Optimal Reservoir Control for Hydropower on Colorado River, Texas

Abstract

The Lower Colorado River Authority (LCRA) of Texas is both a water and energy supplier to central Texas. LCRA's power production includes hydroelectric power plants at the six dams of the Highland Lakes reservoir system, on the Colorado River. To improve power generation, LCRA has investigated alternative operating procedures to increase the winter hydroelectric power generation in the upper reservoirs of the Highland Lakes. A methodology using both optimization and simulation techniques was developed to evaluate the ability of the hydroelectric power plants to meet weather-related winter peak power requirements. A linear-programming procedure determined the hourly generation schedule, over a 24-hr period, that maximized the total power generated over the 6 h of peak power demand. Based on statistical simulation of daily winter inflows and releases using a LOTUS 1-2-3 spreadsheet, it was found that the full generating capacity could be supplied to meet winter power demands with no significant impact on water availability or lake water-surface levels. The developed operating plan is being implemented in LCRA power system operations.