Handbook of Civil Engineering Calculations

"CLEAN" ENERGY FROM SMALL-SCALE

HYDRO SITES

A newly discovered hydro site provides a potential head of 65 ft (20 m). An output of
10,000 kW (10 MW) is required to justify use of the site. Select suitable equipment for
this installation based on the available head and the required power output.

Calculation Procedure:

1. Determine the type of hydraulic turbine suitable for this site
   Enter Fig. 18 on the left at the available head, 65 ft (20 m), and project to the right to in-
   tersect the vertical projection from the required turbine output of 10,000 kW (10 MW).
   These two lines intersect in the standardized tubular unit region. Hence, such a hydrotur-
   bine will be tentatively chosen for this site.


2. Check the suitability of the chosen unit
   Enter Table 5 at the top at the operating head range of 65 ft (20 m) and project across to
   the left to find that a tubular-type hydraulic turbine with fixed blades and adjustable gates
   will produce 0.25 to 15 MW of power at 55 to 150 percent of rated head. These ranges are
   within the requirements of this installation. Hence, the type of unit indicated by Fig. 18 is
   suitable for this hydro site.
   Related Calculations. Passage of legislation requiring utilities to buy electric
   power from qualified site developers is leading to strong growth of both site development
   and equipment suitable for small-scale hydro plants. Environmental concerns over fossil-
   fuel-fired and nuclear generating plants make hydro power more attractive. Hydro plants,
   in general, do not pollute the air, do not take part in the acid-rain cycle, are usually remote
   from populated areas, and run for up to 50 years with low maintenance and repair costs.
   Environmentalists rate hydro power as "clean" energy available with little, or no, pollu-
   tion of the environment.

Turbine output, kW

FIGURE 18. Traditional operating regimes of hydraulic turbines. New designs allow

some turbines to cross traditional boundaries. (Power.)

Head,

feet

Head,

meters

Industrial

pump

Impulse

turbine

Francis turbine

Standardized

tubular unit >

Bulb

unit