What is the primary focus of the Sankey flowchart discussed in the video?

• Plumbing systems

• Energy flow and efficiency

• Transportation networks

• Water distribution

Which stage of energy flow is described as the original source used to produce power?

• Useful energy

• Primary energy

• Secondary energy

• Final energy

What percentage of the world's energy is still supplied by fossil fuels, according to the video?

• 80%

• 70%

• 50%

• 60%

What term is used to describe the energy that is wasted and not used for any purpose?

• Lost energy

• Unused energy

• Rejected energy

• Residual energy

What is one of the biggest culprits of energy inefficiency in electricity generation?

• Solar panels

• Wind turbines

• Steam turbines

• Hydropower plants

What happens to energy efficiency when we reach peak demand?

• It becomes more efficient

• It decreases due to older plants being used

• It remains unchanged

• It improves significantly

How much of the energy from a gas stovetop is actually used for cooking?

• 20%

• 40%

• 60%

• 80%

What is a key advantage of renewable energy sources like wind and solar?

• They are less efficient

• They skip initial energy conversion processes

• They require burning fuel

• They are more expensive

What is the estimated reduction in final energy needed in a fully electrified society?

• 50%

• 40%

• 30%

• 20%

What is the synergy between renewables and energy efficiency described in the video?

• They work independently

• They hinder each other

• They complement each other

• They are unrelated