Micro Pumped Hydro Energy Storage: Sketching a Sustainable Hybrid Solution for Colombian Off-Grid Communities

Currently, electricity generation in off-grid communities is done through polluting and often inefficient diesel generators. When renewable energies are implemented, they are often coupled with chemical batteries, whose specificities do not fit well with remote and harsh environments. As a more sustainable alternative, this paper looks at micro pumped hydro energy storage coupled with solar photovoltaic production. Rural electrification in Colombia is selected as the best potential context for such a solution. Several electrical machines are considered for energy conversion (associated with one pump also utilized as turbine for robustness and cost reasons) and rated over-dedicated criteria: reactive power, efficiency, price, flexibility of power intake, complexity, and robustness. This sketching phase highlights two machines, induction and permanent magnet synchronous machines, both coupled with a variable frequency drive. Two microgrid configurations are also selected that best suit this storage technology to the needs of Colombian non-interconnected zones. A pursuit of low-tech, robust solutions is carried in this paper for reasons of costs, maintenance, and local appropriation.