Water current can be effectively used to generate clean electricity. Generation of electricity from water currents can be accomplished in very large scales, by constructing dams or constructing tidal power plants and ocean surface wave power plants. It can also be done by individual homeowners (homesteaders) and small business owners, to generate and use small amounts of off-grid electricity. When setting up large scale hydroelectric power plants (or dams), the environmental impact of setting up the dam should also be considered as they can actually change the course of a river or create flood situations. The Grand Coulee Dam in the Washington state is an example of large-scale power generation units.
Hydroelectric systems can also be used to generate power from rivers and oceans without constructing dams and examples of such power supplies include the tidal power generator units and ocean wave power generator units. The smalles example would be a new design of a floating waterwheel.
Microhydropower units can also be set up by individual homeowners and these systems can generate up to 10 kW of electricity. In fact, the electricity generated by a microhydropower system can be sufficient to meet the electrical demands of a large home, a small or medium business and a farmhouse or a ranch. Hydroelectric power is one of the most reliable sources of energy, as it provides the power output during entire year (except those floating waterwheels which don’t work in winter, when the river is frozen).
Setting up a microhydropower system requires you the right to access to the flowing water current in your site. In order to calculate the amount of electricity that you can generate from your own personal microhydropower system, you have to calculate the ‘head’ (the vertical distance of water in your system) and the ‘flow’ (the volume of water falling) of the water and find out the electricity that your system will generate. The higher the product of head and flow, the more power can be generated. It is not easy to buy a good site for hydroelectric power plant.
You can successfully go off grid if you are able to set up a microhydropower system, compliant with the local water utilization laws. For example, in Poland, all the rivers are owned by the state, and you would need a lot of paperwork in order to get your own hydroelectric plant. 🙁