Hydro-electric power is both an old and a relatively simple technology, and like wind, one very much suited to the natural resources that we have in abundance in Wales. However, just because you have a stream or a river running through or near your community does not automatically mean you will have the ability to produce power from it. The best sites are those which have both a high flow rate (the amount of water passing down the river) and a high head (the amount of vertical drop in the water flow). Given the hills and mountains in Wales, we have lots of potential sites for large and small scale hydro-electric schemes, but they are generally in remote areas with poor grid connectivity, making export of the electricity prohibitively expensive. It is possible to build a hydro scheme on a river with a low head but high volume of water, but this ‘run of river’ technology requires more expense and a greater scale than the standard channelling of a proportion of the flow of a stream through a generator.
The amount of water flowing in a stream or river can be calculated by actual measurement or be estimated using specially developed software (LowFlows). The later software is complex and not publically available, so you will need to employ a hydro-energy with access to the software to make calculations of mean flows over the course of any one year. The flow estimates allow for a calculation of the amount of power that a turbine could generate and therefore its viability against the cost of installation.
Ownership of the stream, or the land that it passes over is the next key consideration in the viability of a hydro site. Hydro schemes need to draw off some of the water in a stream and run it through a pipe to the turbine, and then discharge the water back into the stream below the turbine. This requires a trench to be dug in which to lay the pipework, which can run for many hundreds of yards, depending on the scheme. There are a number of additional civil engineering works, such as the construction of weirs to house the intake, and the turbine house itself, all of which will require specific consent from all landowners along the route of the stream. In addition, the diversion of water from a stream will also require the approval of Natural Resources Wales (NRW) and the taking out of a number of operating licences to extract and impound water. The ecological sensitivity of the stream will also be a major consideration in the decision on whether or not to grant planning consent for the scheme. Early consultation with all landowners and with NRW is therefore highly recommended.
More information on how you might fund your project can be found on our Funding page.
This page is also available in: Welsh