Attractive Sites

While hydropower can be created on lots of sites where there is flowing water some locations are more attractive than others.  Three examples of particularly attractive situations are:

a)    Hill Burn - with a modest catchment area (around 5km2 would do) where the water descends steeply down the lower reaches (probably over waterfalls) to the loch-side or sea.  Burns that could theoretically produce 150kW are good since they can be reduced in size to maximise the income from Feed-in Tariffs by limiting the volume of water abstracted.  These burns in themselves can be quite small so long as the head (vertical drop) is large.  The other features which can improve the commercial viability are:

  • Physical access to the site of the powerhouse – a track or public road would be ideal
  • Physical access to the site of the intake – you need a track to get civil engineering equipment to the location
  • Overhead power lines – ideally 11kV 3-phase

b)    Weir – an existing weir on most rivers would be a good starting point.  The bigger the river the better, but the mere existence of the weir signals the historical value of the site.  A head (water level difference) of anything above two metres is good, but the more the better. The nature of terrain above and below the weir is of little interest – the working assumption is that we would be looking at putting an Archimedes screw down the side of the weir or around one of the ends. SEPA tends to view existing weirs favourably – the scheme is likely to have only a small additional impact on the watercourse, and over a very short distance at that.

Baldernock Mill c)    Mill-house – usually accompanied by remnants of a waterwheel, weir and a lade, is another good starting point. These are never going to produce lots of power, but depending on the existing infrastructure the costs can sometimes be reduced. The weir might need repaired, the lade dug out and leaks plugged, plus the wheel refurbished or even built from new, but with the addition of a generator and a control system a modest amount of power can be created to off-set the cost of electricity being consumed in local properties.