SUMBER ENERGI UNTUK

PEMBANGKIT LISTRIK

Permasalahan GHG (Gas Rumah

Kaca) serta Solusi dengan

ENERGI BARU TERBARUKAN

Dosen : Ir.SYARIFFUDDIN MAHMUDSYAH,M.Eng.

2

Renewable Sources of Energy

• Currently, alternative energy sources supply

almost 10% of the world’s total energy.

– Suggested these sources could provide

half of the world’s energy needs by 2050.

Hydropower

Wind Turbines

Solar Cells

Biomass Fuels

Hydrogen Fuel

3

Renewable Energy as a Share of Total Energy

Hydroelectric Energy

http://www.mcnarybergeron.com/images/Colorado%

20River%20Bridge%20at%20Hoover%20Dam.jpg

Relationship between the Gross Head and Effective Head of Power

Station :

H = Effective Head

Hg = Gross Head

h1 = Loss Head between point of intake and inlet of water turbine

h = Elevation different between runner center and tailrace outlet level

P = 9.8 x Q x H x x GEAR x G (Kw)

Where :

Q = Flow rate (m3 / sec)

H = Head

= Water turbine efficiency

GEAR = Gear efficiency

G = Generator effiencyh

H

HG

h1

TYPE MICRO HYDRO TURBINE CHOISE

0.4

0.3

0.2

0.1

5

4

3

2

1

0 2 5 10 20 40 60 100

PROPELLER

PELTON

CROSS FLOW

FRANCIS

NET HEAD (M)

RESTART END

CA

PA

CIT

Y (

M3

/SE

C)

HORIZONTAL-SHAFT FRANCIS TURBINE

HORIZONTAL-SHAFT PROPELER WATER TURBINE

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Hydroelectric Power

• Hydroelectric power is created when flowing

water is captured and turned into electricity.

– Damming a river and storing water in a

reservoir is the most common method.

Pumped Storage Plants - Use two

reservoirs separated by a significant

elevation difference.

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Hydroelectric Power

• Currently supplies 15% of world’s electricity.

– China possesses 10% of world’s potential.

• Reservoir construction causes significant

environmental and social damage.

– Loss of farmland.

– Community relocation.

– Reduction of nutrient-rich silt leading to

loss of wetlands.

Three Gorges Dam on Yangtze River

12

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Environmental Effects of Hydroelectric

• Flooding of vast areas of land behind dams.

• Prevention of fish migrations.

• Trapping of silt.

– Stops flow of nutrients downstream.

– Fills in reservoir.

• Mercury Accumulation

• Decaying vegetation produces greenhouse

gases.

http://www.newscientist.com/data/images/ns/cms/dn7046/dn7046-1_567.jpg

15

Tidal Power

• Daily rise and fall of ocean levels relative to

coastlines (tides) are a result of gravitational

forces and the revolution of the earth.

– As water flows from a higher level to a

lower level, it can be used to spin an

electricity - generating turbine.

Since tidal changes are greatest near

the poles, and accentuated in narrow

bays and estuaries, suitable sites are

limited.

PASANGSURUT SEBAGAI TENAGA

PEMBANGKIT LISTRIK

• Pasangsurut dikenal sebagai gerakan osilasi permukaan air laut secara berkala. Gerakan pasangsurut itu sendiri di laut di timbulkan oleh karena adanya gaya tarik dari benda-benda angkasa seperti matahari dan bulan terhadap massa air di bumi, Se- lanjutnya kedudukan matahari, bulan dan bumi yang selalu berubah menyebabkan permukaan laut turun naik pada interval yang berbeda-beda.

• Seperti halnya di laut, kerja dari suatu pasangsurut juga akan menimbulkan suatu perbedaan turun dan naiknya air dalam suatu lingkungan yang tertutup, seperti estuaria. Keadaan ini akan menyebabkan terjadinya perubahan enerji yang nyata.

Rumus WEYL utk TIDAL POWER PLANT

• Berdasarkan pengamatannya, WEYL

• (1970) menyimpulkan bahwa dengan membuat suatu jarak kegiatan yang berbeda antara turbin dengan permukaan air, akan memungkinkan air mempunyai enerji potensial sebesar :

Epot = A. g. h • dimana :

• Epot = enerji potensial

• A = massa air

• g = percepatan gravitasi

• h = jarak perbedaan ketinggian

Sistem pasu tunggal. Pada saat

pasang air laut mengalir

kedalam pasu dan pintu air

(A) ditutup. Pada saat surut. air

dari pasu dibiarkan mengalir ke

laut melalui turbin (B).

Sistem pasu ganda. Pada saat

pasang, pintu air (A) dibuka

dan pintu air (C) ditutup Begitu

air kembali surut, pintu air (A)

ditutup dan air mengalir melalu

turbin (B) ke pasu kiri yang

berisi air dengan ketinggian air

surut. Begitu pasu ini diisi

pintu air (C) dibuka sehingga

terjadi aliran tetap melalui

turbin (B).

Cara memperoleh enerji dari tenaga pasang di esturia ini lebih jelas

digambarkan oleh MACMILLAN (1966) dalam lima tahapan berikut

• 1. Air yang masuk ke esturia pada saat pa sang memberikan suplai listrik.

• 2. Pada akhir pasang, enerji diambil kembali dari jaringan kerja listrik guna memutar turbin pada tahap "over-fill".

• 3. Air meninggalakan esturia pada saat surut dan memberikan enerji listrik.

• 4. Pada akhir surut, enerji diambil lagi dari jaringan listrik untuk tahap "over-em- tying".

• 5. Daun turbin harus diatur sesuai dengan arah aliran air.

20

Geothermal

• In some areas, molten material is close

enough to surface to heat underground water

and form steam - drilled and captured.

– Only practical in limited areas.

– California produces 40% of world’s

geothermal electricity.

– Can cause unpleasant odors and high

mineral content leads to high maintenance.

Corroded pipes and equipment.

21

Geothermal Energy

Air Cooled Binary Cycle

TechnologyMoisture-free turbine expansion

PumpingPreheatingBoilingSuperheatingExpansionCondensing

Preheating

DesuperheatingCondensing

ExpansionBoiling

Pumping

STEAM: Superheater required

to avoid wetness

ORC: No superheat required, vapor dries

while expanding

The losses a binary cycle on the hot side, ie. the temperature difference

between the heating fluid and the working fluid, is demonstrated on

a Q/T (Heat rejected from the heating fluid vs. Temperature) diagram.

This Figure 1 is a typical Q/T diagram of a liquid-type heat source heating

the working fluid in a simple binary cycle. The area between the curves

represents the irreversibility of the conversion cycle. The similarity in shape

of the two curves and the space between them indicate the cycle efficiency

Binary Power Plant Efficiency

The perfect match is not feasible due to limitation in the cooling of the brine

and condensate mixture because of the silica scaling risk as the temp. drops

A recuperator partially overcomes the cooling limit and preheats the vapor exiting

the turbine when the expansion in the turbine is in the dry superheated zone and

the expanded vapor contains heat to be extracted prior to the condensing stage.

The recuperated cycle is typically 10-15% more efficient than the simple cycle

Advanced Flash Steam Power Plant Cycle