Four renewable energies you may not have heard of
Everyone's heard of wind turbines, but what about tidal power.
Renewable energy is the way we’re going to power tomorrow, and already countries are making huge strides in the field.
In 2014, Denmark generated 39.1 percent of its energy from wind turbines, and Scotland produced 40 percent of its energy through renewable sources. The UK’s renewable energy generation was up 15 percent from last year--enough to power 6.7 million homes.
Whitelee wind turbine farm, Eaglesham, East Renfrewshire, Scotland.
And that’s just the tip of the turbine.
Though the iconic white windmills dotting empty fields is a familiar sight, there are so many other innovations in wind and water power to get excited for.
Right now there are terawatts of energy swirling around the world. There’s roughly 332 million square miles of water on earth, and just a fraction of it is being utilized, and sometimes not as effectively as you’d hope. For instance, you’ve heard of hydroelectric dams, but they’re not as green as they’ll lead you to believe.
Their biggest issue is construction the dam itself. It leads reduced water levels, which change river flows and destroy habitats. Roads and powerlines also lead to the destruction of environments. People lose their houses and land due to the resulting reservoir. These are some big issues, and sometimes we forget that there are other ways to harness water.
For instance, have you heard of tidal lagoons?
- Tidal Power
Enter the Swansea Bay Tidal Lagoon Project.
Tidal power is not a new concept to humanity. In the middle ages and possibly as early as Roman times, energy from the waxing and waning of the moon has been captured through the use of tidal mills. By building a dam with a one way gate across an existing estuary, water is kept in an artificial reservoir until the tide goes back out. Then the gate is opened and the water rushing out is used to turn a water wheel.
The Tidal Mill at Yarmouth, Isle of Wight in September 2013.
Tidal lagoons are the next step in harnessing the nearly limitless energy potential of the world’s oceans. Like tidal mills on steroids, they’re man-made harbors that generate energy through the use of the tidal ebb and flow.
A sea wall is built across a bay with high tidal movement, and in the wall multiple massive turbines are placed. As the tide flows into the newly created harbor, the water is funneled through the turbines and spins them, generating power. The instant the tides reach their max height, the valves are shut. Once the tide is as low as possible, the water is once again released through the turbines to make the best use of the tidal head created.
A concept image of the sea wall
The best thing behind tide lagoons is, unsurprisingly, the water. Seawater is 832 times more dense than air, meaning that it transfers significantly more kinetic energy. It’s because of this density difference that a five knot ocean current produces more kinetic energy than a 217 mph wind.
Tidal power is also one of the most reliable forms of renewable energy. Twice a day, every day this project is going to be generating clean energy. And that’s huge. One of the main drawbacks of wind power is that the wind doesn’t always blow, and the places where it’s most reliable are often used as main migratory paths for birds, causing major disruptions in their flight patterns.
Visitor Center and Rock Pool
The Swansea Tidal Lagoon is significantly less disruptive. The project can generate “clean, renewable and predictable power for over 155,000 homes… for 120 years.” And because the sea wall is being build across an existing estuary, the environmental consequences are drastically reduced.
But that’s not the only exciting renewable energy technology that relies on the ocean’s movements.
2) Ocean Currents
UC Berkeley has been working on a concept that mimics the composition of muddy sea floors and uses it to generate power. They call it a seafloor carpet, and they’re using it to both generate clean energy, and protect exposed coastal areas such as ports and harbors from heavy storms.
As the carpet undulates with the waves, hydraulic pumps are activated, generating power. Early testing shows that up to 90 percent of the wave’s energy is able to be absorbed, which is extremely promising. This also doubles as protection for coastal areas, as the dampening of the incoming waves significantly helps reduce storm damage.
Some of the math behind it
UC Berkeley researchers estimate that a 100 square meter carpet on the California coastline could generate as much power as 6,400 square meters of solar panels.
The benefits just go on and on. The system is incredibly durable due to the materials used, and the location on the seabed is much less violent than that on the surface. It is easily moved from one location to another, installed on the seafloor with minimal ecological disruptions, and it works with any directional flow of water.
All in all it’s an incredible new technology that illustrates a thinking outside the box mentality that we’re going to need if we’re to revolutionize the energy industry.
3) Bladeless Turbines
Speaking of outside the box, one company is taking a lesson learned from one of the most interesting disasters ever filmed and putting it to good use. You may not have heard of the name, but I guarantee you’ve seen the footage of the Tacoma Narrows Bridge collapse.
This new technology all comes down to oscillation, and something called a resonance frequency. Physics teaches us that when subjected to certain external stimuli, such as wind or sound waves, everything will start to vibrate. For example, a person singing a certain note can get a wine glass to vibrate. At different pitches, that vibration will increase or decrease.
Resonance is when said external stimuli reaches a Goldilocks level with the subject. The vibrations begin to compound and work off themselves, making the oscillations stronger. It’s this phenomenon that leads a wine glass to shatter.
In 1940 when the Tacoma Narrows Bridge was completed, it was quickly realized that something was wrong. The wind blowing around the bridge was making it vibrate at exactly its resonance frequency, causing it to oscillate dramatically and collapse.
Fast forward 75 years, when one company is using this natural phenomenon to generate clean energy with minimal impact. Vortex Bladeless is pioneering the field of bladeless wind turbines that use this naturally occurring oscillation to generate energy. Their turbines are basically tall poles with the generator at the bottom. The pole naturally vibrates with the wind, and the resulting kinetic energy is converted into power.
The prototype being installed
Removing the blades from wind turbines deals with a lot of the main concerns people have with wind power. Because there are no moving contact parts, Vortex turbines are virtually silent, and the bladeless design is significantly more compact, allowing for more turbines in one area.
It also means that birds won’t be annihilated by giant, metal fans.
These designs are cheaper to maintain, more modular for easy construction, and are scalable for various levels of energy generation. They figuratively go above and beyond other wind power generation technology.
That being said, this next idea is literally above and beyond other technologies. About 2000 feet above.
4) Floating Turbines
Altaeros’ Buoyant Airborne Turbine (BAT) is a complete reimagining of the turbine. While other companies keep building higher and higher poles to reach faster, upper altitude winds, Altaeros just decided to do away with the pole completely. By combining existing balloon and airship technologies with turbines, they’ve created a low maintenance and easily deployable system that can be up to 90 percent cheaper than conventional wind power.
The BAT consists of a large helium filled structure that houses a conventional turbine. Cables tether the balloon and transfer the generated power to a small ground station roughly the size of a shipping container. The BAT naturally rotates to whichever way the wind is blowing, so that as long as there’s a breeze, it will keep generating power. And there’s almost always a breeze 2000 feet up.
It also helps that their design isn’t necessarily intended for energy generation on a large scale. The fact that it can be deployed in 24 hours makes it extremely attractive for energy generation in disaster stricken areas, where sometimes it could take weeks to get power flowing again.
One BAT can generate roughly 30 kilowatts of power, which translates to enough power for about 12 homes, but the company says that’s just the beginning. To learn more and see actual images of the BAT, check out their website.
Humans as a species are getting better and better at generating power, from the oceans to wind currents and beyond. We just need to keep working at it. We can’t cut spending on something that could change the planet for the better just because it’s not as easy as oil.
These techniques are getting more advanced, more streamlined, and more plausible. Countries just need to keep trying and investing. 2014 saw the first increase in green energy investments since 2011, jumping 16 percent to $310 billion worldwide. This is an excellent pattern, but we need to make sure that it keeps happening, and that reusable energy technology doesn’t fall by the wayside.