Pump hydro storage in the integration of intermittent renewables in water drinking systems

This research aims to study the best technical-economic solution, for a hydropower plant located on Madeira Island. In this system exists three reservoirs. The first is in Covão, which supplies water for a small community and the others are located in Socorridos, where there is a turbine and a pump, and in Santa Quitéria, which contains another turbine. From Covão to Socorridos, there is only one pipe, which means the water is pumping and turbining along the operation day.

Simulations were developed in EPANET, to understand the pressure and velocity variations, along the entire system depending on the population needs. For these simulations, it was defined the pump and turbine characteristic curves.

This case study integrates solar and wind energy to compensate the pumping costs. Several scenarios were tested, to obtain the best solution.

In the optimization multipurpose project, it was used the Excel Solver to estimate the operation of the system and to increase the NPV. To solve this problem six different solutions were tested, varying the daily volume to turbine in Socorridos.

It was studied the integration with other energy renewable sources and selected a small land with approximately 5 ha near Covão, to install these energy sources. It was considered an average wind speed at 10 m height and the energy that is possible to produce by each solar panel with 787 Wp, along the day, for the selected location.

Based on this information, it was calculated the minimum number of wind turbines and solar panels, that is necessary to satisfy the energy consumption, for each scenario. The optimal solution was obtained based on the optimization function to maximize the NPV or the profit.