Lecture 19: Ocean energy

Question 1

what causes tides?

Answer 1

• tides caused by the rotation of the earth and the gravitational pull of the moon and the sun

Question 2

Are tides a predictable form of energy? Why or why not?

Answer 2

• they are well understood and predictable
• provides more energy due to the density of water

Question 3

Why are tides a slow growing industry?

Answer 3

• the specific requirements of coastal areas and the difference between energy demands makes it slow growing

Question 4

How is tidal energy generated?

Answer 4

• uses the movement of the water caused by tidal forces to turn turbines, generate electricity

Question 5

What are the forms of tidal energies?

Answer 5

• in stream tidal devices : generates electricity using slow spinning rotors to not harm fish: many technologies being developed
• tidal lagoons: fill inlet and let water flow in / out through turbines
• tidal barrages : dam built along tidal estuary: gates/turbines control water flow and generate power

wave energy: rocking motion pumps high pressure to hydraulic motors that drive electrical generator sites

Question 6

what roles do conservation and energy efficiency play in helping us to meet our energy needs sustainably?

Answer 6

• meeting needs with renewable sources becomes more likely when we pair renewables with energy conservation measures
• stabilization wedge: 8/15 steps would, 1 of the wedges is energy efficiency

Question 7

what is conservation?

Answer 7

• efforts that reduce waste and use our resources more efficiently
• a large part of conservation is changing our behaviour

Question 8

what is energy efficiency?

Answer 8

• a measure of the amount of energy needed to perform a task
  -lower energy required = higher efficiency

Question 9

what is pay back time?

Answer 9

• the amount of time it takes to save the money that was spent on the equipment

Question 10

what are home energy audits?

Answer 10

• helps homeowners determine what actions would provide the best EROEI
• eg; ensure home is well insulated before you installed solar panels

Question 11

what might make a home energy efficient?

Answer 11

• airtight construction, air sealing, high performing equipment and windows, LED lighting, energy star appliances, better insulation

Question 12

What is energy star?

Answer 12

• government backed programs that promote energy efficiency