S.1 Introduction

Renewable energy refers to energy resources

that occur naturally and repeatedly in the environmental and can be harnessed for human benefit.

Driven by three desirable characteristics: -Is abundant and available everywhere -It inherently does not deplete the earth’s natural resources -It causes little, if any, environmental damage

Renewable energy consumption is about 20% of overall world energy consumption

Types of renewable energy sources (RES) namely are biomass , hydropower , geothermal , solar , and wind energy

Renewable Energy Source

P1.1 Acknowledgements

1. Mazlan A.W., Mohd Faizal H.

2. Universiti Teknologi Malaysia ( www.fkm.utm.my/~asialink2006/ )

P1.2 Literature

Author: P-R. Bauquis, 2003 Title: Oil and Gas Journal

Author: Boyle, 2004 Title: “Renewable Energy” Publisher: Oxford University Press

Title: “Trends in Energy Use” Publisher: Earth Policy Institute

Author: Demirbas A. Title: “Biomass Resources for Energy and Chemical Industry” Publisher: Energy Edu Sci Technol 2000;5:21–45.

Author: Tewfik SR. Title: “Biomass Utilization Facilities and Biomass Processing Technologies” Publisher: Energy Edu Sci Technol 2004;14:1-19.

Author: Michael Totten Title:Conservation International

http://www.eia.doe.gov/ Title: “International Energy Outlook 2007” Publisher: Energy Information Administration (EIA)

Presentation by CEMTRE Title: Components of a Micro-Hydro Power System Manufacturer’s Training Workshop on Micro-Hydro Turbine, TUP Visayas, Negros Occidental, Philippines

Volcanoes: Crucibles of Change Publisher: Princeton University Press, 1997

Geothermal Explorers Ltd., 2004

Huttrer, 2000

World Wind Energy Association

Worldwatch Institute, 1990

P1.3 Prerequisites

Minimum: Completion of equivalent “O” level

P1.4 LU and TU

Learning Units: 4 hours

Teaching Units: 2 hours

Explanation: Learning Units (LU) correspond to estimated number of hours for self-learning. Teaching Units (TU) correspond to estimated number of hours for te acher to present the material.

S.2 Educational Objectives

Introduce the fundamentals of renewable energy engi neering concentrating on

biomass, hydropower, geothermal, solar, and wind.

Discuss about the current levels of renewable energ y usage in the different part

of the world

Explain on the different forms of renewable energy

S.3 World Energy Consumption

The status of world energy consumption for 2006 is shown below.

Status of world energy consumption in 2006

Source See the table of trends in energy use See the table of world energy balance

P3.1 Trends in Energy Use

Trend in energy use by source

Source

P3.2 Long Term World Energy Balance

Long-term World Energy Balance

Source

S.4 Biomass Energy

Biomass is normally burned directly for heat or power or c onverted into biofuels. They are derived from processed materials like straw, fo restry waste and wood chips

The decline in coal supply from the early 1900s to the mid 1990s and the increasing proportion of oil and natural gas, indicate the importance of biomass as energy source

Currently biomass supplies some 14% of total world energy Fraction of household energy from biomass for indus trialized and developing nation is

shown in figure below:

Fraction of household energy use from biomass

Source

Continue

P4.1 Biomass

More picture of biomass

P4.1.1 Picture of Biomass

Wheat Straw Wood fuel Palm Fruit Corn Cobs

Rice hull Coconut Shell Tree Barks Switch Grass

P4.2 Importance of Biomass as Energy Source

Source ???

P4.3 Total World Energy

Fuel Shares

Source

Note the 50% increase in world energy supply betwee n 1973 and 2004

It is useful to express the energy content of diffe rent fuels in terms of tonne of oil equivalent based on a characteristic energy content of oil (MJ/kg)

P4.4 More About Biomass…..

Use of biomass offers the potential to greatly redu ce greenhouse emissions.

The solar energy, which is stored in plants and ani mals, or in the wastes that they produce, is called biomass energy. This energy can be recove red by burning biomass as a fuel.

The average majority of biomass energy is produced from wood and wood wastes, followed by solid waste, agricultural waste and lan dfill gases and the distribution is shown in figure

Biomass can be economically produced with minimal o r even positive environmental impacts through perennial crops.

Much of the rural population in developing countri es, which represents about 50% of the world’s population, is reliant on biomass, mainly i n the form of wood, for fuel.

Potential future world roles for bioenergy were pro jected by several researchers as shown in figure

A semi-efficient and ambitious of biomass and other renewable energy scenario has been proposed by Michael Totten as shown in figure

P4.5 Figure of Distribution

Biomass Energy

64%

24%

5%

5%

2%

WOOD AND WOODWASTE

SOLID WASTE

AGRICULTURALWASTE

LANDFILL GASES

OTHERS

Type of biomass energy

Source

P4.6 Potential Future of Biomass

Potential future world roles for bioenergy Source

P4.7 Prediction of Renewable Energy Scenario

Prediction of renewable energy scenario

Source ACTIVITY

P4.7.1 ACTIVITY

Comment briefly about the environmental issues for biomass with respect to climate change, pollution and social impact.

S.5 Hydroelectric Power (Hydropower)

The energy utilized in the generation of hydropower is actually a form of solar energy.

Is renewable energy resource resulting from the sto red energy in water that flows from a higher to a lower elevation under the influence of the earth’s gravitational field.

Hydroelectric Power System

Source

P5.1 Hydropower

The water in rivers and streams can be captured and turned into hydropower, also called hydroelectric power.

Kinetic energy from falling or running water is con verted to shaft work to drive a turbine and generate electricity

The potential power which can be generated is depen dent on the volumetric flow rate of the water and the available head. Their relatio nship is defined by equation 1

P = 9.8 et Q H (1)

Where P = Power required (kW) et = total efficiency

Q = volumetric flow (m 3/s) H = Head (m)

Hydropower is categorized into micro scale, mini-sc ale, small scale and large scale

Type of Hydropower Capacity

Large Hydro Over 10 MW

Mini -hydro Over 100 kW to 10 MW

Micro -hydr o 100 kW and Below

World hydro production is depicted in figure shown next.

P5.1.1 Micro Hydro Plant

The components of the MHP consist of:

Silt Basin

Weir

Channel

Forebay

Penstock

Transmission Lines

Power House

Tailrace

Components of a Micro-Hydro Power Plant Source

P5.1.1.1 Silt Basin

Designed to collect and flush sediments and other w ater-suspended materials and prevent them from entering the penstock and the tur bine

Silt Basin

Source

P5.1.1.2 Weir

Weir 1 Source

Weir 2 Source

Obstructs water flow and raises water level for di version into intake(an opening at the weir

to divert the design discharge from the river to t he power canal)and headrace .

P5.1.1.3 Channel

Leads water to a forebay tank

It follows the contour of the hillside so as to preserve the elevation of the diverted water

It is used to minimize the penstock

length and subsequently reduce cost

It can be simply an earth canal, or be made of rubble masonry or concrete. It depends on the available resources and site accessibility

Concrete Channel Source

P5.1.1.4 Forebay Tank

It is a pond-like structure at the top of the pens tock, which regulates the fluctuation of water

It forms the connection between the channel and th e penstock

The main purpose is to allow the last particles to settle down before the water enters the

penstock.

In front of the penstock a trashrack needs to be i nstalled to prevent large particles from entering the penstock.

Forebay Tank 1 Source

Forebay Tank 2 Source

P5.1.1.5 Penstock

A pipe, which conveys water from the

forebay tank to the turbine

It may be surface mounted or buried underground, depending on the pipe material, nature of terrain and environmental considerations

In the design of the penstock, head

losses due to friction and turbulence in the pipe must be minimized.

More about Penstock Penstock Source

TurbineTurbine This is the primary equipment, which converts the energy from falling water into shaft

work

This energy is then utilized to drive the generati ng unit to produce electricity

Turbines are selected based on available head, wate r and required power

Specific Speeds for Various Types of Turbines Type NS (Specific Speed) Pelton 12 – 30 Turgo 20 – 70

Crossflow 35 – 150 Francis 50 – 400

Propeller and Kaplan 340 – 1000

The turbine’s working speed must correspond to the working speed of the generator Turbines may be equipped with valves to regulate t he flow depending on the load

requirement Specific speeds may be calculated based on the giv en relationship below

4

5H

PNN S =

Where N = working speed of turbine (rev/min) P = maximum turbine output (hp) = 1.4 x maximum turbine output in kW H = net head (m)

5.1.1.5.1.1 Crossflow

Is intended for low head,but high flow Uses long turbine blades to accommodate high volume s of water Also called a Michell Banki Turbine, a crossflow tu rbine has a drum-shapped runner

consisting of two parallel discs connected together near their rims by a series of curved blades

Always has its runner shaft horizontal(unlike Pelto n and Turgo Turbines which can have either horizontal or vertical shaft orientation)

Crossflow Turbine with Generator Source

Crossflow Turbine Source

More About Penstock

Losses due to friction and turbulence occur when the water is conveyed through the pipe

Losses vary depending on the penstock length, configuration (e.g. existence of bends and valves) and pipe material

These factors are related based on equation 2

35

22

10.

f

D

QnL

h= (2)

hf = head loss due to friction (m) L = penstock length (m) n = roughness coefficient D = internal pipe diameter (m) Q = volumetric flow rate (m 3/s)

Penstock2

Source

P5.1.1.6 Transmission Lines

Are used in order to transfer energy from the powerhouse to facilities requiring it

Transmission Lines Source

P5.1.1.7 Power House

This protects the turbine,

generating unit and other equipment

It must be accessible for

maintenance and repair.

Powerhouse Source

P5.1.1.8 Tailrace

Used to transmit the water from the powerhouse bac k to the stream It is a short open canal designed to ensure that e rosion does not occur

P5.1.2 World Hydro Production

World hydro production

Source ACTIVITY

P5.1.2.1 ACTIVITY

Identify the major world hydropower producer in Asi a and Europe and make comparison on the attributes between them.

P5.2 Form of Solar Energy

The cycle steps:

1) Solar energy heats water on the surface,causing it to evaporate

2) This water vapor condenses into clouds and falls back onto the surface as precipitation

3) The water flows through rivers back to the oceans, where it can evaporate and begin the cycle over again

The water cycle Source

S.6 Geothermal Power

Geothermal energy is the heat from the Earth. It's clean and sustainable.(See the detail )

Resources of geothermal energy range from the shall ow ground to hot water and hot rock found a few miles beneath the Earth's surface, and down even deeper to the extremely high temperatures of molten rock called magma (Shown in figure ).

Temperature variation of earth temperature is depic ted in following figure .

There are three type of geothermal steam power plan t: dry steam power plant , flash steam power plant and binary cycle power plant as shown in the following figures.

Currently, there are no commercial applications of this technology. Existing technology also does not yet allow recovery of heat directly f rom magma, the very deep and most powerful resource of geothermal energy.

Geothermal power generation around the end of twen tieth century is shown in following figure.

ACTIVITY

P6.1 Detail of Geothermal Energy

Earth's core maintains temperatures in excess of 5 000°C

– Heat residual radioactive decay of elements

Heat energy continuously flows from hot core

– Conductive heat flow

– Convective flows of molten mantle beneath the crust .

Mean heat flux at earth's surface

– 16 kilowatts of heat energy per square kilometer

– Dissipates to the atmosphere and space.

– Tends to be strongest along tectonic plate boundari es

Volcanic activity transports hot material to near the surface

– Only a small fraction of molten rock actually reach es surface.

– Most is left at depths of 5-20 km beneath the surfa ce,

Hydrological convection forms high temperature geo thermal systems at shallow depths of 500-3000 m.

P6.2 Hot Rock Resource

Hot dry rock resources

Source

P6.3 Earth Interior Structure and Its Dynamics

Geothermal Resources

Source

P6.4 Temperature Deviation

Temperature Variation of Earth Surface

Source

P6.5 Dry Steam Power Plant

Dry Steam Power Plant Source

Use hydrothermal fluids that are primarily steam.

The steam goes directly to turbine,which drives gen erator that produces electricity

No need to burn fossils fuels to run the turbine

The oldest type and today,it is used at The Geysers in northern California,the world’s largest single source of geothermal power

Emit only excess steam and very minor amount of gas es

P6.6 Flash Steam Power Plant

Flash Steam Power Plant

Source

Hydrothermal fluids above 360 OF(182OC) is used in flash plants to make electricity

How it is function:

1)Fluid is sprayed into a tank held at a much lower pressure than the fluid,causing some of the fluid to rapidly vaporize ,or “flash”.

2)The vapor then drives a turbine which drives a ge nerator

3)If any liquid remains in the tank,it can be flash ed again in a second tank to extract

even more energy

P6.7 Binary Cycle Power Plant

Binary Cycle Power plant Source

Most geothermal areas contain moderate temperature water(below 400 OF).

Energy is extracted from this type of plant

How it is function:

1)Hot geothermal fluid and secondary(hence or “bina ry”) fluid with a much lower boiling point than water pass through a heat exchan ger.

2)Heat from geothermal fluid causes the secondary f luid to flash to vapor,which then drives the turbine.

Because this is a close-loop system, virtually noth ing is emitted to the atmosphere

P6.8 Geothermal Power Generation

Geothermal power generation around the end of twentieth century

Source

P6.9 ACTIVITY

Obtain at least 3 geothermal sites in your region a nd describe details of the system. (Via size, technology, reservoir temperature etc)

S.7 Solar Energy

The energy comes from processes called

o solar heating (SH) , o solar home heating (SHH), o solar dryer (SD) , and o solar cooker (SC) , o solar water heating (SWH), o solar photovoltaic (SPV: converting sunlight directly into electricit y), and o solar thermal electric power

See the table of world solar production

The average available solar energy on the surface Source

P7.1 Solar Heater

Solar Heater Source

P7.2 Solar Dryer

The three most popular types of SD are

o box type, o cabinet type, and o tunnel type

P7.3 Solar Cooker

Solar Bowl Above the Solar Kitchen at Auroville, In dia

Source

P7.4 Solar Photovoltaic

Schematic PV panel

Source??

Photovoltaic (PV) systems, other than SHH systems, are used for converting solar energy directly to electrical energy.

P7.5 Solar Thermal

Solar energy collectors

Source

When the sun’s energy is concentrated to heat water and produce steam, which is used to produce electricity).

P7.6 World Solar Power Production

Country

PV Capacity Cumulative Installed in 2004 Off -grid PV [kW]

Grid -connected [kW]

Total [kW]

Total [kW]

Grid -tied [kW]

Australia 48,640 6,760 52,300 6,670 780 Austria 2,687 16,493 19,180 2,347 1,833 Canada 13,372 512 13,884 2,054 107 France 18,300 8,000 26,300 5,228 4,183 Germany 26,000 768,000 794,000 363,000360,000 Italy 12,000 18,700 30,700 4,700 4,400 Japan 84,245 1,047,746 1,131,991272,368267,016 Korea 5,359 4,533 9,892 3,454 3,106 Mexico 18,172 10 18,182 1,041 0 Netherlands 4,769 44,310 49,079 3,162 3,071 Norway 6,813 75 6,888 273 0 Spain 14,000 23,000 37,000 10,000 8,460 Switzerland 3,100 20,000 23,100 2,100 2,000 United Kingdom

776 7,386 8,164 2,261 2,197

United States

189,600 175,600 365,200 90,000 62,000

S.8 Wind Energy

Wind turbines

Source

Wind turbines capture the wind's energy with two o r three propeller-like blades, which are mounted on a rotor, to generate electricity. Schematic diagram of wind turbine – basic operation

See the total installed capacity in MW from 1997 to 2010

See the total installed capacity by country

P8.1 Schematic Diagram of Wind Turbine

Wind Energy System

Source Wind turbine

Source

The turbines sit high atop towers, taking advantage of the stronger and less turbulent wind at 100 feet (30 meters) or more aboveground.

P8.2 Total Installed Capacity

World Wind Energy-Total Installed Capacity(MW) and Prediction 2007-2010

Source

P8.3 Total Installed Capacity By Country

Wind power generating capacity by country,at end 2004

Source

S.9 Summary

Renewable energy is very important to human life cu rrently and the use of this energy is expected to increase in the future

The renewable energy could be used commercially by the presence of technology The dependence of each country to the certain renew able energy depends on their

geographical aspects Even a lot of money must be invested for harnessing renewable energy commercially,

this energy is very practical in the future See the Self Assessment for Renewable Energy -page 1 (Question 1-8) -page 2 (Question 9-14) -page 3 (Question 15-17)

P9.1 Self Assessment (Page 1)

1. Name three constraints which impede additional c onstruction of wind power. 2. Explain one constraint against increasing wind power generation. 3. What are the five top countries that have made t he largest investments in wind

generated electricity, and what are the main reason s why they have. 4. How is geothermal energy captured? How big of a percentage of renewa ble

energy is it? 5. Name 5 factors affecting the real price of solar energy. 6. Biomass has various environmental impacts. Please discuss two examples of

both positives and negatives. 7. In what ways would a drought affect renewable en ergy sources? (PLEASE limit

your responses to 5 reasons or fewer).

8. What renewable energy source has the potential f or the most growth in the next 50 years in your country? Will this growth cau se this source to have a significant impact on the distribution of energy pr oduction?

P9.2 Self Assessment (Page 2)

9. Discuss the factors that currently prevent renew able energy sources such as

wind or biomass from contributing a greater percent age of primary energy consumption.

10. Why do people use fossil fuels, instead of alte rnative fuels if alternative fuels

are supposed to be better for the environment? 11. What are the three main aspects that make an en ergy source sustainable? 12. Discuss at least two reasons why most of the na tions current wind power is in

California. Possible discussion could include after noon breezes create wind when peak power is needed, subsidies, etc.

13. Discuss the constraints on integration of wind energy into electric utility

systems. 14. Why are renewable power sources growing at such a high rate and what

contribution are they expected to make to electrici ty in the future? Name three renewable energy resources. Compare and contrast th em. Give at least three sentences for each resource.

P9.3 Self Assessment (Page 3)

15. The world’s largest energy source (by productio n and BTU) is currently crude

oil, with coal then natural gas following close beh ind. Smaller energy sources are led by hydroelectric power, with nuclear very c lose behind, and others following afterward. Discuss the trends (increasing or decreasing) that these energy sources are following, and comment on the pr os and cons associated with the growth and decline of the energy sources m entioned.

16. Put yourself in the position of China or India, with huge energy demand growth

forecasted for the future. Keeping in mind current technologies, which energy sources would be the most viable to your country an d how/where would you implement those technologies to successfully meet t he needs of your country (remember that demand is not the only factor, but e nvironment, health, and sustainability play a role).

17. How is it that Denmark can obtain such a high p ercentage of its energy from

renewable, but your country cannot (or at least not currently)?