Life cycle environmental and techno-economic assessments of monocrystalline titanium dioxide nanorod-based perovskite solar cells

• Author / Creator

  Kukkikatte Ramamurthy Rao, Harshadeep

• There is an increased interest in utilization of solar energy for power generation. A lot of research effort is being put to improve the efficiency of solar cells. Perovskite architectures that use titanium dioxide nanorods as electron transport layers have been proven to have enhanced efficiency. There is very limited information on life cycle environmental and economic assessments of these perovskite cells (PSC). In this thesis, a cradle-to-grave life cycle analysis is used to evaluate the environmental benefit in terms of energy payback time, greenhouse gas emissions, and the net energy ratio of this architecture. Unlike most studies that focus on the life cycle of the cell processing, this study extends the scope to include the balance of the system and also to evaluate the environmental effects of reusing important components such as fluorine-doped tin oxide glass and the gold layer, which appear to significantly impact energy consumption and associated greenhouse gas emissions (GHG). The energy payback time is calculated to be 0.97 years and the life cycle GHG emissions is 181.50g CO2 eq./kWh of electricity produced for a solar system installed in a colder climate like Alberta, Canada. The net energy ratio is 3.10, indicating the system is a net energy generator. The assembly life cycle stage, comprising the panel production, balance of the system, and mounting of solar panels, generates the most GHG emissions while the contribution from the cell fabrication stage is second. The GHG emissions associated with raw material extraction and production (81%) dominate the on-site GHG emissions caused during cell fabrication and assembly. We observed that the embodied GHG emissions for fluorine-doped tin oxide glass and gold contribute just 4% of the total GHG emissions associated with the perovskite solar cell for a three-time reuse case. Aluminum used during panel production and mounting emits the highest GHG emissions among the materials used.
  Furthermore, to commercialize this PV technology for electricity generation, they must be manufactured at economical costs and have low levelized cost of electricity that can compete with existing technologies. In this thesis, a pathway for production of TiO2 nanorod-based perovskite solar modules is established and cost of manufacturing them is estimated. Material, utilities, and equipment requirements from the available laboratory data to a mass production capacity of up to 21.0 MW annually were estimated through development of scale factors based on first principle. Key parameters contributing to the manufacturing costs are identified, and the minimum sustainable price and levelized cost of electricity are calculated. The direct manufacturing cost of the reference PSC module is estimated at $80.23/m2 and $0.73/W with a production capacity of 3.5 MWp. These costs decline to $47.15/m2 and $0.43/W when estimated for an annual production capacity of 21 MWp due to economy of scale benefits. Material costs dominate the overall costs with fluorine doped tin oxide (FTO) glass being the most expensive material used for fabrication. The labour costs rank second but decrease drastically with increased production. The material costs and the capital cost on the equipment purchased are seen to have a scale factor of 0.81 and 0.78, respectively. The perovskite solar cell panels when installed at residential homes in Alberta, Canada are estimated to have a competitive levelized cost of electricity ranging from 7 to 17 cents per kWh. However, this parameter is found to be extremely sensitive to the module efficiency, lifetime, and the solar insolation at the location of installation.
  Sensitivity and uncertainty analyses were performed for both life cycle assessment and techno-economic assessment studies to identify the key input parameters that have significant impacts on the outputs (energy payback time, greenhouse gas emissions, the net energy ratio, minimum sustainable price, and levelized cost of electricity) and to obtain a range of results (through a Monte Carlo simulation), respectively.

• Subjects / Keywords

  • energy payback time
  • life cycle assessment
  • techno-economic assessment
  • perovskite solar cells
  • energy payback time

• Graduation date

  Spring 2021

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-wtfq-2764

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.