Hydro-Electricity for Settle (?)

Just how much power is there in the Ribble?

Here is Mike slater’s analysis of the likely power of the water wheel at Bridgend Mill.

This is an undershot wheel (see diagram), with about a 2 metre drop.

Mike has a book containing the Francis Weir Formula.
      F   =   3.33   [ L   –   0.2 H ]   H 3/2
      where
           L = width of the weir in feet
           H = depth of water at the weir edge in feet
           F = flow rate, ft 3 / sec

Say L = 10' and H = 0.2'
      \ F = 3.33 × 9.96 × 0.0894
               = 2.97 ft 3/sec

Average velocity of the water over the edge
           V   =   2.97
10 × 0.2 		  =   1.48 ft 3/sec

Converting to SI units:
      F = 0.083 m 3/sec
      V = 0.45 m/sec

Kinetic energy of the water per sec
           =   ½   F ρ   V 2
           = 0.5 × 0.083 × 1000 × 0.45 2
           = 8.4 kg m 2 / sec 3

Potential energy of the falling water per sec
           = F ρ   g   h
           = 0.083 × 1000 × 9.81 × 2.0
           = 1628 kg m 2 / sec 3

which Mike says is:
           = 163 kW

but surely, kg m 2 / sec 3 is joules / sec, i.e. watts.

I find it amazing that the joinery could have been run on 1.63 kW, let alone the mill that preceeded it.