Posts Tagged ‘wind energy’

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Not much of Chinese energy is from wind or solar.

December 2, 2013

A few days ago I wrote about the pollyannish belief that “China is slowing its carbon emissions.”  An essential element of this ridiculous meme is that the Chinese are producing significant portions of their energy via wind and solar. Not true.

Consider just electricity.   Here is a breakdown of China’s installed electricity capacity by fuel type in 2011 and their electricity generation by fuel type for 2000 to 2010 from the The United Stages’ Energy Information Administration’s evaluation of China’s energy consumption (2012)…

"China's installed electricity capacity by fuel, 2011," from the US Energy Information Administration's evaluation of China's energy consumption

“China’s installed electricity capacity by fuel, 2011,” from the US Energy Information Administration’s evaluation of China’s energy consumption

"China's electricity generation by fuel type, 2000-2010" from the US's Energy Information Administration

“China’s electricity generation by fuel type, 2000-2010″ from the US’s Energy Information Administration

What do these charts tell you?

These two charts are drawn from the same data set and appear next to each other in the same document.

As you can see from the top chart, 6.2% of China’s installed electricity capacity is in wind or solar.  That is over 60 gigawatts installed.  Compare that the the US’s 60 gigawatts of installed wind and 10 gigawatts of installed solar.

Alas, the top chart shows installed capacity, not actual production.  There is a little thing called the “capacity factor.”  The capacity factor is the fraction of the time that particular power source can actually produce power at its rated capacity.  For example, a one gigawatt capacity nuclear power plant will have a capacity factor of about 90%, meaning it can produce one gigawatt 90% of the time.  Wind and solar capacity factors tend to be much lower, simply because sometimes the wind doesn’t blow and the sun doesn’t shine.  The capacity factor for wind in China is 22%

The second chart shows the amount of electrical energy actually produced using the various “fuel types”.  Do you see that very, very thin yellow band along the top of the second chart?  That represents the Chinese electricity generation due to that 6.2% of installed wind and solar.  Can’t see the yellow line?  Let me blow up the last year of the chart for you…

Chinas electricity generation by fuel type blown up 3

That 6.2% of installed capacity in the form of wind and solar yields less than 1.5% of the actual energy.

China’s energy future

The Energy Information Administration document tells us…

China is the world’s second largest power generator behind the US, and net power generation was 3,965 Terawatt-hours (TWh) in 2010, up 15 percent from 2009. Nearly 80 percent of generation is from fossil fuel-fired sources, primarily coal. Both electricity generation and consumption have increased by over 50 percent since 2005, and EIA predicts total net generation will increase to 9,583 TWh by 2035, over 3 times the amount in 2010.

Wow!  three times as much as 2010, a mere 21 years from now!  Where will all this energy come from?

Again, the Energy Information Administration…

Total fossil fuels, primarily coal, currently make up nearly 79 percent of power generation and 71 percent of installed capacity. Coal and natural gas are expected to remain the dominant fuel in the power sector in the coming years. Oil-fired generation is expected to remain relatively flat in the next two decades. In 2010, China generated about 3,130 TWh from fossil fuel sources, up 11 percent annually.

Let me be clear, I am not knocking the use of wind and solar.  I have been personally working on solar energy for 17 years.  But I am knocking unrealistic expectations and quasi-religious environmentalist beliefs.  And I am not criticizing the Chinese for their increasing energy consumption.  They understand, correctly, that abundant energy is the key to prosperity.

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Use wind turbines to compress air for compressed air cars?

March 9, 2013

Remember Tata Motors’ plan for a car that ran off of compressed air?  There was a lot of talk about this back in 2009.  They planned to bring such a vehicle, based on Motor Development International’s (MDI) technology, to market by 2011.  But there were many technical problems, with some potential show stoppers.  The compressed air car was not seen as terribly efficient because of various conversion losses, using electric or gas-powered motors to compress the air.

What if?

But what if the compressed air could be acquired without and electric or gas motor?

I have always wondered if this might be an ideal use of wind turbines.  Electrical energy from wind turbines, like electric energy from photovoltaics, suffers from the lack of a practical storage method.  Let’s say you want to run your electric car off of energy from a wind turbine.  Kinetic energy of the wind is converted to mechanical (kinetic) energy of the turbine, which is converted to electrical energy in the generator (suffering from grid losses as it is delivered to your charging station), which is converted to chemical energy in your battery, which then converted back into electrical energy for the magnetic coils of the motor, which is converted back into mechanical energy to turn your wheels.

What if the mechanical energy of the turbine  instead used to compress air or another gas?  A compressed air car pulls up to the storage tank of the turbine compressed air, fills up and drives away.  No generator, no transmission lines, no battery and no electric motor conversions involved.  This would take advantage of the best features of wind turbines and compressed air cars, eliminating some of the losses that make each of them less efficient.

Fluid compressing wind turbine system

I started thinking about this again today when reading about a proposal by Winhyne Energy Group to build a turbine system in Wyoming in which the turbine would compress a fluid instead of turning a generator.  The compressed fluid would them either turn a generator, or be stored to power the generator when the wind was not available.

Here is a schematic of a single turbine/single generator system…

Turbine compressed fluid system designed by Lancaster Wind Systems, Inc.

Turbine compressed fluid system designed by Lancaster Wind Systems, Inc.

Couldn’t something similar be done to compress a gas?

New life for compressed air vehicles

While Tata Motors’ bold claims of bringing a compressed air vehicle to market by 2011 fizzled, the hope is not dead.  Last year Tata said it was done with its first phase of development and it ” has now been successfully completed with the compressed  air engine concept having been demonstrated in two Tata Motors vehicles” and that they were now in the second phase  and and that MDI and Tata “are working together to complete detailed development of the technology and required technical processes to industrialize a market ready product application over the coming years.”

Note that the recently announced Peugeot compressed air car, to be marketed by 2016, is not really the same thing.  This is a hybrid system has a gasoline or diesel engine and does not have an air tank that you “fill up” with compressed air.  Rather, is captures braking energy to compress air, which can then be used for acceleration.  This concept offers great fuel saving potential in cities where frequent stop and start driving causes large energy losses to braking.

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James Lovelock says nuclear better than wind.

January 26, 2013

James Lovelock has worn many hats.  He worked with NASA to make instruments for studying extraterrestrial planetary atmospheres and surfaces.  He invented the electron capture detector for studying traces of various chemicals in gas.  He has been awarded multiple prizes from many academic and environmental groups.

However, he is best known as the founding father of the much-loved (by environmental groups) “Gaia Theory.”  According to GaiaTheory.org…

“The Gaia Theory posits that the organic and inorganic components of Planet Earth have evolved together as a single living, self-regulating system. It suggests that this living system has automatically controlled global temperature, atmospheric content, ocean salinity, and other factors, that maintains its own habitability. In a phrase, “life maintains conditions suitable for its own survival.” In this respect, the living system of Earth can be thought of analogous to the workings of any individual organism that regulates body temperature, blood salinity, etc.”

This seductive reasoning ignores the reality that life evolves, as best it can, to survive in a given environment, and while life may change the environment it does not “automatically control” it to “maintain its own habitability.”  But my point here is not to argue with the Gaia theory.

Lovelock was an icon in environmentalist circles, but since he started publicly endorsing nuclear energy a few years ago his aura seems to be fading.  He has been condemned as being senile or worse (see here or comments here).

In a recent comment (see discussion at Bishop-Hill.net) Lovelock condemns a single proposed wind turbine in a bucolic English setting, calling it “industrial vandalism.”  But more importantly he goes on to say…

“we should look to the French who have wisely chosen nuclear energy as their principal source; a single nuclear power station provides as much as 3200 large wind turbines.”

I am not one to condemn wind turbines for aesthetic reasons.  In fact, I find that modern wind turbines have their own beauty in their graceful structure.  But Lovelock is certainly right in his comparison of the utility of wind turbines with nuclear energy.

Lovelock closes his comments with this homily…

I am an environmentalist and founder member of the Greens but I bow my head in shame at the thought that our original good intentions should have been so misunderstood and misapplied. We never intended a fundamentalist Green movement that rejected all energy sources other than renewable, nor did we expect the Greens to cast aside our priceless ecological heritage because of their failure to understand that the needs of the Earth are not separable from human needs. We need take care that the spinning windmills do not become like the statues on Easter Island, monuments of a failed civilisation.

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Comparing the Interstate Highway System to Scientific American’s “A Path to Sustainable Energy by 2030″

November 14, 2009

091111 November 09 SA cover 2In the November, 2009 issue of Scientific American, Mark Z. Jacobson and Mark A. Delucchi propose a plan to supply the world’s energy needs entirely by solar, wind and water sources by 2030. They conclude that the cost would be $100 trillion. My calculations show the cost to be more like $200 trillion.

This post dissects their comparison between the construction of the Interstate Highway System and their Energy system.

Cost

Interstate Highway System (2009 dollars):  $0.453 trillion
Jacobson’s and Delucchi’s Energy system (2009 dollars): $200 trillion

Jacobson and Delucchi say…

“Our plan calls for millions of wind turbines, water machines and solar installations. The numbers are large, but the scale is not an insurmountable hurdle; society has achieved massive transformations before… In 1956 the U.S. began building the Interstate Highway System, which after 35 years extended 47,000 miles, changing commerce and society.”

The Interstate Highway System is “largest public works program in history.” The concept was first approved by congress in 1944. But it was more than a decade until President Eisenhower signed the Federal Aid Highway Act of 1956. The plan evolved to building 42,500 miles of “super-highway” by 1975.  40,000 miles were completed by 1980.

The expected cost in 1958 was $41 billion. By 1995 the total construction cost amounted to $329 billion (in 1996 dollars). This translates into $58.5 billion 1957 dollars. That is not too far off from the original estimate.  Converting the $329 billion 1996 dollars to 2009 dollars gives $453 billion.

So if Jacobson’s and Delucchi’s estimate for the cost of their energy system is correct, then their energy plan would cost over 200 times as much ($100 trillion / $453 billion) as the Interstate Highway System to which they like to compare it.

If my calculations for the cost of their energy system are correct, then it would cost more than 400 times as much ($200 trillion / $453 billion) as the Interstate Highway System! And since they propose building their system in just 20 years, then it would be like building 20 interstate highway systems (which took about 30 years to build) every single year for twenty years.

Required surface area

Interstate Highway System – paved area: 3,500 km2
Jacobson’s and Delucchi’s Energy system (solar portion only): 500,000 km2

Composite interstate highway imageAnother interesting comparison is the amount of land required. The image at the left (click to enlarge) shows a spot check of interstate highway widths using Google Earth.  A liberal estimate of the average paved width of the Interstate Highway System is about 150 feet (about 45 meters, or 0.045 kilometers).  So, roughly speaking, the 47,000 mile (76,000 kilometer) Interstate Highway System paved over about 3,500 square kilometers ( 0.045 kilometers X 76,000 kilometers).

The area covered by solar panels in the Scientific American plan would be on the order of 500,000 square kilometers, or 150 times larger than the Interstate Highway System. (See calculated land required for Concentrated Solar, PV power plants, and rooftop solar, here)

Let’s rip up the Interstate Highway System and build a new one.

Jacobson and Delucchi claim that the expense of their energy system “is not money handed out by governments or consumers. It is an investment that is paid back through the sale of electricity and energy.” This is a soothing argument that overlooks an obvious fact: We already have a power energy system that pays for itself “through the sale of electricity and energy.”   

This is like pointing out that an Interstate Highway System would have great benefits for us, and then suggesting that we could reap those benefits by tearing down the system we have now and then rebuilding it.

It’s almost like swallowing poison so you can reap the benefits of good health after you recover.

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