Hydrogen is the simplest and most abundant chemical element in the Universe, being made up of 1 proton and 1 electron (at least in the most common isotope, Protium) with atomic number 1. It makes up approximately 74% of the mass of the Universe (if we ignore things like dark matter) with helium making up roughly 24% leaving all other chemical elements, including all the ones that we can see and feel, making up the remaining 2% of the mass of the Universe. All hydrogen was directly formed by fusion in extreme heat and pressure just after the time of the big bang with most of it now clustered together in stars, gas planets and all other celestial bodies.
Here on Earth, it is a colourless, odourless, tasteless, non-toxic but highly combustible gas that generally goes around in a pair with another hydrogen atom, forming a covalent bond to give molecular hydrogen, H2. Molecular hydrogen does not exist in much quantity in our atmosphere and almost all hydrogen atoms on Earth form molecules with other elements, such as oxygen for water (H2O) or carbon for hydrocarbons (oil such as octane C8H18, a component of gasoline or methane/natural gas, CH4).
Unlike hydrocarbons that can be found on Earth and extracted, as hydrogen does not exist in molecular form in any great amount, we do not consider it an energy source but an energy vector. This means we need to generate hydrogen through a process, which we can do with multiple methods such as an input of electricity or another energy such as heat. At HydroGenesis we are focused on using excess renewable energy production to generate hydrogen through electrolysis, where electricity is used to split water into its constituent elements, hydrogen and oxygen.
Hydrogen is an exceptionally light gas and when produced through electrolysis allows large amounts of energy to be stored especially when quantified as energy by mass – when compared to petroleum, hydrogen is capable of storing approximately 3 times the amount of energy per kg!
As long as the energy we are generating to produce the hydrogen is clean then a system that stores energy as hydrogen, sourced from water, is a very clean alternative to using fossil fuels. Much like when we generate hydrogen from water through electrolysis, the only by-products of combusting hydrogen with oxygen or using hydrogen in a fuel cell is pure water and heat. This trait of hydrogen gas gave it its name, which is approximate Greek for ‘water generator’.
Hydrogen can be treated in the same way as other gasses, it is highly compressible and it can be liquified. This means we can store it indefinitely in suitable tanks, it can be compressed/liquified and transported to its point of use by vehicle or it can even be produced at scale in industrial sites before being transported via pipeline networks, in the same way our natural gas networks currently do.
It is these characteristics of abundance, high energy per unit mass, no harmful by products and ability to store and transport it that make hydrogen a very attractive energy vector. As wind and solar in particular continue to become major sources of energy, allowing us to maintain the comforts we’ve all become accustomed to and energizing global communities that are rapidly catching up with the western world in a more green way, energy storage is going to become more and more crucial! Using hydrogen to store excess energy on a long, sunny but windy day to be used on a calm night would allow us to rely less on burning fossil fuels to keep our lights on and our homes warm.
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