Alto Lindoso & Caniçada, Portugal
Alto Lindoso and Caniçada are two reservoir storage hydropower plants, each equipped with Francis turbine units with a total installed capacity of 630 MW and 70 MW, respectively.
At Alto Lindoso, the goal is to implement low-cost opportunities for a high head plant to extend its operating range and optimise flexibility services using GE Renewable Energy’s (GE’s) new smart digital control, the Advanced Joint Control (AJC), which follows the Smart Power Plant Supervisor (SPPS) methodology developed by EPFL for the project. The demonstration will also compare the benefits of increasing the operating range and optimising flexibility services with variable speed conversion (using numerical investigations only). At Caniçada, numerical investigations only are being performed to understand the benefits of variable speed conversion at a medium head plant.
The Alto Lindoso operating range extension is under investigation using the results of numerical simulations by HES-SO performed during 2021, and an extensive reduced scale model test campaign at EPFL during the last quarter of 2021. These new data, together with design-stage technical data, is allowing GE to build a damage model over the entire range of operation of the units. Preliminary results indicate the possibility of significantly improving the operating range of the units. An operation from 0% to 100% of the rated power could be foreseen with a limited risk and potential damage of operation, compared with present modes of operation of approximately 50% to 100% of the rated power.
An AJC tailored for Francis-driven reservoir storage hydropower plants is also under development by GE. This tool will manage the plant’s dispatch rules received by EDP’s trading division and balance the load between the units. It aims to optimise the efficiency of the units while reducing wear and tear and improving start-up and stoppage manoeuvres. The AJC will be packaged into a small cabinet and will be integrated and commissioned within the plant’s control system, with minimal interference in existing architecture, in mid-2022. The final demonstration of this tool will occur in late 2022, aiming to fully assess its benefits.
At Caniçada, two field test campaigns performed by the Polytechnic University of Catalonia (UPC) in April and September 2021, together with GE’s design stage data and numerical simulations performed by HES-SO, allowed the building of efficiency and vibrations/wear and tear models of the operating range. Currently, these models are being leveraged to identify the potential benefits of conversion to variable speed and to support possible future business cases. So far, results indicate that variable speed implementation allows better management of the trade-off between efficiency (i.e. water savings) and wear and tear. The final results of these studies are expected in 2022.
The official demonstration phase is due to start later in 2022.