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is not a primary energy source which can be easily mined like coal, oil or gas. Instead, hydrogen is classed as a secondary energy source in a similar way to that of electricity which must be generated first by using energy from another source, either using photovoltaics or fossil fuels.

We all learnt in our science classes at school that water is a combination of two atoms of hydrogen and one of oxygen (H2O). Because water is so common, most methods to produce hydrogen gas focuses on extracting it from water using Electrolysis.

Electrolysis separates the hydrogen molecules from the oxygen molecules in water using electricity. We can also separate them using sunlight instead of electricity and this process is called “Photolysis”. You may think that using fossil fuel generated electricity to produce hydrogen somewhat defeats the object, but as the electrical energy required to separate the water is small, we can also use photovoltaic cells powered by the sun to generate enough electricity to produce hydrogen. This process is called “Photo-electrolysis”.

Clearly to achieve the benefits of a truly sustainable hydrogen energy supply providing energy to the world, we need to produce large quantities of hydrogen by the process of electrolysis using non-fossil resources, such as water, and ideally using electricity derived from renewable energy sources, for example, photovoltaics, wind turbines, hydroelectricity, etc. Then this ideal scenario of producing sustainable hydrogen energy from the sun by splitting water from our oceans creates a whole new renewable energy term and expression: “Solar Hydrogen”.

Producing Hydrogen Energy using Electrolysis

Electrolysis is the process by which an electric current is passed through water and breaks the chemical bonds that exist between the hydrogen and oxygen atoms. The equipment used for doing this is called an “electrolyser”. An electrolyser basically consists of a positive element called the Anode (A), a negative element called the Cathode (K), both immersed in a liquid called an electrolyte which can carry a current.

Hydrogen Energy from Electrolysis

众鑫彩票注册hydrogen energy from electrolysis

When an electrical voltage supply is connected to the two electrodes, an electrical current is passed through the conducting electrolyte causing electrons to flow from the anode (where oxidation occurs) to the cathode (where reduction occurs) breaking down the water into its constituent elements, of hydrogen and oxygen.

A separator type membrane is used to separate the hydrogen’s protons and electrons. In most cases water electrolysis is used to produce the hydrogen, but the electrolyte can also be a solution of water and acids or metal salts.

The electrical current also breaks the molecular bonds between the atoms and once broken, the atomic particles (hydrogen and oxygen) become either positively or negatively charged and are free to move through the electrolyte.

As the two electrodes are also positively and negatively charged from the battery supply, this attracts the free atoms towards them with the hydrogen atoms being attracted to the negative electrode forming bubbles of hydrogen gas.

Generally, the positive hydrogen atoms gather at the anode (which is negative), while the negative oxygen ions reside at the cathode (which is positive). When the hydrogen and oxygen gases formed at either terminal and large enough they break free and rise to the surface were the hydrogen gas is collected and the oxygen gas is vented. Then we can see that electrolysis is a method of producing chemical energy (hydrogen and oxygen) by passing an electric current through a chemical substance called a watery electrolyte.

Once the hydrogen has been collected and purified, we can then use the clean hydrogen as a fuel in a number of different ways as it has a wider range of flammability limits and a lower ignition energy than many other fuels. Also being used mainly as an industrial gas, the technologies need for the production, storage, and transmission of hydrogen are well established in the chemical industries.

Unlike petrol or alcohol based fuels, which are easily handled liquids at ambient pressures and room temperatures, hydrogen is a lightweight gas at normal ambient temperatures. But the advantage of hydrogen as a fuel is that hydrogen can be converted into a liquid at low temperature, around -253oC and delivered as a liquid by road or rail, or compressed to a high pressure and delivered by gas pipelines. However, the liquefying of hydrogen still remains very energy intensive despite decades of industrial experience.

Hydrogen Energy as a Fuel Source

Having seen how hydrogen energy is produced using electrolysis, one application of using hydrogen as a fuel source is in conjunction with a hydrogen fuel cell. A fuel cell is a device for converting the chemical energy of a fuel, in this case hydrogen, into electrical energy which can be used to power 众鑫彩票注册s, schools or our cars.

Fuel cells can operate using a wide range of fuels, not just hydrogen, and are seen by many as a clean, high-efficiency power source. Fuel cells operate by mixing hydrogen (the fuel) with oxygen (the oxidant) to produce electricity and water (as a by-product).

Then a fuel cell works on the principle of electrochemical combustion by recombining the two atoms to produce an exothermic reaction of light and heat. This offers the opportunity for highly efficient conversion of hydrogen and an oxidant (usually air which contains oxygen) into electrical energy as the hydrogen fuel can be stored as a chemical fuel and converted into electrical energy when needed. The only by-product is water as the hydrogen and oxygen atoms recombine.

But what’s the difference between a fuel cell and a battery. While both the battery and the fuel cell are electrochemical devices that are capable of converting chemical energy into electrical energy, the chemical reaction within the battery releases free electrons that travel between the two terminals and out to the load as electricity.

But more importantly, batteries are expenses and the electricity being consumed by the connected load is constantly using up the batteries stored energy. This is because a battery is a sealed to get your copy of one of the top books on hydrogen energy and fuel cells direct from Amazon today and learn how hydrogen and hydrogen fuel cells can give us the prospect of a cleaner planet.

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4 Comments » for Hydrogen Energy
  1. Roger Bevan Roger Bevan says:

    Interesting article, but is hydrogen really that non-polluting and green. True that a cars fuel cell only produces water and heat as a by-product from its exhaust, but the processes of creating the hydrogen in the first place is not as clean. The electrolysis process for extracting the hydrogen gas uses lots of electricity supplied from coal and oil burning power plants that are highly polluting. Also your comments of extracting hydrogen from natural gas also produces carbon emissions which is exactly what we are trying to avoid in the first place by using hydrogen as a transportation fuel.

    • Hello Roger, Compared to conventional fossil fuel powered vehicles, hydrogen fuel cells are exceptionally clean, efficient and almost endlessly rechargeable. The problem is that to create hydrogen you have to take it from clean water that requires additional energy to break the bonds. Then in the end hydrogen isn’t an energy source just an energy storage system which can be used to power vehicles.

    • Richard Richard Richard Richard says:

      If you got your electricity from a PV cell or a windmill at night, you produce free hydrogen what is the problem?

      • David David says:

        The problem is all the fossil fuels that went into creating PV cells or windmills.
        Given the vast amount of oil and coal that go into mining, refining, processing, transporting the materials that go into PV + Windmills; processes which, by the way, can not be accomplished other than with oil and coal– the fossil fuel industry is mostly amused and not the slightest bit threatened by PV + wind.
        There is no carbon-free energy anywhere. Making Hydrogen from any energy source is criminally inefficient, energy-wise.
        If you got your electricity from a PV cell or windmill…. just charge a battery. Hydrogen is an intermediate step which is totally unnecessary.

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