雅思阅读 17: Bottling the Sun（把阳光装进瓶子）

改编自 UC Santa Barbara / Science（2026年5月）。雅思阅读 Section 3 难度，约 1050 词。 素材来源：https://www.sciencedaily.com/releases/2026/05/260513221821.htm

Reading Passage

A. Solar panels lose their ability to generate electricity when the sun goes down, and renewable energy researchers have spent decades seeking a way to store sunlight economically for use after dark. The dominant solution today — lithium-ion batteries — is effective for short periods but expensive at grid scale and dependent on a supply chain dominated by a handful of countries. A team at the University of California, Santa Barbara, led by Grace Han, has now demonstrated an alternative that stores sunlight not in an electric current but in a molecule. Writing in Science in May 2026, they describe a modified organic compound called pyrimidone that absorbs sunlight, shifts into a strained high-energy configuration, and remains in that state for years until a trigger — a small amount of heat or a catalyst — snaps it back, releasing the stored energy as heat. Storing energy as heat is nothing new: hot-water tanks have done it for a century. But storing it chemically, in a molecule that loses almost none of its charge over years, is a different proposition. Conventional batteries self-discharge and degrade; a molecular spring, in principle, holds its energy indefinitely until deliberately released.

B. The design was inspired by two everyday phenomena. The first is photochromic sunglasses: lenses that darken in sunlight and clear when returned indoors, through a reversible molecular change. The second, less obvious, is DNA, which can reversibly change shape under ultraviolet light. The pyrimidone molecule closely resembles a component found naturally in DNA, adapted by the researchers to maximise energy storage rather than biological function. "We prioritised a lightweight, compact molecule design," says lead author Han Nguyen. "Anything that was unnecessary, we removed to make the molecule as compact as possible." Computational modelling conducted with chemist Ken Houk at UCLA helped explain why the molecule remained stable in its high-energy state for so long without losing its charge. The borrowing from biology is deliberate. Nature has spent aeons perfecting molecules that change shape reversibly under light, and the chemists reasoned that adapting such a molecule would be easier than inventing one from scratch. The computational work was essential because small tweaks to a molecule's shape can completely change how long it holds the twisted form.

C. The system operates like a compressed spring. When sunlight strikes the molecule, it absorbs a photon and twists into a strained configuration — think of a spring that has been wound tight and latched in place. The latch holds for months or years. Applying a catalyst or a small burst of heat releases the latch, and the molecule springs back to its original shape, dumping the stored energy as heat. Unlike a conventional battery, the system has no moving parts, no electrodes that degrade, and no rare metals. In a key demonstration, the team showed that the material could release enough heat to boil water under ambient conditions — a milestone that, Nguyen notes, "is a big achievement" because boiling water is an energy-intensive process. Boiling water matters for a practical reason: demand for domestic heating and hot water peaks in the evening and winter, exactly when solar supply is weakest. A storage medium that returns its energy as useful heat, rather than as electricity that must be converted again, skips a whole stage of losses.

D. The energy density is competitive with lithium-ion. The pyrimidone system stores more than 1.6 megajoules per kilogram, compared with roughly 0.9 MJ/kg for a typical lithium-ion cell. It also outperformed earlier generations of molecular solar-thermal systems, which struggled either to hold energy for long periods or to release it at useful temperatures. The material dissolves in water, which the researchers say opens a route to practical deployment: rooftop collectors could circulate the molecule during the day, store it in insulated tanks at night, and pass it through a heat-exchanger to warm water or living spaces without requiring a separate battery bank. "With solar panels," says co-author Benjamin Baker, "you need an additional battery system to store the energy. With molecular solar thermal energy storage, the material itself is able to store that energy." The implication is a simpler heating system. A house could harvest sunlight on the roof during the day, circulate the stored molecule through insulated pipes, and release its heat at night through a conventional radiator, with no separate battery, inverter or control electronics. Such a system would not yet compete on every front — it stores heat, not grid electricity — but for heating-dominated homes it could be transformative.

E. The technology, known as Molecular Solar Thermal (MOST) storage, is still at an early stage. The current demonstration stores energy as heat, not electricity — it cannot directly replace the function of a solar panel in the electrical grid. But for applications where heat, rather than power, is the end product — domestic hot water, space heating, industrial process heat — it offers a storage medium that loses almost nothing over time and requires no charging electronics. The Moore Inventor Fellowship, awarded to Han in 2025, supports further development. Whether the molecule can be manufactured cheaply at scale, and whether its heat-release temperature can be tuned for specific uses, remains to be seen. But the idea of bottling sunlight in a recyclable chemical spring — and opening the bottle years later for a burst of warmth — has moved from fantasy to laboratory demonstration. The road ahead includes proving the material survives thousands of charge-release cycles without fatigue, and showing that the trigger can be switched on and off cheaply. If those hurdles fall, the vision is of homes warmed not by burning gas but by sunlight bottled, months earlier, in a liquid that flows quietly through basement tanks. It is a modest-sounding ambition, but one that has drawn chemists and engineers together for a reason.

Questions 1-4

Choose the correct heading for paragraphs B, C, D and E from the list of headings below.

List of Headings i. How a molecule winds up and releases energy ii. The biological inspiration behind the design iii. How DNA replicates in cells iv. Energy density and a practical route to deployment v. Why lithium-ion batteries are dangerous vi. The limitations and promise of the technology vii. A history of solar power generation

1. Paragraph B: ____
2. Paragraph C: ____
3. Paragraph D: ____
4. Paragraph E: ____

Questions 5-8

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

5. How does the pyrimidone molecule store energy? A. It converts sunlight directly into electricity. B. It twists into a strained configuration and remains there until triggered. C. It charges an internal battery. D. It decomposes and reforms.

6. What everyday phenomenon inspired the design? A. Solar panel cooling systems. B. Photochromic sunglasses that darken in sunlight. C. Rechargeable lithium-ion batteries. D. Water boiling on a stove.

7. What is the energy density of the new material? A. About 0.9 MJ/kg. B. About 1.6 MJ/kg. C. About 3.2 MJ/kg. D. About 0.5 MJ/kg.

8. What is a current limitation of the system? A. It cannot store energy for more than a few hours. B. It releases heat rather than electricity. C. It requires rare-earth metals. D. It degrades after a single use.

Questions 9-13

Do the following statements agree with the claims of the writer?

Write:

• TRUE if the statement agrees with the information
• FALSE if the statement contradicts the information
• NOT GIVEN if there is no information on this

9. The pyrimidone molecule stores more energy per kilogram than lithium-ion.
10. The material can release enough heat to boil water.
11. The system currently produces electricity directly.
12. The molecule is derived from a component found in DNA.
13. A commercial company has already been established to produce the molecule in large quantities.

Questions 14-15

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

The molecule stores sunlight in (14) __________ bonds and releases it as heat when triggered. The technology is called Molecular Solar Thermal or (15) __________ storage.

答案与解析

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