The use of natural gas to facilitate the transition to renewable electric power generation in South Africa.
| dc.contributor.advisor | Van Niekerk, J. L. | en_ZA |
| dc.contributor.advisor | Petrie, J. | en_ZA |
| dc.contributor.author | Clark, Stephen Richard | en_ZA |
| dc.contributor.other | Stellenbosch University. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering. | en_ZA |
| dc.date.accessioned | 2020-11-26T15:11:34Z | |
| dc.date.accessioned | 2021-01-31T19:44:13Z | |
| dc.date.available | 2020-11-26T15:11:34Z | |
| dc.date.available | 2021-01-31T19:44:13Z | |
| dc.date.issued | 2020-12 | |
| dc.description | Thesis (PhD)--Stellenbosch University, 2020. | en_ZA |
| dc.description.abstract | Research Question: The proposed study aims to address the appropriate role for natural gas in meeting the requirement for dispatchable energy in the South African electricity grid to support the transition to a renewable energy based generation system. As a path for achieving its international commitments on climate change, South Africa intends to develop a renewable energy based electricity generation system to meet its greenhouse gas emission reduction targets. One of the necessary conditions for large scale renewable energy implementation is the corresponding use of dispatchable power to mitigate the variable nature of the renewable sources. This study intends to answer the question of whether natural gas dispatchable power is the best way to meet this need. This involves the determination of timing and amount of dispatchable gas power that will be required, as well as the sourcing of the gas and the economics of this particular use. The analysis covers the time period between 2020 and 2050, but as per the Integrated Resource Plan (IRP) process concentrates on the period up to 2030. This research establishes the economic case for natural gas based dispatchable power. The analysis has been based on system modelling on referenced renewable energy plans using performance data from installed wind and solar generation sources. While there has been much discussion within the South Africa Integrated Resource Plan (IRP) process about the benefit of the transition to renewable generation backed up with dispatchable gas generation, there have always been questions about the source for this gas in the IRPs. This research compares the potential use of shale gas, imported LNG and pipeline gas to meet this need. Review of the IRP scenarios shows there is a large range in the potential requirement for dispatchable power depending on growth in the amount of power required as well as the performance and decommissioning of the existing base load generation system. While there has been general realisation within the IRP process of the benefit of natural gas fuelled dispatchable power, the sourcing for that gas has been left undefined. This analysis shows thatsmall total volumes of gas on an annualised basis are needed for dispatchable generation for any likely scenario. There are several reasonable sources that can be utilised. Previously not discussed in any forum, storing the gas to provide for dispatchable use – large rates for short periods - presents the major challenge for whatever source is utilised. Solutions to store the gas have been reviewed and a conceptual option for storage utilising abandoned mine shafts is proposed. The analysis indicated that the dispatchable energy requirement from the system in 2030 could vary from 5 to 15 GW, with an expected capacity factor between 2 % and 5 %. This corresponds to an fuel requirement of 9 to 78 PJ per year, with an expected value of 27 PJ/a, compared to the current importation of gas into the country of 200 PJ/a. Storage of 140 million cubic meters of gas would likely be required to meet the forecasted demand profile. This work fills in this missing piece that currently exists in the IRP planning for the transition to renewable power generation, The results of this study, explaining the requirementfor gas storage to make gas generation viably dispatchable, can assist policy makers and planners in setting up long term plans for development programmes for renewable generation backed up with dispatchable gas generation. | en_ZA |
| dc.description.abstract | Met die oog daarop om sy internasionale verpligtinge met betrekking tot klimaatsverandering na te kom, beplan Suid-Afrika om ’n hernubare energiegebaseerde elektrisiteitsopwekkingstelsel te ontwikkel om sodoende sy teikens vir die vermindering van kweekhuisgasse te behaal. Navorsingsvraag: Die doel van hierdie studie was om te bepaal hoe toepaslik natuurlike gas is om te voldoen aan die vereiste vir versendbare (Eng: dispatchable) elektrisiteit in die Suid-Afrikaanse elektrisiteitsnetwerk om die oorgang na ’n grootliks hernubare-gebaseerde opwekkingstelsel te ondersteun. Een van die noodsaaklike voorwaardes vir die grootskaalse implementering van hernubare energie is die vereiste van versendbare krag om die variërende aard van die hernubare energie bronne aan te vul. Hierdie studie poog om die vraag te beantwoord of elektrisiteit van gas-kragstasies die beste manier is om hierdie behoefte aan te spreek. Dit behels, onder andere, die bepaling van wanneer en hoeveel versendbare krag benodig sal word, sowel as die bron van die gas en hoe om dit ekonomies te gebruik. Die analise dek die tydperk tussen 2020 en 2050, maar volgens die beplanning van die “Integrated Resource Plan (IRP)” proses word daar gefokus op die periode tot en met 2030. Hierdie navorsing bevestig die ekonomiese meriete vir natuurlike gas gebaseerde versendbare krag. Die ontleding is gebaseer op stelsel modellering van bestaande hernubare energie opwekking deur gebruik te maak van data oor die prestasie van bestaande wind- en sonkragstasies. Hoewel daar deeglike onderhandelinge tydens die Suid-Afrikaanse IRP-proses plaasgevind het oor die voordeel van die omskakeling na hernubare opwekking gerugsteun deur versendbare gas opwekking, was daar altyd vrae oor die bron van hierdie gas in die IRP’s. Hierdie navorsing vergelyk die potensiële gebruik van skalie-gas, ingevoerde vloeibare natuurlike gas en pyplyn-gas om aan hierdie behoefte te voldoen. Ontleding van die IRP scenario’s dui daarop dat daar heelwat speling is in die potensiële vereiste vir versendbare krag, afhangend van die toename in die krag-aanvraag sowel as die prestasie en die aftakeling van bestaande steenkool-kragstasies. Terwyl daar binne die IRP-proses die voordele van natuurlike gas kragstasies uitgelig is, is die verkryging van die gas ongedefinieerd gelaat. Die analise van die studie dui daarop dat die totale volume gas benodig in ‘n jaar klein is vir al die scenario’s wat ondersoek is. Daar is verskeie beskikbare bronne wat gebruik sou kon word. Ongeag van watter bron gebruik word, is ’n wesenlike uitdaging wat nog nie op enige forum bespreek is nie, die stoor van die gas – groot volumes gas word vir kort periodes benodig - om die kragstelsel te ondersteun. Oplossings om die gas te stoor is verder ondersoek en ’n konsep, wat ook gepatenteer is, om verlate mynskagte te gebruik word voorgestel. Die analise dui daarop dat die versendbare energievereiste vanuit die stelsel in 2030 kan wissel van 5 tot 15 GW, met ’n verwagte kapasiteitsfaktor tussen 2 % en 5 %. Dit korrespondeer met ’n verwagte brandstofvereiste van 27 PJ/a, in vergelyking met die huidige invoer van gas van 200 PJ/a. Die stoor van 140 miljoen kubieke meter gas sal waarskynlik benodig word om aan die voorspelde vereistes te voldoen. Hierdie ondersoek verskaf die ontbrekende legkaartstuk in die IRP-beplanning vir die omskakeling na grootskaalse hernubare kragopwekking. Die verwagting is dat die uitkoms van hierdie studie, wat die behoefte aan die stoor van natuurlike gas om dit lewensvatbaar te maak as ‘n bron van versendbare krag te maak verduidelik, beleidvormers en beplanners kan help met die opstel van langtermyn planne vir ontwikkeling van hernubare kragopwekking gerugsteun deur versendbare gasopwekking | af_ZA |
| dc.description.version | Doctoral | en_ZA |
| dc.format.extent | 226 pages | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/10019.1/109312 | |
| dc.language.iso | en_ZA | en_ZA |
| dc.publisher | Stellenbosch : Stellenbosch University | en_ZA |
| dc.rights.holder | Stellenbosch University | en_ZA |
| dc.subject | Energy transition -- South Africa | en_ZA |
| dc.subject | Gas reservoirs | en_ZA |
| dc.subject | Electric power distribution | en_ZA |
| dc.subject | UCTD | en_ZA |
| dc.subject | Renewable energy sources | en_ZA |
| dc.subject | Renewable natural resources | en_ZA |
| dc.title | The use of natural gas to facilitate the transition to renewable electric power generation in South Africa. | en_ZA |
| dc.type | Thesis | en_ZA |