A pre-feasibility study of a concentrating solar power system to offset electricity consumption at the Spier Estate

[摘要] ENGLISH ABSTRACT: The Spier Estate - a wine estate in the Western Cape Province of South Africa -is engaged in a transition towards operating according to the principles ofsustainable development. Besides changes in social and other environmentalaspects, the company has set itself the goal to be carbon neutral by 2017. To thisend, Spier is considering the on-site generation of electricity from renewableenergy sources. This study was initiated to explore the technical and economicfeasibility of a concentrating solar power plant for this purpose on the estate.The investigation was carried out to identify the most appropriate solar thermalenergy technology and the dimensions of a system that fulfils the carbon-offsetrequirements of the estate. In particular, potential to offset the annual electricityconsumption of the currently 5 570 MWh needed at Spier, using a concentratingsolar power (CSP) system, was investigated. Due to rising utility-providedelectricity prices, and the expected initial higher cost of the generated power, it isassumed that implemented efficiency measures would lead to a reduction indemand of 50% by 2017. However, sufficient suitable land was identified to allowelectricity production exceeding today's demand.The outcome of this study is the recommendation of a linear Fresnel collectorfield without additional heat storage and a saturated steam Rankine cycle powerblock with evaporative wet cooling. This decision was based on the system'sminimal impact on the sensitive environment in combination with the highestpotential for local development. A simulation model was written to evaluate theplant performance, dimension and cost. The analysis was based on a literaturereview of prototype system behaviour and system simulations. The direct normalirradiation (DNI) data that was used is based on calibrated satellite data. Theresult of the study is a levelised cost of electricity (LCOE) of R2.741 per kWh,which is cost competitive to the power provided by diesel generators, but moreexpensive than current and predicted near-future utility rates. The systemcontains a 1.8 ha aperture area and a 2.0 MWe power block. Operating the plantas a research facility would provide significant potential for LCOE reduction withR2.01 per kWh or less (favourable funding conditions would allow for LCOE ofR1.49 per kWh) appearing feasible, which results in cost competitiveness incomparison a photovoltaic (PV) solution. Depending on tariff development,Eskom rates are predicted to reach a similar level between 2017, the time ofcommissioning, and the year 2025. The downside is that the plant would notsolely serve the purpose of electricity offsetting for Spier, which may result in areduced amount of electricity that may be generated.Further studies are proposed to refine the full potential of cost reduction by localdevelopment and manufacturing as well as external funding. This includesidentification of suitable technology vendors for plant construction. An EIA isrequired to be triggered at an early stage to compensate for its long preparation.

[发布机构] Stellenbosch University