1

An Introduction

A.GNANASEHARAN, B.E.,

Renewable EnergyRenewable Energy

2

3

Introduction

Wind Energy

Solar Energy

Hydro Energy

Biomass Energy

Geothermal Energy

Contents

4

Introduction

Wind Energy

Solar Energy

Hydro Energy

Biomass Energy

Geothermal Energy

Contents

5

Introduction Renewable Energy – “any sustainable energy source that comes

from natural environment.”

Some Aspects of Renewable Energy

It exists perpetually and in abundant in the environment

Ready to be harnessed, inexhaustible

It is a clean alternative to fossil fuels

Energy that is derived from natural process that are replenished

constantly.

6

Introduction Major Renewable Energy Sources

Hydro Energy

Wind Energy

Solar Energy

Biomass Energy

Tidal Energy

Geothermal Energy

Wave Energy

Bio-fuel

Bagasse

69.3%1.9%

16.1%

12.7%

Thermal

Nuclear

Hydro

Renewable

Thermal176,118.

6 MW

Hydro 40,798.8

MW

Nuclear 4,780

MW

Renewable 32,307.71

MW

Total254,005.1

MW

Indian Power Sector Power Installed Capacity = 253.390 GW

(As of 31st August 2014)

8

Present Installed Capacity of Renewable Energy Sources in India (As of 31st August, 2014)

Renewable Energy Source Present Installed Capacity

Wind 21693 MW

Small Hydro 3826 MW

Biomass including Bagasse cogeneration

4045 MW

Solar 2743 MW

Total RE Installed Capacity – 32307 MW

Source: Ministry of New & Renewable Energy Sources (MNRE)

9

IntroductionSolar Panels Wind Turbine Generators

10

Introduction

Wind Energy

Solar Energy

Hydro Energy

Biomass Energy

Geothermal Energy

Contents

11

Wind Energy - Technology Differential heating of the earth’s

surface and atmosphere induces vertical and horizontal air currents that are affected by the earth’s rotation and contours of the land and generates WIND.

A wind turbine obtains its power input by converting the force of the wind into a torque (turning force) acting on the rotor blades.

The amount of energy which the wind transfers to the rotor depends on the density of the air, the rotor area, and the wind speed.

PLF of Wind Farm is normally in the range of 20 % to 30% depending upon the site conditions and WTG rating.

P Power

ρ Air Density (kg/m3)

A Blade Area -turbine (m2)

V Wind velocity (m/s)

P = 0.5 X ρ X A X V3

12

Major Components of Wind Turbine

Wind Energy - Technology

13

Wind Energy – Present Scenario Wind Power – Fastest growing

renewable energy source Globally, it grew at the average rate

of 27 % pa over the past 10 years. While in India it grew at the average

rate of 33% over the past 10 years. Presently, India is ranked 4th in the

world in terms of Wind Energy Installed Capacity

Drivers of growth Environmental Awareness and

Sustainable Development Growing Global Energy Demand Improving Competitiveness of

renewable energy Security of Supply Concerns New Markets (e.g. India, China

etc) Carbon Trading Fiscal Benefits by Govt.

14

Introduction

Wind Energy

Solar Energy

Hydro Energy

Biomass Energy

Geothermal Energy

Contents

15

Solar Energy - Technology

Solar power is by far the Earth's most available energy source, easily

capable of providing many times the total current energy demand.

Solar power is the conversion of sunlight into electricity.

Two main commercial ways of conversion of sunlight into electricity.

Concentrating Solar Thermal Plant (CSP)

Photovoltaic Plants (PV)

CSP and PV both have their markets. PV is very successful in

decentralized applications, whereas CSP offers advantages for central

and large-scale applications. CSP power plants are the most cost-

efficient way to generate and to store dispatchable CO2-free electricity.

However, there is no competition between both. Rather, they have to be

seen as complementary technologies.

PLF of CSP – In the range of 20 % to 30 %

PLF of PV – In the range of 15 % to 20 %

16

Solar Energy - Technology Concentrating Solar Thermal

Plant (CSP)

It contains; Collector Field Turbine Generator Cooling Tower Transformer

Courtesy: ESP Solar

.

17

Solar Photovoltaic Plants (PV) It contains;

Solar Arrays Inverter Transformer

Solar Energy - Technology

18

Solar Energy - Technology In both CSP and PV technologies, solar resources plays major role. Maps are available to calculate solar resource of a particular region.

However, for both CSP and PV technologies different solar radiations are taken into account.

Basically two types of solar radiations are there; Global Horizontal irradiations (GHI) Direct Normal Irradiation (DNI)

For PV technologies GHI is considered. GHI consists of diffuse radiations and direct horizontal radiations (beam). Minimum GHI – 1000 kwh/m2 pa For CSP, DNI is considered. DNI is the amount of radiation received by a surface which is permanently aligned perpendicular to the incoming beam. Minimum DNI – 1900 kwh/m2 pa

19

Introduction

Wind Energy

Solar Energy

Hydro Energy

Biomass Energy

Geothermal Energy

Contents

20

21

Hydro Energy Advantages

Cheap to operate Long life and lower operating costs than all

other power plants Renewable High yield

Lower energy cost than any other method Pretty plentiful

Some countries depend almost entirely on it Not intermittent (if reservoir is large enough) Reservoirs have multiple uses

Flood control, drinking water, aquaculture, recreation

Less air pollution than fossil fuel combustion

23

Hydro Energy

Disadvantages:Human population displacementMore significant breeding ground for diseaseReduces availability of water downstreamEcosystem impacts

Barriers to migrating fishLoss of biodiversity both upstream and downstreamCoastal erosionReduces nutrient flow (dissolved and particulate)

Water pollution problemsLow dissolved oxygen (DO)Increased H2S toxicity; other DO-related problemsSiltation a big problem (also shortens dam life)

Air pollutionActually may be a significant source of GHGs (CH4, N2O, CO2)

Decommissioning is a big problem

24

Introduction

Wind Energy

Solar Energy

Hydro Energy

Biomass Energy

Geothermal Energy

Contents

Biomass Energy What is it?

Biomass energy is the use of living and recently dead biological material as an energy source

Ultimately dependent on the capture of solar energy and conversion to a chemical (carbohydrate) fuel

Theoretically it is a carbon neutral and renewable source of energy How it works?

Traditional: forest management, using wood as fuel Use of biodegradable waste

Examples: manure, crop residue, sewage, municipal solid waste Recent interest in agricultural production of energy crops

Should be high yield and low maintenance Examples: corn, sugarcane, hemp, willow, palm oil and many others Does not have to be a food crop Recent interest in bioengineered (GM) plants as fuel sources

Production of a liquid or gaseous biofuel Biogas due to the breakdown of biomass in the absence of O2

Includes capture of landfill methane Bioethanol from fermentation, often from corn. Cellulosic bioethanol is usually

from a grass

Biomass Energy Carbon neutral

CO2 ultimately released in energy generation is recently captured and so ideally does not change total atmospheric levels

Carbon leaks can result in a net increase in CO2 levels

Sequestration in soil can result in a net decrease in CO2 levels

27

Biomass Energy Advantages

Versatile Renewable No net CO2 emissions (ideally) Emits less SO2 and NOx than fossil fuels

Disadvantages Low energy density/yield

In some cases (eg, corn-derived bioethanol) may yield no net energy

Land conversion Biodiversity loss Possible decrease in agricultural food productivity

Usual problems associated with intensive agriculture

Nutrient pollution Soil depletion Soil erosion Other water pollution problems

29

Introduction

Wind Energy

Solar Energy

Hydro Energy

Biomass Energy

Geothermal Energy

Contents

30

Geothermal Energy

Geothermal Energy How it works

Geothermal power plants Use earth’s heat to power steam turbines

Geothermal direct use Use hot springs (etc) as heat source

Geothermal heat pumps Advantages

Renewable Easy to exploit in some cases CO2 production less than with fossil fuels High net energy yield

Disadvantages Not available everywhere H2S pollution Produces some water pollution (somewhat similar to

mining)

32

Wind Energy

33