Economic Analysis
Thanks to funding from the Swiss Office of Energy (BFE/OFEN), an international study group combining partners from industry and academia was formed to examine the techno-economic viability of a hypothetical 10 MWe solar thermochemical base-load power plant for Alice Springs in Central Australia.
The main project partners were Ammonia Casale S.A. (Lugano, Switzerland), FC Consulting (Rickenbach, Switzerland), L.&C. Steinmüller GmbH (Gummersbach, Germany), Siemens Power Generation (Kuala Lumpur, Malaysia) and the Energy Research Centre as well as the Centre for Sustainable Energy Systems of the Australian National University (ANU).
The study group was able to formulate a first-pass power plant design that could be constructed by dominantly using proven and standard materials, components and technologies. The design considered the application of two solar technologies. These were ANU's 400 m2 paraboloidal dish collector technology and L.&C. Steinmüller's volumetric-air "power tower" technology. The latter technology was assessed to be less effective for this thermochemical storage concept than the dish-based technology due to a less direct energy transfer from the sun to the ammonia system.
In terms of the dish-based solar system, a mainstream power plant design proposal using off-the-shelf equipment was conservatively evaluated as having a net solar-to-electric conversion efficiency of 12 % and as producing electricity on a base-load or load-matching basis with a capacity factor of 80% and a levelised energy cost (LEC) of AUD 0.36 per kWhe.
But analysis of the possibilities for sub-system improvements, that would come from a thorough pre-construction design study, revealed that the overall system performance of such a first demonstration power plant could be significantly augmented. Whilst still using standard components and techniques, a net solar-to-electric conversion efficiency of the order of 16% - 18% was predicted for such an optimised design, delivering an LEC of AUD 0.20 - 0.25 per kWhe. These results were encouraging for what would be a first pre-commercial demonstration system.
Considering the inherent potential for cost reduction from progressing through development stages and from economy-of-scale, it was concluded that this technology could well become one of the earliest and potentially cost-effective solution to the challenge of producing solar-only electricity on a continuous 24-hour basis. Provided the necessary project progress and experiences can be accomplished, an LEC of as low as AUD 0.12 - 0.15 can be expected in the future.
Further reading: Luzzi A., Lovegrove K., Filippi E., Fricker H., Schmitz-Goeb M., Chandapillai M. and Kaneff S. (1998) Base-load solar power using the 'Haber-Bosch' process. Final Report, Swiss Office of Energy (BFE/OFEN), Bern 3003, Switzerland.
