Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: As a renewable energy source, wave energy has the potential to contribute to the increasing
global demand for power. In South Africa specifically, the country’s energy needs may
easily be satisfied by the abundance of wave energy at the South-West coast of the country.
Commercially developing and utilizing wave energy devices is not without its challenges,
however. The ability of these devices to survive extreme weather conditions and the need
to achieve cost-efficacy while achieving high capacity factors are but some of the concerns.
Constant changes in wave heights, lengths and directions as well as high energy levels and
large forces during storm conditions often lead to difficulties in keeping the complexity of
the device down, avoiding over-dimensioning and reaching high capacity factors.
The point absorber device developed as part of this research is based on an innovation
addressing the abovementioned issues. An approach is followed whereby standard "offthe-
shelf" components of a proven hydraulics technology are used. The size of the device
is furthermore adaptable to different wave climates, and the need for a control system is
not necessary if the design parameters are chosen correctly.
These characteristics enable low complexity of the device, excellent survivability and an
exceptionally high capacity factor. This may lead to low capital as well as low operationand
maintenance costs.
In this paper the working principle of this concept is presented to illustrate how it utilises
the available wave energy in oceans. The results obtained from theoretical tests correlate
well with the experimental results, and it is proven that the device has the ability to
achieve high capacity factors. As the device makes use of existing, "off-the-shelf" components,
cost-efficient energy conversion is therefore made feasible through this research. / AFRIKAANSE OPSOMMING: As ’n hernubare/ herwinbare energiebron bied golfenergie die potensiaal om by te dra tot
die bevrediging van die stygende globale energie-navraag. In spesifiek Suid-Afrika kan die
oorvloed van beskikbare golfenergie aan die Suid-Weskus van die land gebruik word om
aan die land se energiebehoeftes te voldoen.
Betroubaarheid en oorlewing in erge weerstoestande, koste-effektiwiteit en die behaal van
hoë kapasiteitsfaktore is beduidende struikelblokke wat oorkom moet word in die poging
om ’n golfenergie-omsetter wat kommersieël vervaardig kan word, te ontwikkel.
Daarby dra voortdurende veranderings in golfhoogtes, -lengtes en -rigtings sowel as hoë
energievlakke en groot kragte tydens storms by to die feit dat dit moeilik is om die
kompleksiteit van die stelsel laag te hou. Dit terwyl daar voorkom moet word dat die
toestel oorontwerp en verhoed word dat hoë kapsiteitsfaktore bereik word.
Die puntabsorbeerder-toestel wat in hierdie navorsing ontwikkel is, bestaan uit ’n ontwerp
wat spesifiek ontwikkel is om die bogenoemde probleme aanspreek. ’n Unieke
benadering is gevolg waardeur standaard, maklik-bekombare komponente gebruik is en
die komponent-groottes ook aangepas kan word volgens golfgroottes. Indien die ontwerpsdimensies
akkuraat gekies word, is die moontlikheid verder goed dat ’n beheerstelsel nie
geïmplementeer hoef te word nie. Hierdie eienskappe verseker lae stelselkompleksiteit,
uitstekende oorlewingsvermoë en ’n uitstaande kapasiteitsfaktor. Lae kapitaal- sowel as
onderhoudskostes is dus moontlik.
Die doel van hierdie dokument is om die werking van die konsep voor te stel en teoreties
sowel as prakties te evalueer. Die resultate van teoretiese toetse stem goed ooreen met
eksperimentele resultate, en dit is duidelik dat die toestel hoë kapasiteitsfaktore kan behaal.
Aangesien die toestel verder gebruik maak van bestaande komponente wat alledaags
beskikbaar is, word die koste-effektiewe omsetting van golfenergie dus moontlik gemaak
deur hierdie navorsing.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/19950 |
| Date | 03 1900 |
| Creators | Du Plessis, Jacques |
| Contributors | Van Niekerk, J. L., Stellenbosch University. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | 127 p. : ill. |
| Rights | Stellenbosch University |
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