Renewable energy is a perfect alternative to fossil fuels and is helping many nations curtail their dependence on oil supply and attain an environmentally friendly space. Therefore, new investments in renewable energy such as solar, wind and biomass are helpful in meeting electricity demands and in minimizing the threats of global warming.
Climate change effects have been found to have a direct impact on renewables, which finally affects their electricity generation. For instance, hydroelectricity generation highly depends on water inflow, which is responsible for turning the hydro-turbines. In addition, the amount of water inflow counts on the amount of precipitation, a climate variable that is normally presented in rainfall-runoff models. Precipitation analyses in different places show contrasting rainfall characteristics as compared with historical data, and this is expected to intensify in days to come.
It therefore becomes important to account for different climatic scenarios in the analyses of renewable energy when designing efficient power systems. In a recent work published in Renewable Energy Professor Anderson Rodrigo de Queiroz and colleagues reported considerable advances in the investigation of climate change and climate scenario effects on water inflow generated by the regional Eta climate model. An optimization model is implemented when making a decision in the event of a hydro-thermal scheduling problem. Their work indicates that climate change can affect the system assured energy and the system’s capacity to supply load. The assured energy represents the amount of energy that a set of power plants can generate at a risk of 5% of deficit.
The authors considered two configurations of the Brazilian Power Generation System for their analysis. One was the existing generation system representing the current condition of the Brazilian Interconnected power system while the second was the future generation system, which represented the planned configuration. The proposed future generation system had ten sub-systems with two fictitious interconnection nodes.
The team implemented results from climate models to represent natural processes as well as their interactions in the atmosphere, and physical features. They used information from models, which accounts for characteristics of elements such as aerosols, snow, clouds, and solar radiation, to first simulate present climatic conditions before future projections.
The authors implemented the large basin rainfall-runoff hydrological model to evaluate rainfall-runoff functions for every river basin of the selected system. The model included selected soil and vegetation attributes of each region represented, and is composed of mathematical relations of soil water balance, surface and subsurface drainage as well as interception.
The researchers realized that the system assured energy was bigger for the first period taking into account the four members of the climate model. This was a concern considering that all the existing plants will most likely produce less electricity in days to come. From the results of the future generation system, the study indicated a similar decrease in electricity generation implying that with the proposed hydro power plant expansion, the effects of climate change will take the overall generation to approximately 28% less than the projected hydro-power production using the historical series. In fact, they recorded a drop of about 15% and 28% for existing generation system and future generation system respectively.
An increase in other water uses was also found to significantly affect the system’s assured energy. Increased domestic and industrial water demands would lead to reduced water inflows in the hydro plants, and consequently lead to reduced power generation.
In this paper, the authors provided a framework and performed an investigation implementing a combination of climatic projections scaled at regional levels, a generation optimizer and a rainfall-runoff model. This was in a bid to evaluate the effects of climate change in hydro power generation.
Anderson Rodrigo de Queiroz1, Luana M. Marangon Lima2, Jose W. Marangon Lima3, Benedito C. da Silva4, and Luciana A. Scianni3. Climate change impacts in the energy supply of the Brazilian hydrodominant power system. Renewable Energy, volume 99 (2016), pages 379-389.Show Affiliations
- CCEE Department at North Carolina State University, 2501 Stinson Dr., 27607, Raleigh, NC, USA
- Institute of Electrical and Energy Systems at the Federal University of Itajubá, BPS Av., 1303, 37500-903, Itajubá, MG, Brazil
- MC&E Research, R. Sebastião Pereira Leite, 48, 37500-099, Itajubá, MG, Brazil
- Institute of Natural Resources at the Federal University of Itajubá, BPS Av., 1303, 37500-903, Itajubá, MG, Brazil
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