Date post: | 04-Apr-2018 |
Category: |
Documents |
Upload: | ed-chikuni |
View: | 229 times |
Download: | 0 times |
of 21
7/31/2019 Chikuni Okoro Schumacher Cput
1/21
10/19/2012 International Conference onDomestic Use of Energy 2006
1
SUSTAINABLE ENERGY TECHNOLOGIES - REVIEW OF
CURRENT INTERNATIONAL TRENDS AND LESSONS FORSOUTHERN AFRICA
E. Chikuni,
Department of ElectricalEngineering
Polytechnic of Namibia
7/31/2019 Chikuni Okoro Schumacher Cput
2/21
10/19/2012 International Conference onDomestic Use of Energy 2006
2
Presenter Ed Chikuni
The presenter has worked on renewable R&D
project as well as conventional enterprises in the
transport & manufacturing sectors. For the past 10years he has been an academic.
7/31/2019 Chikuni Okoro Schumacher Cput
3/21
10/19/2012 International Conference onDomestic Use of Energy 2006
3
Introduction
The problems of waste, over-consumption and
inappropriate use of resources (especially energy)
and ramifications for future generations werehighlighted in E.F. Schumachers celebrated book,
Small is Beautiful [1] published 27 years ago .
In this book, the USA, for example with 6% of the
worlds population consumes 40% of its resources
7/31/2019 Chikuni Okoro Schumacher Cput
4/21
10/19/2012 International Conference onDomestic Use of Energy 2006
4
Dominance of Oil Coal & Natural Gas on the Energy Scene
7/31/2019 Chikuni Okoro Schumacher Cput
5/21
10/19/2012 International Conference onDomestic Use of Energy 2006
5
South African Scenario
7/31/2019 Chikuni Okoro Schumacher Cput
6/21
10/19/2012 International Conference onDomestic Use of Energy 2006
6
Who is polluting
7/31/2019 Chikuni Okoro Schumacher Cput
7/21
10/19/2012 International Conference onDomestic Use of Energy 2006
7
Sustainable Energy According to Davidson sustainable energy is
defined as energy that will provide affordable,accessible and reliable energy services that
meet economic, social and environmentalneeds within the overall developmental contextof the society for which the services areintended, while recognising equitable
distribution in meeting those needs (Davidson2002).
7/31/2019 Chikuni Okoro Schumacher Cput
8/21
10/19/2012 International Conference onDomestic Use of Energy 2006
8
About This Presentation
This presentation will cover the following:
Brief review of the global primary energy consumption
Wind Energy Biomass
Fuel Cells
Geothermal
Photovoltaics
Conclusion
7/31/2019 Chikuni Okoro Schumacher Cput
9/21
10/19/2012 International Conference onDomestic Use of Energy 2006
9
Wind Energy
7/31/2019 Chikuni Okoro Schumacher Cput
10/21
10/19/2012 International Conference onDomestic Use of Energy 2006 10
Wind: Germany
Current Installed Capacity: 4444 MW
Germany remains the largest wind energy market
in the world. In an average wind year, 31.6 billionkWh of electricity can be generated already
today reaching 6.2 % of the net power
consumption in Germany. The further expansion
of wind energy utilisation in Germany in future willno longer be confined to land, but will increasingly
be offshore.
7/31/2019 Chikuni Okoro Schumacher Cput
11/21
10/19/2012 International Conference onDomestic Use of Energy 2006 11
Germany
In Germany, the most successful sites are in the northern
coastal state of Lower Saxony. There are two techniquesused to connect the turbine system to the generator, direct
coupling or through a gearbox. Both systems have been
used successfully; the geared system represents a
traditional tried and tested approach while the directcoupling method with is multi-pole, ring generator, is
associated with revolutionary design which may well set
the direction for new large turbines. Figure 2 shows a large
wind turbine (2.5 MW) of a type seen in many locations inEurope. Figure 3 shows its power curve. Currently the
largest turbines are rated around 5MW
7/31/2019 Chikuni Okoro Schumacher Cput
12/21
10/19/2012 International Conference onDomestic Use of Energy 2006 12
ermany: nWind energy development has been boosted in Germany by the
Renewable Energy Feed in Law (REL) which obliges utilities to
purchase at a premium renewable energy produced byindependent power producers (IPP). The REL operates a
differential pricing system for each technology, with local
adjustments for energy resource availability and reducing
payments over the projects duration. For example, the overall
price for wind-power is set at DM 0.178/kWh during the first five
years of operation.Solar PV systems will now receive DM
0.45/kWh, with a degression of 5 % for new installations, starting
in 2002 - to reflect the expected costs reduction potential of a
technology which is still expensive. Renewable PortfolioStandards (RPS) are targets, for example 10% of electricity
supply from renewables by a certain date.
7/31/2019 Chikuni Okoro Schumacher Cput
13/21
7/31/2019 Chikuni Okoro Schumacher Cput
14/21
10/19/2012 International Conference onDomestic Use of Energy 2006 14
Biomass: Resources, Applications
7/31/2019 Chikuni Okoro Schumacher Cput
15/21
10/19/2012 International Conference onDomestic Use of Energy 2006 15
Fuel Cells
A fuel cell can be described as a closed container towhich a fuel such as hydrogen and oxygen is addedand which generates electrical energy, heat and water.The cell contains two electrodes and one electrolyte,after which the fuel cell type is usually named. Theadvantages of the fuel cell, in addition to itscomparatively high electrical efficiency, are that ithas limited or zero local emissions, allows very
flexible operations, has a modular construction andproduces low noise emission.
7/31/2019 Chikuni Okoro Schumacher Cput
16/21
10/19/2012 International Conference onDomestic Use of Energy 2006 16
Geothermal Resource Geothermal energy comes from the structure of the earth and
its interior heat source and circulation. There is a continualflow of heat energy outwards towards the surface. SurfaceManifestations Include:
Volcanoes
Hot springs
Geysers
Strictly speaking Geothermal Energy is not renewable andshould be treated like fossil fuel. A study by the University of
Oregon [4] on one site estimated that at the design rate of theplant, the resource would last 26 years. Geothermal energy
applications include space heating and steam power plants
7/31/2019 Chikuni Okoro Schumacher Cput
17/21
10/19/2012 International Conference onDomestic Use of Energy 2006 17
Photovoltaics Photovoltaics (PV) is the direct conversion of sunlight
into electricity using devices made of thin semiconductorlayers. Silicon technology is the most mature and a
crystalline silicon cell can convert up to 23.5 % of the
sunlight in electricity. Cheaper cells made of amorphous
silicon actually have stable efficiencies of 7 %. Modules
including cells made with other materials are not yet in
market. A module is an aggregation of solar cells and it
produces power between 10 and 200 W/sqm. With the
best modules available in the market it is possible to
produce electricity at 0.14 ECU per kWh
7/31/2019 Chikuni Okoro Schumacher Cput
18/21
10/19/2012 International Conference onDomestic Use of Energy 2006 18
A Solar Tracking Photovoltaic Array at Gobabeb: Namibia
7/31/2019 Chikuni Okoro Schumacher Cput
19/21
10/19/2012 International Conference onDomestic Use of Energy 2006 19
Conclusions
The potentional of each of the renewable energy
technologies described above varies from country
to country. While solar-thermal energy potential
holds the most promise for most Southern Africancountries, there are some countries, in particular
those with costal boundaries, where there is good
wind and wave power prospects, for example
South Africa and Namibia. Currently there areprojects to promote and exploit these energy
resources.
7/31/2019 Chikuni Okoro Schumacher Cput
20/21
10/19/2012 International Conference onDomestic Use of Energy 2006 20
Conclusions
Africa is endowed with the renewable
energy resource, but is perhaps the
continent least aware of its potential.
There is a need to sensitize not only the decisionmakers but also the general population bout the
potential and desirability of sustainable Energy
Technologies.
f
7/31/2019 Chikuni Okoro Schumacher Cput
21/21
10/19/2012 International Conference onDomestic Use of Energy 2006 21
Importance of Research