Environmental sustainability PDF

Running head: ENVIRONMENTAL SUSTAINABILITY
ENVIRONMENTAL SUSTAINABILITY
Name of the Student
Name of the University
Author Note

2ENVIRONMENTAL SUSTAINABILITY
ABSTRACT
The sustainable development of the mankind is the key to human survival in the planet. The
growing anthropogenic impact on the environment has made the planet vulnerable for the
existence of life. The continuous degradation of the environment and depletion of its resources to
satisfy human demand has left the environment in a state that can no longer be reversed. It is
time that that alternative sources of energy production and sustainable methods are identified and
put to practice to reverse the impacts thus created. The paper will look into the different energy
storage systems and how they are used to store energy created from non conventional sources.
The cleaner sources of energy have huge potential and optimum utilization of these resources can
solve the existing issues of global energy requirements. Human technology is yet to develop to
full tap the energy from sources of nature and the report will also look into the various
applications and technologies that are being developed to tap the energy and store in different
forms. The environmental impacts, their advantages and disadvantages will also be reviewed in
the paper. The paper will also review and understand the competitive options that include Solar
PV Panels and Wind turbines. The paper concludes with recommendations of these technologies
and a review of current and future prospects in the field of sustainable energy development.

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Table of Contents
Introduction......................................................................................................................................4
Energy storage systems: the pros and cons..................................................................................5
Advantages of Energy Storage Systems: The Pros..................................................................6
Disadvantages of the Energy storage Systems: The Cons.......................................................7
Commercial application of energy storage systems....................................................................7
Environmental impact of storage systems...................................................................................9
Cost effective recommendations: Solar PV and Wind turbine systems....................................12
Solar PV Panels.....................................................................................................................12
Wind Turbines.......................................................................................................................13
Energy Storage Systems: The Future Prospects........................................................................15
Geothermal Energy................................................................................................................15
Fly Wheel Storage System.....................................................................................................16
Tidal Energy..........................................................................................................................16
Super Conducting Magnetic Storage.....................................................................................17
Ongoing Research: Microbial Fuel Cell and Bio Fuels.........................................................17
Conclusion.....................................................................................................................................18
References......................................................................................................................................20

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Introduction
With the growing environmental issues and the degradation of the environment, the
world has started to look into alternatives and means that can provide sustainable growth and
allow for more concrete development with lesser anthropogenic impact on the environment.
Since the advent of time, the goal of necessary development has been dependent on energy
extensively. The journey from non renewable fossils fuels to cleaner renewable fuels happened
with the growing consciousness of the environment. The concept for sustainable development
developed with the first Earth Summit held at Rio de Janeiro in 1992. The Earth summit first
addressed issues regarding environmental pollution and degradation of the environment. Prior to
the 1970s very efforts were made to integrate and evaluate environmental degradation and it’s
the social and economic impact (Barrow, 2006). Initially the concept of environmental
management started with natural resources management which later was modified into
sustainable environment management. The natural resources management was not promulgating
and addressing the interest of the environment and a need for sustainable development arose to
prevent the environment. The energy supplies of the world are majorly contributed by non
renewable resources mostly petroleum and coal. The U.N General Assemble adopted ‘Agenda
2030’ in 2015 for achieving Sustainable Development Goals or SDGs which is dedicated to
ensure sustainable plans for energy for all. The Paris Agreement and the Agenda 2030 for
Sustainable development focuses on cleaner and environment friendly energy. The introduction
of Solar PVs and Wind Turbines as sources of sustainable energy have gained momentum and
over the years and is being promoted to meet the SDGs goal (Barton and Infield 2004).

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The issue that comes with creating safe energy and reducing the environment impact is
the storage of the energy and the life cycles assessment of these storages and the kind of impact
they have in the environment. The report will look into the several kinds of storages that are
available, the impact that they have on our environment, the sustainability of the non-
conventional sources of energy and the way they create scope for sustainable environmental
management.
Energy storage systems: the pros and cons
The recent growth of the several renewable sources of energy it has become important to
store the produced energy in storage systems. The future will see constant rise in production of
energy mostly from renewable energy resources and the storage systems will be influential in
determining the use of these sources of energy in the time to come. Decentralized electrical
production from renewable sources yield more productivity and assures supply with fewer
environmental hazards. The character of production of renewable sources being unpredictable
requires proper systems of storage that would ensure uninterrupted power supply. The renewable
energy resources fluctuate in their productions and therefore it is mostly important to have
adequate storage facilities for the power being generated. The importance of storage systems
therefore is paramount in any site of energy production. The section will look into the several
concepts and types of storage systems that are being used to store energy produced form non
conventional means (Dash, 2010).
Generally, storages are done in dry cells mostly including lithium ion for lower
capacities. Higher capacity intakes are generally stored in system with complex structures which
include mostly compressed air and flow batteries and fuel cells. Though compressed air and fuel
cells are relatively younger technologies and field results are still not confirmed. Fly wheels and

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Super Capacitors are generally more preferable. Hydraulic and magnetic storages are also
reliable means of intermittent storage. A look at the all the storage systems that can potentially
create opportunities for the renewable energy will help us to evaluate the advantages they
provide and the drawbacks that resist them from implementation in commercial scale (Sternberg
and Bardow, 2015).
Advantages of Energy Storage Systems: the Pros
The advantages of storage systems in storing energy resources include transmission in
remote area and locations and
decentralizing of transmission. Storage
systems are environmentally cleaner as
compared to transmission of conventional
sources of energy. There are several factors
that add up to the advantages of storage
systems apart from accessibility and
installation of these systems in remote
locations. Autonomy of the storage systems
make them competent enough for installation in remote places (Barton and Infield, 2004).
Autonomy refers to the continuous supply of energy from the storage and is defined in terms of
the ratio between energy capacity and discharge capacity. The next advantage that the storage
systems hold is the efficiency. Different systems have different capacities of energy storage and
efficiency depends on the load they serve and the amount of energy that is being handled by
these systems. Generally, storage systems are characterized by their ability to be permanent
establishments or portable units. This gives an advantage over transmission systems and general
Image 1: Hydro storage system
Source: (TheGreenAge, 2018)

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methods of energy transmission. The option of energy storage in terms of duration is an also a
flexible choice and an added value to the storage systems. The storage systems can be devised in
terms of long term storage and short term storage systems and hence modulations according to
requirement can be made. The storage systems can be moulded in to several requirements based
on the amount of energy required and therefore these units can be made according to the
maximum capacity required (Barrow, 2006).
Disadvantages of the Energy storage Systems: the Cons
Looking over to the negative effects of the storage systems, the energy storage systems
being recent inventions, innovations and advancement of technologies are still yet to come. The
storage systems have a number of imitations that limit their applicability while establishment of
units. The storage systems have been grossly studied over their durability and life. The self
discharge also demotes their application to various fields. The Self discharging character of most
of the energy storage systems is generally an issue that affects the storage systems. The storage
systems also require regular monitoring and maintenance with equipment controlling therefore
they are less encouraged. Cost is one of the major factors attached to storage systems. Any form
of energy production and transmission incurs huge investment costs and storage systems are not
an exception (Hemmati and Hooshmand, 2017). The cost attached to the establishment and
commissioning of these units have huge cost initial cost attached which is negative factor for the
concern. Apart from these, operational constraints and reliability issues due to their unpredictable
nature are major drawbacks of storage systems.
Commercial application of energy storage systems
Since storage systems have been recent inventions most of their commercial potential is
still under trials or field tests. The several technologies that are being used in storage systems

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have their advantages and disadvantages, which depend on their usage and application. Batteries
are the most common forms of storages but are restricted to low capacity usages. A look at the
following storage systems will enable us to understand the various storage systems that are in
common use for storing energy from renewable sources.
The storage systems include:
 Pumped Hydro storage (PHS)
 Thermal Energy storage (TES)
 Compressed Air Energy Storage (CAES)
 Small scale Compressed Air Energy Storage (SSCAES)
 Natural Gas Storages (NGS)
 Flow Battery Storages (FBS)
 Fuel Cell Storages (FCS)
 Fly Wheel Energy storages (FWE)
 Super Conducting Magnetic Energy Storages (SMES)
 Energy storage in Super capacitors
The various storage systems have several applications and are generally used based on their
application and requirement (Sternberg and Bardow 2015). The most commercial viability
depends on several factors that include the amount of energy required and the budgetary
allocations available. The geographical factors are also taken into considerations while
considering their availability.
The pumped hydro storage or the PHS storage facility is a system involving the storage of energy
by accessing the power of water. It has the capacity to store high capacity energy that can range

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to almost 100 MW and is readily available where water resources are abundant. The system
involves pumping water from a lower storage to a higher storage when water inflow is less,
during peak load times water is allowed to flow from the higher reservoir to the lower one
producing higher capacities of electricity (Chen et al 2009).
The Thermal Energy Storage uses the power of heat to transform fluids into steam and thereby
turn turbines to generate electricity. Generally different compounds are tried to store heat in
forms and mostly include Sodium, Molten salt and pressurized water systems. The general
techniques involve transforming the preserved heat into other forms of energy. The TES has a
high efficiency and does not have geological constraints.
The compressed air energy storage systems are the most cost effective means of energy storage
systems. They achieve similar efficiencies compared to their competitors. The CAES uses the
mature technical application using high pressure compressed air to store the energy at lesser
operational costs (Lund and Salgi 2009). This increases feasibility and cost effectiveness of the
issue. Generally deep salt mines or rock caverns deep underground are used to store the
compressed air and are simultaneously used to generate electricity. Researches reveal that air can
be compressed in cisterns and similar pressure which would remove the geological constraints
and allow commercial viability of the storage facility.
The other storage system uses technologies that have not been commercially applicable and have
only been lab tested so far. These applications are yet to be tested commercially and further
innovations will still going on in these systems of energy storage.

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Environmental impact of storage systems
The storage systems have an environmental impact that can be that can be analysed
depending on the lifecycle assessment of the different storage systems. Most of the storage
systems that store renewable energy require use different compounds and processes to harness
and store the energy (Sternberg and Bardow 2015). A brief look into the various storage systems
will allow us to understand the impacts that they can create and will help us to see their positive
or negative effects in the surrounding.
The storage systems are generally cleaner and have less environmental impact as
compared to their counterparts in the conventional formats. The environmental impacts of the
energy storage systems can be evaluated through an over view of the life cycle analysis of the
various systems based on their consumption of energy for operation which requires the sources
from traditional means. The establishment of the facilities and their operation incurs an impact
which also needs to be taken into account. The impact on the environment can be measured in
terms of a functional unit and the necessary impact can be understood through the evaluation of
the unit per capacity. The impact of the environment can be accessed through their impact on
global warming, fossil depletion and resource depletion. An impact on the environment includes
categories that have promote eutrophication in fresh water and marine ecosystems, human
toxicity, mineral resource degradation, ionizing radiation, ozone depletion and photochemical
oxidation (Ibrahim, Ilinca and Perron 2008). The impact will also include acidification,
categorization according to the carbon and water footprint that follow throughout the life cycle of
the energy storage systems. A brief schematic below will allow us to understand the impact with
respect to global warming and CO2 footprint and greenhouse emissions.

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Schematic 1: Assessment of environmental impacts of Energy Storage Systems.
Source: (Sternberg and Bardow 2015)
The several process through out the life cycle of the energy storage systems include
various impacts at each stage and therefore the impacts vary depending on the basis of the
compounds being used in the processes.
The impact of the HES storage systems include water footprint due to their massive use
of water as a mens to store energy. The amount of water stored incurs heavy impact on the
footprint for the HES systems (Hemmati and Hooshmand 2017). The HES systems generally
have no other environmemntal impacts apart from the water usage and impacts in the ecology
while establishment is constructed. The toxicity of the chemical storage systems and and
chemical batteries inculde impact from the radiation of the compounds that are used in the
storage systems.

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Mostly the impact created by the ESS are environmetally cleaner and less impactful in
the environement. Most of the ESS being based on renewable and greener energy sources have
less footprint that is attached to the production of these sources. The storage capacitors that
involve compressed air, Natural gas storage systems and the Magnetic storages mostly store
energy in different forms that mostly using energy dynamics and capacitors thereby reducing the
impact on the environment (Sternberg and Bardow, 2015).
Cost effective recommendations: Solar PV and Wind turbine systems.
Solar PV Panels
With the growing environmental concerns and introduction of the energy storage systems
in renewable sectors of energy, there has been constant evolution of the several technologies that
are being installed. The Solar PV or the Solar Photovoltaic cell has gained popularity in domestic
use and has been the most used energy storage system since the advent of the technology. The
most important cost effectiveness of the Photovoltaic cells lies in the fuel cost which is
completely free (Reichelstein and Yorston,
2013.). The fuel being solar power is
abundant and completely free of cost. The
low cost production of the Solar PV cells
have seen increased production and around
3500MW of Photovoltaic systems have
been installed around the world currently.
Looking at the cost effectiveness of the
Solar Cells, a major portion can be attributed to the operational cost which is fairly low, a
number of government subsidies that have been allowed for installation of the solar PV systems
Image 2: Solar PV
Source: (TheGreenAge 2018)

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have made it more cost efficient for domestic purposes, which eventually has increased the
popularity of the technology.
Given its potential with respect to energy production at lower costs, recommendations
have been made all around the world. Solar PVs are basically of three different types and
generally include Monocrystalline, Polycrystalline and Thin film of which the efficacy of
monocrystalline is the most competitive. With growing technological advancements, it is
estimated that the Solar PV technology will increase considerably. There has been almost 17GW
production in 2010 which has been around 250% increase relative to 2009 production output
(Reichelstein and Yorston 2013). The future of the Solar Photovoltaic technology seems
promising with its applicability in off-grid domestic and non domestic sectors. The On grid
applications are also in the use and seem promising in the years to come. The cost efficiency
being gradually increasing with newer technologies, Solar PVs are the future of energy
productions
Wind Turbines
The next possible prospect of energy production relative to cost efficiency seems
probable through Wind Turbines. Among renewable sources of energy, wind turbines have
grown considerably with competent technological advancements. The next few decades are
supposed to see an increase in wind power production through Wind turbines. 238351 MW of
power was produced from wind turbines across the world in 2011 (Blaabjerg and Ma 2013).
There future growth of wind power seems promising with the rising installations of wind farms
and turbines. The VAWT or the Vertical Axis Wind Turbine technology is estimated to dominate
the wind power generation sector in the coming years. The necessary elements that count for
wind power will now be dependent on the cost efficacy of the system and its versatility. The

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levelized cost of energy or the LCOE is the annual cost of generating electricity divide by the
annual energy production. The LCOE for wind turbines will allow us to understand the
feasibility of Wind turbines in commercial and domestic use (Kumar et al 2016).
Looking at the cost structure of the wind turbine systems, the cost effectiveness can be
evaluated. The establishment cost was initially higher during the 1980s but with recent
technological developments, the costs of establishment have gone down. The operational costs
are comparatively lower compared to their counterpart technologies in conventional sources
(Martínez et al 2009). There is completely no cost of the fuel which is wind being available
completely free of cost allows for competent
prices for the output. There is reduction in
dependency on fossils fuels, and less
environmental degradation, no harmful
emissions as compared to other sources and
relatively safer impacts. In favourable
conditions with good wind speed at round 8-9
m/s, the cost of electricity can come down to 4-5 cents/kWh, which will definitely decrease with
increasing technologies in the sphere (Ondraczek, J., Komendantova and Patt 2015). The average
life of wind turbines being 25 years can also elongate to greater numbers with technical
advancements. Given the life cycle of the assets the cost of the electricity can be further
decreased.
With government subsidies and several other promotional policies the Wind turbines can
are probable recommendations for the future source of energy. The average capital costs have
Image 3: Wind turbines
Source: (TheGreenAge 2018)

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reduced substantially since the initiation of the technology and future times are more promising
with further evolved implications such as VWAT technologies.
Energy Storage Systems: The Future Prospects
The future world of energy productions with emphasis on greener and sustainable
production of energy and their storage facilities will reach new heights. The non-conventional
sources of energy are no longer ‘non conventional’ and are comparatively becoming popular in
use and application. The changing climate of the globe, with serious environmental degradations
has compelled humanity to seriously look into the resources and technologies that tap the
enormous energy available in the environment in safer and less impactful means. The various
storage systems and their modifications have allowed man to create more opportunities than ever
to tap resources from the renewable sources. Apart from the most popular technologies of Solar
Photovoltaic cells and Wind Turbines, Hydro power and storage systems, several other
technologies have been recently being researched and developed for future implications in
commercial scale. The tapping of the geothermal energy, the Tidal energy and inventions of Fuel
Cells show possibility of more cleaner and accessible ways of energy productions. The Fuel cells
are the most recent of the technologies that involve transformation of chemical energy into
electrical energy. The necessary developments have been recently in research in this technology.
The developments have been made in microbial fuel cells which can derive energy from
microbial activity and chemical transformations (Santoro et al 2017).
Geothermal Energy
The geothermal energy is a comparatively older technology but very few applications are
operational. The tapping of the geothermal steam to rotate generates in creating electricity is

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currently being used through natural geysers (Kırlı and Fahrioğlu 2018). Though the technology
has a geographical constraint, technological modifications can make it a possibility in the future.
Fly Wheel Storage System
The Fly Wheels are mechanical arrangements where either steel or recently carbon fibre
wheels are rotated at high speed generally in a
vacuum chamber to eliminate energy loss and
generate electricity from the rotational energy of
the wheels (Dagnæs-Hansen 2018). This is a
completely newer technology and that will see
more developments and field application in the later
years. The technology uses mechanical bearings that
sustain the energy in the system. Conservation of energy is applied in the field to store energy.
Tidal Energy
Tidal power tapping, is done by converting the energy of tides into power resources
mostly electrical. The technology is not widely used but has the immense potential to create huge
sources of energy given the huge amount of
resource available in the planet. The technology
involves the generating electricity by rotating
turbines through tidal power and storing the energy
through Tidal Energy Storage Systems (Martin et
al 2018). These storage systems harness the energy
created through the turbines and store them Image 5: Tidal energy
Source: (TheGreenAge 2018)
Image 4: Fly wheels
Source: (Boeing.com 2018).

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through electrolysers or electrolyte membranes to generate hydrogen and store the energy in the
form of fuel cell.
Super Conducting Magnetic Storage
Few other technologies include the Super Conducting Magnetic Energy Storage devices
that can harness the power and transform them into competent energy storage systems. The
system stores energy in magnetic fields that is created by superconducting coils at extremely low
temperature or cryogenic temperatures where energy is stored indefinitely (MIYAZAKI et al
2018). The SMES store energy and release back by discharging and are potential storage systems
for energy preservations. The technology is a younger and cost constraint technology and is
currently used only for short duration energy storages. The technology has the potential for
greater future applications at a commercial scale.
Ongoing Research: Microbial Fuel Cell and Bio Fuels.
The recent developments in bio fuels and microbial fuel cells have generated much
interest. There have been recent developments in these sectors and mostly include energy storage
in forms of natural gas from anaerobic digestion and biological residues that are obtained from
organic sources (Altawell 2014). Several researches from probable sources as sugar cane,
sunflower, soybeans and cow-dung are being practiced at smaller non commercial scales. The
use of biomass in energy generation and storage in bio cells have provide promising possibilities
in alternate storage systems and energy storage systems. The newer developments and
technological advancements provide hope for the future towards sustainable development and
energy production.

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Conclusion
Energy is the most important need of all times and without adequate and enough energy
the world would cease to exist. With environmental stress and degradation, the world needs to
look into sources and technologies that provide sustainable solutions to energy production and
energy storages for future uses. The potential of the natural energy reserves to generate power
and provide energy is infinite and it is time to understand the pathways of these energy systems
and tap them for future and current use. The technologies that are already in use show
progressive results and it proves their competence to producing solution to sustainable energy.
The growing popularity of Solar PVs and Wind Turbines and similar other cost effective sources
can provide plausible solution sustainable sources of energy production. With growing
technological innovations in energy storage systems and their increasing capacities in terms of
efficiency and effectiveness will foster the growth of energy production through sources that
have less impact and would allow optimum use of the available resources. Though most of the
technologies are still cost effective, feasible technologies are just a matter of time. It is important
for the countries to promote sustainable energies for greater use and mass production.
The technical innovation and progress will not only allow us to find a sustainable
alternative but at the same time offer job opportunities fostering in the economic development.
Storing energy in different forms gives an infinite opportunity to harness the greater forces of
nature and storing them in different forms. The recent technologies that are developed will see
further innovation along time and the efficiency of the storage systems and sources of energy
will be enhanced. The issue that restricts the usage of the systems and sources of power also
needs to be modified. The issues regarding reliability, efficacy and cost needs to be re innovated

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and competitive attributes should be developed. The use and application of these technologies
should be promoted and encouraged to ensure sustainable growth.
The investment behind research and development also needs to be enhanced to promote
faster innovations applications of these technologies. The promotion of cleaner sources of energy
will not only create cleaner environments, but economic growth will also be improved with the
implementation of these technologies. It is time to understand the need of the hour and
concentrate our efforts and resources in more sustainable development.

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References
Altawell, N., 2014. The selection process of biomass materials for the production of bio-fuels
and co-firing. John Wiley & Sons.
Barrow, C., 2006. Environmental management for sustainable development. Routledge.
Barton, J.P. and Infield, D.G., 2004. Energy storage and its use with intermittent renewable
energy. IEEE transactions on energy conversion, 19(2), pp.441-448.
Blaabjerg, F. and Ma, K., 2013. Future on power electronics for wind turbine systems. IEEE
Journal of Emerging and Selected Topics in Power Electronics, 1(3), pp.139-152.
Chen, H., Cong, T.N., Yang, W., Tan, C., Li, Y. and Ding, Y., 2009. Progress in electrical
energy storage system: A critical review. Progress in natural science, 19(3), pp.291-312.
Dagnæs-Hansen, N.A., 2018. Magnetic Bearings for Offshore Flywheel Energy Storage
Systems.
Dash, M.C., 2010. Environment, Energy and Development from Stockholm to Copenhagen and
beyond the Celebrations. The Bioscan, Special Issue, 1, pp.1-11.
Hemmati, R. and Hooshmand, R.A., 2017. Impacts of renewable energy resources and energy
storage systems on the flow-gate prices under deregulated environment. Journal of Renewable
and Sustainable Energy, 9(3), p.035502.
Ibrahim, H., Ilinca, A. and Perron, J., 2008. Energy storage systems—characteristics and
comparisons. Renewable and sustainable energy reviews, 12(5), pp.1221-1250.

22ENVIRONMENTAL SUSTAINABILITY
Japikse, D. and Di Bella, F.A., 2018. An Analysis of an Advanced Compressed Air Energy
System (CAES) Using Turbomachinery for Energy Storage and Recovery and for Continuous
On-Site Power Augmentation as an Air Brayton Cycle. Mechanics and Mechanical
Engineering, 22(2), pp.479-493.
Kırlı, M.S. and Fahrioğlu, M., 2018. Sustainable development of Turkey: Deployment of
geothermal resources for carbon capture, utilization, and storage. Energy Sources, Part A:
Recovery, Utilization, and Environmental Effects, pp.1-13.
Kumar, Y., Ringenberg, J., Depuru, S.S., Devabhaktuni, V.K., Lee, J.W., Nikolaidis, E.,
Andersen, B. and Afjeh, A., 2016. Wind energy: Trends and enabling technologies. Renewable
and Sustainable Energy Reviews, 53, pp.209-224.
Lund, H. and Salgi, G., 2009. The role of compressed air energy storage (CAES) in future
sustainable energy systems. Energy Conversion and Management, 50(5), pp.1172-1179.
Martin, L., Franck, S.A. and Alexandre, S., 2018. Integration of tidal range energy with undersea
pumped storage. Renewable energy.
Martínez, E., Sanz, F., Pellegrini, S., Jiménez, E. and Blanco, J., 2009. Life cycle assessment of a
multi-megawatt wind turbine. Renewable energy, 34(3), pp.667-673.
MIYAZAKI, Y., MIZUNO, K., YAMASHITA, T., NAKAO, K., MUKOYAMA, S. and
MATSUOKA, T., 2018. Development of Superconducting Magnetic Bearing Capable of
Supporting Large Loads in Flywheel Energy Storage System for Railway
Applications. Quarterly Report of RTRI, 59(4), pp.281-286.

23ENVIRONMENTAL SUSTAINABILITY
Ondraczek, J., Komendantova, N. and Patt, A., 2015. WACC the dog: The effect of financing
costs on the levelized cost of solar PV power. Renewable Energy, 75, pp.888-898.
Reichelstein, S. and Yorston, M., 2013. The prospects for cost competitive solar PV
power. Energy Policy, 55, pp.117-127.
Saikia, K., Kakati, B.K., Boro, B. and Verma, A., 2018. Current Advances and Applications of
Fuel Cell Technologies. In Recent Advancements in Biofuels and Bioenergy Utilization(pp. 303-
337). Springer, Singapore.
Santoro, C., Arbizzani, C., Erable, B. and Ieropoulos, I., 2017. Microbial fuel cells: from
fundamentals to applications. A review. Journal of power sources, 356, pp.225-244.
Scally, R., 2006. GIS for environmental management. Esri Press.
Sharaf, O.Z. and Orhan, M.F., 2014. An overview of fuel cell technology: Fundamentals and
applications. Renewable and Sustainable Energy Reviews, 32, pp.810-853.
Sternberg, A. and Bardow, A., 2015. Power-to-What?–Environmental assessment of energy
storage systems. Energy & Environmental Science, 8(2), pp.389-400.
Boeing.com (2018). Boeing Frontiers Online. [online] Boeing.com. Available at:
http://www.boeing.com/news/frontiers/archive/2004/november/i_tt.html [Accessed 28 Nov.
2018].
TheGreenAge (2018). Wave Energy - TheGreenAge. [online] TheGreenAge. Available at:
https://www.thegreenage.co.uk/tech/wave-energy/ [Accessed 28 Nov. 2018].