Hydroelectric Power Plant

Hydroelectric Power Plant Diagram: Working and Types


The UN Framework Convention on Climate Change (UNFCC) recognizes that:


The rapid and responsible deployment of clean, renewable energy is crucial to meet the goals of the Paris Climate Change Agreement, which is to limit the global average temperature so that the worst impact of climate change can be avoided.” 


UNFCCC also mentions that “one technology remains a cornerstone of the renewable energy mix in some regions of the Earth: hydropower.” 


The current drive towards clean energy is a timely boost to energize the hydropower market to further expand and bring new power engineering solutions. Nonetheless, Premel has built up a comprehensive track record in the hydroelectric power market for decades now using its brand of hydro-mechanical engineering. The company, which designs, builds and operates hydroelectric plants with powers ranging from 20 kVA to 5 MVA, has put into operation over 60 plants across Switzerland and Europe. 

Hydroelectric power accounts for 70% of the world’s renewable generation capacity as of 2018 with overall efficiency of almost 90% from water to wire. It also contributes around 17% of the world’s electric generation as of 2020. The question often asked is when did hydropower start and how does a hydroelectric power plant work? 


History of Hydroelectric Power Generation

The concept of using water for power began many years ago with one of the earliest innovations found in China between 202 BC and 9 AD, where trip hammers powered by a water wheel were used to pound grain, break ore, and make paper

In 1771, hydropower was used to spin cotton in England. But it was the British–American engineer James Francis who developed the first modern water turbine in 1849. This development was followed by several innovations which led to the assembly of the first hydroelectric project used to power a lamp in Northumberland, England, in 1878. Four years later, the first commercial hydroelectric plant opened in Wisconsin, USA, followed by the operation of hundreds of hydropower plants within a decade.


Concept of Hydroelectric Power Generation

Hydropower is produced as the energy extracted from water moving from higher to lower locations. This is easier said than done as it requires accurate planning and sophisticated engineering solutions to bring about a spark of electricity from rushing water. It is the volume of the water flow and the change in elevation from one point to another which define the amount of available energy in a particular system. 

Hydroelectric power plants therefore are located on or near a water source. The change in elevation is what is known as head. In general, the greater the water flow and the higher the head, the more electricity a hydropower plant can produce. From an elevated source, water flows through a pipe, or penstock, then pushes against and turns blades in a turbine to spin a generator to produce electricity.


Types of Hydroelectric Power Systems

There are several types of hydroelectric systems beginning with the conventional run-of-the-river system, where the force of the water, usually from a river or stream, applies pressure to turn the turbine. There is also the storage system, where water amasses in reservoirs held by dams on streams and rivers and then released through hydro turbines to generate electricity.


A Premel designed hydroelectric system is shown in the diagram below:

hydroelectric power plant diagram


A pumped-storage hydropower facility is another type of hydroelectric storage system where water is pumped from a water source up to a storage reservoir with a higher elevation and then released to power hydro turbines located below. 

There are other types of hydroelectric power systems that are being developed to adapt to existing landscapes and/or optimize existing systems. The in-stream technology for instance works by installing a hydrokinetic turbine in river streams or canals to generate energy to optimize existing facilities like weirs, barrages and falls. There is also a gravitational water vortex system which is a horizontal form of the hydroelectric system that uses an artificial vortex to drive water instead of gravitation to push turbines. 

In addition, there are a variety of turbines differing in shapes, size and power that suit particular types of hydroelectric systems and other functionalities. The research and development involved in hydroelectric power generation is continuing as new challenges and opportunities arise.

Premel Approach to Hydroelectric Power System

The hydroelectric power system is both a simple and complex system at the same time. For any customer, it is often a challenge to assess and choose a system that is most suited to one’s local needs and resources. The planning stage of a hydroelectric power system is the most important step in the project development process and this is where Premel comes in; to offer comprehensive assistance to its customers in this type of project undertaking. This ensures that the customer takes the necessary first step of the development process in the right direction.


Premel services include evaluation of the location, conduct of the feasibility study, finding options for financing solutions, planning of the system and testing of all sys tem components.The company guides its customers on which type of system to build given the location and resources while computing the optimal power to be generated by the system. Premel experts work closely with customers to tailor fit solutions to their needs. Premel believes that this is the only way to guarantee that the hydropower plant will generate economic added value while minimizing risks to the environment and other stakeholders.

Our works

In the commissioning phase, Premel is not only a partner for the assembly of the turbine and generator, but also for the laying of the pressure lines, the hydraulic steelwork and the installation of the electromechanical controls. Premel works with the world's most efficient suppliers when it comes to power plant technology. Premel in addition provides technical training of staff in systems operation and maintenance as part of its comprehensive service.


Premel has a highly specialized after-sales service team available 24 hours a day to perform regular checks and initiate remote maintenance orders to guarantee long-term economic maintenance of hydropower plants.


Premel’s solution is based on smart hydro mechanical engineering approaches and guided by strict social, topographic and environmental considerations ensuring minimal impact on people and the environment. The company is ISO 9001 certified which attests to the quality of its electromechanical engineering systems, products and services. The company’s approach to engineering solutions are highly compliant with Occupational Health and Safety and environmental guidelines thereby ensuring that environmental, social and governance (ESG) principles are met and improved.



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