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}
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.
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}
• Limited availability of suitable sites.
• Environmental support.
• Government support.
• Cost of development.
A Department of Trade and Industry (DETI) report into offshore wind and
marine renewable energy in 2009 concluded that offshore renewables (such as
wave and tidal power) could make a significant contribution to the proposed
40% target for renewable energy in Norther Ireland.
Discuss the constraints on developing wave and tidal power from the seas
around Northern Ireland.
Your answer should focus on the following areas:
* Research and development / commercial viability
* Conflict with other sea users
* Availability of suitable sites
* Impact on marine life and habitat
* Visual and noise pollution
The quality of written communication will be assessed in your answer. {10}
Constraints:
* Significant amount of research and development is required to make tidal /
wave energy systems, which are consistently commercially viable.
* The UK / Ireland operate busy shipping lanes and therefore locating the
devices is difficult – the need to ensure that they do not impact on navigation /
undersea infrastructure (cables etc.) / fishing areas.
* Not all locations are suitable – e.g. tidal systems require a sufficient difference
in high and low tides to ensure efficiency of the technology.
* Impact of tidal barrages, wave attenuators on migration of marine life and
habitats (e.g. wading birds, mudflats etc.).
* Visual and noise pollution; unsightly appearance within scenic locations and
sensitive locations; undesirable noise created byturbines.
All relevant, valid responses will be given credit. {10}
Harnessing the energy of the tides is a priority concern for Northern Ireland.
Explain four constraints on developing tidal technology.
1: {2}
2: {2}
3: {2}
4: {2}
Availability of suitable sites is limited. [1] There is the need to ensure that they
do not impact on navigation/commercial fishing areas/ undersea infrastructure.
[1]
• Development costs are high. [1] A significant amount of costly research
and development is required to make systems which are consistently
commercially viable. [1]
• Tidal systems require a sufficient difference in high and low tides
[1] to ensure efficiency of the technology so only certain locations meet this
criterion. [1]
• Impact [1] of tidal barrages, wave attenuators on migration of marine life
and marine habitats (e.g. wading birds, mudflats etc.) needs to be assessed to
ensure the environmental impact is minimal. [1]
Tidal stream generators and tidal barrages are the two main generating
methods for tidal power. Compare and contrast these two methods. {5}
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}.
Name this type of installation and outline two advantages that it has over a tidal
barrage installation.
Name__________________________________________________________
Advantage 1 ____________________________________________________
Advantage 2 ____________________________________________________
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.
Compare and contrast tidal stream generators and tidal barrages as generating
methods for tidal power with regard to power generation, cost and
environmental impact
Power generation: {2}
Cost: {2}
Environmental impact: {2}
Power generation: tidal stream generators are basically underwater turbines
whereas tidal barrages are like a small hydro-electric dam; the tidal barrage
tends to generate more power than the tidal stream generator [2]
Cost: tidal stream generators cost significantly less as they are just individual
turbines placed on the seabed whereas tidal barrages are large constructions
built across estuaries [2]
Environmental Impact: tidal stream generators turn slowly and have less
impact on the environment and marine life whereas tidal barrages can have
extensive impact on marine life and estuarine habitats [2]
Harnessing the energy of the tides is a priority concern for Northern Ireland.
Name one major generating method for tidal power. {1}
Tidal stream or Tidal barrages
The figure below illustrates a simple wave attenuator device. With reference to
the figure, outline the operational processes of an attenuator type device. {5}
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}.
Explain how a tidal barrage generate energy form the tides. {5}
• 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}.
Fig 2 below shows a type of wave energy convertor. With reference to figure 2
name a type of wave convertor shown and describe the processes involved in
its operation. {5}
- Wave Attenuator
- Attenuators are oriented parallel to the direction of travel of the waves
- They typically consist of a series of long cylindrical floating devices
connected with hinges and anchored to the seabed (e.g. Pelamis) - The relative movement of the cylindrical parts drives rams in the
connecting sections. - The rams in turn drive an electrcal generator
- The attenuators send electricity to shore via cables laid on the seabed
Describe three environmental implications that must be considered when
deciding to install wave energy convertors at a particular site. {3}
Any three from;
• Impact on marine life and habitat.
• Risk of toxic pollution.
• Visual and noise impact.
• Conflict with other sea users.
Wave and tidal energy have the potential to make a significant contribution to
future energy needs in the British Isles. However, there can be environmental
impacts associated with obtaining this energy. Outline two environmental
impacts which can occur when wave or tidal energy devices are installed at a
particular marine location. {2}
Any two impacts from the following:
* Impact on marine life/marine habitat
* Risk of toxic pollution
* Visual
* Noise pollution
* Conflict with other sea users
Define what is meant by a ‘smart material’. {2}
A material with the ability to alter its basic physical properties or change its
shape {1} when an external influence such as temperature, light level, pressure
or electricity changes {1}.
Define what is meant by a smart material and give one example of a smart
material that could be used to support environmental management. {2}
Definition: A material with the ability to alter its basic physical properties [1]
when an external influence such as temperature, light level, pressure or
electricity changes [1]
Explain how smart glass can be used to support environmental management.
{2}
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}
Give one example of a smart material that could be used to support
environmental management. {1}
Any one from:
• Smart Glass
• Shape Memory Alloys
• Phase-Change materials
Outline the use of smart systems and describe their benefits taking into account
the following: • explain what is meant by a smart system
Smart systems have a wide range of applications and generally involve the use
of a miniaturised sensor which ‘senses’ a change in the environment and
informs an actuator to respond appropriately.
There are three main processes:
• Sensing of changes in the environment being controlled and monitored.
• Actuation of devices in response to the changes identified.
• Controlling the situation taking account of the changing variables in the
surrounding environment.
Discuss the benefits of a smart waste system. {4}
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.
Describe one application of a smart system with reference to engineering,
transportation or waste management. {2}
Any one application from:
* Engineering (medical technology) – use of smart systems can lead to
improved diagnostic tools and less intrusive operating procedures {1}. Sensors
and feedback systems will raise an alarm if there is a concern {1}.
- Transportation – there could be an increase in the development of more
energy efficient devices for mobility {1}, e.g. hybrid vehicles and electric traction
and the efficient control of traffic movement in our cities {1}. - Waste management – the use of smart systems for the disposal and
control of waste {1}. This would also allow us to dispose of waste more
efficiently and/ or economically {1}.
Outline one example of smart systems being applied in the area of
transportation. {2}
Any one from:
Transportation: the development of pre-crash systems, more energy efficient
devices for mobility, e.g. hybrid vehicles and electric traction and the efficient
control of traffic movement in our cities
Outline the use of smart systems and describe their benefits taking into account
the following:
• describe the range of applications offered by a smart system with
reference to transportation and waste management;
Describe the range of applications offered by a smart system with
reference to transportation and waste management.
• Transportation – there could be an increase in the development of more
energy efficient devices for mobility, e.g. hybrid vehicles and electric traction
and the efficient control of traffic movement in our cities.
• Waste management – the use of smart systems to optimise waste
collection rates, frequencies and vehicle loads. This would also allow us to
dispose of waste more efficiently and/or economically.
• discuss the potential environmental and economic benefits offered by the
use of smart systems.
Environmental Benefits
• Sensors can be used in the home to automatically turn off/on appliances
as needed therefore saving electricity/heating fuel, meaning less fossil fuels
have to be burnt, e.g. thermostat on a heating system.
• Sensors can be used to help sort waste and redirect it to a more suitable
place rather than landfill.
• A smart grid is a smart system which can make the most efficient use of
the available energy mix using renewables and nuclear in place of traditional
fossil fuel burning power plants, therefore emitting less carbon dioxide.
• A hybrid car uses sensors to detect when the car is most efficiently run
by the battery and when it is most efficient to use the petrol or diesel engine.
This reduces the amount of fossil fuels being used as the process is much more
efficient.
Economic Benefits
• If sensors are used to switch off appliances/heating system when not in
use the resident will save money on electricity and heating bills.
• If waste can be redirected from landfill and sorted, money could be
saved,
e.g. if glass is recycled then less raw materials and manufacturing has to be
purchased.
• A smart grid allows for a larger energy mix meaning power companies
will have to make their prices more competitive in the market.
• A hybrid car will use less fuel therefore saving money on a fuel bill.
Explain what is meant by Carbon Capture and Storage (CCS) from fossil fuel
plants. {2}
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.
