Rivarolo, M., Bogarin, J., Magistri, L., and Massardo, A.F.
International Journal of Hydrogen Energy. Mar2012, Vol. 37 Issue 6, p5434-5443. 10p.
INDUSTRIAL efficiency, HYDROGEN production, HYDRAULICS, ELECTROLYSIS, and ELECTRICITY
Abstract: In this paper hydrogen generation and storage systems optimization, related to a very large size hydraulic plant (Itaipu, 14GW) in South America, is investigated using an original multilevel thermo-economic optimization approach developed by the Authors. Hydrogen is produced by water electrolysis employing time-dependent hydraulic energy related to the water which is not normally used by the plant, named “spilled water”. From a thermo-economic point of view, the two main aspects of the study are the optimal definition of the plant size and the whole system management. Both of them are strongly influenced by (i) spilled water energy variability related to its time-dependent distribution during the whole year, (ii) time-dependent electricity demand of Paraguay and Brazil (the owners of the Itaipu plant) electrical grids, and (iii) the hydrogen demand profile. The system analyzed here consists of a very large size hydrogen generation plant (hundreds of MW) based on pressurised water electrolysers fed with the so called “spilled water electricity”, the related H2 storage, and the H2 demand profile for Paraguay transport sector utilization. Since H2 plant optimal size is strongly correlated to optimal management and vice-versa, in this paper two hierarchical levels have been considered hour by hour on a complete year time period, in order to minimize capital and variable costs. This time period analysis is necessary to properly take into account spilled energy variability to find out H2 production system optimal size, optimal storage solution and best economical results. For the optimal storage size, two different solutions have been carefully investigated: (i) classical long time H2 physical storage using pressurised tanks at 200 bar; (ii) hybrid one using reduced size physical storage (one day time demand) where the energy to feed electrolysers is taken from electrical grid when spilled water energy is not available [Rivarolo M, Bogarin J, Magistri L, Massardo AF. Hydrogen generation with large size renewable plants: the Itaipu 14 GW hydraulic plant case. In: 3rd international conference of applied energy (ICAE), 16–18 May 2011, Perugia; 2011.]. For both the two solutions, time-dependent results are presented and discussed with particular emphasis to economic aspects, system size, capital costs and related investments. It is worthy to note that the results reported here for this particular H2 large size plant case represent a general methodology, since it is applicable to different size, primary renewable energy, plant location, and different H2 utilization. [Copyright &y& Elsevier]
HYDROELECTRIC power plants, PRODUCT life cycle, WATER power, CAPITAL investments, ELECTRIC power consumption, EMISSIONS (Air pollution), and ITAIPU Reservoir (Brazil & Paraguay)
Abstract: Representative Life-Cycle Inventories (LCIs) are essential for Life-Cycle Assessments (LCAs) quality and readiness. Because energy is such an important element of LCAs, appropriate LCIs on energy are crucial, and due to the prevalence of hydropower on Brazilian electricity mix, the frequently used LCIs are not representative of the Brazilian conditions. The present study developed a LCI of the Itaipu Hydropower Plant, the major hydropower plant in the world, responsible for producing 23.8% of Brazil''s electricity consumption. Focused on the capital investments to construct and operate the dam, the LCI was designed to serve as a database for the LCAs of Brazilian hydroelectricity production. The life-cycle boundaries encompass the construction and operation of the dam, as well as the life-cycles of the most important material and energy consumptions (cement, steel, copper, diesel oil, lubricant oil), as well as construction site operation, emissions from reservoir flooding, material and workers transportation, and earthworks. As a result, besides the presented inventory, it was possible to determine the following processes, and respective environmental burdens as the most important life-cycle hotspots: reservoir filling (CO2 and CH4 emission; land use); steel life-cycle (water and energy consumption; CO, particulates, SO x and NO x emissions); cement life-cycle (water and energy consumption; CO2 and particulate emissions); and operation of civil construction machines (diesel consumption; NO x emissions). Compared with another hydropower studies, the LCI showed magnitude adequacy, with better results than small hydropower, which reveals a scale economy for material and energy exchanges in the case of Itaipu Power Plant. [Copyright &y& Elsevier]
New York Times. 11/11/2009, Vol. 159 Issue 54856, p16. 0p.
HYDROELECTRIC power plants, AIRPORTS, ELECTRIC power failures, and ELECTRICITY
A problem with the Itaipu hydroelectric power plant plunged Paraguay and large parts of Brazil into darkness on Tuesday night, virtually paralyzing the two countries. Power was being restored to Brazilian cities early Wednesday, The Associated Press reported. The power failure had knocked out electricity in Sao Paulo, Rio de Janeiro, Brasilia and other cities; it also forced the shutdown of major airports in Rio and Sao Paulo, as well as the Sao Paulo metro system, the G1 news Web site reported. [ABSTRACT FROM PUBLISHER]