2.8 Emerging technologies

Question 1

The production of energy from wave and tides is a priority concern of Northern Ireland and a significant amount of investment is being made within both of these areas.
Evaluate the constraints in the development of wave and tidal power in the UK and Ireland.
The quality of written communication is assessed in this question. {8}

Answer 1

Answer;
Indicative content;

Constraints

 Significant amount of research and development to make systems which are consistently commercially viable.

 The UK / Ireland operate busy shipping lanes and therefore locating the devices is difficult – need to ensure that they do not impact on navigation.

 Devices need to be robust and able to survive significant changes in sea conditions: they are also required to withstand sea water corrosion.

 Tidal systems require a sufficient difference in high and low tides to ensure efficiency of the technology – not all locations are suitable.

Question 2

Wave and tidal energy have been described as a priority concern for Northern Ireland. Identify two main constraints on developing wave and tidal technologies in Northern Ireland. {2}

Answer 2

 Limited availability of suitable sites.

 Environmental support.

 Government support.

 Cost of development.

Question 3

Question;
Tidal stream generators and tidal barrages are the two main generating methods for tidal power. Compare and contrast these two methods. {5}

Answer 3

Answer;

Tidal stream generators make use of the kinetic energy of moving water to power turbines {1}

Tidal barrages make use of the potential energy in the difference in water height between high and low tides {1}.

With the receding tide, this potential energy is then converted into kinetic energy as the water is released through large turbines that create electrical power through the use of generators {1}

Tidal stream generators have the advantage of being much cheaper to build {1}

And do not have as much of an environmental impact as tidal barrage {1}.

Question 4

Apart from tidal barrage generators, identify the other type of tidal generator and outline two advantages that system has over a tidal barrage installation.

Answer 4

Answer;

Name – Tidal stream generator {1}

Any two advantages from;

 They are cheaper to construct.
 They are smaller and have less environmental impact.
 The turbine blades turn slowly and have less effect on sea life.

Question 5

Question;
The figure below illustrates a simple wave attenuator device. With reference to the figure, outline the operational processes of an attenuator type device. {5}

Answer 5

Answer;

Attenuator; These devices are orientated parallel to the direction of the wave. {1}

Attenuators are typically a series of long cylindrical floating devices connected to each other with hinges and anchored to the seabed (Pelamis).

The cylindrical parts drive hydraulic rams in the connecting sections {1} and those in turn drive an electrical generator {1}.

The devices send the electricity through cables to the sea floor where it then travels through a cable to shore {1}.

All relevant, valid responses will be given credit.

Question 6

Explain how a tidal barrage generate energy form the tides. {5}

Answer 6

 A barrage is built across an estuary with gates and turbines built into the wall of the dam {1}.

 As the tide flow in the gates are open and the turbines are operated producing electricity {1}.

 At high tide the gates are closed trapping the water inside {1}.

 When water outside has fallen sufficiently (e.g. 5m) the gates are opened {1}.

 The released water turns the turbines again producing electricity {1}.

Question 7

Question:
Describe three environmental implications that must be considered when deciding to install wave energy convertors at a particular site. {3}

Answer 7

Any three from;

 Impact on marine life and habitat.
 Risk of toxic pollution.
 Visual and noise impact.
 Conflict with other sea users.

Question 8

Explain how smart glass can be used to support environmental management. {2}

Answer 8

Smart glass changes light transmitting properties when voltage is applied. {1}

Allows individual to control the light and heat of any room, can save costs relating to heating, air conditioning and lighting. {1}

Question 9

Question;

Discuss the benefits of a smart waste system. {4}

Answer 9

Answer should contain some reference to the following benefits of a smart waste system:

 Identifies peak times of waste,

 Can organise disposal when required.

 Anticipate need.

 More cost effective.

 Better planning of collection of schedules.

Question 10

Explain what is meant by Carbon Capture and Storage (CCS) from fossil fuel plants. {2}

Answer 10

Carbon Capture and Storage (CCS) is the name given to the technology and process designed to prevent carbon dioxide exhaust when burning fossil fuels from entering the atmosphere {1}

The exhaust gas from the combustion of fossil fuels is ‘captured’ and then stored rather than being released into the atmosphere.

Question 11

Clearly outline in the spaces provided the three main phases of Carbon Capture and Storage and the processes associated with each.

Answer 11

Phase 1 – Trapping and separating {1}. Entails taking the gas emitted from the process and separating CO2 from the other gases which are present {1}.

Phase 2 – Transport {1}. Involves moving the isolated CO2 to a location for its storage normally through a system of pipes {1}.

Phase 3 – Storage {1}. Refers to the long term location for the captured gas. Currently this is done either underground or underwater.

Question 12

Question; Discuss one advantage and one risk associated with geo-engineering as the deliberate modification of the Earth’s atmosphere to offset the effects of climate change. {2}

Answer 12

Answer;

Any one advantage from;

 Counteract increasing global temperatures.

 Facilitates the control of greenhouse gases

 Counteracts climate change.

 Some technologies (e.g. cool roof technologies) are inexpensive and effective.

Any one risk from;

 Risks associated with control and predictability of technologies and processes.

 Little known about the long term side effects.

 Ethical concerns and risks associated with the use of geo-engineering.

 Governance risks.

Question 13

Give one example of a ‘geo-engineering’ technique and explain how it could be applied. {2}

Answer 13

 Cloud seeding {1} where clouds are injected with crystals to produce ‘rain on demand’ {1}.

 Space reflectors {1} which block a proportion of the sun’s rays from entering the earth’s atmosphere thereby reducing global warming {1}.

 Afforestation {1} whereby global scale planting of trees absorbs CO2 from the atmosphere {1}.

 Biochar {1}, the process of ‘charring’ biomass so that the carbon it contains is locked up in the soil {1}.

Question 14

Question;

Describe the operation of Bio-Photovoltaic (BPV) devices. {2}

Answer 14

Answer;

Bio-Photovoltaic (BPV) devices generate electricity from light energy {1} by exploiting the photosynthesis of living organisms such as moss, algae, cyanobacteria and vascular plants {1}.

Question 15

State the potential energy that could be generated by wave and tidal energy to meet 2020 targets.

Answer 15

Wave energy: 500 MW

Tidal energy: 200 MW