Environmental requirements
The head and flow of available water determine the amount of electricity that can be generated. When planning a hydroelectric power plant, it is necessary to pay attention to seasonal and annual differences in water availability. In particular, for river power plants, the water flow must be above a certain minimum throughout the year to be able to generate electricity throughout the year.
Engineering and infrastructure requirements
Micro- and pico-hydro plants are best suited for isolated areas where there is no electricity grid. Off-grid power plants require local load regulation to stabilize the supply frequency and voltage. Their advantage is that they are usually designed for individual households or small villages and can be developed using local materials and labor. For small pico-hydro turbines, the turbine-generator set can be purchased as an “off the shelf” module, while from micro-hydro and above, the turbines are specifically designed for the location.
From mini-hydro and upwards, traditional engineering approaches are used. Then the size of the equipment is such that it is feasible to approach by road. Mini hydropower plants are most often connected to the grid.
Small hydropower plants usually do not have a form of water storage.
Planning requirements
In order to proceed with a small hydropower scheme, it is necessary to obtain the right to use all of the relevant land, and it is important to clarify how contractors will access the various sections of the hydropower scheme with the necessary equipment. Therefore, it is advisable to approach the relevant landowners at an early stage to identify any objections to the proposed project and to discuss land access. As watercourses often define property boundaries, ownership of banks and existing structures can be complicated. Failure to address these issues at an early stage can lead to delays and penalties in the subsequent project.