Marine energy

Question 1

How many tidal periods are there in a 7 day week?

Answer 1

13.5

Question 2

What are the highest tides called and how often do they occur

Answer 2

spring tides occuring once every week

Question 3

What is a tidal barrage?

Answer 3

A tidal barrage is a dam-like structure used to capture the energy from masses of water moving in and out
of a bay or river due to tidal forces

Question 4

What is a tidal lagoon?

Answer 4

Made of retaining walls embedded with turbines that can capture the potential energy of tides. The created
reservoirs are similar to those of tidal barrages, except that the location is artificial and does not contain a
pre-existing ecosystem

Question 5

Advantages of tidal stream generators

Answer 5

• easier installation than a tidal barrage/lagoon
• can be consolidated onto existing structures
• wildlife steer clear of underwater turbines due to acoustics (not the case with wind turbines)
• cheapest to construct out of the tidal technologies

Question 6

Disadvantages of tidal stream generators

Answer 6

• cannot produce as much energy as barrage systems

- susceptible to saltwater corrosion and must be engineered to minimise the impact of this

Question 7

What are wave activated devices

Answer 7

Wave motion is directly transferred to mechanical motion of some kind

Question 8

What are overtopping devices

Answer 8

Incorporates a ramp/tapered chnnel that forces water of incoming waves to spill into a reservoir

Question 9

What are oscillating water columns

Answer 9

Waves cause the water surface in a partially submerged pipe to oscillate thereby pumping air in the pipe through a turbine