Solar roof tiles : towards a macro-economic model

[摘要] ENGLISH ABSTRACT:The thesis examines whether a residential solar power system (comprising a solar photovoltaic [PV] system and a solar water heater [SWH]), a demand-side option, has a lower life-cycle cost than a coal-fired power plant, a supply-side option, or vice versa. It also investigates whether a million residential solar power systems could potentially replace a 4 800 MW coal-fired power plant in South Africa. The study also explores, should a million solar power systems be installed on residential units, what the total energy output, the equivalent in coal-fired generation capacity, and the comparative costs of the two power systems would be. The common belief is that solar PV technology is unviable for electricity production because it is too expensive compared to coal-based electricity. Statements such as these are made because the initial capital costs (procurement costs) are often used as the primary (and sometimes only) criterion for project, equipment or system selection based on a simple payback period. Due to life-cycle stages, often the real costs of the project or equipment are not reflected by the upfront capital costs. In this thesis, a methodology is developed to investigate the life-cycle cost effectiveness of a residential solar power system (comprising a 5 kW PV roof tile system and a 300 litre SWH) and a 4 800 MW coal-fired plant in order to choose the most cost effective alternative in terms of the project‟s functional unit (kWh). A 5 kW solar PV roof tile system and a 300 litre SWH system have been installed at Lynedoch Eco-village. The operational results from this experiment was used as a basis for developing a model for a million residential rooftops that will have a 5 kW PV roof tile system plus a 300 litre SWH system. The focus of the million rooftops model is operating costs over the lifetime of the solar power system, on the assumption that the capital costs will be financed from coal-fired generation capacity that will no longer be needed.The results of the study indicate that a residential solar power system is most cost effective over a 40-year life-cycle period in terms of the project‟s functional unit (kWh). The thesis also finds that a million residential solar power systems (comprising a 5 kW PV system and a 300 litre SWH) could potentially replace 40% ofa 4 800 MW coal-fired generation capacity. In total, 2.3 million residential solar power systems are needed to replace a 4 800 MW coal-fired generation capacity. Emissions of 37 million tonnes of CO2 equivalent per year could be avoided if 2.3 million residential solar power systems were to be installed. However, the investment needed to install Lynedoch solar power systems (comprising a 5 kW PV roof tile system and a 300 litre SWH) on 2.3 million residential rooftops is fifteen times more than the investment needed to build a 4 800 MW coal-fired power plant. The investment needed to install 2.3 million Lomold residential solar power systems (comprising a 5 kW Lomold PV roof tile system and a 300 litre SWH) is six and half times more than the investment needed for a 4 800 MW coal-fired power plant. It was established during the study that if Lynedoch residential solar power systems were to be installed on the roofs of a million South African households, 152 308 jobs would be created in the manufacturing and installation supply chain. For the 2.3 million Lynedoch residential solar power systems needed to replace an entire 4 800 MW of coal-fired generation capacity, 340 690 jobs would be created in the manufacturing and installation supply chain. Installation of a million Lomold residential solar power systems would create 63 929 jobs in the supply chain. Installation of 2.3 million Lomold residential solar power systems would essentially create 147 298 jobs.

[发布机构] Stellenbosch University