雅思阅读 33: Unlocking the Heat Beneath（解锁地下的热能）

改编自 Information Technology and Innovation Foundation（2026年5月）。雅思阅读 Section 3 难度，约 1050 词。 素材来源：https://itif.org/publications/2026/05/18/advanced-geothermal-energy-widely-available-clean-maybe-cheap-enough/

Reading Passage

A. The demand for electricity in the United States is rising faster than at any point in recent memory. Hyperscale data centres, the relentless expansion of artificial intelligence, the reshoring of manufacturing and the wider electrification of transport have all placed fresh strain on a grid that is simultaneously retiring its oldest generating stations. Grid operators now find themselves hunting for sources of steady, round-the-clock generation. Coal is increasingly unattractive on both environmental and financial grounds, nuclear reactors take a decade or more to construct, and gas leaves utilities exposed to volatile fuel prices. Wind and solar, although cheap, cannot by themselves supply the constant output that servers and factories require; their output peaks in the middle of a sunny or windy day and collapses overnight, so operators must pair them with batteries that are still expensive and far from perfect. One underused option has long sat beneath people's feet: the Earth's own internal heat, which radiates outward from a molten core and is, by its nature, available at every hour. For most of its history, however, geothermal electricity has been confined to a handful of volcanic corners of the world — until a series of engineering innovations, borrowed from an unexpected industrial quarter, began to loosen that geographical straitjacket.

B. The reason geothermal power was once so restricted is geological, not technological. A conventional hydrothermal plant needs three coinciding conditions to work: rock that is hot enough and close enough to the surface; underground water or brine to carry that heat upward; and natural fractures or pores through which the fluid can circulate. Where these three features overlap naturally — usually near active volcanoes, hot springs and geysers — relatively shallow wells can bring steam or hot water straight to the turbines without any engineering of the reservoir itself. At the hottest sites, above two hundred degrees, pressurised water simply "flashes" into steam as it reaches the surface and drives a turbine directly; at cooler sites, a secondary fluid with a lower boiling point is evaporated in a heat exchanger. Almost every geothermal station operating today, both in America and worldwide — around 3.7 gigawatts in the United States and sixteen worldwide — sits on exactly such a lucky intersection. Outside those rare volcanic belts, the necessary heat is certainly present, but it is locked inside dry, impermeable rock from which no natural water will rise. For a century, that absence of underground fluid and permeability made the vast majority of the planet essentially off-limits to geothermal development.

C. Enhanced Geothermal Systems, or EGS, set out to remove the two missing ingredients by force. Instead of waiting for nature to supply water and open rock, engineers drill deep into hot, dry granite and then deliberately create an artificial reservoir. The method draws directly on the techniques that fuelled the shale revolution: long horizontal wells and multi-stage hydraulic stimulation, in which water is pumped at pressure to open and prop open a network of fractures, kept from closing by grains of sand. Once that engineered network connects an injection well to a production well, surface water is circulated down one side, heated as it crosses the hot rock, and returned as steam to drive a generator. Operators string fibre-optic cables along the wells themselves, so that the temperature and the tiniest tremors in the rock can be watched in real time and the treatment steered precisely. The approach is no longer merely experimental. In late 2023 a developer called Fervo Energy began feeding 3.5 megawatts from its Project Red site in Nevada into the network serving Google's data centres, and construction has since begun on a far larger facility, Cape Station, in Utah, whose output the company intends to reach hundreds of megawatts within a few years.

D. What has surprised even its proponents is how rapidly the economics are improving. Drilling a deep geothermal well used to be slow and expensive, but operators now apply the lessons of the oilfield — more capable rigs, longer-lasting drill bits that resist the extreme heat of the granite, and fibre-optic cables strung downhole to monitor temperature and seismic movement in real time. Fervo reports that the time needed to drill one of its wells has fallen by roughly 70 per cent in just two years, and that the horizontal sections its wells routinely reach have more than lengthened since the company's first fractured well, which carried a lateral of around a thousand metres. A rival design, known as advanced or closed-loop geothermal, goes further still: rather than fracturing the rock at all, it runs a sealed loop of pipe through which a working fluid is recirculated, eliminating the induced earthquakes that can worry local communities and regulators. A Canadian-backed firm used this approach to feed its first commercial electricity into a grid in Bavaria in late 2025, while also supplying heat to nearby homes. Whether fracturing or closed-loop ultimately dominates is still open, but both routes are now reaching paying customers rather than laboratory benches.

E. Taken together, these advances suggest a resource that could be deployed almost anywhere. The US Geothermal Technologies Office estimates that engineered systems could unlock at least 90 gigawatts of domestic generating capacity by 2050 — including states east of the Mississippi, where no geothermal power currently exists — providing firm, near-zero-emission power with a tiny land footprint and no need for backup when the sun does not shine or the wind drops. Demand is real: technology giants have signed long-term power deals with geothermal developers specifically to run their data centres, and the workforce and heavy equipment required already exist within the oil and gas sector, which is shedding workers as conventional production declines. The political climate is favourable too, with support spanning both major parties. Yet caution is warranted. The industry still leans on clean-energy mandates and federal support, and whether it can fully match the price of fossil fuels and cheap renewables without assistance remains to be proven. The next decade will determine whether a heat source once limited to volcanoes becomes a genuinely everywhere resource — or remains a promising experiment that never quite reaches the mass market.

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 engineers manufacture a reservoir where nature failed ii. Why conventional geothermal was limited to volcanic belts iii. The rising cost of electricity for ordinary households iv. The speed at which drilling economics are improving v. The debate over whether geothermal causes tsunamis vi. What the future may hold — and what remains uncertain vii. The history of the oil and gas industry

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. Why could conventional geothermal plants operate only in certain places? A. They required water, heat and natural permeability to occur together. B. They could only be built near rivers. C. They needed direct sunlight to heat the rock. D. They depended on seasonal rainfall.

6. What is the core idea behind an Enhanced Geothermal System? A. Importing hot water from volcanic regions. B. Building reservoirs on the surface to collect solar heat. C. Creating an artificial fractured reservoir in hot, dry rock. D. Drilling only wells that are perfectly vertical.

7. According to the writer, what has improved most strikingly? A. The purity of the steam produced. B. The speed and cost of drilling wells. C. The number of volcanoes in the United States. D. The temperature of the Earth's core.

8. What advantage does closed-loop geothermal have over EGS? A. It produces more electricity per metre of pipe. B. It can operate without any heat source. C. It removes the risk of induced seismic events. D. It requires no pumps at all.

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. Most conventional geothermal stations today are located in volcanic regions.
10. Fervo Energy's Project Red was built in Utah.
11. Drilling times for geothermal wells have recently increased.
12. The United States currently generates geothermal power in every state.
13. Geothermal still depends partly on government support.

Questions 14-15

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

Engineers create an EGS reservoir by drilling deep into hot, (14) __________ rock and then stimulating it with water under pressure. The approach has been borrowed from the (15) __________ industry, which pioneered horizontal wells.

答案与解析

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