Run-of-river hydropower – they use the natural regime of the water source with no need for prior accumulation of water qantities. This is the most environment-friendly alternative for electricity generation.

Storage hydropower – typically a large system of equipment that diverts water from rivers or reservoirs and leads it to the plants. Electricity is produced by releasing water from the reservoir through a turbine, which activates a generator.

Pumped-storage hydropower- are hydropower plants which not only use the energy of water quantities for electricity generation, but also store energy in the form of water in an upper reservoir, pumped in another reservoir at a lower elevation. These plant are typically highly efficient because they can prove very beneficial in terms of balancing load within the overall balancing system and can facilitate accurate and secure network operation and stability. Pumped-storage is proven to be far the most efficient energy storage technology

Weir type Hydroelectric power plant – при подязовирни водноелектрически централи падът се създава чрез преграждане на водното ниво в самото речно корито посредством язовирна стена

Offshore hydropower- Ocean wave energy is captured directly from surface waves or from pressure fluctuations below the surface. Regions with promising opportunities for generating ocean wave energy include western coasts of Scotland, northern Canada, South Africa and Australia, as well as the northeastern and northwestern coast of the US.