Listen to part of a lecture in an environmental science class. The professor is discussing the use of renewable energy sources. Today we're going to look at a common misconception about solar power. Many people assume that solar panels are most effective in hot, sunny climates. However, research shows that the efficiency of solar panels actually decreases as temperature rises. In fact, panels operate best in cooler conditions with direct sunlight. For example, Germany, which has a relatively cool climate, is one of the world's leaders in solar energy production. The reason is that photovoltaic cells convert light into electricity, not heat. High temperatures cause electrons to become overexcited, which reduces the voltage and thus the panel's output. So, while sunny deserts like the Sahara receive more solar radiation, they often suffer from efficiency losses due to extreme heat. This is why engineers are developing new cooling technologies to keep panels at optimal temperatures. So, next time you see solar panels in a snowy region, don't be surprised—they may be working just as well, if not better, than those in tropical areas.
❓ คำถาม What point does the professor make about solar panels?
A. Solar panels are most effective in hot, sunny climates.
B. Solar panels work better in cooler temperatures with direct sunlight.
C. Solar panels cannot produce electricity in snowy regions.
D. Solar panels in deserts operate at maximum efficiency due to high radiation.
✅ คำตอบที่ถูกต้อง
Solar panels work better in cooler temperatures with direct sunlight.
TOEFL Listening Tips
Skim the questions first to predict the content
Watch for signal words in lectures and conversations (however, actually, in fact)
For main idea questions, focus on the beginning; for detail questions, focus on examples and data
For attitude questions, pay attention to the speaker's tone and word choice
Take notes on keywords; don't try to write down every word
