Tidal Energy Is Not Renewable
It is incorrect to consider tidal power as renewable energy. Harnessing tidal energy will pose more severe problems than using fossil fuels. This study provides quantitative estimates to show how using tidal energy can destroy the environment in a short amount of time. Tides are induced by the rotation of the Earth with respect to the gravity of the Moon and Sun. The rotational energy of the Earth is naturally dissipated by tides slowly. Consuming tidal energy further reduces the rotational energy, accelerates the energy loss rate, and decelerates the rotation of the Earth. Based on the average pace of world energy consumption over the last 50 years, if we were to extract the rotational energy just to supply 1% of the world's energy consumption, the rotation of the Earth would lock to the Moon in about 1000 years. As a consequence, one side of the Earth would be exposed to the Sun for a much longer period of time than it is today. The temperature would rise extremely high on that side and drop extremely low on the other side. The environment would become intolerable, and most life on Earth could be wiped out.
Oopsie
The author is saying if we use tidal energy to cover 1% of our total energy usage AND if we assume our energy usage will increase exponentially year by year, after 1000 years we’ll stop the earth spinning.
No shit.
If we sap an exponentially growing amount of energy from the earth’s inertia, at some point in the future it will stop because the amount of energy feeding into the system (sun) is relatively fixed in value.
If I was to bet, this paper was tongue in cheek joke between the student and their instructor.
Its a pretty good joke though, you gotta admit. Nothing like someone with a phd and the knowledge to mess with people not literate in the subject matter. Kudos to dr liu.
There is another problem with tidal power. A big tidal project can change the tidal range over large geographic areas. There was a plan to do a tidal project in the Bay of Fundy in Maine in the 1970s. The study showed is would change tides as far away as Washington, DC. It was scrapped.