4. Water Energy [Autosaved]

8/2/2019 4. Water Energy [Autosaved]

1/22

http://www.renewcology.nu 1

Water energy Water on Earth

Categorisation of hydro-sources

Equipment for transformingenergy from hydro-sources

Waterwheels

Hydraulic turbines

Power plants using the heatenergy of oceans and seas

River hydropower plants

Power plants and their location

Water energy and humanecology


2/22


Water on Earth

oceans and seas contain 96%of all water on Earth

60 million km2 of tropical seasabsorbs a daily amount ofsolar energy equivalent of 40

billion litres of fuel oil water streams could

theoretically generate 4 700GW of energy; only one half ofthis amount is technicallyutilisable (note)

sea ebb and flow couldtheoretically generate energyequal to the combined energyoutput of all rivers and streamsin the world. In practical terms

it canonly generate energyequivalent to one third of all


3/22


Categorisation of hydropower sources

1. Energy of seas and oceans

Energy of warm water

Energy of sea torrents

Energy of sea waves Energy of sea turf

Energy of ebb and flow

2. Energy of water streams

Energy of running water

this inexhaustible source ofenergy is provided by thehydrologic circle


4/22


Equipment for transforming hydro-energy

1.waterwheels there are two basic

construction designs of waterwheels

: blade wheels

: bucket wheels

the use of waterwheels : mills,

sawmills, piston hydraulicengines etc.


5/22


Equipment for transforming hydro-

energy

2.Hydraulic turbines Equipment for transferring mechanical energy into electricity

An appropriate turbine to be used in a particular power plantdepends on the type of water stream. Therefore they cannot be

compared in terms of quality.

These are the currently used types of hydraulic turbines:

Pelton wheel

Bnki turbine

Francis turbineKaplan turbine

Driaz turbine

Reversion turbines for pumped-storage power plants


6/22


Diagrams of some types of waterturbines

generator

Turbinemoving wheel

Francis Kaplan Banky Pelton


7/22


Electricity production from hydro power

The rotor can drive a

generator, and then

electrical power

is produced

Generator


8/22


Power plants using the heat energy ofoceans and seas

Oceans and seas are a huge accumulator of thermal energy. Thisresults from the fact that water table reflects sunrays less than dryland, and the heat is absorbed by water.

These power plants utilise the temperature differences between thewarm water near the surface and the cold deepwater.

An outline of a power plant using the thermal energy of the seas(OTEC)

Location of power plants that use the thermal gradientof sea water

Mini - OTEC : Hawaiian Islands 50 kW experiment(Ocean Thermal Energy Conversion)

OTEC 2 : Hawaiian Islands 1 MW proposal

The project is currently being drafted


9/22


The utilisation of sea undercurrents

Sea undercurrents move periodically in a constant direction and speed.The currents transport huge masses of water and have crucial impact

on the temperature of the surface and deep water and also oncontinental climate

A plan has been carried out aimed at using the energy of the GulfStream in the Heterras area. The planned project should use turbineswith the diameter of 170 m

(with 2 runners and the speed of 1 revolution per minute), which will beaffixed to the seabed by steel ropes

However, this project is accompanied by vast ecological risk, as theinstallation might slow down the flow of the Gulf Stream, which couldhave catastrophic consequences.

Another such project is the installation of 100-metre discs in the seacurrent alongside the coastline of Japan, Iberian Islands and Sicily,which would rotate in the same direction as the current and thereforewould not disturb its stability.

However, the utilisation of the energy potential of sea currents is still atthe stage of theorising and experimenting.


10/22


Areas suitable for the utilisation of seacurrents

areas around massive torrents and depths exceeding 1000m

The equipment for using sea undercurrents is still being explored


11/22


Energy of sea waves

The combined energy generated by all seas and oceans has been calculated at

340 billion MJ.This source has so far been used only to a limited extent, as itsutilisation is only at the research stage. There are several types of equipment

transforming the energy of waves into electricity:

Swaying ducks

Dam - Atol.

Tidal power plants


12/22


A diagram of a swaying duck

The diagram of using the energy of seewaves

1.Rear stabilisation part

2.Central part with power house, waterengine and alternator3.Wave-breaking front part of the vessel

Floating wave-propelled power plant


13/22


Location of power plants propelled bythe energy of sea waves

Chennai (Madras) : India 350 MW tidal

Bergen : Norway 150 MW tidal

The energy-yielding potential of equipment such as swaying ducksand Dam-Atol is still being tested, withou any industrial application


14/22


Energy of the ebb and flow The phenomenon of ebb and flow is generated by the gravitation

forces of the Earth, Moon and Sun, namely the influence whichthese forces exercise on the oceans. The movement and mutualinteraction of all three astral bodies causes periodical fluctuations ofsea levels. During a lunar day there are two ebbs and two flows. Theheight of the tidal wave differs in relation to geographical location.

Utilisation of so-called tidal phenomena for generating electricity

Tidal power plants are built in places with strong ebb and flow(where the difference between ebb and flow water level is 8-12m)

There are only a few places suitable for this kind of utilising theenergy of the seas. One of them is for example near the Bretagnetown of Sant Malo, where the tidal wave rises up to 14m.


15/22


A tidal power plant

The largest tidal power plant in the world is situated in Bretagne, in theestuary of the river Rance. It is equipped with 24 reversion turbines andhas an installed capacity of 240 MW. However,the average output ofthe plant only amounts to 60 MW.


16/22


Location of tidal power plants

Bretagne : France 240 MW

Anapolis : Canada 200 MW under construction

Severn Estuary : Great Britain 7 200 MW - under construction

Gulf of Kutch : India 600 MW - under construction


17/22


Summary Pros(energy of oceans and seas)

1. It is a renewable source of energy which does notgenerate hazardous waste substances

2. Technologies developed only for tidal power plants

3. These plants do not depend on weather and theseasons of the year (apart from the energy of the seawaves)


18/22


Summary- Cons(energy of oceans and seas)

4. these sources are dependent on the geographicallocation

5. this source is dispersed and depends on weather (withthe exception of the energy of ebb and flow)

6. the technologies are not sufficiently developed (withthe exception of the energy of ebb and flow)

7. corrosions and sedimentation on the equipment, dueto sea water

8. risk of the leakage of hazardous substances (NH3)9. the transformation process has low efficiency

10. large initial investment

11. Impact on the local ecosystem


19/22


Water mills

very significant constructions inhistorical terms, they were builtfrom the ancient times until thebeginning of the last century;they are still used in the Middle

East the core equipment of water

mills are waterwheels

in addition to mills, waterwheelswere also used in sawmills,laundries, water engines etc.

Most water mills have alreadyperished. Some of the are usedas museums

Tiber Ancient RomeSeine - FranceRivers of Asia MinorRivers of the Balkans
http://images.google.com/imgres?imgurl=www.mbfys.kun.nl/~thom/gif/molens.jpg&imgrefurl=http://www.mbfys.kun.nl/~thom/ancestry.html&h=383&w=500&prev=/images?q=water+mill&start=20&svnum=10&hl=cs&lr=&ie=UTF-8&oe=UTF-8&sa=Nhttp://images.google.com/imgres?imgurl=www.mbfys.kun.nl/~thom/gif/molens.jpg&imgrefurl=http://www.mbfys.kun.nl/~thom/ancestry.html&h=383&w=500&prev=/images?q=water+mill&start=20&svnum=10&hl=cs&lr=&ie=UTF-8&oe=UTF-8&sa=Nhttp://images.google.com/imgres?imgurl=www.virtourist.com/america/staugustine/imatges/15.jpg&imgrefurl=http://www.virtourist.com/america/staugustine/15.htm&h=337&w=450&prev=/images?q=water+mill&svnum=10&hl=cs&lr=&ie=UTF-8&oe=UTF-8&sa=G


20/22


River hydropower plants

Energy generated in theseplants accounts for asignificant share of the overallenergy output, especially insome countries

The basic propellant of theplant is a turbine. The choiceof a particular type of turbinefor installation depends onmany factors, such as theheight of the falling water, the

rate of flow etc.

Summary
http://images.google.com/imgres?imgurl=www.usbr.gov/aamsden/hoovrclr.jpg&imgrefurl=http://www.usbr.gov/aamsden/laborguide.html&h=300&w=239&prev=/images?q=water+powerplant&start=20&svnum=10&hl=cs&lr=&ie=UTF-8&oe=UTF-8&sa=N


21/22


Summary(energy of water streams)

Pros

1. a renewable source of energy which does notgenerate pollutants

2. well-developed and well-tried technologies

3. reasonable operation costs4. high efficiency

5. low failure rate

6. easy to service and maintain

7. fast start-up8. accumulation capacity to a limited extent (pumped-

storage power plants)


22/22


Summary (energy of water streams)Cons

9. there is only a limited number of water streams (potential future use of water streams in third worldcountries)

10. high initial cost of building the power plants

11. power plants suffer from silting

12. the construction of a hydropower plant interferes withthe local landscape and biotope

13. danger of massive breakdownsImpact on human health : 1,13

Impact on environmental : 1,11,12,13

4. Water Energy [Autosaved]

Documents

Transcript of 4. Water Energy [Autosaved]