03 Energy and the Energy Transition Free Online FlashCards

What is primary energy?

Primary energy comes directly from sources such as coal, sunlight, wind, or uranium.

What is secondary energy?

Secondary energy, such as electricity or hydrogen, is produced by converting primary energy.

Why is electricity use not the same as total energy use?

Electricity use measures only one form of energy use; total energy use also includes fuels such as petroleum used for transport, as well as conversion and delivery losses.

Which fuels are fossil fuels?

Fossil fuels are coal, petroleum, and natural gas formed from ancient organic matter.

What are key environmental and health effects of fossil fuels?

Burning fossil fuels releases carbon dioxide, a heat-trapping greenhouse gas. Their extraction and transport can also release methane, and combustion produces harmful air pollutants.

How can fossil-fuel infrastructure lock in emissions?

Long-lived plants, pipelines, and industrial equipment may keep operating for decades, locking in emissions and making it harder to reduce them.

What makes an energy source renewable?

Renewable energy comes from sources replenished on human timescales, including solar, wind, hydropower, geothermal energy, and bioenergy.

Why does solar and wind electricity output vary?

Solar and wind output varies with weather and time of day because they depend on available sunlight and wind.

What role can batteries play in a high-renewable electricity system?

Batteries store electricity and can shift it from sunny or windy periods to times of higher demand; they do not produce energy.

How is nuclear power classified in relation to renewable and low-carbon energy?

Nuclear power is not renewable, but it is low-carbon because it generates electricity with very low operational carbon dioxide emissions.

What does energy efficiency mean?

Energy efficiency means providing the same service with less energy, as with efficient motors, LED lighting, or better insulation.

Why can a heat pump provide more heating energy than the electricity it uses?

A heat pump transfers heat instead of generating it through combustion or resistance, so it can provide more heating energy than the electricity it consumes.