Green energy and renewable energy are too often used in the same breath. That is to say, if someone mentions the concept of green energy, they often refer to renewable sources like wind, solar and wave energy. It has created the false illusion that all green energy initiatives are renewable, and that all renewable energy sources are green. Long story short: not necessarily the case.
Green Energy: Wind Turbines And Solar
In a similar sense, the term carbon-free is not exclusively reserved for renewables. There are several energy sources that are not-renewable, but definitely carbon-free. This makes them great - and not frequently talked about - alternatives for the famed wind turbines and solar panels. Obviously, the fact that they cannot be renewed means that they are not the all-inclusive solution to our current problem, nor can they be exclusively relied upon to power the growing demands of the world.
What that means to say is that renewables should always be a part of the energy mix. Yet they hold downsides, including the large energy requirements for the build, maintenance and storage. Furthermore, the amount of square footage required to build enough windmills and solar panels is substantial, meaning that either ground will have to be acquired or people will have to be encouraged to build it on their land.
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Nuclear Energy Has A Bad Rep For No Real Reason
It is about time that we stop referring to renewables as the only green source. It is unlikely that they will ever be generating sufficient energy for all of us, so the search for other green energy sources should never cease. Some are staring us right in the face, like nuclear energy. Over the past century, this form of energy generation has saved the atmosphere from millions and millions of tonnes of CO2 being emitted into it. Yet it is still suffering from a pretty bad rep.
Bumper cars, Chernobyl
Most people will instantly mention ‘Chernobyl’ or ‘Fukushima’, making the dangers of a potential meltdown seem much larger than they actually are. With the proper precautions and warning mechanisms, I dare say that fears for a second Chernobyl have been reduced to mere figments of the mind. Yet the public opinion matters, and that opinion is pretty loud and clear - we do not want more nuclear waste, nor do we want to live next to a nuclear reactor.
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There might be a solution. Although it is not yet implemented anywhere in the world due to its priciness and complexity, there might be a way of splitting atoms without the waste, meltdowns and costs associated with building and maintaining the reactors.
Green Energy Which Is Not Renewable: SMR Nuclear Is Ideal
Yes, it does have nuclear in the name. This might already lose some interest of some, but try to bear with me, as it might be the nuclear implementation that we have been waiting for. SMRs, or Small Modular Reactors, could be the solution. In particular Liquid Fluoride Thorium Reactors, or LFTRs, are showing great promise - in theory, that is.
Thorium is an element on the periodic table of elements that is just two behind uranium. This makes it a weakly radioactive substance - with the upside that it is much more abundant than its radioactive brother. A golf ball-sized bit of thorium could, theoretically, power a small city for several decades. After that it cannot be re-used, hence the non-renewable part - but that really kind of pales in comparison to its upsides.
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Green Energy: Technical Details Of Thorium Power
Thorium and the Future of Nuclear Energy
The LFTR resembles an ‘ordinary’ reactor, although there are some technical differences. Thorium-232 and uranium-233 are mixed with fluoride salts in the reactor core. During the fission, the released heat and neutrons are absorbed by the salt surrounding it. This leads to the creation of a uranium-233 isotope, with thorium-232 taking on an additional neutron. Next, the salt melts and is used to heat gasses like helium, which power a turbine - and generate electricity.
There is no waste. The uranium is separated from the salt after the process, and then re-used in the core. Another benefit is the lower costs for the commissioning of the thorium reactor: the salts are about $150/kg and the thorium some $30/kg. This price is likely to go down if thorium becomes popular, as it is abundantly available in the earth’s crust. The world’s supply of thorium can power a large number of LFTRs for thousands of years. Not quite renewable, but pretty close.
More arguments for those who need convincing: thorium can be used in its natural state, so no expensive processing is required. And the fuel used in the LFTR will almost completely be re-consumed by the reactor, making it clean and low-waste.
Not Renewable: Why SMR Nuclear Is Safer Than Traditional
So, there is significantly less radioactive waste. Separated uranium can be re-used in the fission process, while the fluoride salts have a high boiling point, eliminating the need for high-pressure water coolants. This high boiling point, combined with the design of LFTRs to work as low-pressure systems, means that the reactors are much more stable and less susceptible to incidents.
Combine this with the failsafe shutdown sequence, where an overheated core will trigger a gravity-enabled passive response. The radiated salt will be sent into an underground containment chamber while the reactor is powering down. This makes it extremely safe: you just can’t argue with gravity.
Not Renewable: The Downsides
No energy source comes without its flaws. While the concept of thorium-based energy sounds great in practice, opponents will argue that it is as of yet untested, not commercially viable, and - most importantly - still nuclear. The safety arguments for this technology seem valid, although they have not been tested in real life. This really forms the major concern, with much-needed research on the necessary materials missing and the processing facilities for the used salts still a rough concept drawn up in explorative papers but nowhere near viable construction.
The argument of it still being nuclear should not be overlooked either. Nuclear means that, theoretically, waste could be stolen and used to create deadly nuclear weapons or wreak all other sorts of havoc on the world. Although it has not been proven that LFTR reactors will have waste that could be used for this purpose, proper safely and security measures will be a must if we are to go through with this.
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Green Energy Which Is Not Renewable: What’s Next?
Once again, let me reiterate that I do not believe that thorium-based energy will solve all of our problems. As mentioned before, it is all about getting that energy mix right. We can and must invest in renewable sources, regardless of their intermittent nature - and fill up the gaps with clean and green non-renewable sources. All energy sources bring along their own set of problems, which makes the balancing of the mix even more complicated.
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Yet the best we can do now is figure out how to make the most out of non-renewable green sources, even if that means diving in the deep with previously untested sources.
Before you go!
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