As we all know the expansion of renewable energy sources is vital in reducing our carbon emissions. How to go about this though is up for debate.

One overlooked potential was discussed in an article in The Engineer last month. Our resident expert and head of technology Steven Harris gave his opinion on small scale hydropower. He states that “it’s like all renewable technologies. We’re just starting to see the obvious and asking; why haven’t we done this before?”

At their best, micro hydro projects have the potential to account for 1 per cent of the UK’s projected energy demands by 2020. The Environment Agency believes there are around 4,000 areas in England and Wales where river power can be tapped. As these are mostly rural areas they would have the additional benefit of providing a long term sustainable income stream, significantly reduced carbon emissions and may increase a local sense of cohesion for the community.

This is technology that has been around for thousands of years in various forms but is currently not being used to its full potential in the UK. This may in part be due to environmental and social concerns usually associated with large scale hydro plants in places such as Canada. Thoughts of hydroelectric plants often conjure images or giant dams, displaced populations and flooded plains.

However, small scale hydro generation has minimal immediate environmental impacts. Also recent advances mean that concerns about continuously tweaking water levels, opening valves and wicket gates have become a thing of the past. These things can now be done automatically.

One significant issue is that up until recently it would take 5 years to get the planning permission required. Attempts to reduce this to two years though appear to be going well.

The social enterprise group h2oPE who aim to get investors involved in community hydroelectric schemes recently launched a £1m social share offer to finance three community-led hydroelectric projects. People can invest anything from £250 to £20,000 with returns estimated at three per cent in the first five years and five per cent the following years. Let’s hope that uptake is like that of a smaller 2008 project in North Yorkshire which was so popular that it was oversubscribed.