Pumped Storage Hydropower – Maximizing Energy Efficiency

Hydro Power Storage Maximizing Energy Efficiency

Pumped storage hydropower (PSH) is one of the most established energy storage technologies. Today, it accounts for more than 90% of bulk electrical energy storage capacity worldwide.

Pumped storage allows renewable power plants and other sources of variable generation to generate power at peak times while saving excess production for times of lower demand. This helps smooth out load fluctuations on the grid, eliminating the need for peaking power plants that may operate at higher costs or with less efficiency than base-load thermal power plants.

1. Optimized Reservoir Design

Reservoirs are essential elements in hydro power storage, controlling how much water is necessary to generate energy. Therefore, optimizing reservoir design for maximum energy efficiency is paramount.

This has driven extensive research into reservoir optimization for years. Numerous algorithms have been devised to solve this problem, including some metaheuristics like Genetic Algorithm (GA) and Differential Evolution (DE).

Metaheuristic methods and conventional approaches to reservoir optimization are employed as well. These include linear programming and dynamic programming, the former having the advantage of handling nonlinear objective functions and constraints. It can be employed to determine optimal reservoir release under various inflow ensembles.

2. Optimized Pumping

Optimizing water pumping into reservoirs is an integral component of any hydro power storage system, helping to save energy and extend their lifespan.

Monitoring pump efficiency can be done to detect when they are degrading. Once you know when they are losing efficiency, taking action to remedy it and save money on running costs will become much simpler.

When electricity demand changes, pumped hydro storage systems can act quickly to provide a range of grid services like resource adequacy and load balancing. Furthermore, they control electrical network frequency to stabilize the grid, which is essential in avoiding grid incidents.

Pumped storage plants function similarly, pumping water up the upper reservoir during times of low demand and then releasing it back into the lower one through a turbine that generates electricity. This cycle repeats itself as long as there remains an energy demand.

3. Optimized Turbine Design

The turbine is an important element of hydro power storage, converting kinetic energy to mechanical and then electrical energy.

Optimizing turbine design is essential for increasing energy efficiency. This includes minimizing losses, using materials with better high temperature capabilities and optimizing the thermodynamic performance of the entire cycle.

Axial flow turbines utilize inlet and outlet streams that enter the turbine along its axis of rotation. As this propels the turbine around its center of mass, it produces a net torque.

The turbine can also be programmed to minimize steam consumption, known as partial admission. This enables it to operate at peak efficiency over part of its load range without being adversely affected by nozzle control, which controls nozzle number.

4. Optimized Controls

Pumped hydropower is the most widely-used form of grid-level energy storage. This technology works by using water reservoirs at various elevations to store energy when demand exceeds supply, then releasing it back into circulation via a turbine in a lower reservoir when needed on the grid.

Pumped hydropower not only stores energy, but it also offers numerous useful services to the grid. These include reactivity, frequency regulation and voltage control.

Enhancing the reliability of pumped hydropower storage is critical to its capacity to provide essential grid services. Furthermore, an effective repair, protection and improvement strategy is necessary to guarantee the safety of pumped hydro assets.

INL creates models to assist hydropower plant owners in reconditioning their systems, accurately representing both electrical and water subsystems of a hydropower plant. Doing this helps guarantee controllers and power converter hardware operate efficiently and securely, maximizing their capabilities.