Álvaro Serna

Offshore Desalination Using Wave Energy

This paper evaluates the design of an offshore desalination plant currently under preliminary development. The purpose is to test the feasibility of producing drinkable water using wave energy in out-of-sight installations, as an alternative for those locations where land use, civil engineering works, and/or environmental impact make a coast-based solution inadequate. After describing the components, a proposal for sizing them is studied, based on using buoy-measured data at the expected location and their mathematical models of the different sections of the plant. Finally, by using measured buoy data, the influence of sizing on the expected performance is studied for a specific location, and one of the designs is developed in detail.

Model predictive control of hydrogen production by renewable energy

This paper presents the formulation of a control strategy based on model predictive control ideas to produce hydrogen from renewable energy in an offshore platform. Power generation based on wave and wind energy is considered as energy source which feeds a set of electrolyzers that produces hydrogen. The proposed advanced control system allows to regulate the operation of the electrolyzers, taking into account the renewable energy available and optimizing the performance of the plant. Simulation results obtained using a specific case study are presented, showing the correct operation of the plant under this advanced control.

Heuristic control of multi-stage desalination plants under variable available power

A heuristic strategy is presented and evaluated to operate desalination plants designed for variable power availability. This control strategy is based on two consecutive steps: first developing a prioritized list of units of the water plant based on the current state of the plant and the expected water demand, and then distributing the available energy among those units following the prioritized list. The proposed strategy is evaluated on a case study: a desalination plant designed for production of demineralized water powered by a combination of wind and wave energy. Simulation results show the correct operation of the plant under this control.

Mixed-Integer-Quadratic-Programming based Predictive Control for hydrogen production using renewable energy

An Energy Management System (EMS) to balance the production of renewable sources with the consumption by a set of electrolization units is proposed here based on Model Predictive Control ideas (MPC). This EMS regulates the operating point of each electrolyzer and its connections or disconnections using a Mixed-Integer-Quadratic-Programming algorithm. A case study is given for an installation composed of wave and wind energy sources and a set of 3 alkaline electrolyzers. Validation using measured data at the target location of the installation shows the adequate performance of the proposed EMS.

Evaluation of a Long Term System coupled with a Short Term System of a hydrogen-based microgrid

Coupling of a Long Term System (LTS) with a Short Term System (STS) of a hydrogen-based microgrid is considered here in this work to control the operation of a set of electrolyzers that produce hydrogen from renewable energies. Both systems are based on Model Predictive Control (MPC) ideas. The LTS manages the on/off conditions of the electrolyzers taking into account control and prediction horizons in terms of hours (high level control), regulating the operation point of the devices using meteorological predictions. The STS adapts in a low-level control the behavior of the electrolyzers with the rest of the components of the microgrid (battery and ultracapacitor). The plant is modeled in the Mixed Logic Dynamic (MLD) framework due to the presence of logical states such as the start-up/shut down of the electrolyzers and charge/discharge states in the battery and ultracapacitor. These systems are validated in a simulation showing the adequate operation of the components of the microgrid.