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
On one hand, this follows roughly the same logic as saying wind turbines will use up all the wind.
On the other hand, tidal locking is such a cool premise for a sci-fi dystopia.
That reminds me, ‘The Tides Return Forever’ is a cracking album by German prog band Eloy. I’m now going to be playing that this week 😉
It’s a bit of a moot point anyway right? Tidal energy generation requires resonably specific geography to work. While it can probably generate a respectable amount of energy, you can’t just install it everywhere.
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.
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.
No shit.
I have a BSc in Geosciences and heard about this issue for the first time today.
Not everyone knows everything.
You’re hearing about it for the first time, because it’s not a realistic issue. The math is (I assume) correct, but the circumstances describe are impossible.
If you boil down the authors claim, it comes down to:
If you extract energy from a system, with a finite rate of replenishment, at an exponentially growing rate, eventually all of the energy will be absorbed.
To me, that’s a ‘no shit’ sorta thing.
This is BS
The moon is too small and too far away to cause the earth to stop spinning no matter what we do with the water from the tides. With his kind of reasoning, the water held in reservoirs from daming rivers would have stopped the earth from spinning and windmills (and sail boats) would have stopped the wind from blowing.
Actually the axis of the earth has shifted a measureable amount due to groundwater exploitation by humans shifting around the weight distribution of earth.
Also in your comparision to windmills you need to consider the very strong difference, that the wind is generated by the heat energy that comes from the sun, whereas earths spinning has no external energy source to maintain it.
Funny enough, if harvesting tidal energy were enough to stop the Earth’s rotation, then a civilization advanced enough to use all that energy without burning the planet to a crisp should easilly be able to restart the rotation or even pause the slowing long before it becomes a real issue.
We could intentionally force a 24hr day, and/or a 365.25 day year at that point, because fuck it, why not? Show Mars and Venus what happens if they don’t get with the program, right quick.
