Conference Paper

Hydropower and Powere-to-Gas Storage Options: The Brazilian Energy System Case

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Abstract

In this study, a 100% renewable energy (RE) system for Brazil in 2030 was simulated using an hourly resolution model. The optimal sets of RE technologies, mix of capacities, operation modes and least cost energy supply were calculated and the role of storage technologies was analysed. The RE generated was not only able to fulfil the electricity demand of the power sector but also able to cover the 25% increase in total electricity demand due to water desalination and synthesis of natural gas for industrial use. The results for the stand-alone power sector show that the total installed capacity is formed of 165 GW of solar photovoltaics (PV), 85 GW of hydro dams, 12 GW of hydro run-of-river, 8 GW of biogas, 12 GW of biomass and 8 GW of wind power. For solar PV and wind electricity storage, 243 GWhel of battery capacity is needed. According to the simulations the existing hydro dams will function similarly to batteries, being an essential electricity storage. 1 GWh of pumped hydro storage, 23 GWh of adiabatic compressed air storage and 1 GWh of heat storage are used as well. The small storage capacities can be explained by a high availability of RE sources with low seasonal variability and an existing electricity sector mainly based on hydro dams. Therefore, only 0.05 GW of PtG technologies are needed for seasonal storage in the electricity sector. When water desalination and industrial gas sectors' electricity demand are integrated to the power sector, a reduction of 11% in both total cost and electric energy generation was achieved. The levelized cost of gas and the levelized cost of water are 71 €/MWhLHV and 1 €/m 3 , respectively. The total system levelized cost of electricity (LCOE) decreased from 61 €/MWh to 53 €/MWh when the sector integration was added.

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... The lowest contribution share is given in Eurasia, since prosumer PV obtains the lowest share due to highly subsidized electricity prices and excellent wind resource availability. In general it can be stated that solar PV is complemented quite well by wind energy, as already found earlier by Gerlach et al. [68], but also by hydro power, in particular hydro dams, since they act as virtual batteries balancing solar PV and wind generation, shown best for the case of Brazil [69], but also more flexible biomass power plants balance the resource fluctuations of solar PV and wind energy. [30], India/SAARC (bottom left) [32] and Southeast Asia (bottom right) [44,45]. ...
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... It can be observed in Table 6 that the available potential for A-CAES storage in Eurasia is orders of magnitude larger than the demand, which still decreases to zero in scenarios in which the regions are geographically grid integrated. [52]. A-CAES is somewhat in between on a weekly to monthly basis, which seems to be substitutable by establishing a continental grid due to the availability of some wind in a large region in any given hour. ...
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