Renewable Energy Sources for Environmental Sustainability

This study aims to develop understanding of renewable energy sources as a key issue in environmental sustainability. Annotated bibliography of 10 academic sources is provided.

Running head: ENVIRONMENTAL SUSTAINABILITY
Environmental Sustainability
-Renewable Energy Sources
Name of the Student
Name of the University
Author Note

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Aim of this study is to develop understanding of renewable energy sources as a key
issue in environmental sustainability. 10 academic sources (including peer to peer reviewed
journal articles, books and newspapers) were identified that provided key insights into
renewable sources of energy that is used to prepare an annotated bibliography, followed by
the development of a short research paper incorporating the key findings.
Search for the journal articles was made on NCBI PubMed Database using the
keywords ‘Renewable Energy’ and selected journals published in the last 5 years.
Annotated Bibliography:
1. Aziz, N. I. H. A., & Hanafiah, M. M. (2017). The potential of palm oil mill
effluent (POME) as a renewable energy source. Journal of Green Energy, 1(2),
323-346. (150)
The authors study the utility of palm oil mill effluents (POME) as an alternative
source of renewable energy in this journal article. According to the authors, the effluents
from the palm oil mills as well as its byproducts causes environmental problems near the oil
mills, and thus using the extract as a source of energy provides a double benefit of renewable
energy plus the protection of the environment. According to the authors, the POME (which is
a thick brownish liquid) has high content of grease, oil and solids and have a high Chemical
Oxygen Demand (COD) and Biological Oxygen Demand (BOD value wich makes it an
effective energy source. Even though POME is not toxic in nature, discharge of untreated
POME can adversely affect the aquatic ecosystems due to the high COD and BOD. Thus ithe
study supports that POME as a renewable source of energy can help environmental
conservation and sustainable development.

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2. Ekpeni, L. E., Benyounis, K. Y., Nkem-Ekpeni, F., Stokes, J., & Olabi, A. G.
(2014). Energy diversity through renewable energy source (RES)–a case study of
biomass. Energy Procedia, 61, 1740-1747.
In this study, the authors assessed the utility of biomass (such as microalgae, grass,
yeast and renewable biomass substrates) as a renewable energy source. The authors point out
that using biomass as an energy source can help to reduce the emissions of greenhouse gases
through the reduced utilization of fossil fuels and can also help waste management practices
in rapidly urbanizing areas. Authors also suggested that biodiesel and bioethanol can be
combined with the traditional fossil fuels to provide a substitute fuel that can be used in the
traditional combustion engines. However, the authors also pointed out that one of the most
important consideration in the usage of biomass as alternate source of energy is the
conversion of biomass into the combustible form which might need additional energy,
depending on the type of biomass used. However still, it can be implied that biomass still
serve as a potential source of alternative energy.
3. Surendra, K. C., Takara, D., Hashimoto, A. G., & Khanal, S. K. (2014). Biogas as
a sustainable energy source for developing countries: Opportunities and
challenges. Renewable and Sustainable Energy Reviews, 31, 846-859.
In this paper, the authors studied the utility of Biogas as an alternate source of energy
for developing countries. According to the authors, almost three billion people across the
developing countries still depend on biomass in the form of wood, animal dung and crop
residues as an energy source. Using this energy source of environmental, health and social
problems, however, converting the biomass to biogas can overcome this problem and provide
a cleaner source of energy for these countries. According to the authors, regular waste
products such as kitchen waste, animal manure, crop by byproducts and green waste can be

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converted to biogas through anaerobic digestion in special reservoirs. The authors also
pointed out that such technology can be very expensive to install and hence it can be difficult
to develop in remote communities. In such scenarios, it can be useful when funding support is
provided by the government in the development of this technology.
4. Habibullah, M., Masjuki, H. H., Kalam, M. A., Rahman, S. A., Mofijur, M.,
Mobarak, H. M., & Ashraful, A. M. (2015). Potential of biodiesel as a renewable
energy source in Bangladesh. Renewable and Sustainable Energy Reviews, 50,
819-834.
In this journal article, the authors studied the potential of biodiesel as an alternative
source of renewable energy. The authors pointed out that the different forms of biodiesel
have similar functional properties compared to the conventional diesel making them viable
replacements for the fossil fuel for ignition engines. Additionally, the use of biodiesel also as
some added advantages such as lower emission of Carbon Monoxide and Hydro Carbons,
overall reduction in the environmental pollution through the reuse of organic waste and
provide a cheap source of renewable energy. Authors also suggested that in countries where
livestock rearing is very common, the production of biodiesel is very convenient due to the
plentiful supply of organic waste from the farms. Authors also proposed that biodiesel can
also be made from mustard oil, soybean oil,. Cottonseed oil, coconut, micro algae, rubber
seed, sesame, seed, mosna oil, castor, linseed oil, neem, jatropha and karanja.
5. Sarralde, J. J., Quinn, D. J., Wiesmann, D., & Steemers, K. (2015). Solar energy
and urban morphology: Scenarios for increasing the renewable energy potential
of neighbourhoods in London. Renewable Energy, 73, 10-17.
In this paper the authors studied the potential of harvesting solar energy in the cities.
The author studied the urban morphology of the Greater London area to find if the city

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structures can be used to optimize the harvest of solar energy. Their studies showed that in
the city buildings, usage of solar panels in the roofs or rooftops can increase the harvest yield
of solar energy by 9% while using solar panels on the facades can increase the yield by about
45%. Based on such findings the authors also provided recommendations for urban designing
in a way that can maximize the harvest of solar energy, such as the planning of the roof,
distance between buildings, model of façade, average building height and area coverage of
the building. From the study it can be implied that through effective design of the building
and proper use of solar panels the harvest of solar energy can be significantly improved in the
urban areas.
6. Holmes, D. E., & Smith, J. A. (2016). Biologically produced methane as a
renewable energy source. In Advances in applied microbiology (Vol. 97, pp. 1-61).
Academic Press.
In this study, the authors studied the utility of methane as an alternative fuel source.
The authors also studied the utility of methanogens (a group of anaerobic archaea) in the
production of methane. According to the authors, these archaea produces methane and
anerobically reduces carbon dioxide and are commonly found in the environment. It is also
highlighted that these methanogens are responsible for the production of 71% of the
atmospheric methane (which is also a powerful greenhouse gas). It was proposed by the
authors that by anaerobically digesting organic wastes such as animal manure or dung,
sewages from households, waste food, methane can be produced, which is the bulk of the
biogas. The authors also suggested that the rate of anaerobic digestion (that is the conversion
of the organic substrate into methane) can be accelerated using conductive materials and
electrically active cathodes to stimulate the process and thus optimize the production of
methane.

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7. Cavusoglu, A. H., Chen, X., Gentine, P., & Sahin, O. (2017). Potential for natural
evaporation as a reliable renewable energy resource. Nature communications,
8(1), 617.
The authors in this paper identified a completely new approach in the extraction of
renewable energy. According to the authors, in the process of natural evaporation can create
significant amount of energy which is equivalent to other sources of renewable energy such
as wind energy and hydro electric energy. The authors suggested that in the United States
alone, about 325 Giga Watt of energy can be harvested from the evaporation of water from
open water surfaces. Additionally, because of the large specific heat capacity of water, excess
energy can be stored in the water itself which can help to improve the reliability of the energy
as well as reducing its intermittency. Thus the authors suggested that more research should be
done to find materials and equipments that can harness the energy from the evaporation of
water thus significantly helping the development of renewable energy resources.
8. Evans, S. (2018). What are the cheapest renewable energy sources? - Power
Technology. Retrieved from
https://www.power-technology.com/features/cheapest-renewable-energy-sources/
In this article the author discusses the affordable resources of renewable energy.
According to the author, the use of renewable energy is on a rising trend using low carbon
alternatives of fuel and development in technology. The author pointed out to a recent study
by the International Renewable Energy Agency (IRENA) that found renewable energy are
becoming cheaper every year and can provide a considerable cheaper source of electricity
compared to traditional forms of fuels. According to the author, the most significant sources
of energy in this aspect are: solar and wind energy (USD 0.06 per kWh for wind energy and
USD 0.04 per kWh for solar energy) and tidal energy. The authors supported that the costs of

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electricity from these sources of energy were considerably lower compared to the use of
fossil fuels to generate electricity (costing about USD 0.05 to 0.17 per kWh). Additionally,
the costs of energy from wind and solar farms can further reduce the price of electricity in the
next 2 years (to USD 0.03 per kWh).
9. iea.org. (2018). Renewables: Our work. Retrieved from
https://www.iea.org/topics/renewables/
This page by the International Energy Agency provides information regarding the
usage of renewable energy throughout the world. According to their report, the use of
renewable energy have increased sharply over the years which was triggered due to a decline
in the costs of equipments needed to harness the energy, such as photovoltaic cells and
windmills. Their study projects that by 2022, the generation of renewable energy will
increase by one third of its current utilization. The authors however pointed out that the use
of renewable emergy in the generation of heat and in transportation are still very inadequate.
This shows the necessity of increasing the utilization of renewable sources of energy in
transportation and vehicles.
10. Vaughan, A. (2017). Time to shine: Solar power is fastest-growing source of new
energy. Retrieved from
https://www.theguardian.com/environment/2017/oct/04/solar-power-renewables-
international-energy-agency
In this news article, the author proposed that solar energy is the fastest growing source of
renewable energy and that renewable sources of energy currently amounts to one thirds of the
new power added to the world’s grid, showing the fast increase in the trend. The author
predicts that in the next five years, the usage of solar energy wills surpass any other form of
renewable energy such as wind energy, hydroelectricity and biomass/biogas/biooil. The

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authors suggested that solar energy has a huge potential of grown over the next few years and
countires like China and India, who are already investing in solar energy harvesting
technology will dominate the growth in solar energy usage. This shows a positive
development in the market and provides a promising future of the renewable energy usage.

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References:
Aziz, N. I. H. A., & Hanafiah, M. M. (2017). The potential of palm oil mill effluent (POME)
as a renewable energy source. Journal of Green Energy, 1(2), 323-346.
Cavusoglu, A. H., Chen, X., Gentine, P., & Sahin, O. (2017). Potential for natural
evaporation as a reliable renewable energy resource. Nature communications, 8(1),
617.
Ekpeni, L. E., Benyounis, K. Y., Nkem-Ekpeni, F., Stokes, J., & Olabi, A. G. (2014). Energy
diversity through renewable energy source (RES)–a case study of biomass. Energy
Procedia, 61, 1740-1747.
Evans, S. (2018). What are the cheapest renewable energy sources? - Power Technology.
Retrieved from https://www.power-technology.com/features/cheapest-renewable-
energy-sources/
Habibullah, M., Masjuki, H. H., Kalam, M. A., Rahman, S. A., Mofijur, M., Mobarak, H. M.,
& Ashraful, A. M. (2015). Potential of biodiesel as a renewable energy source in
Bangladesh. Renewable and Sustainable Energy Reviews, 50, 819-834.
Holmes, D. E., & Smith, J. A. (2016). Biologically produced methane as a renewable energy
source. In Advances in applied microbiology (Vol. 97, pp. 1-61). Academic Press.
iea.org. (2018). Renewables: Our work. Retrieved from
https://www.iea.org/topics/renewables/
Sarralde, J. J., Quinn, D. J., Wiesmann, D., & Steemers, K. (2015). Solar energy and urban
morphology: Scenarios for increasing the renewable energy potential of
neighbourhoods in London. Renewable Energy, 73, 10-17.

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Surendra, K. C., Takara, D., Hashimoto, A. G., & Khanal, S. K. (2014). Biogas as a
sustainable energy source for developing countries: Opportunities and challenges.
Renewable and Sustainable Energy Reviews, 31, 846-859.
Vaughan, A. (2017). Time to shine: Solar power is fastest-growing source of new energy.
Retrieved from https://www.theguardian.com/environment/2017/oct/04/solar-power-
renewables-international-energy-agency

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Literature based research paper:
Introduction:
Renewable energy is a significant aspect of environmental sustainability and
sustainable development (Ellabban et al., 2014). The significance of renewable and clearn
energy source becomes apparent under the context of the environmental impact due to the
usage of non renewable sources of energy such as fossil fuels which has adverse effect on the
environment due to emission of greenhouse gases (Jebli et al., 2016; Fais et al., 2016).
Moreover, with the gradual depletion of the fossil fuel reservoirs, a need for alternative
sources of emery becomes even more necessary to keep up with the ever increasing need for
energy to fuel the development of our civilization (Capellán-Pérez et al., 2014; McGlade &
Ekins, 2015).
Discussion:
From the review of literature, several important sources of energy could be identified
as well as strategies to maximize the utilization of different renewable energy. These key
findings are discussed below:
Palm Oil Effluents:
Palm Oil Mill Effluents (POME): Studies by Aziz et al (2017) showed that effluents
from the palm oil mills are viable sources of renewable energy as it has high chemical oxygen
demand as well as biological oxygen demand. Using this form of resource can provide the
Palm Oil industry a viable source of energy as well as income as the fuel can be barreled as
sold to other industries and serve as an alternative fuel source apart from helping to reuse the
waste from the palm oil mills. This has also been supported by other studies that show how

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palm tree products can be energy rich and a good source of fuel (Ahmed et al., 2015; Garcia-
Nunez et al., 2016).
Biomass, Biogas and Biodiesel:
Ekpeni et al. (2014) suggested that biomass can be a potentially viable source of
energy in many developing countries, and animal waste as well as a variety of plant products
can be used to prepare biomass. Thus biomass can be another important source of renewable
energy. Moreover, biomass can be used to make other forms of biofuels such as biogas or
biodiesel. The significance of biogas was studied by Surendra et al. (2014) who showed that
biomass can easily be used in the development of biogas using variety of plant products as
well as animal waste. Through the anaerobic digestion of the organic matter gases such as
methane can be produced which are viable forms of renewable energy. According to Holmes
et al. (2016), methanogens can be used to successfully produce methane from the organic
waste products collected from households and farms to undergo anaerobic digestion. The
process can be accelerated further using conductive materials and electrodes. Setting such
equipments can be expensive and through the help of funding, this system can be successfully
implemented (Surendra et al., 2014). Similarly, biodiesels can be produced from biomass
which can be used in ignition engines and thus provide alternatives to fossil fues in ignition
engines (such as those used in transportation) (Pratama et al., 2017; Gómez et al., 2015).
Solar Energy:
The use of solar energy as a renewable source of energy is increasing globally. The
increase in the use of this form of energy is significantly supported by technological advances
that have helped to reduce the costs of equipments needed to harness solar energy as well as
reduce the cost of harnessing the solar energy, thus providing a much cheaper solution for
alternative energy source (Vaughan, 2017; Lewis, 2016). Evans (2018) also supported that

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solar energy is one of the cheapest forms of renewable energy as of now. Sarralde et al.
(2015) proposed that the utilization of solar energy in an urban setup can be further optimized
by effective planning and designing of cities and using solar panels on vantage locations such
as the rooftops and façade, thus helping to harvest more solar energy from the solar panels.
Reports by International Energy Agency also pointed out that usage of renewable energy is
increasing globally and most significantly in the solar energy sector (Najafi et al., 2015;
Energy Information Administration, 2016).
Using alternative fuels in automobiles:
Studies by IEA show that even though these is an increase in the use of renewable
energy, globally, the usage of this form of energy particularly in the automobiles and vehicles
are inadequate. Some authors havge proposed that the reduced or limited usage is mainly
because the compatibility of alternative fuels in the ignition engines and the possible adverse
effects on the longevity and output of the engines. However studies by Habibullah et al.
(2015) showed that biodiesel prepared from various pland and animal products can be safely
used in the ignition engines. Thus biodiesels can be a suitable replacement of conventional
diesels and can help to increase the utility of renewable energy in automobiles and vehicles
(Dharma et al., 2016; Yilmaz & Vigil, 2014).
Methane:
Methane that is produced from anaerobic digestion of biomass can be a good source
of renewable energy owing to its energy density. Methanogens can be used to produce
methane from farm and household waste and thus also help in waste management and
protection of the environment and achieve sustainable development objectives (Stempien et
al., 2015; Holmes & Smith, 2016).

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New Horizon for energy: Latent Energy of Vaporization of water
Cavusoglu et al. (2017) proposed a novel surce of clean and renewable source of
energy which can be researched on. The energy source is a regular phenomenon of water
vaporization. The energy that is created while water vaporizes can be equivalent to the energy
produced from wind and water. This source provides a new direction for research on
renewable energy resources that can be utilized in the future. Moreover, the vast expanses of
open water that covers more than 70% of the world’s surface provides a vast reservoir for
potential energy source which can be harvested in a safe manner without causing pollution or
degradation to the environment thereby supporting sustainable development.
Conclusion:
Thus from the above study it can be concluded that several sources of renewable
energy are available which cam help to replace fossil fuel thereby hel[ping to reduce the
environmental impact of using the fossil fuels. One of the most significant and promising
source is solar energy that is becoming vastly popular and cheap. Along with proper
placement of solar panels, optimal energy can be harvested. Moreover, sources such as bio
fuels (such as biomass, biogas and bio diesel can be another significant source of energy
considering that the organic substrates (plant and animal waste, household waste, organic
sewage and agricultural wastes) that is required for their production is abundant. Moreover
using these substrates also helps in the management of the waste further reducing the
environmental impacts. New technologies can also be developed that can harness energy
from water vaporization which provides a potentially equivalent amount of energy generated
from wind and water.

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References:
Ahmed, Y., Yaakob, Z., Akhtar, P., & Sopian, K. (2015). Production of biogas and
performance evaluation of existing treatment processes in palm oil mill effluent
(POME). Renewable and Sustainable Energy Reviews, 42, 1260-1278.
Aziz, N. I. H. A., & Hanafiah, M. M. (2017). The potential of palm oil mill effluent (POME)
as a renewable energy source. Journal of Green Energy, 1(2), 323-346.
Capellán-Pérez, I., Mediavilla, M., de Castro, C., Carpintero, Ó., & Miguel, L. J. (2014).
Fossil fuel depletion and socio-economic scenarios: An integrated approach. Energy,
77, 641-666.
Cavusoglu, A. H., Chen, X., Gentine, P., & Sahin, O. (2017). Potential for natural
evaporation as a reliable renewable energy resource. Nature communications, 8(1),
617.
Dharma, S., Ong, H. C., Masjuki, H. H., Sebayang, A. H., & Silitonga, A. S. (2016). An
overview of engine durability and compatibility using biodiesel–bioethanol–diesel
blends in compression-ignition engines. Energy conversion and management, 128,
66-81.
Ekpeni, L. E., Benyounis, K. Y., Nkem-Ekpeni, F., Stokes, J., & Olabi, A. G. (2014). Energy
diversity through renewable energy source (RES)–a case study of biomass. Energy
Procedia, 61, 1740-1747.
Ellabban, O., Abu-Rub, H., & Blaabjerg, F. (2014). Renewable energy resources: Current
status, future prospects and their enabling technology. Renewable and Sustainable
Energy Reviews, 39, 748-764.

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Energy Information Administration (US), & Government Publications Office (Eds.). (2016).
International Energy Outlook 2016: With Projections to 2040. Government Printing
Office.
Evans, S. (2018). What are the cheapest renewable energy sources? - Power Technology.
Retrieved from https://www.power-technology.com/features/cheapest-renewable-
energy-sources/
Fais, B., Sabio, N., & Strachan, N. (2016). The critical role of the industrial sector in reaching
long-term emission reduction, energy efficiency and renewable targets. Applied
Energy, 162, 699-712.
Garcia-Nunez, J. A., Ramirez-Contreras, N. E., Rodriguez, D. T., Silva-Lora, E., Frear, C. S.,
Stockle, C., & Garcia-Perez, M. (2016). Evolution of palm oil mills into bio-
refineries: literature review on current and potential uses of residual biomass and
effluents. Resources, Conservation and Recycling, 110, 99-114.
Gómez, M. F., Téllez, A., & Silveira, S. (2015). Exploring the effect of subsidies on small-
scale renewable energy solutions in the Brazilian Amazon. Renewable Energy, 83,
1200-1214.
Habibullah, M., Masjuki, H. H., Kalam, M. A., Rahman, S. A., Mofijur, M., Mobarak, H. M.,
& Ashraful, A. M. (2015). Potential of biodiesel as a renewable energy source in
Bangladesh. Renewable and Sustainable Energy Reviews, 50, 819-834.
Holmes, D. E., & Smith, J. A. (2016). Biologically produced methane as a renewable energy
source. In Advances in applied microbiology (Vol. 97, pp. 1-61). Academic Press.
iea.org. (2018). Renewables: Our work. Retrieved from
https://www.iea.org/topics/renewables/

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Jebli, M. B., Youssef, S. B., & Ozturk, I. (2016). Testing environmental Kuznets curve
hypothesis: The role of renewable and non-renewable energy consumption and trade
in OECD countries. Ecological Indicators, 60, 824-831.
Lewis, N. S. (2016). Research opportunities to advance solar energy utilization. Science,
351(6271), aad1920.
McGlade, C., & Ekins, P. (2015). The geographical distribution of fossil fuels unused when
limiting global warming to 2 C. Nature, 517(7533), 187.
Najafi, G., Ghobadian, B., Mamat, R., Yusaf, T., & Azmi, W. H. (2015). Solar energy in Iran:
Current state and outlook. Renewable and Sustainable Energy Reviews, 49, 931-942.
Pratama, Y. W., Purwanto, W. W., Tezuka, T., McLellan, B. C., Hartono, D., Hidayatno, A.,
& Daud, Y. (2017). Multi-objective optimization of a multiregional electricity system
in an archipelagic state: The role of renewable energy in energy system sustainability.
Renewable and Sustainable Energy Reviews, 77, 423-439.
Sarralde, J. J., Quinn, D. J., Wiesmann, D., & Steemers, K. (2015). Solar energy and urban
morphology: Scenarios for increasing the renewable energy potential of
neighbourhoods in London. Renewable Energy, 73, 10-17.
Stempien, J. P., Ni, M., Sun, Q., & Chan, S. H. (2015). Production of sustainable methane
from renewable energy and captured carbon dioxide with the use of Solid Oxide
Electrolyzer: a thermodynamic assessment. Energy, 82, 714-721.
Surendra, K. C., Takara, D., Hashimoto, A. G., & Khanal, S. K. (2014). Biogas as a
sustainable energy source for developing countries: Opportunities and challenges.
Renewable and Sustainable Energy Reviews, 31, 846-859.

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Vaughan, A. (2017). Time to shine: Solar power is fastest-growing source of new energy.
Retrieved from https://www.theguardian.com/environment/2017/oct/04/solar-power-
renewables-international-energy-agency
Yilmaz, N., & Vigil, F. M. (2014). Potential use of a blend of diesel, biodiesel, alcohols and
vegetable oil in compression ignition engines. Fuel, 124, 168-172.