An optimization model for the design of an off-grid micro-hydro power plant considering profitability and degradation in a multiple time period setting

• Main Authors: Hernandez, Juan Carlo B., Penas, Carlos Jan P., Tiu, Adrianne Ressa C.
• Format: text
• Language: English
• Published: Animo Repository 2019
• Subjects: Small scale hydropower—Design and construction; Operations Research, Systems Engineering and Industrial Engineering
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/18629
• Institution: De La Salle University

It is estimated that around 1.3 billion people globally still have either limited or no access at all to electricity. These, in tum, have directed greater focus on affordable, accessible, and environmental-friendly renewable energy systems. Micro hydroelectric power is a clean and efficient source of energy that has been used for the electrification of rural off-grid communities around the world. However, numerous micro hydro installations around the world have failed as caused by factors such as poor site selection, uneconomical design of materials, wrong estimate of demand, lack of productive end-use possibilities, and wrong sizing (under sizing/oversizing) of the plant. These in turn have resulted to micro hydro power plants experiencing weak cash flows and plant breakdowns, putting communities that depend on the plant at risk of losing access to electricity. Furthermore, the degradation of the micro hydro power plant continues to be an issue as well, reducing the power production of the plant over time. Using mixed-integer linear programming, an multi period optimization model for the design of an off grid micro hydro power plant considering degradation is developed. The proposed model is able to provide the necessary technical specifications such as the penstock dimensions, turbine choice, weir height, and site choice in order to fulfill a community's demand while simultaneously maximizing the net present value of the investment. The model may choose amongst different productive end uses, with each being subject to a respective investment cost as well as a set-up time and degradation rate. The proposed model is a multiple integer nonlinear programming model, which was then ran using the MATLAB software. This was then validated through a combination of actual data and hypothetical data. The results of the base run achieved a net present value of$ 2,413.21, while providing the investor with all the necessary design specifications. Furthermore, the model chose to invest in two different productive end uses and subsequently only closed one down towards the end of its useful life to ensure that it is still able to provide electricity to the community it was built for. Scenario analysis was also done in order to show the different capabilities of the model by addressing real life scenarios that may be relevant for micro hydro power plant investors. These scenarios showed how the model would respond to specific changes. The first scenario showed how changing the demand affected the model in terms of its profitability as well as the other design parameters. The second scenario explored how a change in capacity of the micro hydro power plant result to changes in the decision variables. The third scenario analyzed the implications of degradation to the purchase of batteries per year. The last scenario explored the effect of streamflow on the capacity of the micro hydro power plant to generate electricity and meet the community's demand.