A study commissioned by the Government body has concluded that there is vast untapped potential across the England and Wales for generating energy from rivers.
Waterways in Wales, the upper reaches of the Thames, the Humber, the Aire, Severn and the Mersey have been identified as having the most potential.
The report found 5,000 sites for small and medium hydropower installations and another 21,000 sites were possible if river ecology could be adequately protected. The non-technical version of the report [pdf] reveals that the study focused on low-head hydro:
A total of 25935 ‘barriers’ have been identified and assessed. The term ‘barriers’ describes sites with sufficient drop to provide a hydropower opportunity. They are mostly weirs, but could also be other anthropogenic structures or natural features, such as waterfalls. The estimated average maximum power generation capacity on a barrier was 45kW, with a total potential capacity of nearly 1200MW, which could provide a maximum of about 1% of the UK’s projected electricity demand in 2020. In reality, the practical potential will be a fraction of this due to practical and environmental constraints.There was immediate oppositon from fishermen and preservationists, but the authors of the report also suggest that, done properly, small hydro can provide benefits for watercourse ecology:
There is significant potential for win-win schemes that deliver hydropower and improvements in fish passage. Initial analysis suggests that about 4000 barriers were identified as potential win-wins. This represents half of the total power potential. Grants for fish passes alongside hydropower schemes could help unlock this potential.It is doubtful that opponents will be so readily convinced of the supposed "win-win" nature of the idea. However, hydrokinetic turbines like the Hydrovolts Flipwing Turbine can often work in these sites as well because water moves fast where it drops. There are certainly many more sites without these "barriers" but which also have fast water.
The report posits that more "fish-friendly" turbines like the Archimedes Screw would be necessary, along with safe passage routes for fish and sufficient flow to allow them to avoid the turbines altogether. The Hydrovolts Flipwing Turbine fits the need and the constraints perfectly.
The report concludes that additional hydropower may amount to only 1% of projected demand, but would still be very worthwhile to pursue:
Despite these small figures, hydropower offers a number of other advantages. It is a reliable and proven technology and is particularly attractive to local communities. Furthermore, the UK’s target of generating 15% of its energy from renewables by 2020 is extremely ambitious. In the Renewable Energy Strategy (2009), the Department for Energy and Climate Change suggest that 31% of electricity will need to be renewable to meet this target. This means we will need to exploit all available renewable energy sources to their sustainable maximum.The UK is also introducing a feed-in tariff next month that will pay handsomely for small scale hydropower. Many good sites, fish-friendly, significant financial incentives, renewable energy targets--a perfect blend for the advance of small hydropower, particularly hydrokinetic turbines.