Hydrogen
Hydrogen is the simplest and most abundant element in the universe. It consists of a positively charged nucleus (proton) and a negatively charged electron and has the lowest atomic weight of any element. Under normal or standard conditions, hydrogen is a colourless and odourless gas.
Hydrogen can be produced from a variety of resources, such as natural gas, nuclear power, biogas and renewable power like solar and wind. The challenge is harnessing hydrogen as a gas on a large scale to fuel our homes and businesses. Despite hydrogen being a very energy-dense gas per unit mass, it is very voluminous and requires compression to store a useful quantity of energy.
Types of Hydrogen
Green hydrogen
Green hydrogen is created by using electricity from surplus renewable energy sources to electrolyse water. The production of green hydrogen is currently expensive but will eventually come down in price as it becomes more common. Whilst green hydrogen claims carbon neutrality, the technology cannot work in isolation as it can only store energy converted from electricity, which is arguably inefficient when accounting for losses in the electrolyser.
Blue hydrogen
Blue hydrogen is produced mainly from natural gas, using a process called steam reforming, which brings together natural gas and heated water in the form of steam. The output is hydrogen, but carbon dioxide is also created as a by-product.
Grey hydrogen
Grey hydrogen is created from natural gas, or methane, using steam methane reformation but without capturing the greenhouse gases made in the process. Grey hydrogen is essentially the same as blue hydrogen but without carbon capture and storage. This is currently the most common form of hydrogen production.
Clear Hydrogen
Our Wild Hydrogen technology takes wet, unprocessed biogenic material and turns it into hydrogen and carbon dioxide. The carbon dioxide is captured and stored; the resulting hydrogen fuel is carbon negative. For every tonne of hydrogen, we remove 14 tonnes of carbon dioxide. Therefore, the more we produce the more carbon dioxide we remove from the atmosphere.
General Terms
The carbon cycle is how carbon travels between the air, plants, animals, soil, and oceans. It’s a natural process that keeps carbon balanced. Plants take in carbon dioxide from the air and use it to grow. Animals eat plants, and when they breathe, they release carbon dioxide back into the air. When plants and animals die, their remains release carbon into the ground. Over time, some carbon becomes fossil fuels. When we burn them, carbon dioxide goes back into the air, affecting the climate. The ocean also absorbs and releases carbon. The carbon cycle is a delicate balance, and changes caused by humans can affect it in ways that impact the whole planet.
Carbon intensity is a measure of how clean our electricity is. It refers to how many grams of carbon dioxide is released to produce a kilowatt hour (kWh) of electricity. The electricity that’s generated using fossil fuels is more carbon intensive, as the process by which it’s generated creates CO2 emissions. Renewable energy sources, such as wind, hydro or solar power, produce next to no CO2 emissions, so their carbon intensity value is much lower and often zero.
When something is carbon negative, it goes beyond just balancing out its carbon emissions. It actually removes more carbon dioxide from the environment than it puts into it. This helps to actively reduce the amount of carbon dioxide in the atmosphere, which is good for fighting climate change.
Being carbon neutral means that the amount of carbon dioxide emitted is equal to the amount of carbon dioxide removed from the environment. In other words, there’s a balance between what’s released and what’s taken away, resulting in no net increase in carbon dioxide levels in the atmosphere. This balance is often created through carbon offsetting.
Carbon sequestration is the capturing, removal and storage of carbon dioxide from the earth’s atmosphere. Carbon sequestration can happen in two basic forms: biologically or geologically. Biological carbon sequestration happens when carbon is stored in the natural environment. This includes what is known as ‘carbon sinks’, such as forests, grasslands, soil, oceans and other bodies of water. This is also known as an ‘indirect’ or passive form of sequestration. Geological carbon sequestration happens when carbon is stored in places such as underground geological formations or rocks. This process is mainly artificial or ‘direct’, representing an effective way of neutralising emissions put into human practices, such as manufacturing or construction.
Carbon capture and storage (CCS) is a way of reducing carbon emissions, which could be key to helping to tackle global warming. It’s a three-step process involving: capturing the carbon dioxide produced by power generation or industrial activity; transporting it; and then storing it deep underground.
As well as CCS, there is a related concept, CCUS, which stands for Carbon Capture Utilisation (or sometimes this is termed ‘usage’) and Storage. The idea is that, instead of storing carbon, it could be reused in industrial processes by converting it into, for example, plastics, concrete or biofuel.
Greenhouse gases are gases in the Earth’s atmosphere that trap heat from the sun and contribute to the greenhouse effect, which warms the planet. Here are some common greenhouse gases along with examples:
Carbon Dioxide (CO2)
Source: Burning fossil fuels (coal, oil, natural gas), deforestation.
Example: Car emissions, power plant exhaust.
Methane (CH4)
Source: Livestock digestion, natural gas production, wetlands.
Example: Cow burps, leaks from natural gas pipelines.
Nitrous Oxide (N2O)
Source: Agricultural practices, industrial processes, fossil fuel combustion.
Example: Fertiliser use on farms, certain industrial activities.
Water Vapour (H2O)
Source: Evaporation from oceans, lakes, and rivers.
Example: Natural component of the atmosphere; levels influenced by temperature.
Ozone (O3)
Source: Created by chemical reactions involving pollutants and sunlight.
Example: Ground-level ozone is a pollutant; the ozone layer in the stratosphere protects from harmful UV radiation.
Fluorinated Gases (HFCs, PFCs, SF6)
Source: Industrial processes, refrigerants, electronics manufacturing.
Example: Used in air conditioners, refrigerators, and electronics.
These greenhouse gases play a crucial role in regulating the Earth’s temperature, as they naturally keep the planet warm enough to support life. However, human activities have significantly increased the concentration of these gases in the atmosphere, leading to an enhanced greenhouse effect and global warming. This is a major driver of climate change and its associated impacts.
Put simply, net zero refers to the balance between the amount of greenhouse gas that’s produced and the amount that’s removed from the atmosphere. It can be achieved through a combination of emission reduction and emission removal. Net zero will only ever be enough to halt climate change worsening – to start reversing the changes we have made we need to be significantly carbon neutral.
