Wave energy comes from the usage of the ocean waves. It’s a “clean” energy, this is, without any costs for the environment.
The movement of the waves in direction to the coastline produces kinetic energy, which is used to put a turbine working. Through devices that allow to “capture” that kinetic energy, trough the elevation of the wave in an air chamber, this provokes the air output inside, the movement from this is what spins the turbine and that’s how mechanical energy from the turbine transforms in electrical energy. It’s simple. When the wave collapses, the air does the inverse movement, going through the turbine again, enters the air chamber and turns the turbine again, producing electric energy.
But, there are more ways to take advantage of the energy from the waves and tides, like using the movement of the highs and lows of the wave (that is, it’s oscillation) that gives potency to a piston that moves up and downs inside a cylinder. And it’s that piston that puts the generator working.
Advantages and disadvantages of Waves and Tides
There are several advantages and disadvantages to note in this type of energy
Advantages of the energy of waves and tides
1. Source of renewable and infinite energy. The energy of the waves will never cease to exist, there will always be waves crashing on the coastlines of countries, next to coast zones habitable. The waves don’t limit to a determinate season, they exist all over the year, and don’t men to form themselves.
2. Environment friendly. In opposition to fossil fuels, taking energy from the waves doesn’t generate prejudicial gases for the environment, nor pollution. This energy is taken directly and transformed in electricity through a group of generators and coils.
3. Several ways to harvest energy from the waves. There are various the existent ways to get energy from the waves. From installing a central with hydro generators or even platforms installed in the sea to harvest the strength from the waves (like big cylinders, with pistons inside).
4. Easy to predict. Another big advantage of the force of the waves is that contrary to other sources of energy, this one is easy to predict, we can calculate it’s production capacity.
5. Reduces the dependency of fossil fuels. Choosing this type of energy production, we will reduce the necessities of fossil fuels and with that, reduce the CO2 emissions to the atmosphere.
6. No damage to the surface of the Earth. In opposition to fossil fuels, that we must drill to find them.
7. Low costs of maintenance and functioning. The collectors of wave energy can be placed anywhere in the coast, just needing the sea. There is only the initial investment, but for a long term there is only benefits.
Disadvantages of the energy of waves and tides:
1. Suitable only for some locations. It’s one of the biggest disadvantages from this type of renewable energy, because only cities next to the shore can use this energy source, it’s not viable to all countries, or all zones. But even that is an excellent source of clean energy!
2. It affects the marine ecosystem. Even being a clean way taking energy from the waves, the way it’s harvested can harm some marine animals. That due to the machinery that’s necessary to put in the water. It will harm the marine flora, change the habitat of the coast, or even create noise that will affect marine life.
3. It can affect private and commercial ships routes. The installation of these structures next to the coast to capture the energy from the waves can lead to marine routes disturbance.
4. Wave dimension. The force of the wind depends on the dimension of the wave, that is, from the speed of the wave, length of the wave and water’s density. It’s necessary a constant flow of waves to generate a significative energy output from the waves.
5. Storms affect the performance. The performance of the devices of energy conversion of the waves in electric energy is reduced during the bad weather, like the storms.
6. Visual pollution. The generators of energy from the waves can be excellent in generating electrical energy, but depending the models applied, we can have visual pollution (due to the size and location of the devices). It can also produce noise, but this is canceled by the sound of the waves!
7. Comparing to other sources of electric energy, wave energy is expensive. The cost of generating electricity with waves can go up to 20€/kWh, that’s why there is not much investment in this type of renewable energy. And because of that, it’s not the primary source renewable energy.