Advantages and Disadvantages of Hydrogen Energy

Advantages and Disadvantages of Hydrogen Energy

With carbon emissions from our gas and oil boilers contributing to global warming and subsequent climate change, the world’s attention has turned to finding alternative heating and energy systems. We need to find sources of energy which are renewable and/or do not produce harmful pollutants.

One potential solution is hydrogen energy, but while it does not harm our atmosphere, it is not necessarily a simple fix. Here we explore the key advantages and disadvantages of hydrogen energy and how it could theoretically be used to power our future.

What is hydrogen?

Our universe is made up of a huge range of different components, each playing its own part in the delicate balance of our planet’s ecosystem. The components which are most prevalent are hydrogen, nitrogen and oxygen with hydrogen accounting for 75% of the universe and forming 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 a lot 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 the most simple of all our elements being made up of just one proton and one electron. This means that in most scenarios it doesn’t exist by itself but is combined with other elements (e.g. water or H2O is 2 parts hydrogen to one part oxygen). However, hydrogen is a clean source of energy which, if we can extract it from water, natural gas or biomass, can be used to power and heat our societies.

How do we extract hydrogen?

There are two methods used to extract hydrogen: electrolysis or steam-methane reforming.

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 required and in order to create the electricity, fossil fuels (e.g. natural gas, oil or coal) are burned which produces carbon emissions. If the electricity used in electrolysis is obtained via solar panels, wind farms or hydropower, however, we can avoid these carbon emissions.

Steam-methane reforming is the process of separating carbon and hydrogen in methane. It is the method used most commonly at the moment because hydrogen can be extracted in large quantities, but it results in the emission of carbon dioxide and carbon monoxide. Both of these gases are harmful to our atmosphere and will contribute to global warming.

However, it is possible to capture the carbon emitted during the process of producing hydrogen with Carbon Capture Storage (CSS) systems which would prevent the carbon from being released into the atmosphere.

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.

Hydrogen energy is not toxic

Hydrogen does not cause damage to human health unlike nuclear energy or natural gas.

Hydrogen energy is 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 can be dangerous

Hydrogen is incredibly flammable which makes it a dangerous fuel if not handled correctly. There is also no smell to hydrogen so sensors are required to detect leaks.

Could hydrogen be used in home heating?

At the moment the vast majority of UK homes rely on fossil-fuel heating systems such as natural gas and oil boilers. In order to reduce our carbon emissions in line with government targets and fight climate change, we need to change the way we heat our homes. One of the possible solutions is to swap the gas we use to heat 84% of UK homes from natural gas to hydrogen.

The theory is that rather than cause major upheaval and expense by asking most homes in the UK to replace their heating system with a completely alien technology, we replace natural gas with hydrogen. Gradually we could increase the levels of hydrogen supplied to homes and decrease our reliance on natural gas until we are using 100% hydrogen. The main benefits being:

  • Hydrogen is highly efficient (1kg of hydrogen can produce as much energy as 2.8kg of natural gas)
  • There would be no carbon emissions from hydrogen boilers (only produce water vapour and heat)
  • Hydrogen could be used in existing gas grid infrastructure
  • Boilers are a familiar heating system for homeowners, unlike renewable heating systems (heat pumps and solar)
  • In theory, this all makes sense but it would require every gas boiler in the UK to be replaced by a hydrogen-ready boiler. Rather than expecting industry and homeowners to make the switch overnight, it could happen gradually, i.e. when a natural gas boiler comes to the end of its natural life it would be replaced with a hydrogen-ready boiler. That way, when the hydrogen network is ready, the fuel would be switched rather than the heating system which minimises disruption.

    Worcester Bosch have already revealed their very first hydrogen-ready boiler. The boiler is still compatible with natural gas but after a short visit from a heating engineer it can work on a 100% supply of hydrogen.

    As an alternative to boilers, it’s also possible for a hydrogen fuel cell to provide heating and energy to a home. A fuel cell converts chemical energy from a fuel, in this case hydrogen, as well as an oxidant (oxygen) into a supply of electricity. Heat is also produced during this process which can be used to heat the home. The Vitovalor CHP by Viessmann is one fuel cell heating system already on the market.

    Find out more in Hydrogen Boilers: An Alternative to Gas Central Heating?

    So, is hydrogen heating a viable option?

    The advantages and disadvantages of hydrogen energy hydrogen make the topic anything clear cut. Unfortunately, hydrogen production is currently very expensive to produce and our current production process can emit carbon which defeats the object of swapping to a hydrogen network somewhat.

    However, according to industry experts, hydrogen has a major role to play in the future of home heating. Hydrogen heating trials are already taking place in the UK where a combination of hydrogen gas and natural gas is already in use in some areas. More trials are planned for the next few years.

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    Whatever the outcome of these trials, hydrogen boilers are unlikely to be an option for UK homeowners for the foreseeable future. If you are looking to replace your heating system with a more environmentally friendly solution now, you might want to consider installing a heat pump, solar thermal panels or a biomass boiler.

    To get professional advice and free installation quotes from renewable heating companies near you, send us an enquiry today. We’ll provide you with up to 3 free no-obligation quotes so you can compare and choose the best option for your home.