2.1 Extended Type Questions Flashcards
Discuss the factors which must be taken into consideration when planning and
siting a commercial wind farm venture.
Your response should include reference to;
• Environmental,
• Social factors and
• Energy output issues. {15}
ISSUES AFFECTING POWEROUT;
• Wind speed – faster more powerful winds generate more energy – link to
wind survival speed.
• Relationship between rotor swept area and output – i.e. blade diameter.
• Air density (temperature and altitude)
• Orientation of the wind – linked to yawing.
• Turbine design – hub height, blade length, blade materials, number of
blades, mass of turbine.
• Wind / temperature profile.
ENVIRONMENTAL AND SOCIAL ISSUES;
• Existing infrastructure e.g. roads access for assembling turbines and
maintenance work.
• Environmental impact assessments, e.g. habitat (specifically bog land), plant
and wildlife, (specifically birds and bats).
• Social impact, noise, aesthetics, shadow flicker.
In 2013, Northern Irelands Department of Enterprise, Trade and Investment
(DETI) announced that there is ‘an exciting opportunity for NI to take a
leadership role in the expansion of smart grid solutions’.
Discuss the main factors that must be considered when assessing the future
opportunity of smart grid.
Your response should include reference to;
• The concept of a smart grid;
• Problems associated with delivering energy from renewable sources to the
grid;
• The need to develop energy storage facilities capable of storing energy from
renewable energy sources;
• The use of interconnectors between European countries in a smart grid
scenario;
• Potential benefits of smart grid to the NI economy; {15}
The concept of smart grid;
• An electrical grid is a network which facilitates the distribution of energy from
one place to another as required by the users of the grid.
• A SMART grid relies on a computerized control system to divert energy from
one renewable source to another as demand for energy varies on the grid.
Problems associated with delivering energy from renewable sources to
the grid;
• Energy generated from renewable sources is intermittent. For example, the
wind may be blowing at high speeds during the night but there is little demand
for energy at this time.
• The intermittent nature makes control of the system more difficult.
The need to develop energy storage facilities capable of storing energy
from renewable energy sources;
• The use of storage technology in a smart grid system allows for more control
over the total available energy resource in the system.
• When energy is generated, for example by a wind farm, but there is little
demand, then it can be stored.
• Energy storage technology poses the greatest challenge for smart grid. This
technology is in its infancy with huge investments being made presently in research
and development into energy storage.
• Examples of energy storage include pumped storage (most widely used at
present), compressed air storage, battery systems etc
The use of interconnectors between European countries in a smart grid
scenario;
• The use of interconnectors between Ireland, UK and Europe offers more
opportunity to control the distribution of electrical energy. Dealing with
a larger available pool of energy from a greater variety of renewable resources.
• Each country in the EURO grid has its unique renewable energy resources. For
example, Ireland (North and South) has the best location for wind in Europe,
Austria has extensive forests and is therefore better suited for bioenergy;
Norway has extensive capacity for hydro energy; Spain and Portugal have
excellent capacity for solar energy; Finland has excellent maritime capacity etc.
• This variety of renewable resources allows for a more efficient system on a
European basis.
Potential economic benefits to Northern Ireland with the use of smart grid.
• Ireland (North and South) currently imports 92% of their energy and are subject
to price and currency fluctuations.
• Smart grid will facilitate energy security.(Have energy when we need it)
• Use of renewable resources will reduce environmental implications of energy
generation. (Counteracting economic implications of greenhouse gases).
• Allow for more competitively priced energy.
• Northern Ireland has the potential to produce in excess of its total energy
requirement annually from on and off shore wind energy. This provides an
excellent opportunity to sell energy to other European countries through the
smart grid. Northern Ireland could be a net exporter of energy.
Fossil fuels have played an important part in the development of modern
society. Many people believe that this has been at a high cost to society and
the environment. Discuss the cost of society reliance on fossil fuels.
Your response should make reference to;
• The trends in fossil fuel use globally.
• The concept of fuel security.
• The environmental impact of fossil fuel use.
In November 2016 the Department for Business, Energy and Industrial Strategy
and Ofgem published proposals for the development of a smarter, more flexible
energy system in the UK. The proposals include a specific focus on energy
storage and aim to remove the regulatory and commercial barriers to the further
deployment of energy storage in the UK.
Discuss the storage of energy from renewable energy sources and outline how
this can contribute to the development of a smarter, more flexible energy
system.
Your answer should address each of the following:
• The problems associated with delivering energy from renewable energy
sources and the need to develop energy storage facilities that can store
energy produced by renewable sources.
• The basic operational systems of the two main grid-scale renewable energy
storage systems and the types of locations where each of these could be
installed cost effectively.
• How energy storage can contribute to the development of a smarter, more
flexible energy system.
The quality of written communication will be assessed in this question. {15}
Indicative content:
The problems associated with delivering energy from renewable energy sources
and the need to develop energy storage facilities that can store energy
produced by renewable sources:
• Wind, wave and sun energy are not reliable sources of energy
• Wind, wave, sun and tidal are intermittent sources of energy
• Because of this unreliability/intermittency, the renewable energy may be wasted
unless stored effectively
Storage of electrical energy is difficult and it may need to be converted into another
energy form for easier storage
The basic operational systems of the two main grid-scale energy storage
methods and the types of location where energy storage could be cost effective
• Compressed Air Energy Storage:
• Air compressed in underground caverns
using surplus renewable energy;
• Released air drives turbine and generates electricity when grid needs it.
• Pumped Hydro Energy Storage:
• Water pumped up to high level reservoir
using surplus renewable energy;
• Released water drives turbine and generates electricity when required
• Suitable sites:
• Existing underground caverns (CAES);
• Existing high level reservoirs/suitable topography (pumped hydro);
• Good access to power distribution networks
How energy storage can contribute to the development of a smarter, more
flexible energy system:
• surplus renewable energy can be stored and released
into the grid at times of high demand
• this provides greater energy flexibility and allows the
main power generating stations to run at a more
constant and efficient output level
Biomass fuel chains have the potential to provide up to 21% of UK electricity
demands at a viable cost. The UK could build internationally competitive
industries in several areas of biomass such as in energy crop breeding, in
established combustion and process engineering sectors, in novel biogas
technologies and in large-scale biomass process engineering.
Discuss the types and use of biomass as an energy source. Your answer
should focus on the following:
• The types of biomass and its use for macrogeneration and microgeneration
• Advantages and disadvantages of commercial anaerobic digesters
• The composition of biogas {15}
The types of biomass and its use for macrogeneration and
microgeneration
• Biomass is material derived from growing plants or from animal manure.
Some of the main plant crops that are grown commercially to produce biomass
are willow, poplar, elephant grass, maize and sugar cane.
• Biomass can be used for the large-scale generation of electricity. It can
directly replace fossil fuels.
• The heat energy from biomass combustion turns water into steam in a
boiler. The pressurised steam drives a turbine coupled to a generator that
produces an electric current.
• Biomass can be used for microheat generation, e.g. woodchip pellet
boilers.
• Biomass is carbon neutral and renewable. It uses carbon dioxide during
growth and releases it on combustion.
• Biomass has lower energy densities than fossil fuels so greater volumes
are required.
Advantages and disadvantages of commercial anaerobic digesters
• Treats waste and reduces greenhouse gases.
• Anaerobic digestion can take place at a location local to where waste or
energy crop is produced which reduces the need for transportation.
• Requires a steady supply of a consistent feedstock.
• The process can be slow, particularly during the winter months and may
require the addition of extra heat.
The composition of biogas
• Anaerobic digestion is the process used to form biogas.
• Anaerobic digestion is the biological breakdown of organic materials in
the absence of oxygen.
• Organic materials include waste from agriculture and food waste.
• Biogas is a mixture of methane and carbon dioxide.
For the 12 month period April 2018 to March 2019, 38.6% of total electricity
consumption in Northern Ireland was generated from renewable sources
located in Northern Ireland. The remaining portion of energy used in Northern
Ireland was imported or produced by a traditional power station.
As the variety of sources of our electricity increases, the method of delivery
must also change and adapt. Outline the traditional method of electricity
production and delivery and discuss how the use of a smart grid system can be
beneficial for Northern Ireland.
Ensure that you make reference to the following points in your discussion:
• the main phases in the large-scale generation of electricity from fossil fuels;
• describe how electricity is distributed throughout the National Grid;
• the concept of a smart grid;
• the long-term economic and environmental benefits of the development of a
smart grid using Irish, UK and European interconnections.
The quality of written communication is assessed in your answer. {15}
The main phases in the large-scale generation of electricity from fossil
fuels;
• The fossil fuel (usually coal) is burned and used to heat water.
• This produces steam which is used to turn a turbine which powers a
generator where kinetic energy is turned into electrical energy.
Describe how electricity is distributed throughout the National Grid;
• Transformers are necessary to step up the voltage of the electricity as it
leaves the power station.
• This reduces losses through sound, resistance and heat as the electricity
travels through the wires.
• Transformers are also needed to step down the voltage to ensure it is
safe to be used by the consumer.
The concept of a smart grid;
• A smart grid is a network which facilitates the distribution of energy from
one place to another as required by the users of the grid.
• A smart grid incorporates traditional energy generation and renewable
systems.
• A smart grid relies on a computerised control system to divert energy
from one renewable source to replace another as demand for energy varies on
the grid.
• A smart grid also makes use of energy storage systems such as CAES
or Pumped Hydro to ensure that minimal energy is wasted.
• Energy can be stored at off-peak times, e.g. in the middle of the night
when demand is low, and stored until peak times such as breakfast time.
The long-term benefits of the development of a smart grid using Irish, UK
and European interconnections;
• Interconnections between the UK, Ireland and Europe will increase
energy security in Northern Ireland.
• Interconnections allow more control over the supply and distribution of
energy, allowing energy from renewables to be used most efficiently. This in
turn should lower reliance on fossil fuel power stations, benefitting the
environment.
• Flexibility: Different locations are favourable for different types of
renewable. Interconnections allow each country to use the methods which suit
their terrain best, e.g. Ireland is suitable for wind farms, Norway is suitable for
hydroelectric energy etc.
• More competitive pricing.
• Northern Ireland could use the wind resource to produce energy which
could be sold to other countries, thus creating an income.
Discuss the development of plastics for the future. Your discussion should focus
on the following:
• The current issues surrounding the global production and use of plastics.
• The manufacture of and uses for degradable plastics.
• Experimental methods used to compare the degradability and tensile
strength of polythene and photodegradable plastic.
The quality of written communication will be assessed in your answer. {15}
Answer:
Indicative Content
The current issues surrounding the global production and use of plastics
• Global production of plastic continues to increase each year.
• Plastic production is the largest single user of crude oil outside the
energy and transport sectors.
• Polymers and plastics made from crude oil derivatives cannot be broken
down by micro-organisms or easily recycled.
• Toxic gases are released by incinerating plastic materials.
The manufacture of and uses for degradable plastics
• Incorporating additives into the polymer during the manufacturing
process to enhance biodegradability.
• Modifying the manufacturing process to enhance thermal and photo
degradation.
• Producing compostable plastics that can improve soil composition in
regions where soil structure is poor.
• Use for agricultural films, packaging and labelling.
Experimental methods used to compare the degradability and tensile
strength of polythene and photodegradable plastic.
• Degradability is compared using a propagator with ultraviolet (UV) bulbs.
• Samples of plastics of equal size are used.
• UV light is shone on the samples for a fixed time and the progress of the
plastics is monitored at intervals by e.g. taking photos.
• Tensile strength is compared using a Newton meter.
• Tensile strength is the ability (of a plastic) to withstand force applied to it.
