The Untapped Zero Carbon Energy Source

An incredibly powerful clean energy source is going unused around the world.

Humanity is in a race against time. Our self-made climate change apocalypse is ever-presently looming in the distance, threatening to inflict planet-scale karma upon us all. Yet this calamity can be averted by inventing, adopting, and scaling new zero-carbon technologies as fast as we can. We have already managed to partially achieve this feat by enlisting the use of solar and wind power, which employ the immense strength of nature to keep humanity alive without further contributing to climate change. But there is still one expansive natural energy source that is going untapped. It even has the potential to be more environmentally friendly and powerful than solar or wind power. This incredible unutilised energy is called tidal power. So why aren’t we using it? And could it soon have its time to shine?

So, what is tidal energy? Well, several different designs fall under the banner of ‘tidal,’ but they all work in similar ways and produce no carbon emissions. Firstly, each design uses tidal turbines to capture the energy of the ocean’s tide and then ‘pinch’ it, concentrating and speeding up the flow over the spinning blades. One example of this is a natural harbour with a narrow entrance. As the tide rises and falls, it is forced to rush through this narrow passageway, which means that when we drop a turbine into this flow, we can gather electricity. Another method is to use a man-made harbour (or dam) that floods due to the incoming tide. By placing turbines in the entranceways, we can again generate electricity.

There are plenty of variations in how these dams and harbours are built, especially in relation to the diversity of turbine designs. For example, some turbines look like underwater wind turbines, whereas others more closely resemble water pumps.

But no matter how they are designed, all tidal power plants have some staggeringly impressive advantages in comparison to any other form of renewable energy.

Firstly, tidal power is a consistent energy source. Some days, the Sun doesn’t shine and the wind doesn’t blow, leaving solar and wind power unusable. This is why these energy sources need massive grid batteries in order to help them persist through their respective energy droughts. But unless some supervillain decides to blow up the Moon, we will always have our mighty tides every 12 hours, making tidal power far more reliable.

This, in turn, means that tidal power, unlike wind or solar, doesn’t require massive grid batteries. Instead, it only needs a relatively small one to see it through slack water (the times at high and low tide when the water flow stops and reverses). Given batteries are very carbon intensive, have some questionable mining practices associated with them, and currently cost an arm and a leg to procure, this cutback is incredibly advantageous as it makes tidal power more environmentally friendly and reduces its cost.

On the line of environmental friendliness, it’s also important to note that tidal power has the potential to barely impact marine life at all. You see, marine ecosystems use space very differently from terrestrial ecosystems. That is why land-based wind turbine farms (and solar farms) can negatively impact terrestrial wildlife through habitat loss, but offshore wind turbines can actually boost biomass and biodiversity. If tidal power is planned appropriately (i.e. not built over key spawning areas or exposing turbines to wildlife), it too has the potential to be incredibly harmonious with ocean and terrestrial ecosystems.

Tidal power also has an incredibly long shelf life. It does need regular maintenance to keep the turbines clean and functioning well, but in theory, a tidal power plant could stay operational for centuries, whereas other renewables, such as solar and wind, only last a few decades before the entire system needs replacing. Again, this makes tidal power cheaper in the long run and potentially far more eco-friendly than its renewable competitors.

To add a cherry on top of the cake, the amount of tidal power available to us is gigantic. Current estimates put it at 3,000 gigawatts. For some comparison, mankind as a whole used 2,700 gigawatts of power on average in 2019. So, in theory, we could be exclusively powered by this ultra-low carbon and ultra-environmentally friendly power source.

So, why aren’t we? Well, two reasons: practicality and price.

Tidal power is useless for inland cities or land-locked countries. Transporting tidal power over a great distance can incur significant losses, which dramatically affects its overall efficiency and renders the entire endeavour nearly useless. Furthermore, not every coastline has the potential to host tidal power. For example, much of the Mediterranean has minuscule tides.

Despite these factors, a lot of the world does have the potential to utilise tidal power. So why don’t they?

Well, the cost. Tidal power currently costs around $130-$280 per megawatt-hour. For some comparison, wind power is only $20 per megawatt-hour. This is because, unlike wind and solar, the price of tidal power is massively front-loaded. To build the dams, turbines, and infrastructure costs an awful lot. So, even though tidal power plants last far longer than their solar or wind counterparts, meaning the process can be cheaper long-term, it is far more expensive in the short and mid-term.

So is that it for tidal power? Not quite.

We are currently living through an energy crisis, which means that resorting to more expensive forms of energy like tidal becomes increasingly viable. Therefore, areas with the geography capable of harnessing tidal power can start considering implementing this fantastic power source. Furthermore, as we adopt more and more renewable energy, it is becoming apparent that a diversified energy infrastructure is needed to ensure reliable power. Simply put, governments know we can’t solely rely on wind and solar, and they have tidal power in their sights to help secure their country’s energy needs. So, who knows? Soon tidal power plants may be commonplace worldwide.

It is absurd to think that humanity has neglected such an abundant, potentially environmentally harmonious and useful power source simply because of cost and practicality. But now, thanks to the darkly fortunate combination of rising energy costs and rapid renewable energy adoption, we are finally poised to embrace it. The clock is ticking down to our promethian climate change Armageddon, and technology like this has the potential to stop it. That is, if we use it before it is too late.