I posted about this 2 years ago when it was being built http://wigtonphysics.blogspot.co.uk/2015/08/building-hayeswater-gill-hydorelectric.html I've been back and it is finished. I was right about the head. I had it as 200m and it is stated as 180m. 850000 kWh divided by 250 houses is 3400 kWh per house or 9 kWh per house per day.
