Minicentrales Hidroeléctricas — Manuales de Energías Renovables
About this book
Minicentrales Hidroeléctricas — Manuales de Energías Renovables, published by the Spanish Institute for Energy Diversification and Saving (IDAE — Instituto para la Diversificación y Ahorro de la Energía) as part of the Renewable Energy Manuals series, is the primary Spanish-language technical reference for the planning, design, and permitting of small and micro hydropower systems. Targeting run-of-river schemes up to approximately 10 MW, the manual covers the full development process from initial resource assessment through hydraulic design to grid connection and environmental compliance under Spanish and European Union regulations. The publication begins with a classification of hydropower by installed capacity: pico hydro (below 5 kW), micro hydro (5-100 kW), mini hydro (100 kW - 1 MW), and small hydro (1-10 MW).
While large-scale hydropower has been a mature technology for over a century, the small and micro hydro segment is underutilised in Spain and throughout Europe despite significant untapped potential in mountain streams, irrigation canals, and drinking water supply networks. Hydrological analysis methods are presented in detail. The Flow Duration Curve (FDC) — derived from daily or monthly streamflow records maintained by the Confederaciones Hidrográficas — is the primary tool for estimating available flow, design flow selection, and annual energy production calculations.
The manual explains the statistical treatment of streamflow data, the distinction between naturalised and regulated flows, and the application of minimum ecological flow requirements (caudal ecológico mínimo) as prescribed under the Spanish Water Framework Act and EU Water Framework Directive. Civil works design covers intake structures (weir types, fish passes, sediment flushing), penstock routing and sizing (pressure head, flow velocity, pipe materials), powerhouse siting, and tailrace design. Electromechanical equipment selection is addressed through performance curves for different turbine types: Pelton turbines (for high head, low flow sites), Francis turbines (intermediate head), and Kaplan/propeller turbines and Archimedes screws (low head, high flow).
The manual provides specific Spanish engineering and equipment suppliers as reference sources. Permitting and regulatory chapters cover the administrative concession process (Confederación Hidrográfica), environmental impact assessment requirements, water rights, grid connection applications under Spanish REE regulations, and the evolution of the Spanish renewable energy premium system (from feed-in tariffs under RD 436/2004 and RD 661/2007 to the current auctioned capacity regime under RD 960/2020).