What is wind energy?

Wind energy is a form of renewable energy. It provided 29.5% of Ireland’s total electricity in 2021. It is by far Ireland’s largest contributor to renewable energy. For context, in 2021, the other renewable energy sources produced a 5.6% share of Ireland’s electricity.

So how does it work?

A wind turbine is a device that  takes in kinetic energy from the wind and converts it into electricity. Kinetic energy is the energy that particles have due to their motion. A group of wind turbines together are called a wind farm.  There most common type of wind turbine is called a “Horizontal- Axis Turbine”, named so because the blades spin around a horizontal axis. The main factors that influence how much electricity a wind turbine can produce are wind speed, blade radius, and air density. The stronger the wind, the more energy that is produced. The larger the “swept area” of the blades, the more energy that can be produced- doubling the radius can result in 4 times more power. The denser, or “heavier” the air, the more lift that is exerted on a rotor and hence the more energy that is produced- this is why farms at sea level are favoured over farms at altitude; the air is denser at sea level. Other factors that can influence wind farm production are the layout of the turbines and the grid connection of the farm. The turbines cannot be too close to one another as the turbulence caused by one turbine will affect the others around it- wind turbines are generally more effective when hit with laminar flow as opposed to turbulent flow, i.e., a smooth and orderly flow is generally better than chaotic motion of fluid particles when it comes to wind energy production.

The drawbacks to wind energy

The main drawback is the obvious one- when there is no wind, there is no wind energy. Although we live on a windy island, we do (occasionally) get periods of high-pressure weather systems when the weather is calm. Wind turbines have a range of wind speeds for which they are safe and efficient to operate in. If the weather is such that the wind speed is outside this range, the wind turbines must be switched off. This also means that when we get stormy weather with lots of gusts, a time when there is lots of wind energy to be harvested, we actually get none.

Other challenges to wind energy include the installation challenges associated with building wind farms in remote areas, sometimes even at sea. Upgrading national grid networks to reliably connect these isolate wind farms to urban areas is an ongoing project in many countries, something which could significantly reduce the cost of expanding wind energy capabilities. Turbine noise, and interference with wildlife are also drawbacks to wind energy, although it is worth noting that noise and interference with wildlife are not unique problems to wind energy production and wind energy does have a relatively low impact on wildlife. Public perception and the fear of the impact that wind turbines will have on the landscape are also challenges which wind energy faces.

Another (more physics- related) point to note is Betz’s Law which states that theoretically no turbine can extract more than  of the kinetic energy of the wind, irrespective of turbine design. This limit puts a bound on the amount of energy which can be extracted from a site.

The way forward

Is there a way around the drawbacks to wind energy or is it doomed to be an intermittent power supply, ultimately incapable of meeting a nation’s energy needs?

The answer is that wind energy is part of the solution. The other part is energy storage. Within the last decade, novel ideas have sprung regarding the storage of excess wind power. The main idea is that the wind will generate electricity when it is windy, and then use a battery to discharge power when the wind stops blowing. The wind will charge the battery when the power grid does not need the electricity that it is generating. One such solution was built in Tullahennel, Co. Kerry, where each of the turbines was fitted with a lithium- ion battery roughly the size of a car.

Another, more daring, solution was designed in Germany. This solution involved the integration of wind and hydro- power. The design involved placing wind turbines, fitted with large water reservoirs around their bases, on a hill above a hydro-power plant. The water reservoirs were the “batteries”, analogous to the lithium batteries in Kerry. Water would be pumped uphill to the reservoirs when the energy demand was low and released back downhill to power to the hydro-plant when needed.

These collaborative ideas might be the future of renewable energy. Such ideas allow for renewable energy to overtake and eliminate fossil fuel power, hopefully leading to a less volatile energy market and a greener future.


Here are the sources I used for this blog:

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Focus on Climate Change

The greatest challenge of the 21st century will surely be the concerted attempt to supersede traditional carbon-based fuels with renewable and cleaner energy sources. In 2021 human activity contributed 36.3 billion tonnes of carbon dioxide into the environment according to the International Energy Agency ([1] IEA, 2022). Most notably carbon dioxide retains excess solar heat in the atmosphere which is driving rapid variations in temperatures and weather patterns across the planet. Other pollutants such as sulphur dioxide and  nitrogen oxides, which can be emitted from car exhausts, contribute to worsening acid rain that weakens higher altitude forests and vegetation. There is now a significant inter-disciplinary effort between physicists and chemists to develop novel technologies that will enable cleaner energy production in the near future.  These green sources must satisfy an ever-increasing global energy demand whilst simultaneously reducing any harmful environmental impacts to meet this challenge.

Figure 1: artist’s impression of terrestrial climate change. Credit: [2] NASA, 2015.

Hydrogen Fuel 

Hydrogen is the prime candidate to be the green energy source of the future. It is the most common element in the cosmos making up 75% of the visible universe ([3] Scharf, 2011). It is an abundant form of renewable energy that only produces water when burned. Most impressive is its stored energy which is approximately three times higher than gasoline per gram. This means that a standard sized car would require 1kg of Hydrogen to drive 100km ([4] Crow, 2019). Hydrogen fuel sounds ideal but it presents difficulties that are inhibiting it from replacing gasoline in our automobiles any time soon. Hydrogen is known for being an explosive and flammable gas. This uncomfortable fact was etched into the minds of the public and regulators after the Hindenburg air disaster in 1937. It is a clear reminder of what can go wrong if hydrogen fuel is not used safely. One other difficulty that has been less publicised is the obstacles that the gaseous state of hydrogen under standard pressures and temperatures present to using it as an everyday fuel source.

Figure 2: Hindenburg disaster in New Jersey on May 6, 1937. Credit: [5] The Guardian, 2017.

The Problem with Gaseous Fuels

Gas molecules possess a great deal of kinetic energy in comparison to tighter held particles in solid and liquid states. It would be a nauseous experience if we could sit and ride along on a gas molecule. The molecule would be careening through space while colliding with its neighbours and ricocheting off the walls of the container. Thence it is unsurprising that gas molecules dislike being close together under standard conditions. In fact a fuel tank would need a volume of 11m3 to store just 1kg of hydrogen under atmospheric pressure at room temperature. As previously mentioned this would just be enough to travel only 100km (from Dublin to Tullamore). Hydrogen would need to be compressed at 700bar to squeeze in 5kg of the element at room temperature. ([4] Crow, 2019). This would allow a hydrogen powered car to travel the length of Ireland which is a reasonable range. However the pressurised fuel tank would have to be reinforced adding weight and hence decreasing the predicted mileage. A more fundamental problem is that regulators stipulate that fuel tanks used in consumer vehicles must be limited to pressures of at most 100bar ([6] Dumé, 2020). Luckily there is one other property of gases that may offer a promising low-pressure storage solution. The property is that gas molecules can be made to stick to surfaces and the solution comes in the form of nanoparticles called metal-organic frameworks.

Introducing MOFs

Metal-organic frameworks (MOFs) are porous crystalline materials that act like nano-sponges. They consist of metal ions that are connected via organic linker molecules and physically look like cages that can trap gas molecules inside them. MOFs are highly porous with an astonishing surface area commonly above 2000m2/g. NU-1501-M is an example of a promising MOF that was  synthesised at Northwestern University in the United States. The M stands for metal which is either aluminium or iron. The nano-material can store 14% of its weight as hydrogen which sails past the 4.5% target set by the US Department of Energy in 2020 ([6] Dumé, 2020). NU-1501-M has enough internal surface area in just 1g to cover 1.3 American football fields. Researchers in the Snurr Group at Northwestern University are also designing low temperature tanks that can contain the same volume of hydrogen at 100bar as 700bar by using temperatures as low as -196ºC ([7] Bowser, 2016).

Figure 3: a cartoon of a metal-organic framework trapping a gas molecule inside its cage-like structure. Credit: [7] Bowser, Chemistry World, 2016.

The properties of these materials are impressive and the idea behind using them is rather rudimentary. The principle being employed here is that hydrogen gas molecules can be made to stick to these huge internal surface areas thus allowing larger volumes of gas to be stored without requiring highly pressurised containers. This provides an opportunity for the production of a hydrogen fuel tank that would satisfy current regulations.

MOF Design and Self-Assembly

The natural question arises as to how physicists can design and build these elegant nano-cages in the lab. The formation of a MOF takes place via a thermodynamic process called self-assembly. In physics, self-assembly occurs when ordered structures spontaneously emerge from disordered building blocks. It is an equilibrium process governed by the laws of thermodynamics. The second law of thermodynamics tells us that a quantity called the free energy (ΔG) must decrease for the process to happen spontaneously. Self-assembly is also responsible for the formation of other complex structures such as the DNA double-helix molecule.

Computational simulations are used to analyse metal-linker combinations. There are too many possible combinations to synthesise all of them and so virtual analysis is required. The Snurr Group at Northwestern has alone tested over 13,000 different MOFs for optimal low temperature storage of hydrogen ([7] Bowser, 2016). The amazing thing about MOFs is the customisability that they offer. It’s rather like a high-tech Lego set on the nanoscale. The pore size and polarisability (i.e. the stickiness) are two important characteristics that can be fine-tuned. The pores should be big enough to fit the particular gas molecule inside and sticky enough to just hold the molecule in place. In fact the design process can go one step further to create a single MOF with multiple pore sizes.

Figure 4: Simulation of a MOF designed to store hydrogen. The yellow points here indicate the binding sites. Credit: [4] Crow, Chemistry World, 2019.

Using MOFs as Emission Filters

Metal-organic frameworks offer yet another solution to curb the presence of deleterious gases in the atmosphere. MOFs can be used as gas filters to remove harmful compounds from the air. The application operates under the same physical principle utilized in the low pressure storage of hydrogen. A copper based MOF called Cu-BTC has recently been designed to carry out this very function. It is being researched as a means of separating and storing multiple gas types e.g., separation of carbon dioxide from methane and carbon monoxide. The application of MOFs as nano-filters could be a powerful tool in achieving a cleaner planet. It is conceivable that MOFs could be placed in our rivers and oceans to remove pollutants molecule by molecule. Further research is still ongoing as to how to process and neutralise the trapped molecules. How can we wring the sponge so to speak without allowing the dirty water back into the environment.

Figure 5: a cartoon of the MOF Cu-BTC containing three cages for storing and hence separating three different kinds of gas molecules. Credit: [8] Grajciar et al, 2011.

A Promising Solution

The current development of metal-organic frameworks specific to low-pressure hydrogen storage looks promising. The area of research is still very much in its infancy but the demand for cleaner fuel sources is rising by the day. Countries such as Japan are leading the way and are aiming  to have 800,000 hydrogen powered vehicles on their roads by 2030 ([4] Crow, 2019). Hydrogen still remains a highly combustible and explosive fuel source. However MOFs may be the key to taming this temperamental element. Its natural abundance, energy density and production of just water when burned in oxygen make it much too tempting to ignore.


[1] Press Statement by International Energy Agency  I.E.A. (2022), Global CO2 emissions rebounded to their highest level in history in 2021, Available at: < > [Accessed: 08/05/2022]

[2] Tenenbaum, LF. (2015). When global warming gets you down, come back stronger, Available at: <  > [Accessed: 08/05/2022]

[3] Scharf, CA. (2011). The molecules that made the universe, SCIENTIFIC AMERICAN, Available at: < > [Accessed: 08/05/2022]

[4] Crow, JM. (2019). Hydrogen storage gets real, Chemistry World, Royal Society of Chemistry, Available at: < > [Accessed: 09/05/2022]

[5] Walters, J. (2017). The Hindenburg disaster, 80 years on: a ‘perfect storm of circumstances’, The Guardian, Available at: < > [Accessed: 08/05/2022]

[6] Dumé, I. (2020).  Ultraporous metal-organic frameworks could make clean energy carriers, physicsworld, Institute of Physics, Available at: < > [Accessed: 09/05/2022]

[7] Bowser, S. (2016). MOF menagerie fuels search for hydrogen storage solution, Chemistry World, Royal Society of Chemistry  Available at: < > [Accessed: 09/05/2022]

[8] Grajciar, L.,Wiersum, AD., Llewellyn, PL., et al. (2011). Understanding CO2 Adsorption in CuBTC MOF: Comparing Combined DFT–ab Initio Calculations with Microcalorimetry Experiments, The Journal of Physical Chemistry  115 (36), 17925-17933, DOI: 10.1021/jp206002d


Nuclear Fusion: Future or Fallacy?

With the energy crisis nearing, if not already upon us, there emerges a need for energy sources that give more than they take. Many debate about the means of energy production, with arguments favoring wind energy, solar energy, and energy through hydropower. They each also have their drawbacks, with particular criticism being made of Nuclear fission power by Green Parties in various countries. The main reason cited is that the nuclear waste produced has lethal effects for the environment and is a solution to the energy crisis with a lot of strings attached to it.

While there continue to be many sides to the debate, this blog is not focused on the the benefits and drawbacks of nuclear fission. This blog discusses a relatively lesser talked about (for obvious reasons) source of clean energy: Nuclear Fusion. I will present to you the bare bones that there is to know about Nuclear Fusion. What it is, method of energy production, viability, related technology, and the pros and cons. It is then unto you to reflect and to evaluate this method of energy production.

Nuclear Fusion refers to the controlled process where the nuclei of two atoms are smashed together such that they fuse, liberating energy in the process. The reason energy is released can be explained by the concept of binding energy.

We must first recall one of the most famous equations in the world of Physics. Einstein’s relation between mass and energy. E=mc^2. The relation says the mass and energy of a particle are proportional to each other, and indicates that the mass of a particle can be converted to energy and vice versa.

When two or more particles bind together, the overall energy of the system decreases due to finding a stable configuration, and hence the mass of the system decreases. When a nucleus is assembled, with all its nucleons (constituent particles), the sum of the nucleus is less than the sum of the individual masses of the nucleons. This mass difference results in an energy difference, which is called the binding energy. Consequentially, the binding energy is the amount of energy put into a nucleus to separate all of its nucleons into their individual selves.

Energy can not just disappear, it has to go somewhere. Hence, during the creating of a nucleus, the binding energy of the nucleus is liberated.  This makes the creation a nucleus a theoretically viable process for energy production.

Granted, one does not make a nucleus out of thin air, we need the components to make a new nucleus. One way to do it is by using other nuclei. This method is called nuclear fusion. The nuclei of two atoms are brought together, and fused to make a new nucleus with a larger number of nucleons in it. The process releases a lot of energy.


The Binding energy per nucleon against nuclear mass


The above image gives us the binding energy for each nucleon in a given element. The mass number refers to the total number of protons+ neutrons in the nucleus. We notice at this point, that the graph assumes a particular shape. One with a peak, a maximum binding energy. This occurs for the element Iron, which has 56 nucleons.  Now that we know what nuclear fusion is, the question becomes, which two atoms do we fuse to liberate energy?

The curve serves as an indicator. To have energy be liberated, the binding energy of the atoms before fusion must be less than the binding energy of the atom after fusion. Hence, to produce energy via nuclear fusion, one must fuse atoms of a smaller mass number than 56, hence creating an atom with a higher mass number, thus higher binding energy.

Keep in mind that the atoms to be fused need to have a mass number less than 56, so everything to the left of iron fuses, but nothing to the right of iron will produce fusion energy. This is because the binding energy decreases after iron.

Fantastic, this is a method that can produce more energy for a given amount of mass being fused than even nuclear fission (splitting heavy nuclei to the right of Iron to smaller nuclei). Then, why is it not the most used form of energy production? The answer boils down to the net energy liberated.

The nucleus repels itself, due to the presence of protons in it. Hence, to get two nuclei to stick together, one must first overcome this repulsive electrostatic force, and push them all the way close until, at the point of the separation, the attractive ‘strong nuclear force’ is higher than the repulsive electrostatic force. The issue is that poshing repelling nuclei towards each other takes energy, and to achieve the outlined scenario, the fusing energy is larger than the energy liberated, hence resulting in the net energy loss. Even if there is no net energy loss but gain, the gain is so small, that it is of no use for mainstream energy production.


One of the main research interests in viable methods for fusion is the TOKAMAK project. It explores the idea of magnetic fusion. To get nuclei to fuse, massive pressure must be put on them. Also, the nuclei can be smashed at very high velocities so that they fuse. This is the principle of magnetic fusion. It is conducted via the means of a high temperature plasma. Plasma is a state of matter where the atoms can exist as separate electrons and nuclei at high temperatures. The higher the temperature, the faster the nuclei in the plasma move, hence more successful high speed reactions result in higher amount of fusion.


The TOKAMAK is a donut shaped “cage”, that uses magnetic fields to confine extremely high temperature plasma where nuclear fusion can take place. The advantage a magnetic field offers is that no solid material can contain the plasma at such high temperatures, but a magnetic field can confine the plasma. Hence, the high temperatures can be confined in a magnetic field and then shielded with vacuum, hence creating an insulation. So far, magnetic fusion is one of the most successful methods of nuclear fusion known to man, with other methods not yielding as well. Research continues to be done in the field, with the focus now on the idea of minimizing energy losses, how to achieve even higher temperatures, and extracting the produced energy.


Therefore, Nuclear Fusion remains a hot (hah!) bed for research, and the viability as a real source of energy is a question of when, not if.  The advantages nuclear fusion offers is more than any other method of energy production. Some of them include no carbon footprint, abundancy of fuel, and very low level of radioactive waste. With the very small amount of drawbacks, this makes it one of the best energy sources we have available.

Authors: Pratheek Kishore, Octavian Stoicescu, Nicollas S.M. Borges, Abhijith Jyothis P.

Nuclear energy has been suggested as a possible solution for climate change for a while, but how effective is this solution? What are the benefits of nuclear energy that would help with the current climate predicament? The purpose of this blog is to explore nuclear energy as a viable alternative energy source for cleaner emission and how this aids in alleviating climate change. We will consider the current state of the climate, the theory behind nuclear energy, comparison of different energy sources and their risks, and finally the future of nuclear energy (nuclear fusion?). 

We often hear about global warming being a current issue,  what we don’t hear is that this is something that’s been having an impact on our world for quite some time. The total average land and ocean surface temperature increase from 1850 to 2012 is 0.78  ͦ C. Total Glacier mass lost around the world except glaciers present on the periphery of ice sheets from 1971-2009 is 226 Gt per year. The Global Mean Sea Level (GSML) has risen by 0.19 m, as is estimated from a linear trend, from 1901-2010 and permafrost temperatures have increased in most regions worldwide from observations of trends since the early 1980s.Humans have been clearly impacting the climate of the planet for a very long time, but what does this all mean? It’s easy to look at statistics and forget these numbers have real world implications. For example, in some terrestrial systems, “Spring Advancement” can clearly be observed, which is the premature occurrence of spring-related events such as hibernation, breeding, flowering, and migration. Ocean acidification due to climate change decreases calcification which favours the dissolution of calcium carbonate and bioerosion, ultimately yielding coral reefs that are poorly cemented. Rocky shore animal and algae distribution, as well as abundance, has been observed to be altered due to climate change along with a significant decline in mussel bed biodiversity in the Californian coast. The body sizes of several marine species such as the Atlantic cod have been clearly negatively linked to changes in the temperature. The effects of climate change can be observed all around us, from the forests to the oceans, from the desert to the tundra, but perhaps the most relatable and personal effect would be the impact of climate change on humans. Climate change can have varying effects on several ecosystems, which can lead to food security issues globally. Climate extremes might increase the spread and ultimately the likelihood of attaining some diseases and infections. We can observe from studies on heat waves the effect increased heat will have on health, which leads to  increases in cardiovascular and respiratory disease, and generally increased mortality. During 2004-2018, in the United states alone, an average of 702 deaths annually were heat related (287 deaths had heat as a contributing cause, and 415 had heat as an underlying cause). So as you can see, climate change is an issue that has clear and direct effects on our ecosystems, on our environment, and on ourselves. If this matter is not addressed with the utmost of care and research, it may lead to dire consequences for us and our future on this planet. This is why there must be a global effort to utilise trialed and tested solutions to counter this problem. Currently our energy is supplied primarily by fossil fuels, which are not only limited in supply and depleting quickly, but major contributors to climate change through the emission of greenhouse gasses. Following this trajectory is not a viable solution for our future. But what could such a solution be? It turns out we had one answer from the mid-20th century: Nuclear Energy.

The atom with masses as small as 1.6735575 × 10-27 and length scales of around 10-10 m is our current best bet at tackling climate change? As small as atoms are one must realise the immense magnitudes of energy they hold in the form of binding energy of its nucleus i.e. the energy required to hold the atom together. Einstein’s famous formula E = mc2 is what is in-fact used to calculate the energy that gets released. The difference in masses of the reactants and products of a nuclear reaction, called the mass defect, is multiplied by c2 which as we know is a massive number. Hence this explains the enormous amount of energies released during such reactions. One can extract this energy methodically via nuclear reactors using a fuel source-fissile material.  The energy released by an average sized nuclear reactor in a day is of the order of 1013 J! A measure of the efficiency of  such power/energy generating plants is the so-called capacity factor which is defined as the ratio of the actual energy output during a specific period of time to the maximum energy that can theoretically be produced during the same period. Nuclear energy has a capacity factor of 93% twice that of coal. Currently this amount of energy at these rates of efficiency can be produced by no other source . Moreover, the carbon footprint associated with actual energy production or running of the nuclear power plant is almost nil. This, coupled with the high energy densities of the fuels, makes it a leading contender in providing a potential solution to the current climate change crisis. Current estimates of nuclear fuel reserves suggest that there is enough to power all the nuclear reactors in the world for 200 more years! To get a sense of this note that a volume of ideally enriched uranium fuel of the size of a golf ball is sufficient to provide an average human being more than sufficient to meet the energy needs for their lifetime. Despite not being a popular source due to its high initial setup cost’s nuclear energy currently responsible for up to 10% of global electricity generation, in spite of only being dominantly used in around 30 countries or less.

There are multiple fuel source categories such as oxide fuel, metal fuel, non-oxide ceramic fuels, liquid fuels etc. But the dominant fuel used in most nuclear reactors is oxide fuel of Uranium-235. Although to achieve the efficiency and numbers we have just stated above one needs to enrich mined uranium by percentages of around 3-5 % To ensure a sustainable chain reaction of the neutrons, the exact percentages may vary based on type of reactor and other factors/requirements. As a result, less than 1% of mined uranium can actually be used as fuel. Some of the principal methods that are widely used to enrich fuel are gaseous diffusion, gas centrifuge and laser separation.

As it is with everything there is no light without the dark and so it is with uranium fuel. extracting/ mining uranium is a high energy consuming process with a large carbon footprint! And there are safety risks also associated with its transportation, treatment and back-end activity associated with spent nuclear fuel management. However there exist certain strategies such as Twice-through fuel cycles and advanced fuel cycles which are aimed at reducing the mitigating and avoiding such issues. 

A further possibility to handle the issue is via using alternative fuels such as Thorium which provide a better alternative! Almost all the thorium that is mined may be used as fuel unlike uranium. Other advantages are that it produces far lesser nuclear waste and is much safer! But almost every reactor currently works only on uranium. There’s always a catch isn’t there ? The problem is that while thorium is extremely fertile i.e. All of it as is mined in theory can be transmuted into fissile material which is the actual fuel that can work in a nuclear reactor it is not fissile itself i.e. it  cannot be directly used as nuclear fuel. However there is currently a lot of research going around in order to develop efficient thorium fuel cycles that may be used by the nuclear reactors! Which sure seems like a step forward in the right direction. 

One of the other disadvantages with nuclear energy are high investment energy sources. However, one can say for certain that we are more capable today in handling nuclear energy than we have ever been in the past. And it is certainly a worthwhile investment. Surely its advantages can be weighed over its disadvantages. As a result, Further research in nuclear reactor methods, Alternative fuel cycles and safety protocols can immensely boost the impact nuclear energy may have in pulling back the adverse effects of climate change. To quote an Indian physicist, the late Dr Homi Bhabha: “No energy is more expensive than no energy“. 

One way of measuring how “effective” a process (in this case, a type of energy production) is, is by doing a life-cycle assessment (LCA). LCA takes into account the extraction of the fuel, processing, distribution, and disposal of the waste.  A life-cycle assessment can measure the impact that the production of nuclear energy could have. An LCA from a 2017 study predicts that the life-cycle emissions from fossil fuels with carbon capture and sequestration plants to be between 78 and 110 gCO2eqkWh⁻¹ by 2050. The same study gives the life-cycle assessment for a combination of nuclear, wind and solar to be between 3.5 and 11.5 gCO2eqkWh⁻¹. Another study on nuclear power says that so far, nuclear power has prevented 64 gigatonnes of CO2 greenhouse gas emissions and 1.84 million air pollution-related deaths (as of 2013) and could prevent another 80-240 gigatonnes of CO2 and 420000 – 7.04 million deaths by 2050.

Fusion energy has been in development for decades and it’s a common joke that fusion energy is always thirty years away. The strife towards fusion is because there is minimal environmental impact, unlike fission reactors fusion produces no radioactive waste, and even if there would be a nuclear meltdown the radioactive material (tritium) is only a transition element which is present only in small amounts in fusion reactors. The half life of tritium is around 12.3 years and hence it would not render the facility radioactive for centuries. Also if there would be a breach in the reactor, the plasma would be extinguished meaning the reactor will be intrinsically safe. The only byproduct of the reactor is helium which is not a greenhouse gas, and being the second lightest element, it would ascend in the atmosphere and drift off into space. Fusion is when you take two atomically light nuclei and smash them together to create a heavier nuclei, however the heavier nuclei is not an exact sum of the mass of the two original ones hence the extra mass is converted to energy accompanied by the release of a couple of bosons. There are several different types of fusion reactors currently being researched and developed, some examples being magnetic confinement fusion (MCF), inertial confinement fusion (ICF), Stellartor and magnetized target fusion (MTF). MCF, as it might sound, is when you confine a plasma within a volume and heat It enough so that fusion is possible. However the temperatures required to initiate fusion such that on average a particle has enough energy to break the Coulomb barrier is around 170 million degrees kelvin, which is roughly 11 times the temperature of the core of the sun! So you can imagine why physicists are having such a hard time developing this technology. However MCF currently holds the most hope for a fusion future as an experimental fusion reactor has been heavily invested  in by India, the EU, USA, Korea, Russia and Japan, which is designed to show the scientific feasibility of fusion as an energy source. It is set to have its first plasma test at the end of 2025, but will only be fully operational by 2035. It is designed to have a Q = 10, meaning it will produce ten times the amount of energy it ingests. If the reactor is deemed successful in achieving its Q value and testing the feasibility of fusion. A new fusion reactor will be built called DEMO which will be used to produce electricity, which is scheduled to be completed by the 2050s. Even though fusion shows great promise it is a technology of the future and should not be relied upon in dealing with the climate crisis, because for the moment reducing carbon emissions using fusion is just a fantasy. We cannot rely on the possible technology of the future to solve today’s problems.