Hydro Generation Technologies

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Hydro Power the Most Efficient Form of Generation from Naturally Exploitable Resources

Try asking any experienced Renewable Energy engineer what he/she looks for first when evaluating a site for its energy generation potential and they will all give you the same answer; "evidence of a permanent water resource with a reliable historic record, of sufficient flow characteristics to exploit its kinetic energy potential using a turbine generator of some description".

The combination of being able to successfully exploit gravity (free) and a water resource (free) as the main drivers for hydro generation, are the key attributes that elevate hydro power above all other forms of generation technology known today. The downside is that these attributes are not always available when or where they are wanted, or if available not always of sufficient hydraulic performance to be guaranteed useful or cost effective generation solutions.

Pico hydro relates to generation systems under 50 kW. This is a very exploitable size in small, remote communities globally that require only a small amount of electricity; for example, to power some LED lighting and a TV or radio for several close vicinity homes. Even smaller turbines of 200 - 300 W may power a single home in a developing country with a head of about only 1 metre required. A Pico hydro setup can typically be a run-of-the-river type system, meaning that dams or elevated catchments are generally not required but rather closed pipes (or even open channels) can be used effectively to divert some of the stream flow through a pipe/channel run and down a gradient to a small turbine generator before returning the water flow efflux back to the stream.

Beyond Pico scale hydro power, there is no theoretical limit to hydro power designs except the availability of a permanent and sufficient water resource to compliment the system design parameters, and > 1 GW capacity hydro generation plants are commonplace all over the world now.

A recent global trend is to create a 'closed loop recirculating' hydro solution in partnership with a Solar PV pumping system. This is called 'pumped hydro storage' and although it is not a highly efficient form of generation due to the requirement to artificially create sufficient gravity head and a complimentary scaled storage reservoir or catchment, it does offer design versatility in not requiring a more traditional permanent water resource being available as it can maintain a continuous water resource through a closed loop pumping strategy. This technology is essentially a self supporting 'closed loop water resource hydro generation' concept.