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Thu Apr 26, 2012, 09:38 AM

Arizona solar project reaches 100MW mark

http://www.upi.com/Business_News/Energy-Resources/2012/04/26/Arizona-solar-project-reaches-100MW-mark/UPI-77551335440824/

YUMA, Ariz., April 26 (UPI) -- Set to become the world's largest photovoltaic power plant, the Aqua Caliente project in Arizona reached the 100-megawatt milestone, companies said.

Executives from NRG Energy Inc., MidAmerican Solar and First Solar Inc., met with Arizona representatives to commemorate delivering the first 100 megawatts to the grid from the 290 MW Aqua Caliente solar project.

"Agua Caliente will provide a positive impact on the environment and create jobs," said Paul Caudill, president of MidAmerican Solar. "Projects such as Agua Caliente will play a central role in our nation's long-term electric energy supply and in our national transition to cleaner energy sources."

Utility company Pacific Gas and Electric has a 25-year purchase agreement for the project's entire capacity. When completed in 2014, it will be the largest PV power plant in the world, offsetting roughly 5.5 million tons of carbon dioxide during the next 25 years.

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Reply Arizona solar project reaches 100MW mark (Original post)
jpak Apr 2012 OP
rurallib Apr 2012 #1
PamW Apr 2012 #2
jpak Apr 2012 #3
PamW Apr 2012 #4
Dead_Parrot Apr 2012 #5

Response to jpak (Original post)

Thu Apr 26, 2012, 10:02 AM

1. 100 megawatt could power what for how long?

I always have trouble understanding what this means -
eg - could it power Los Angeles, or maybe the whole state of California?

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Response to rurallib (Reply #1)

Thu Apr 26, 2012, 11:05 AM

2. Not even close..

A 100 Mw(e) power plant is about 10% the size of a typical coal or nuclear unit.

Additionally, that 100 Mw(e) is the peak power; not the average power.

What is missing is something called the "capacity factor" which is the ratio of the actual energy a power plant develops in a given time, divided by the amount of energy it could generate if it were able to operate at its maximum output for that same period of time.

For "dispachable" power plants, like fossil, hydro, and nuclear which are power "on demand"; the typical capacity factor is in the high 90%s.

For a solar power plant, the peak capacity factor that it can ever reach is less than 50%; because solar power plants don't provide any energy at night.

PamW

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Response to PamW (Reply #2)

Thu Apr 26, 2012, 11:13 AM

3. What is missing is your inability to understand power output from PV arrays

That plant will produce power tracking incident solar energy - every day.

Power output from that plant will track AZ summer AC loads and offset the need for expensive (gas-fired) peak power - something that nuclear plants cannot provide.

Under full sun at local solar noon - that plant will provide 100 MW of electricity to the grid.

I am always amused that some people do not "get" the concept of ***solar*** power.

Yup

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Response to jpak (Reply #3)

Thu Apr 26, 2012, 04:00 PM

4. All the misunderstanding is on your part.

Power output from that plant will track AZ summer AC loads and offset the need for expensive (gas-fired) peak power - something that nuclear plants cannot provide.
==================

Why do you think that nuclear power plants can't "load follow". They certainly can. In the USA, because the fraction of our electric energy that comes from nuclear power is about 20%; which is less than the baseload fraction - all our nuclear power plants are run in baseload mode - that is 100% all the time.

However, in France, where the percentage of nuclear power plants exceeds the baseload fraction; some of their plants are run in "load following" mode:

http://en.wikipedia.org/wiki/Load_following_power_plant

In France, however, nuclear power plants use load following. French PWRs use "grey" control rods, in order to replace chemical shim, without introducing a large perturbation of the power distribution. These plants have the capability to make power changes between 30% and 100% of rated power, with a slope of 5% of rated power per minute. Their licensing permits them to respond very quickly to the grid requirements.

or

http://www.oecd-nea.org/ndd/reports/2011/load-following-npp.pdf

However for countries with high nuclear shares or desiring to significantly increase renewable energy sources, the question arises as to the ability of nuclear power plants to follow load on a regular basis, including daily variations of power demand.

So the load following capability of nuclear power plants can actually help integrate renewable sources in to the grid.

NOTHING that you said in your post contradicted anything that I said. Yes, I know that the solar power plant mentioned will put out 100 Mw(e) at local noon. However, it will only put out 100 Mw(e) at noon. Let's be generous to the solar plant, and assume that it puts out 100 Mw(e) of power for 6 hours. Therefore, for the day; this solar plant puts out 600 Mw-hours of energy.

Now lets compare that to the large coal or nuclear power plant which puts out 1000 Mw(e) for 24 hours for a total daily energy output of 24,000 Mw-hours. If we take the ratio of the two daily energy outputs, we find that this solar installation puts out only 2.5% of the energy of a large coal or nuclear power plant on a daily basis.

Like most solar proponents, you've become too enamored with what the power plant can do for a short fraction of the day, and can't mathematically integrate the total daily energy output; which is a small percentage of what the more conventional and nuclear power plants can attain.

In noting the laughing figure; those that don't really understand are so easily amused.

PamW

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Response to rurallib (Reply #1)

Thu Apr 26, 2012, 04:25 PM

5. In theory, about 75,000 households

(At least, during the day )

So, think of the residential bits of Des Moines and you are getting there.

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