Context: Shuman built the world’s first solar thermal power station in Maadi, Egypt, between 1912 and 1913. Shuman’s plant used parabolic troughs to power a 45–52 kilowatts (60–70 hp) engine that pumped more than 22,000 litres (4,800 imp gal; 5,800 US gal) of water per minute from the Nile River to adjacent cotton fields. Although the outbreak of World War I and the discovery of cheap oil in the 1930s discouraged the advancement of solar energy, Shuman’s vision and basic design were resurrected in the 1970s with a new wave of interest in solar thermal energy. In 1916 Shuman was quoted in the media advocating solar energy's utilization, saying:

Question: Where did Shuman build the world's first solar thermal power station?
Answer: Maadi, Egypt

Question: How many liters of water per minute did Shuman's engine pump in litres?
Answer: 22,000

Question: In what decade were Shuman's ideas about solar energy revived?
Answer: the 1970s

Question: Where was the first solar thermal power plant built?
Answer: Maadi, Egypt

Question: What was used to power the plants engine?
Answer: parabolic troughs

Question: From what river did the engine pump water?
Answer: Nile River

Question: What slowed down the growth of solar energy?
Answer: the outbreak of World War I and the discovery of cheap oil

Question: When was the interest in solar energy restored?
Answer: the 1970s