Gravity as a Renewable Energy Source
Science Fiction or Near Future?
Keyboard buttons. Coffee grounds. Cow farts. What do these things have in common? Over the years, they’ve all been put forward as possible sources of renewable energy. While they may seem crazy, scientists’ creativity is understandable — the search for clean, renewable energy is arguably the most pressing issue in modern science. Now, some scientists say the search may be over — and unlike the previous suggestions (involving complex concepts like piezoelectricity, acid-microorganism extraction, and micro nuclear physics), this idea revolves around a concept we’ve all known since elementary school: gravity.
This idea is not new — in fact, New York legislators were considering a proposal to classify gravity as a renewable energy source way back in 2011. The idea was inspired by elevators: when heavily weighted elevators go down and lightly weighted ones go up, gravity naturally helps to complete the motion and electricity can be generated from the “gravity-powered” motor rotation.
Another innovative idea was the gravity-powered lamp. One model, called Gravia, uses a simple weight on a ball screw to power the lightbulb. As the weight slides down the screw over the course of 4 hours, the friction powers the lamp with the energy of a 40-watt bulb. The issue with this model is that it requires manual labor to power it — the user must physically bring the weight to the top of the lamp every 4 hours.
This brings us to the issue with gravity as an energy source. In both of these scenarios, the way to get excess energy from a gravitational field is to move an object from an area of high potential to low potential. The issue here is that moving the object back to the area of high potential -or putting it there in the first place- requires the exact same amount of energy as the movement generates. No net gain is possible in this scenario; no energy is generated. It is only converted from one form to another.
This brings us to the Linthal hydropower plant. Located in Switzerland, this plant is currently using gravity to produce the same amount of pure power as a nuclear power plant. This facility works as a huge battery, using water to store potential energy. Water is stored in reservoirs, and when energy is needed, the gates open and the power of gravity causes the water to flow through huge turbines. When energy consumption is low, water is pumped back up to the reservoir until more is needed. The power of the water through the turbines generates huge amounts of energy — over 1450 megawatts at a time. This much energy is enough to power over a million homes.
Clearly, this kind of energy generation can have a huge impact. So, is gravity really the energy source of the future? Only time will tell. However, it seems to be an incredibly useful source of energy on both a small and large scale. And because we certainly aren’t going to run out of gravity anytime soon, it may be the most renewable source on earth.
