Types Of Hydro Generation
MICRO & PICO HYDRO
There remains a focus on microgeneration and community schemes, and there is still an interest in redeveloping many disused watermill sites and small off-grid hydro projects. Micro hydro development in the UK is still popular, which includes pico, micro and mini. There remain opportunities for sensitively sited micro hydro installations (up to 100kW installed capacity) that can supply cheap, reliable generation with minimal visual and environmental impact.
Pico hydro is traditionally hydroelectric power generation of under 5 kW. This has proven to be useful in small, remote communities that require only a small amount of electricity.
Even smaller turbines of 200–300 W may power a single home with a drop of only one meter. Pico-hydro setups typically are run-of-stream, meaning that a reservoir of water is not created, only a small weir is common, pipes divert some of the flow, drop this down a gradient, and through the turbine before being put back to the stream.
SMALL RUN OF RIVER
Small-scale hydro (100kW to 5MW installed capacity) is highly efficient and where suitable sites are available, it remains one of the cheapest forms of renewable electricity per unit. Small-scale hydro has a key role to play in the development of the world’s renewable energy resources. Clean and reliable – it is a valuable resource just waiting to be utilised.
Hydropower solutions can be more reliable than other renewable options, and with their generating components engineered to last many years, they can be simpler to maintain and service. Larger scale hydropower stations (run-of-river, dams or reservoir storage), can also help to develop a whole range of infrastructure facilities.
Pumped storage is the oldest kind of large-scale energy storage and works on a very simple principle – two reservoirs at different altitudes are required and when the water is released from the upper reservoir to the lower reservoir, energy is created by the downflow, which is directed through a turbine and generator to create electricity.
TIDAL RANGE & OFF SHORE
Tidal power provides predictable and secure generation capacity. Research into a number of tidal range technologies and offshore hydropower is proceeding at a number of sites around the British Isles. Tidal range energy is created by the diffference in head between high and low tides.
Waterwheels are a viable proposition for producing electriciy for domestic purposes. They are simple to control and aesthetically pleasing. Although they run realtively slowly and require a high ratio gearbox to drive a generator, for low powers – say below 20kW – and heads below 8m, they are worth considering.