Tidal Energy
How is your source used to generate electricity?
-There is a huge dam-like structure that narrows and has many gates and turbines at the bottom. When the tide rises, the water pushes through the turbines, moving them one way, and when the tide falls, the water pushes through the turbines again, moving them.
Is your source renewable or non-renewable?
-Renewable
What are some pros and cons of your source?
PROS
-Some changes can cause an increase of different types of invertebrate species
-More food for birds
-Birds there might be different from the usual ones
CONS
-Interferes with the flow of water
-The dams make reservoirs (the reservoirs flood land)
-Silt is usually “dumped on the river's flood plain, providing a source of nutrients for the soil” , but because it's being built up in the reservoir, the soil on the river's flood plain is not getting the nutrients it needs (farmers that live downstream from one of these dams say that they get 10% less silt than normal so the farmers have to rely on artificial fertilizers).
-Algae need the nutrients of the silt to survive and multiply, when algae die they are rotted by bacteria and the more algae die, the more bacteria is created, and the bacteria use up the oxygen in the water. The more bacteria, the less oxygen for the fish and other organisms and the lack of oxygen causes them to die.
-Makes it so that there are no really high or low tides
-Mud flats and salt marshes (that are low to the ground) can become permanently flooded; wading birds lose their habitat, and in estuarine places, it's abundant.
-The time it takes for the water to move out of the dam-like structure can increase, this causes pollutants to stay there longer then drain out and be deposited into the open sea.
-Salt Concentration can go down and this harms marine organisms.
How widely used is your source?
-Not very widely used.
- Used mostly in Europe and the Atlantic coast of North America
What is the approximate cost (per kwh) of electricity generated by your source?
- Between 1.8 and 2.8 cents per kwh