Quiz on Renewable Energy

A photovoltaic cell converts sunlight directly into which form of energy?

• Heat
• Electricity ✓ (Correct answer)
• Hydrogen
• Steam

Source: Unlike solar water heaters, photovoltaic cells skip heat entirely and make electricity on the spot.

Hydroelectric dams generate power mainly from what?

• Ocean tides
• Wind over water
• Falling water ✓ (Correct answer)
• Underground heat

Source: It's gravity at work: water falling through turbines is the oldest modern renewable.

Inside a wind turbine, the spinning blades drive what component to make electricity?

• A generator ✓ (Correct answer)
• A battery
• A transformer
• A radiator

Source: The blades spin a generator, the same principle as a bicycle dynamo, just enormous.

Which renewable source harnesses the gravitational pull of the Moon on the sea?

• Tidal ✓ (Correct answer)
• Wave
• Wind
• Solar

Source: The Moon drags the oceans, and tidal turbines turn that steady pull into power.

Rotting food scraps and manure can be captured to produce which usable fuel gas?

• Oxygen
• Carbon dioxide
• Biogas ✓ (Correct answer)
• Hydrogen

Source: Landfills and farms trap this methane-rich gas to run stoves and even power buses.

In the Northern Hemisphere, rooftop solar panels catch the most sun facing which way?

• North
• East
• West
• South ✓ (Correct answer)

Source: South-facing roofs soak up the most daylight north of the equator; it flips below it.

Which country installs and generates the most solar power overall?

• United States
• China ✓ (Correct answer)
• Germany
• Australia

Source: China makes most of the world's solar panels and leads in installing them too.

Which country produces nearly all its electricity from geothermal and hydropower?

• Norway
• Germany
• Switzerland
• Iceland ✓ (Correct answer)

Source: Sitting on a volcanic ridge, Iceland heats most of its homes with the Earth's own warmth.

Brazil produces most of its biofuel ethanol from which crop?

• Corn
• Sugarcane ✓ (Correct answer)
• Wheat
• Soybeans

Source: Brazil's cars run on sugarcane ethanol, while the US mostly ferments corn.

What is the world's largest source of renewable electricity?

• Hydropower ✓ (Correct answer)
• Solar power
• Wind power
• Geothermal

Source: Hydropower still generates more clean electricity worldwide than solar and wind combined.

Most commercial solar panels are made primarily from which material?

• Copper
• Lithium
• Graphene
• Silicon ✓ (Correct answer)

Source: Sand-derived silicon, not lithium, is the workhorse of nearly every solar panel.

Offshore wind farms are built out at sea mainly for which advantage?

• Stronger steadier wind ✓ (Correct answer)
• Cheaper land
• Warmer water
• Less salt

Source: Out at sea the wind blows harder and steadier, with no hills or buildings in the way.

Geothermal power plants are most practical in regions with plenty of what?

• Volcanic activity ✓ (Correct answer)
• Sunshine
• Flat farmland
• Strong rivers

Source: Where tectonic plates meet, underground heat sits close enough to the surface to tap.

Pumped-storage hydropower acts essentially as a giant version of what?

• Solar panel
• Battery ✓ (Correct answer)
• Turbine
• Magnet

Source: It pumps water uphill when power is cheap and releases it later: a giant water battery.

A solar 'inverter' is needed because the panels themselves produce which current?

• Alternating current
• No current
• Direct current ✓ (Correct answer)
• Static charge

Source: Panels make DC; the inverter flips it to the AC that your home and the grid use.

Which Scandinavian country generates roughly half its electricity from wind?

• Sweden
• Norway
• Finland
• Denmark ✓ (Correct answer)

Source: Flat, windy Denmark pioneered modern turbines and now leads the world in wind share.

The 'duck curve' that troubles grid operators is mostly caused by abundant what?

• Wind power
• Coal plants
• Solar power ✓ (Correct answer)
• Nuclear power

Source: Midday solar floods the grid then drops at dusk, and the dip-and-spike looks like a duck.

Concentrated solar power towers store heat for nighttime using tanks of what?

• Compressed air
• Liquid hydrogen
• Molten salt ✓ (Correct answer)
• Ice

Source: Mirror fields heat molten salt past 500C, letting the plant keep making power after sunset.

'Green' hydrogen is made by splitting water with renewable electricity through which process?

• Combustion
• Fermentation
• Distillation
• Electrolysis ✓ (Correct answer)

Source: Electrolysis splits water into hydrogen and oxygen, but it's only green if the power is too.

The world's largest solar park, Bhadla, sprawls across a desert in which country?

• China
• India ✓ (Correct answer)
• Egypt
• Morocco

Source: India's Bhadla park in Rajasthan covers an area larger than many entire cities.