Thermoelectric Current and Submarine Cables: Why It's Not Feasible for Energy Generation

Submarine cables have become an indispensable part of our modern communication infrastructure, enabling global data transfer and connectivity. However, a question often comes up in discussions about the potential energy harvesting methods involving these cables: can we generate energy by exploring the thermoelectric current principle in very long submarine cables? The answer is generally a resounding no, largely due to key technical and economic challenges.

Why Not in Submarine Cables?

Under the sea, temperatures are typically very constant, usually around 5°C, unless near a thermal outpouring. While this consistency might seem promising for energy generation, it is far from sufficient to make it a viable option. The thermoelectric current principle relies on a temperature gradient, which in this case is relatively small. Therefore, even if a cable is placed in an area with a distinct temperature difference, the power generated would be minuscule.

Resistive Losses and Economic Feasibility

Electricity generated through resistive heating would face significant challenges due to resistive losses. These losses occur as electrical current flows through the cable's conductive material, which is inevitable and substantial. For a submarine cable, the resistive losses can consume up to 90% of the generated power before it can even be used. This means that out of every watt potentially generated, only a small fraction is actually available for practical use. Such a low efficiency makes the endeavor economically unviable.

The Technical Challenge of Minuscule Power Output

Even if one were to invest the necessary funds and energy to set up such a system, the power output would be extremely low. For instance, exploiting the temperature difference between the surface and the bottom of the ocean for energy generation would produce so little power that it would be consumed entirely by resistive losses. By the time the energy reaches the point of use, there would be virtually no power left, rendering the endeavor completely impractical.

Alternative Energy Harvesting Methods

Instead of relying on thermoelectric principles in submarine cables, there are other, more efficient ways to harness energy from the ocean.

Harvesting Energy from Ocean Currents

For example, tidal turbines can be used to generate significant amounts of power from the natural flow of ocean currents. These systems are already being implemented on a large scale, and their effectiveness far exceeds any potential benefits from thermoelectric methods.

Utilizing Rainfall and Candle Energy

While the idea of exploiting energy from falling raindrops or burning candles might seem far-fetched, it is true that such methods could theoretically power small devices, like micro-drones. However, the scale of energy required for larger applications cannot be reasonably achieved. For instance, charging a normal phone or running a home would require an impractical amount of these energy sources.

Thermoelectric Generators in Specific Circumstances

Thermoelectric generators can make sense in certain scenarios, such as charging a phone from a woodstove in a remote forest cabin. Here, the efficiency and convenience of these generators can be appreciated because they require minimal maintenance and can operate in conditions where other energy sources are not viable.

Conclusion

Submarine cables are energy consumers rather than potential energy generators through the thermoelectric current principle. While global connectivity via submarine cables is crucial, the idea of using them for energy generation is not economically or technically feasible. Instead, researchers and engineers should focus on more efficient and practical methods for harnessing oceanic energy, such as tidal turbines, to meet the growing global demand for sustainable power solutions.

Key Takeaways:

Submarine cables consume more energy due to resistive losses than they can generate through thermoelectric methods. The small temperature gradient in the ocean makes thermoelectric generation inefficient. Tidal turbines and other ocean-based energy solutions offer more practical and high-yield alternatives to energy generation.