单选题 Cheerleaders for renewable energy are fond of pointing out that patches of desert receive enough energy each year from sunlight to power the entire world. But few could explain how the construction of the millions of solar cells required to convert that energy into electricity would be financed. Public utility bosses and policymakers tend to dismiss wind and solar power as noble but expensive distractions, sustainable only through huge subsidies. But new studies suggest that renewables might not be as dear as skeptics suspect.
In a report that was due out on July 6th, Greenpeace, an environmental group, argues that public utilities would save money by investing in renewables. Windmills may cost more to build, the logic runs, but they do not require the purchase of fuel, unlike coal or gas-fired power plants. Those future fuel costs, Greenpeace says, massively outweigh the extra investment costs of renewables. If nuclear power were phased out and renewables' share of electricity generation rose dramatically, it calculates the average annual savings between 2004 and 2030 would be $180 billion.
These figures, of course, rely on all sorts of questionable assumptions. In Greenpeace's picture, the prices of gas and coal will rise, despite stagnating consumption of the former, and a steep drop in demand for the latter. It also helps that the future as Greenpeace sees it includes a big dose of energy efficiency, although its business-as-usual projections do not. Public utilities, at any rate, must not be making the same assumptions, since they continue to invest in power plants run on fossil fuels.
Other studies make a slightly less sweeping claim: that adding wind power to the electricity network can reduce the overall cost of electricity. The cost of producing wind power is almost nothing, since the fuel—wind—is free. So on a windy day, the cheapest power comes from wind turbines. That power, in turn, displaces electricity generation from sources with higher fuel costs, such as gas-fired plants. So power prices tend to fall when the wind is blowing. Nuon, a Dutch utility, calculates that in 2005 the average power price on the local spot market was over Euro 45 per megawatt hour when there was no wind, but under Euro 30 when the average wind-speed topped 13 metres per second.
Researchers in Denmark have gone a step further and put a value on this effect. They believe that wind power saved 1 billion kroner ($ 167m) off Danish electricity bills in 2005. On the other hand, Danish consumers also paid 1.4 billion kroner in subsidies for wind power. But this year, reckons Rune Moesgaard of the Danish Wind Industry Association, wind power will actually save consumers' money for the first time, as the benefits resulting from lower power prices outweigh the falling cost of the subsidy.

单选题 According to the author, cheerleaders for renewable energy
A. are optimistic about the finance of the solar power construction.
B. could hardly explain how solar cells convert sunlight into electricity.
C. in general ignore the cost of the solar power construction.
D. suspect that solar cells in desert are expensive.

单选题 It can be inferred from Paragraphs 1-2 that
A. windmill costs less than traditional power plants.
B. it is expensive to use windmills to generate power.
C. nuclear power will be replaced by the renewable.
D. public utilities would not invest in wind and solar power.

单选题 What does the word "stagnating" (Para. 3) most probably mean?
A. Inactive. B. Active.
C. Flexible. D. Instable.

单选题 According to the passage, wind power
A. could actually cost consumers a lot of money.
B. will replace gas-fired power plants on windy days.
C. will lower the price of fuel shortly.
D. can lower the power prices at any time.

单选题 How will wind power help consumers save money?
A. The subsidy cost is lower than consumers' electricity bills.
B. Money saved in their electricity exceeds their subsidy cost.
C. More consumers are using wind power.
D. Wind power does not need subsidy any more.