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# Solar energy plants use a number of mirrors to focus sunligh

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Manager
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Solar energy plants use a number of mirrors to focus sunligh  [#permalink]

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27 Jan 2014, 14:54
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76% (01:41) correct 24% (02:05) wrong based on 273 sessions

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Solar energy plants use a number of mirrors to focus sunlight and produce electricity for about ten cents per kilowatt hour. The problem with the wide spread acceptance of solar energy plants is that electricity can be generated from coal for seven cents per kilowatt hour. In a free market system consumers will choose the lowest-cost form of electricity. Consequently, there will not be a market for the electricity produced by solar energy plants.

Which of the following, if true, does most to weaken the conclusion presented above?

A. Electricity plants that rely on coal produce large quantities of pollution that contribute to acid rain.

B. The supply of other forms of renewable energy, such as wind energy from turbines, is more unpredictable than that produced by solar energy plants.

C. Solar energy plants produce their largest amounts of energy during the daytime in the summer, when electricity is most expensive, often costing utilities more than fifteen cents per kilowatt hour to purchase.

D.The solar energy farms must be located in areas of constant, intense sunlight and therefore cannot be constructed in the eastern United States.

E. Many people believe that solar energy will be the most important energy source in decades to come

I was too much confused with the OE of this question.
Please if any expert could explain it.
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Re: Solar energy plants use a number of mirrors to focus sunligh  [#permalink]

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28 Jan 2014, 07:27
Sukant2010 wrote:
Solar energy plants use a number of mirrors to focus sunlight and produce electricity for about ten cents per kilowatt hour. The problem with the wide spread acceptance of solar energy plants is that electricity can be generated from coal for seven cents per kilowatt hour. In a free market system consumers will choose the lowest-cost form of electricity. Consequently, there will not be a market for the electricity produced by solar energy plants.

Which of the following, if true, does most to weaken the conclusion presented above?

A. Electricity plants that rely on coal produce large quantities of pollution that contribute to acid rain.

B. The supply of other forms of renewable energy, such as wind energy from turbines, is more unpredictable than that produced by solar energy plants.

C. Solar energy plants produce their largest amounts of energy during the daytime in the summer, when electricity is most expensive, often costing utilities more than fifteen cents per kilowatt hour to purchase.

D.The solar energy farms must be located in areas of constant, intense sunlight and therefore cannot be constructed in the eastern United States.

E. Many people believe that solar energy will be the most important energy source in decades to come

I was too much confused with the OE of this question.
Please if any expert could explain it.

Step 1 : Type of Question : weaken

Step 2 : What is to be weaken : conclusion

Step 3 : Conclusion ? there will not be a market for the electricity produced by solar energy plants.

Basis of Conclusion :
Cost of Energy from solar Power Plant : ten cents per kilowatt hour
Cost of Energy from coal : seven cents per kilowatt hour
In a free market system consumers will choose the lowest-cost form of electricity.
So people will prefer Coal energy

Option C : Solar energy plants produce their largest amounts of energy during the daytime in the summer, when electricity is most expensive, often costing utilities more than fifteen cents per kilowatt hour to purchase.

During Daytime summer
Cost of Energy from solar Power Plant : ten cents per kilowatt hour
Cost of Energy from any source : more then 15 cents per kilowatt hour

So people will prefer Solar Power plant. IMO C

My Question : Here we have to assume that summers will be for extended period of time. What if summers are for short period of time during the year ... Any prudent customer will compare cost per annum and then decide. Should we make such assumptions?

What is the source ?
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Re: Solar energy plants use a number of mirrors to focus sunligh  [#permalink]

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28 Jan 2014, 10:08
Solar energy plants use a number of mirrors to focus sunlight and produce electricity for about ten cents per kilowatt hour. The problem with the wide spread acceptance of solar energy plants is that electricity can be generated from coal for seven cents per kilowatt hour. In a free market system consumers will choose the lowest-cost form of electricity. Consequently, there will not be a market for the electricity produced by solar energy plants.

Which of the following, if true, does most to weaken the conclusion presented above?

C. Solar energy plants produce their largest amounts of energy during the daytime in the summer, when electricity is most expensive, often costing utilities more than fifteen cents per kilowatt hour to purchase....clearly weakens the argument by giving advantages of solar over coal generated means of power production....
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Re: Solar energy plants use a number of mirrors to focus sunligh  [#permalink]

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29 Jan 2014, 04:20
The argument made in the question is that since Solar energy is not cost effective compared to Coal energy, there will not be a market for it. What you must try to find is an argument that contradict this in the sense that in some case Solar can be less expensive than Coal energy or, even though Solar energy is more expensive than Coal energy, there are strong reasons to believe there will still be a market for it.

So when looking at the different answers I would say:

A) not relevant, the fact that Electricity plans pollutes a lot does not give us any information about whether there is a market for Solar or not
B) would be relevent if it was talking about Coal, but it is talking abour other sources of power
C) YES, this gives us the information that in a particular scenario Solar is more interesting than Coal, therefore there are reasons to believe there can be a market
D) this strenghtens the argument, it is an argument against Solar energy
E) does not give us any information about whether there is a market. It is not because people think it will become important that they will buy it.
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Re: Solar energy plants use a number of mirrors to focus sunligh  [#permalink]

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29 Jan 2014, 09:05
Conclusion: There won't be much of a market for energy produced by solar power plants
Now, to weaken the argument, we need to choose an option that talks in favour of electricity produced by solar power plants over other means

A. Electricity plants that rely on coal produce large quantities of pollution that contribute to acid rain. Does not concern anywhere for the market for the electricity produced by solar energy plants

B. The supply of other forms of renewable energy, such as wind energy from turbines, is more unpredictable than that produced by solar energy plants. Does not support the use of solar energy as required by the question

C. Solar energy plants produce their largest amounts of energy during the daytime in the summer, when electricity is most expensive, often costing utilities more than fifteen cents per kilowatt hour to purchase. This makes sense as solar energy comes out cheaper than other options, contrary to what is stated by the conclusion

D.The solar energy farms must be located in areas of constant, intense sunlight and therefore cannot be constructed in the eastern United States. Does not weaken the conclusion, but, in fact, supports it.

E. Many people believe that solar energy will be the most important energy source in decades to come. Does not weaken the conclusion, but supports it
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Re: Solar energy plants use a number of mirrors to focus sunligh  [#permalink]

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29 Jan 2014, 10:00
A. Electricity plants that rely on coal produce large quantities of pollution that contribute to acid rain. Does not attack conclusion directly, we are concerned with cost.

B. The supply of other forms of renewable energy, such as wind energy from turbines, is more unpredictable than that produced by solar energy plants. Totally irrelevant.

C. Solar energy plants produce their largest amounts of energy during the daytime in the summer, when electricity is most expensive, often costing utilities more than fifteen cents per kilowatt hour to purchase. Correct. It tackles conclusion directly; proving that solar energy is a better alternative, which weakens the conclusion.

D.The solar energy farms must be located in areas of constant, intense sunlight and therefore cannot be constructed in the eastern United States. Irrelevant.

E. Many people believe that solar energy will be the most important energy source in decades to come. Futuristic and does not relate to conclusion, thus irrelevant.
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Re: Solar energy plants use a number of mirrors to focus sunligh  [#permalink]

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30 Jan 2014, 08:24
SUKANT2010

premise 1 ....Solar energy plants COSTS ten cents per kilowatt hour.
premise 2 ....Coal can produce same for seven cents per kilowatt hour.

CONCLUSION- There will not be a market for the electricity produced by solar energy plants.

we have to show that there will be market for solar energy..

A. Electricity plants that rely on coal produce large quantities of pollution that contribute to acid rain.pollution is not being discussed here....will there be market for solar energy- is being discussed

B. The supply of other forms of renewable energy, such as wind energy from turbines, is more unpredictable than that produced by solar energy plants.predictability of other forms of energy is not being discussed here...will there be market for solar energy- is being discussed.

C. Solar energy plants produce their largest amounts of energy during the daytime in the summer, when electricity is most expensive, often costing utilities more than fifteen cents per kilowatt hour to purchase.gives a strong reason for market for solar energy

D.The solar energy farms must be located in areas of constant, intense sunlight and therefore cannot be constructed in the eastern United States....location of farms is not important...will there be market for solar energy- is being discussed.

E. Many people believe that solar energy will be the most important energy source in decades to come...what people believe is not being doscussed here....will there be market for solar energy- is being discussed

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Re: Solar energy plants use a number of mirrors to focus sunligh  [#permalink]

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14 Mar 2017, 06:46

C only suggests that solar energy plants will be beneficial over coal plans in summer. But the question stem does not provide any information about the place. Also conclusion here is very general, not specific to any season.
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Re: Solar energy plants use a number of mirrors to focus sunligh  [#permalink]

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15 Mar 2017, 00:09
RMD007 wrote:

C only suggests that solar energy plants will be beneficial over coal plans in summer. But the question stem does not provide any information about the place. Also conclusion here is very general, not specific to any season.

Solar energy plants use a number of mirrors to focus sunlight and produce electricity for about ten cents per kilowatt hour. The problem with the wide spread acceptance of solar energy plants is that electricity can be generated from coal for seven cents per kilowatt hour. In a free market system consumers will choose the lowest-cost form of electricity. Consequently, there will not be a market for the electricity produced by solar energy plants.

Which of the following, if true, does most to weaken the conclusion presented above?

A. Electricity plants that rely on coal produce large quantities of pollution that contribute to acid rain.

B. The supply of other forms of renewable energy, such as wind energy from turbines, is more unpredictable than that produced by solar energy plants.

C. Solar energy plants produce their largest amounts of energy during the daytime in the summer, when electricity is most expensive, often costing utilities more than fifteen cents per kilowatt hour to purchase.

D.The solar energy farms must be located in areas of constant, intense sunlight and therefore cannot be constructed in the eastern United States.

E. Many people believe that solar energy will be the most important energy source in decades to come

Conclusion : there will not be a market for the electricity produced by solar energy plants.
Assumption : There is no way the cost of producing electricity from solar energy will be lesser than the cost of producing electricty from coal.

To weaken we need to attack this linkage.
Option C does that. which says the cost of electricity from coal will be higher than the cost of electricity from solar energy.
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Solar energy plants use a number of mirrors to focus sunligh  [#permalink]

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15 Mar 2017, 15:02
Solar energy plants use a number of mirrors to focus sunlight and produce electricity for about ten cents per kilowatt hour. The problem with the wide spread acceptance of solar energy plants is that electricity can be generated from coal for seven cents per kilowatt hour. In a free market system consumers will choose the lowest-cost form of electricity. Consequently, there will not be a market for the electricity produced by solar energy plants.

Which of the following, if true, does most to weaken the conclusion presented above?

A. Electricity plants that rely on coal produce large quantities of pollution that contribute to acid rain.
The acid rain caused by the coal plant or any other kind of enviromental damages caused are not the part of the scope of the argument.

B. The supply of other forms of renewable energy, such as wind energy from turbines, is more unpredictable than that produced by solar energy plants.
The comparison between the various sources of renewable energy is also not in scope of the argument.

C. Solar energy plants produce their largest amounts of energy during the daytime in the summer, when electricity is most expensive, often costing utilities more than fifteen cents per kilowatt hour to purchase.
Correct answer .The illusive labguage got me too,but the sentence means that solar plants produce energy at the time when the consumers utilize the energy the most and also are paying the most ie 15 cents per unit. ,so even if the price of solar energy is higher it is still affordable for people who are paying 15 cents per unit.This is definate weakener.(now if anyone has a doubt after reading the explaination ,i will reveal my true identity (I AM BATMAN )) haha

D.The solar energy farms must be located in areas of constant, intense sunlight and therefore cannot be constructed in the eastern United States.
this is strengthening the argument(in a limited way though) as the palces of the installation of solar energy are limited.

E. Many people believe that solar energy will be the most important energy source in decades to come
what many people believe is not the scope of the argument and also not impacting the argument in any way. For example i believe in the holy batman ,but that doesnt change my present reality in any way ,
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Re: Solar energy plants use a number of mirrors to focus sunligh  [#permalink]

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24 Mar 2017, 07:27
Solar energy plants use a number of mirrors to focus sunlight and produce electricity for about ten cents per kilowatt hour. The problem with the wide spread acceptance of solar energy plants is that electricity can be generated from coal for seven cents per kilowatt hour. In a free market system consumers will choose the lowest-cost form of electricity. Consequently, there will not be a market for the electricity produced by solar energy plants.

Main point- In a free market system consumers will choose the lowest-cost form of electricity.

Only C deals with cost comparison. Straight C.

Which of the following, if true, does most to weaken the conclusion presented above?

A. Electricity plants that rely on coal produce large quantities of pollution that contribute to acid rain.
-No cost comparison.
B. The supply of other forms of renewable energy, such as wind energy from turbines, is more unpredictable than that produced by solar energy plants.
-No cost comparison.
C. Solar energy plants produce their largest amounts of energy during the daytime in the summer, when electricity is most expensive, often costing utilities more than fifteen cents per kilowatt hour to purchase.
Correct.
D.The solar energy farms must be located in areas of constant, intense sunlight and therefore cannot be constructed in the eastern United States.
Irrelevant.

E. Many people believe that solar energy will be the most important energy source in decades to come
Does not matter.
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Re: Solar energy plants use a number of mirrors to focus sunligh &nbs [#permalink] 24 Mar 2017, 07:27
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