Optimizing hydroelectric power production in an environment plagued by climate change

A guest article written by student Ben Smiley, edited by Tyler Perini.

The global energy market has been heavily reliant on the burning of coal and oil for over a century, and they have become one of the largest contributors to climate change. The serious threat posed by a one degree increase in average global temperatures has initiated an international search for methods of power production that are less harmful to the environment. Many of these methods, such as hydropower, utilize the naturally occurring systems of the earth. However, the results of climate change thus far have already disturbed such systems, making traditional methods of hydroelectric production unreliable and inefficient. In order to continue a global shift towards renewable energy, hydroelectric production must adapt to the changes in the hydrological cycle using mathematical optimization.

The article “Hydropower plant operation rules optimization response to climate change” by Jianxia Chang et. al. (2018) focuses on building an optimization model for the Hanjiang River hydropower plant system. Subject to the conditions of climate change and the design of the respective plants, the objective of the model is to maximize energy production. The plant designs include cascade reservoirs, which contain a certain amount of water that is strategically used to run the plants and produce energy. The water levels in these reservoirs depend directly on the amount of inflow experienced from the river, which has become increasingly unpredictable due to glacier retreats and abnormal snowfall.

Model

The linear programming (LP) model uses the following four decision variables:

The following are three constraints in the model:

First, the energy output of plant i during period t must meet a base level energy production required by the population to function normally (Nmin). However, energy production cannot surpass the maximum level the plant was designed to produce (Nmax). Second, Second, the plant must maintain a minimum discharge flow of Qmin but is unable to surpass the maximum potential discharge of the plant, Qmax. Third, the amount of water within the reservoir at the end of period t is equal to the amount of water present that the beginning of the period plus the difference between the inflow and outflow of the reservoir (q-Q) multiplied by the difference in periods.

Chang, J., Wang, X., Li, Y., Wang, Y., & Zhang, H. (2018, July 17). Hydropower Plant Operation Rules Optimization response to climate change. Energy. Retrieved November 23, 2021, from https://www.sciencedirect.com/science/article/pii/S036054421831363X.