Geothermal Power: Principles, Systems, and Potential

This article provides an overview of geothermal power, including its principles, systems, and potential. It discusses the different types of geothermal power stations and their practical applications. The article also explores the operating geothermal stations around the world and their locations. It highlights the environmental problems and engineering challenges associated with geothermal power. Additionally, it delves into the potential of geothermal power in Australia.

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INTRODUCTION
Geothermal power is the generated power which originates from the geothermal energy.
Applications of this technological generation of electricity include the dry steam, flash steam and
the binary cycle. This invention was first tested by Prince Pierre Ginori Conti in July forth 1904
in Larderello in Italy due to the high demand of electricity hence seeing the geothermal power as
the only source. The first commercial geothermal was built in this place in the year 1911.
Currently, almost 24 nations are using power generated from geothermal while the geothermal
heating is being applied by 70 c0untries around the world.
Principles of engineering behind geothermal electricity
There are three varied main types of geothermal power stations. They include dry steam,
flash steam and binary cycle. These three examples of thermal plant apply the steam turbine
technology in electricity generation. The water is steamed and then it is transported through a
turbine which transports steam where that steam is converted to electricity by the use of a
generator in a process known as electromagnetic induction. The cooling process is done to the
fluid then transported back to be heated in the source of heat.
Dry steam power type of plant uses the resources that are the working fluid stream from
the underground. They are located mainly in the geysers in California and in Wyoming in
Yellowstone national park. The most common ones are the flash steam power plant they use
super-hot water that flows through the ground under the pressure of its own. Lastly binary cycle

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power plant uses the working fluids which involve the organic compound which contains low
boiling point that is heated with hot water to boil.
Practical systems of geothermal stations
There are many operating geothermal power stations in the world which some are
functioning up to date while others are not examples of operating power stations are koala and
larderelo power station.
Krafla power station
It is a geothermal power facility generator which is located in Iceland close to Krafla
volcano and Lake Myvatn. It has 33 Bore halls and is considered the largest Iceland power
station. This plant contains 30-megawatt units with inlets that have double pressure and dual
flow turbines which are located 5 steps on each side. ( Brüggemann, D., 2015) . Its energy is
taken from a pressure high production of 17 and wells which contains 110kg/ second of 7.7 bar
and five low-pressure production wells with 36kg/ seconds of 2.2 bars. These turbines use 52.5
and 17.8 kg/s of high and low-pressure production steam well each. Raising inlet pressure and
the mass flow in both turbines will lead to an increase in the output level to about 35 megawatts
(Wang, L., 2016). This power station has an additional well in scripted as IDDP-1 it is known to
be the world hottest geothermal well with its borehole reaching magma at its lowest point with a
temperature of about 4300 c.

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Larderelo geothermal station
This power station is located in Italy. And it is the first world power station established in
1911 which currently is still supporting almost one million families with almost 5000 GWh per
year which correspond to almost 10 -12% of the world total electricity production generated by
the geothermal (Pambudi, A., 2018). Its operation works in the sense that the cold fluid is
pumped down to super- hot granite rocks which are situated almost to the surface (Zhu, G.,
2018). This cold water is heated to form steam of almost 2000 c which contains very high
pressure. This pressure returns the steam which turns the turbines hence generating electricity
known as geothermal electricity.
Summary of the world operating geothermal stations and their locations
Apart from the two, there are other geothermal stations around the world depending on
their size and their level of operation which indicate the level of energy production.Other
operating GTPs in the world are as summarized in the table below including their energy
capacity generated in 2018 and their percentage national share generation
Table 1:showing the summarized currently operating GTP locations throughout the world including Australia.
country Example of geothermal station Capacity
(MW)
National
share
Generation
in
percentage
USA Cal energy salon sea, 3591 0.3

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CA
INDONESIA Darajat station, Wayang windu
station
1948 3.7
PHILIPPINES Malitbog station, tiwi
complex
1868 27.3
NEW ZEALAND Kawarau power
Station
1005 14.5
MEXICO Cerro prieto geothermal which
Has power station 1,2,3,4 and
5
951 3
ITALY Serrazzano power station and
Larderello power station
944 1.5
ICELAND Svartsengi power station 755 30
KENYA Olkaria geothermal station 1, 2,
3, 4 and 5.
676 51.0
AUSTRALIA Paralana and copper basin 100 0.1
World GTP potential
The GTP potential exists in various dimension, for instance, the theoretical potential,
technical potential, economic potential, sustainable potential and lastly the developable potential.
The world GTP cuts across this five potential in a different dimension. ( Harris,s, 2015).GTP is a
renewable source of energy for both power and heating. It has got the potential to generate about

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3-5% of the energy world demand by the year 2050. It is predicted that it has a potential in
economic incentives that by the year 2100 it will be able to cater to the 10% world energy
demand. Research shows that as from 2015 the capacity of geothermal power all over the world
was 12.8 gig watts in which 28% of this capacity is the USA installations. The growing rate of
this market is at an annual average rate of 5% up to 2015 and the capacity is expected to reach
14.5-17.6 gigawatts by the year 2020.
So far the GEA estimated that 6.9% has been achieved of the total world potential. Also,
the IPCC states clearly that the world geothermal potential lies between 35 gigawatts to 2
terawatts, the countries which support heavily to these estimations at around 15% include Kenya,
Philippians, Iceland, New Zealand and Costa Rica. The technical potential predicted by the IPCC
is that the geothermal power production will amount to almost 200 gigawatts and this can only
be achieved the application of emerging technologies such as enhanced geothermal systems is
introduced worldwide.
GTP potential in Australia.
Australia is identified as a country with the potential resources which favours the
installation of the geothermal power station which would generate the highest amount of energy
that is estimated to sustain the nation for over 400 years ( Santoyo, E., 2017). In Australia, the
application of geothermal power is very low but it is still growing. The potential locations
located at the central part of the nation contain hot granites at the lowest level that hold good
potential for geothermal energy development ( Bertani, R., 2016). Their future potential for
enhancing the application of geothermal energy in this country is great despite the financial
constraint it faces. Explorations have been conducted in this region. The central part of the

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country contains a large deep-seated granite system which has a high temperature at and drilling
is being done by nations companies such as Panax geothermal and geodynamics ltd.
In the southern part, it has been given a description that Australia’s hot rock haven. Since
the geothermal generated heat can be estimated to be 6.8% of Australia base power load required
by 2030. Research reveals that Australia has the potential of generating enough geothermal
power to produce electricity that can sustain the country for 450 years. Parts such as Tasmania
can be able to generate power up to 280 megawatts this would mean that 25% electricity needed
in this region will have been catered for.
Environmental problems associated with GTP
Although the application of GTP is essential in electricity generation, it has an impact on
the environment. The liquid which is drawn underground contains the mixture of gases such as
carbon dioxide, hydrogen sulfide, methane, ammonium and radon. When these gases are emitted
into the atmosphere they lead to global warming and acid rain. The boiled water which generates
steam that comes from the ground from the geothermal sources may contain chemicals which are
toxic traces such as mercury, arsenic, boron and antimony. These chemicals are harmful and may
damage the environment if emitted.
The construction of these stations also causes land instability. The geothermal systems
which are enhanced may lead to earthquakes due to water injection. The risk of drilling the
geothermal may also cause land degradations (Yang, Y., 2015). It also covers a large amount of
space and also requires the use of freshwater which may be used for other purposes for instance
agriculture or domestic use respectively. It also disrupts the natural cycles of geysers making

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them stop erupt due to the establishment of the dual flash station, for example, the Beware and
the Nevada geysers.
Engineering challenges of GTP
Geothermal power requires super-hot fluid which is found in volcanism areas. Since not
all places are located in these volcanic areas they cannot be built anywhere unlike wind energy
and solar energy. Another challenge, entering the geothermal powers requires important
elements such as hot rock, water and resource which are close, so drilling is required hence,
therefore, engineers should deal with differing technical challenge facing geothermal.
Construction of these safe geothermal stations is also a challenge to the engineers. His
construction should be done so as to meet the capacity of the geothermal plant and some other
extra reserves in the range of about 8-15 % above the site capacity. Other constructions involve
the designing, constructing of plant and steam gathering systems and then interconnect the
transmission line.
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