From sun up to sun down they are in the sunlight.  They even turn and track the sun as it rises overhead, travels across the sky and sets.  To maximize the amount of sunlight hitting these panels.  Of course the larger the installation the larger the maintenance.  And the panels have to be clean.  That means washing these arrays to keep them dirt and bird poop free.  Some of the biggest plants in service today have about 200 MW of installed solar arrays.  One of the largest is in India.  Charanka Solar Park.  When completed it will have 500 MW of PV arrays on approximately 7.7 square miles of land.  With a generous capacity factor of 30% that comes to 150 MW.  Or about 19 MW/square mile.  The coal-fired Robert W. Scherer Electric Generating Plant in Georgia, on the other hand, generates 3,520 MW on approximately 18.75 square miles.  At a capacity factor of about 90% for coal that comes to about 3,168 MW.  Or about 169 MW/square mile.  About 9 times more power generated per square mile of land used.

 So you can see the reason why we use so much coal to generate our electric power.  Because coal is a highly concentrated source of fuel.  The energy it releases creates a lot of reliable electricity.  Day or night.  Summer or winter.  A large coal-fired electric generating facility needs a lot of real estate but the plants themselves don’t.  Unlike a solar plant.  Where the only way to generate more power is to cover more land with PV solar panels.  To generate, convert and store as much electric power as possible.  All with electronic equipment full of semiconductors that don’t operate well in extreme temperatures (which is why our electronics have vents, heat sinks and cooling fans).  So the ideal conditions to produce electricity are not the ideal conditions for the semiconductors making it all work.  Causing performance and maintenance issues.  Which makes these plants very costly.  Even if the fuel is free. 

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