standards / manuals / guidelines for small hydro development

Gigawatt (gw)Gigawatt-hour (GWh)Glacier (ice sheet)Global positioning systems(GPS)GovernorGravel EjectorGravity arch damGravity damGridGross generationGross Head (H G )Ground water tableGround-faultinterrupter (GFCI)circuitUnit of power equal to 1 billion watts.One billion watthours of electrical energy.A large thick mass of ice formed on land by thecompacting and recrystallization of old snow and moveunder the influence of gravity. Glaciers survive from yearto year, and creep down slope or outward due to the stressof their own weight.Space-based radio positioning systems that provide 24-hour, three-dimensional position, velocity, and timeinformation to suitably equipped users anywhere on or nearthe surface of the Earth.Device for controlling turbine operation, there are threeconventional types of governor:• Speed governor, operates to keep turbine operating atthe design rotational speed.• Water level control operates to keep forebay waterlevel constant (between prescribed limits).• Load control governor operates to keep turbineoperating at a selected load. .All three functions may be provided in a single moderndigital governor.A gravel ejector intercepts and diverts bed load and somesuspended sediment load moving close to the bed. Gravelejectors are of two generic types:• Under sluice type• Vortex typeA gravel ejector would be considered where the probabilityof some fraction of bed load entering an intake isconsidered to be significant. These structures are alsoknown as silt ejectors and gravel traps.A dam designed to combine load resisting features of botha gravity and arch type dam.A dam constructed of concrete and/or masonry whichrelies on its weight and internal strength for stability.A system of interconnected power lines and generators thatis managed so that the generators are dispatched as neededto meet the requirements of the customers connected to thegrid at various pointsTotal amount of electrical energy produced by a generatingstation or stations, measured at generator terminals.Difference in elevation between the water levels of theforebay and tailrace.The upper boundary of ground water where water pressureis equal to atmospheric pressure, i.e., water level in a borehole after equilibrium when ground water can freely enterthe hole from the sides and bottom.An electrical device designed to protect people (notequipment) from electrical shockAHEC/MNRE/SHP Standards / General ­ Small Hydropower Definitions and Glossary of Terms 14