Advantages Of Geothermal Energy

Green organizations in Dhahran aim to save environmental energy as possible as they can. Green organization found in Dhahran 2007 , from that time , organization prepare to start this huge project in 2010 to conserve energy in Saudi Arabia . In our project team we separated our team with respect to our majors. So, we end up with five parts to work on energy conservation.

The main problem in our environment that we concern on , is environment pollution and conventional energy wastes. In Saudi Arabia they uses only one source to produce electricity by using fossil fuels, and we all know that is harmful and produce a lot of waste. Moreover, conventional energy has a limit of source , so over the time we may not have these sources to produce electricity.

However, in our organization we found some powerful solutions, and as a Mechanical Engineer in this organization I found that the suitable energy we can use is the renewable ones, So, I found geothermal energy is the most powerful type.

Many of kinds of energy we use in our daily life , in home, cars, etc. are not renewable forms of energy. The major source of these types is fossil fuels, as we know that fossil fuels took millions of years to form, so its impossible to make it now.

Unfortunately, these kinds of energy has limited amounts of sources. Moreover, these sources cannot be renewed , when they are gone they cannot be used again .So, we need as a green organization and as a part of people live in our environment to save these energy as much as we can .

However , there are many other kinds of energy called ” renewable energy “.These types of renewable energy always can be renewed or restored. Unlike fossil fuels , which harm the environment, renewable energy has much less effects to our environment.

In this report I will introduce one of the most powerful type of energy , not harmful , renewable , and good efficiency .

Heat is form of energy , and the heat that inside the earth is the major source of the renewable energy that I will talk about. The part of the heat inside the earth that people can use it and exploits it to form energy is called “Geothermal Energy” .

I will give you a brief history ,then I will talk about current status of geothermal energy activity in the world, and I will give you some idea about the resources , then I’ll explain how geothermal energy plants work , then I will talk about advantages & disadvantages and make some comparison , after that I’ll give you some numbers & statistic , moreover , talking about future of this energy will be exciting. Finally I am going to list some of the milestones of geothermal energy power plant.

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-Brief History:

The thermal phenomena , volcanoes ,and hot springs must led our ancestors to believe that the interior part of the earth is hot . Moreover, when the first mines were excavated to about few hundred meters between the sixteenth and seventeenth century , the man who dig he recognized that as he go more deep as the temperature increase .

By 1904, the first electricity generating attempt was being made from geothermal steam; again, it was to take place at Larderello, Italy (Figure 1).

Figure 1 , Mary H. Dickson and Mario Fanelli

Istituto di Geoscienze e Georisorse, CNR , Pisa, Italy

Prepared on February 2004, < http://www.geothermal-energy.org/pliki/Image/geo/What_is_geothermal_en_html_3316a7eb.jpg>

The engine used at Larderello in 1904 in the first experiment in generating electric energy from geothermal steam, along with its inventor, Prince Piero Ginori Conti.

This experiment was successful and it was indication of the industrial value of geothermal energy. Moreover, Larderello in Italy succeed in commercial electricity generation. And by 1942 the installed electricity which generated by geothermal energy reached 127,650 kWe . However , other several countries start follow Italy , for example , in 1919 Japan drilled there first wells in Beppu, 1921 in USA , 1958 in New Zealand , and in 1959 in Mexico, and followed by many other countries.

From that time the geothermal studies applied to earth . And the thermal energy now increase ,but mankind can only use fraction of this energy until now.

-Current Status :

The thermal energy increases with time, and so far the uses of this energy is limited to areas where water in the liquid phase or steam .

If we take USA status now , we can see that geothermal energy is not powerful , because USA has a special case where there are some reasons for that. First, in competing generating technologies , prices of fuels used are decreased. Moreover , demand for electricity has a slow growth. Another reason that has been a surplus of electricity in USA .

On the other hand , we can get benefits from that repudiation of geothermal energy in USA . KSA has different conditions about electricity generation , we have only one source of electricity and the demand on that increases relative to time. So as a green organization we can contract with these companies that worked in USA , so we can get the experience and they can reactivate there work here in KSA.

– Resources of Geothermal Energy :

Complex processes lead to heat concentration at accessible depth under the earth , this is the main source of geothermal energy. However, there are many different forms of geothermal energy resources , such as hydrothermal, hot dry rock, geopressured, magma, and earth heat. As an example , temperature of highly viscous or partially molten rock is between 1,200 and 2,200°F , these can be exist everywhere under the earth surface at depth of 80 to 100 kilometers.

There are different characteristic of geothermal resources . First, hydrothermal resources, these are steam or hot water where we can drill and reach these reservoirs and deliver the heat to earth surface to generate electricity. Second , hot dry rock (Figure2) , these rocks stores heat at very high temperature and the plant inject cold water to these areas and extract this water after being hot from other well. Third, geopressured resources consist of deeply buried brines at moderate temperature that contain dissolved methane, however , this resource are not economically competitive currently, so no funds are directed toward accessing these resources. Fourth, magma , this resorce give extremely high temperature but there is no technology to get that heat energy until now. Finally, we can use earth heat as a resource and it is proven technology.

< Figure 2 .

– Types of Geothermal Power Plants:

There are three types of geothermal power plant, depend on the way that electricity generated. Here are the three types:

1- Dry Steam Power Plant:

These plants uses the hot steam which extracted from the earth by wells to rotate the turbine that generate electricity.

2- Flash Steam Power Plant:

This is the most common type of geothermal power plant. These plants extract hot water from the earth at 360 °F, pressure decrease as water flows up through wells , as a result of pressure decreases, water converted to steam . So, steam is used to rotate the turbine.

3- Binary Cycle Power Plant:

These plants uses the heat from lower-temperature reservoirs to boil the working fluid which vaporized by heat exchanger and used to power a generator. The remaining water which never comes into direct contract with working fluid is injected back to the ground by injection wells.

– Procedure of Geothermal Energy in Details:

Water in underground reservoirs is heated to high temperature by magma , production wells drilled up to 3 kilometers below the earth surface tapping to this hot fluid. Under its own pressure ,fluid flows up through these wells towards the surface , as it travels , the pressure decrease causing small amount to become steam. Then, hot fluid and steam move through a surface pipeline to a well head separator where the pressure in reduced, here, most of the fluid vaporizes and flashes into high pressure steam. After that, any fluid not flashed into steam moves to a standard pressure crystallizer to produce standard pressure steam . Then, remaining fluids is flashed at a lower pressure to create low-pressure steam. Finally, all steam created in the plant is sent to a turbine onside. The force of the steams spins the turbine plates which turns a shaft connected to an electronic generator. As a result, an electric charge is created and directed to a transformer , where the voltage is increased. However, any fluid not flashed into steam return to the underground reservoir where in time they will be reheated and reused.

– Advantages of Geothermal Energy:

There is no consumption of any type of fossil fuels. Moreover, geothermal energy doesn’t product any type of greenhouse effect. Also, if we talk about energy consumption, geothermal energy does not consume any energy since its renewable energy, so there is no limit of using geothermal energy. Furthermore, it is great for protecting the natural environment since the power plant shouldn’t be huge.

– Disadvantages of Geothermal Energy:

There are several disadvantages to geothermal energy. First, you cannot build the power plant in any vacant land, there must be studies on the area , and the area chosen should consist of hot rocks to get the geothermal energy as we want. Also, not any type of rocks we can drill into, there are some kinds which is possible to drill into.

– Advantages of Geothermal Energy Compared With Other Conventional Energy:

* Fewer & more easy to control emissions of atmospheric pollutions.

* Fewer amount of wastes.

* Demands of areas for a power plant is much less than other conventional plants.

* Continues circle , renewable.

– Cost of Geothermal Power Plant:

In general, economically competitive geothermal power plant cost $3400 per kilowatt. However , the cost of construct new geothermal power plant is higher than natural gas facilities, but over a long term they are similar in cost. This is because natural gas construction costs one third of the total price and remaining two third of the cost represented by fuel. While, construction of new geothermal power plant cost two third of the total price. So, initial investment for geothermal power plant is high, but with time it is economically comparable with natural gas plant.

If you wondering that is the cost of geothermal power plan fluctuating like other fossil fuels, I can say no, because whenever you build a geothermal plant you should know most of power production and few market parameter can modify them.

There many factors effect the cost of a geothermal power plant cost. First in construction period, steel and metals effect the price of the plant. Also, drilling price varies. Moreover, place of the plant effect the price because of connection of electric grid. Buy or rent land will raise the cost, because to fully study and explore a geothermal resource you need at least 8 km2.

Energy and investment costs for electric energy production from renewables (from Fridleifsson, 2001)

Current energy cost

US¢/kWh

Potential future energy cost

US¢/kWh

Turnkey investment cost

US$/kW

Biomass

5 – 15

4 – 10

900 – 3000

Geothermal

2 – 10

1 – 8

800 – 3000

Wind

5 – 13

3 – 10

1100 – 1700

Solar (photovoltaic)

25 – 125

5 – 25

5000 – 10 000

Solar (thermal electricity)

12 – 18

4 – 10

3000 – 4000

Tidal

8 – 15

8 – 15

1700 – 2500

– Future of Geothermal Energy in KSA:

Green organization always try to save our environment as possible as they can. After talking about the geothermal energy in detailed I think this is the time to conserve energy for our environment. So, KSA companies and government always accept new idea which conserve our environment. I think Saudi Arabia will have huge improvement in geothermal energy ,since the land behavior and hot climate and the increment of electricity demand as we see in figure below.

– Some Famous Milestones of Geothermal Power Plant:

Here are some famous geothermal power plant milestones where Saudi Arabia can get benefit from there experience .

Early 1900s

First geothermal electricity commercialization

Conversion of high-grade hydrothermal resources to electricity began in Italy in the early 1900s.

1960

U.S. commercialization

The first commercial-scale development tools were placed at The Geysers in California, a 10-megawatt unit owned by Pacific Gas &Electric.

1970

Reinjection of geothermal fluids

Injection of spent geothermal fluids back into the production zone began as a means to dispose of waste water and maintain reservoir life.

1972

Deep well drilling

Technology improvements led to deeper reservoir drilling and access to more resources.

1977

Hot dry rock demonstrated

In 1977, scientists developed the first hot dry rock reservoir at Fenton Hill, New Mexico.

1978

Federal research and development (R&D) funding exceeds $100 million

U.S. Department of Energy (DOE) funding for geothermal research and development was $106.2 million (1995 dollars) in fiscal year 1978, marking the first time the funding level surpassed $100 million. It remained above $100 million until fiscal year 1982, when it was reduced to $56.4 million (1995 dollars). Currently, the budget is in the $30 million to $40 million range.

1978

Public Utility

Regulatory Policies

Act (PURPA)

enacted

PURPA mandated the purchase of electricity from qualifying facilities (QFs) meeting certain technical standards regarding energy source and efficiency. PURPA also exempted QFs from both State and Federal regulation under the Federal Power Act and the Public Utility Holding Company Act.

1980

First commercial

binary system

The first commercial-scale binary plant in the United States, installed in Southern California’s Imperial Valley, began operation in 1980.

1980s

California Standard Offer Contracts

California’s Standard Offer Contract system for PURPA QFs provided renewable electric energy systems a relatively firm and stable market for output, allowing the financing of such capital-intensive technologies as geothermal energy facilities.

1982

Hydrothermal

generating capacity

of 1,000 megawatts

Geothermal (hydrothermal) electric generating capacity, primarily utility-owned, reached a new high level of 1,000 megawatts.

1989

Geopressured power plant demonstrated

In 1989, DOE and the Electric Power Research Institute operated a 1-megawatt demonstration plant in Texas, extracting methane and heat from brine liquids.

1990

Drop in Federal

funding for

geothermal R&D

to $15 million

DOE funding for geothermal energy research and development declined throughout the 1980s, reaching its low point in fiscal year 1990.

1991

Magma drilling

project reaches a

depth of 7,588 feet

The world’s first magma exploratory well was drilled in the Sierra Nevada Mountains to a depth of 7,588 feet. It did not encounter magma at that depth inside the caldera.

1994

Industry consolidates and looks at new markets

California Energy became the world’s largest geothermal company through its acquisition of Magma Power. Near-term international markets gained the interest of U.S. geothermal developers.

1985-95

Capacity outside

The Geysers exceeds 1,000 megawatts

Since 1985, U.S. geothermal developers have added nearly 1,000 megawatts of geothermal electric generating capacity outside The Geysers.

1995

Worldwide

geothermal capacity

of 6,000 megawatts

Worldwide geothermal capacity currently totals 6,000 megawAtts in 20 countries.

– Conclusion:

After we see the advantages of geothermal energy, and after we know that geothermal energy have nothing to emission to the environment. Moreover, geothermal energy is the best type of renewable energy in terms of cost , efficiency ,and safety. Consequently, I think the most powerful alternative type of energy in KSA is geothermal energy. As I said, its renewable, so we will not lose any energy and this is enough to start geothermal energy production in KSA.