Hydrogen energy is an up-and-coming energy source; it is efficient and produces no carbon dioxide emissions when it is combusted.
What is hydrogen energy?
Hydrogen, nitrogen, and oxygen make up 75% of the universe and form the foundation of much of our planet’s life.
Hydrogen is found in almost all plant matter and water. The Sun is also made up of vast amounts of hydrogen, but it is so light that it evaporates from the surface of the Earth through the heat of the Sun’s rays.
Hydrogen is manufactured in several ways. These include:
- Reaction of methane from natural gas with steam.
- Cracking of crude oil fractions (hydrogen is a by-product of this process).
- Electrolysis (passing a current of electric through something) of water.
Methane is a non-renewable fossil fuel made from natural gas, a finite resource. The production of hydrogen from natural gas or from crude oil offers no advantage over petrol.
The electrolysis of water needs large amounts of electrical energy. There can be advantages and disadvantages of producing hydrogen by the electrolysis of water.
Hydrogen can be renewable if the electricity is generated from renewable resources, such as sunlight and wind; however, most electricity worldwide is generated from coal, oil, or natural gas. Hydrogen produced this way will be non-renewable.
There are two methods used to extract hydrogen: electrolysis (green hydrogen) or steam-methane reforming (gray or blue hydrogen). Electrolysis involves passing a high current of electricity through water to separate the oxygen and hydrogen atoms.
It sounds simple enough, but this is a costly process due to the amount of electricity needed. To create the electricity, moreover, fossil fuels (natural gas, oil, coal) are burned, producing carbon emissions.
If the electricity used in electrolysis comes from solar panels, wind farms, or hydropower, then we can avoid these carbon emissions.
Advantages of hydrogen energy
- Hydrogen is renewable
Hydrogen is a renewable energy source which means we cannot run out of it, at least not on a human timescale. It’s a rich source of energy which is all around us.
- Hydrogen is a clean energy source
When we burn hydrogen no harmful byproducts are released into the atmosphere. In fact, once hydrogen has been used as an energy source, it can be converted to drinking water for astronauts.
- It’s not toxic
Hydrogen doesn’t cause damage to human health unlike nuclear energy or natural gas.
- Highly efficient
Hydrogen is incredibly dense in energy and is able to provide a lot of power. It is 3 times more powerful than most fossil-based fuel sources. So, less hydrogen is required to perform the same tasks. This is why hydrogen is used in space exploration to fuel spaceships, aeroplanes, boats, cars, and fuel cells.
Disadvantages of hydrogen energy
- Hydrogen is volatile
Because of its high energy content, hydrogen gas is a highly flammable and volatile substance which makes it a risky fuel to work with.
- Hydrogen energy is expensive to produce
Both steam-methane reforming and electrolysis are expensive processes which prevents a lot of countries from committing to mass production. Research and trials are in process to try and discover a cheap and sustainable way to produce enough hydrogen without contributing more carbon into the atmosphere.
- Hydrogen energy is difficult to store
Hydrogen is a much lighter gas than gasoline which makes it difficult to store and transport. To be able to store it we need to compress it into a liquid and store it at a low temperature. The high amounts of pressure needed to store hydrogen makes it a difficult fuel to transport in large quantities.
Hydrogen energy and the United Kingdom
In 2020, the UK Government set out its 10 point plan for a green industrial revolution. Included in the plan is the government’s vision for hydrogen energy.
One of the government’s main goals is to work with industry, and aim to generate 5 GW of low-carbon hydrogen production capacity by 2030 for industry, transport, power, and homes; and to develop the first town heated entirely by hydrogen by the end of the decade.
The government plans to invest up to £500 million in hydrogen, including for trialling homes, using hydrogen for heating and cooking. The project would start with a Hydrogen Neighbourhood in 2023, moving to a Hydrogen Village by 2025, with an aim for a Hydrogen Town – equivalent to tens of thousands of homes – before the end of the decade.
Of this funding, £240 million will go into new hydrogen production facilities.
