IELTS Reading 練習 太陽能創新（含題目+詳解）

Solar Power Innovation

When researchers at the Bell Telephone Laboratories in New Jersey unveiled the first practical silicon solar cell in 1954, they could power only a small toy. The cell converted around six per cent of incoming sunlight into electricity, and at the prevailing manufacturing cost the technology was useful only where no alternative existed at all — most famously, on satellites that could not carry fuel for chemical batteries. For three decades solar power remained a niche technology used by space agencies and a handful of remote off-grid installations.

The transformation came not from a single breakthrough but from the steady, almost unglamorous work of incremental engineering. Each doubling of cumulative installed capacity has reduced the average cost per watt by about twenty per cent — a relationship engineers call a "learning curve". By 2010, the panels themselves accounted for less than half the cost of a finished solar installation; mounts, wiring and labour had become the larger expenses. By 2023, utility-scale solar electricity was cheaper than electricity from new coal or gas plants in most of the world, a reversal that almost no analyst predicted in the 1990s.

Several technical advances are converging on the next stage. Silicon cell efficiencies, long stuck below 20 per cent for commercial panels, now routinely exceed 22 per cent. Researchers at Oxford and elsewhere have developed perovskite materials that, when layered on top of a conventional silicon cell, can capture additional wavelengths of sunlight and push laboratory efficiencies above 33 per cent. Mass production of these "tandem" cells is expected within the decade.

The remaining challenge is no longer the panel itself but the question of timing: solar power produces electricity only when the sun shines, and demand often peaks in the evening. The cost of grid-scale lithium batteries has fallen sharply, but storing several hours of a city's electricity remains expensive. Alternative approaches — pumped hydropower, compressed air, and using surplus solar power to make hydrogen — are all being trialled. None has yet proven decisively cheaper than the others. The fate of solar power as the cheapest source of electricity may now depend less on the sun than on what happens after it sets.

1. The 1954 Bell Labs solar cell could only generate a tiny amount of power.
2. By 2010, panels were the most expensive part of a solar installation.
3. Perovskite cells alone have reached over 33 per cent efficiency in laboratories.
4. Lithium battery costs have decreased significantly in recent years.

Choose the correct letter, A, B, C or D.

1. According to the passage, the dramatic fall in solar costs was caused mainly by:

- A. a single major scientific breakthrough - B. steady incremental engineering improvements - C. government subsidies in the 1990s - D. the failure of competing technologies

1. The writer suggests that the future of solar power depends most on:

- A. raising silicon panel efficiency above 22 per cent - B. solving the problem of storing or shifting electricity for evening use - C. abandoning lithium battery technology - D. building more satellites

Complete the sentences below using NO MORE THAN TWO WORDS from the passage.

1. The relationship between cumulative capacity and falling cost is known as a ______.
2. Layering perovskite on top of a silicon cell produces a so-called ______ cell.
3. One alternative to batteries involves using surplus solar power to make ______.

1. TRUE Supporting sentence: "they could power only a small toy". A small toy needs only a tiny amount of power. Direct paraphrase.

2. FALSE Supporting sentence: "By 2010, the panels themselves accounted for less than half the cost of a finished solar installation; mounts, wiring and labour had become the larger expenses". Panels were less than half — not the most expensive part. The statement contradicts the passage.

3. FALSE Supporting sentence: "perovskite materials that, when layered on top of a conventional silicon cell, can ... push laboratory efficiencies above 33 per cent". The 33 per cent figure refers to tandem (perovskite + silicon) cells, not perovskite alone. The statement misreads the source.

4. TRUE Supporting sentence: "The cost of grid-scale lithium batteries has fallen sharply". "Fallen sharply" matches "decreased significantly".

5. B — steady incremental engineering improvements Supporting sentence: "The transformation came not from a single breakthrough but from the steady, almost unglamorous work of incremental engineering". Direct paraphrase; A is the trap (the passage explicitly denies a single breakthrough).

6. B — solving the problem of storing or shifting electricity for evening use Supporting sentence: "The fate of solar power as the cheapest source of electricity may now depend less on the sun than on what happens after it sets". The "after it sets" framing points to evening storage and timing.

7. learning curve Supporting sentence: "a relationship engineers call a 'learning curve'". Two-word phrase, exact match.

8. tandem Supporting sentence: "Mass production of these 'tandem' cells is expected within the decade". Single-word answer; the passage uses "tandem" in quotation marks for exactly this concept.

9. hydrogen Supporting sentence: "using surplus solar power to make hydrogen". Single-word answer.