11 advantages and disadvantages of hydropower

There are different advantages and disadvantages of hydropower depending on the terrain where a hydropower plant is built and its rainfall cycle.

Table of contents

• When is hydropower applicable?
• The advantages and disadvantages of hydropower
• How to use all the advantages of hydropower while minimising the disadvantages

Hydropower is obtained from the kinetic energy generated by moving water, usually in hydroelectric power plants next to a hydroelectric reservoir. The water flow and force is harnessed to drive turbines or watermills, which then spin a generator connected to a rotor. It is the turning of the rotor that produces electricity, according to Faraday’s principles. On the surface, this is a renewable energy, as water is always flowing, but we will see below that there are also advantages and disadvantages of hydropower that need to be taken into account.

When is hydropower applicable?

Hydropower offers a continuous, but very limited and specific, energy supply. In addition, there needs to be a reservoir in a river or lake so that the force of the water is sufficient for the turbines to generate electricity.

The advantages and disadvantages of hydropower

As we shall see, it has more advantages than disadvantages, which is why it is currently the most widely used to supply electricity to homes and businesses.

Advantages

1. It is a renewable energy: as it is obtained from falling water in a reservoir, which in turn is fed by rainfall, as long as the water cycle is maintained and the reservoir does not dry up, energy can continue to be produced from hydropower.
2. It is a clean energy: the production of hydroelectric energy does not produce waste of any kind, neither physical nor chemical, nor greenhouse gases.
3. It provides stable electricity: it does not occur as in the case of wind or solar energy, where on days when there is no wind or the sky is cloudy, no energy is produced. The water to obtain hydroelectric energy is always flowing, because the rainwater has been previously stored in the reservoir, i.e. hydroelectric energy does not depend daily on rain to produce electricity because there are very significant water deposits.
4. It is safe: it cannot cause dangerous accidents like nuclear energy and neither does it produce dangerous pollutants or toxic waste for our health or that of the animal and plant species in the vicinity of the generating plant, so it is clean and environmentally friendly. In fact, it is one of the safest energies we can use. 
5. The production is adaptable and flexible: you can regulate the outflow of water that moves the turbines, so you can easily adjust if you need more or less energy, allowing the possibility of generating more or less electricity depending on the needs.
6. It is very economical in the long term: we can say that it is expensive to build the hydroelectric power plant, however, the energy source is renewed free of charge and does not depend on market variations.

Disadvantages

1. It can be affected by droughts: Although, as we have pointed out, dams always maintain a reserve of water for when it does not rain, in areas where there are prolonged droughts this energy is not viable or involves costly and difficult work, such as the diversion of the course of another river that feeds the reservoir. This is why seasons with many droughts can be a real handicap when it comes to generating electricity in this way.
2. It requires a large initial investment: a large amount of capital is needed to finance the construction of a hydroelectric power plant, but it is also true that the maintenance costs are not very high afterwards.
3. Environmental consequences: it must be taken into account that the construction of hydroelectric power plants generates changes in the ecosystem, seriously affecting animals and plants, as well as water quality.
4. Finding a suitable site: it is somewhat difficult to find a suitable site, as it needs to have the right orography and be dependent on the watercourse in order to get the most out of the land.
5. High initial investment: setting up the hydroelectric power plant is expensive, which makes the investment to build the plant very high. In addition, on many occasions, it will require the expropriation of land with the cost of compensation that this entails.

How to use all the advantages of hydropower while minimising the disadvantages

In order to overcome the problems posed by this form of energy, such as dependence on rainfall and drought cycles or successfully harnessing a diverted riverbed, it is important to have a good understanding of the land on which a hydroelectric plant is to be built.

In addition, knowing the advantages and disadvantages of hydropower in a given location can also help us to study whether there are other renewable and clean energy alternatives, such as wind energy or solar energy. Therefore, studying a Master’s Degree in Energy Efficiency and Renewable Energies can be of great importance now in order to face the environmental problems of the present and ensure energy availability in the future.