What is Hydrogen Energy and How is Hydrogen Energy Converted into Electricity?

What is Hydrogen Energy?

Of all elements present in the universe, hydrogen is the most abundant. Hydrogen gas has remarkable characteristics including colorless, tasteless and invisible that make it hotly pursued. It can also be transformed into a renewable, nonpolluting and zero emission energy resource. It’s considered the cornerstone of the new energy economy. The pursuit of hydrogen energy began way back in 1776 by the British scientist Henry Cavendish.

He first identified it as a distinct element after he developed hydrogen gas by subjecting zinc metal to hydrochloric acid. Henry Cavendish made another remarkable discovery during a demonstration to the Royal Society of London when he introduced a spark to hydrogen gas, producing water in the process. This historic development led to his conclusion that water (H2O) is composed of hydrogen and oxygen. Since then, hydrogen technology has grown in leaps and bounds, and today, it is used as an energy source to power cars, electric systems, and production of pure water.

hydrogen-gas

Hydrogen is the simplest and most abundant element in the universe. It does not occur naturally. While it exists pretty much everywhere- in the air, in space, in the ground- it is rarely alone. It’s obtainable in combination with other elements such as water. Water is made up of hydrogen and oxygen. This means that it is usually combined with another element, making it necessary to extract and convert it to make it a usable energy source. Hydrogen also occurs in numerous organic compounds, for example, hydrocarbons that result in fuels like natural gas, gasoline, propane, and methanol. The biggest challenge to harnessing hydrogen is harvesting it in its purest form.

Hydrogen’s chemistry is very simple- a single atom is made up of only a proton and an electron. In a gaseous form, it can be burned as a fuel. It can be stored in power cells that generate explosive energy and propel rockets and spaceships. It is volatile and combustible, and very, very powerful.

Hydrogen can be stored cryogenically (frozen) or in compressed air containers as a gas. It takes a lot of storage space to house significant amounts of hydrogen. This is because the molecules are far apart, and the gas is lightweight, making it very spread out. To contain the same amount of hydrogen in a cylinder as gasoline, for example, creates a much heavier container.

How is Hydrogen Energy Converted into Electricity?

Hydrogen gas is an expensive and complex fuel to make because it has to be separated from whatever element it is joined to. It often takes a lot of energy to make hydrogen gas, making it a costly power source. There are a number of ways to separate hydrogen from its companion elements.

Before we look at how hydrogen is converted into electricity, it would be beneficial to know how hydrogen is produced. Hydrogen is produced using two main methods; steam reforming and electrolysis (commonly referred to as water splitting).

Steam reforming

This method produces hydrogen from hydrocarbon fuels such as methane, oil, renewable liquid fuels, gasified biomass, gasified coal and natural gas. A processing device called a reformer is used in this hydrogen production process. The reformer react steam with the hydrocarbon fuels at extremely high temperatures to generate hydrogen. Today, over 90% of hydrogen gas is produced using the steam reforming technique.

Electrolysis

Electrolysis is a method that utilizes direct current (DC) to instigate a chemical reaction. In the production of hydrogen, electrolysis decomposes water and splits it into its main elements, which are hydrogen and oxygen by use of an electric current. The electricity used in the electrolysis process can be derived from fossil fuels such as oil, natural gas, and coal or hydrocarbons.

Conversion of hydrogen into electricity

The most effective way to convert hydrogen into oxygen is using a fuel cell. A fuel cell converts chemical energy into electrical energy. A fuel cell enables hydrogen and oxygen to blend in an electrochemical reaction. The result is production of electricity, water, and heat. Fuel cells mimic batteries since they both convert the energy generated by the electrochemical reaction into useful electric power. Nonetheless, the fuel cell will generate electric power as long as fuel, mainly hydrogen, is available.

Fuel cells represent a potential technology for use a source of electricity and heat for buildings. It’s also a promising source of power for electric and hybrid vehicles. Fuel cells function best on pure hydrogen. However, other fuels such as gasoline, methanol, or natural gas can be reformed to generate the needed hydrogen for fuel cells.

With technology moving fast, hydrogen could come on par with electricity as a vital energy carrier. An energy carrier transmits energy to the customer in a ready to use form. Some renewable energy sources such as wind and sun may not be able to generate energy around the clock, but are able to produce hydrogen and electric power and stored for later use.

Pros of Hydrogen Energy

  1. Eco-friendly

It’s hard to come across a fuel source that befits the title non-toxic. Hydrogen is a nontoxic form of fuel since it doesn’t release harmful gasses into the environment. Some fuel sources like gasoline, coal, oil and nuclear energy are toxic and occur in areas with hazardous environment. In fact, when hydrogen is combusted, the only by-product is water vapor, which is not toxic. Since hydrogen is friendly to Mother Nature, it can be utilized in places where other forms of fuel cannot work.

  1. It’s a renewable energy source

Hydrogen is abundant virtually everywhere, and this means it’s a never-ending source of energy. Other sources of fuel such as oil, natural gas, and coal are considered nonrenewable, meaning they will get exhausted at some point. Hydrogen is one source of energy that can be generated on demand.

  1. It’s powerful and efficient

The methods used to produce hydrogen yield a powerful and efficient energy source. Hydrogen’s power and efficiency are the reasons it’s used in rockets and space ships. It’s also preferred in space ships because it doesn’t produce greenhouse gasses. According to statistics, hydrogen is 3 times more potent than gasoline and other fossil based fuel sources, meaning it has the ability to accomplish more with less.

  1. Has a vital application in the oil and gas industry

Hydrogen is deployed to process crude oil into refined fuels like diesel and gasoline. Hydrogen is also used to get rid of contaminants such as sulfur from these fuels. Other industries also leverage hydrogen fuel, for example, chemical production, food processing, metal refining, and electronics manufacturing.

Cons of Hydrogen Energy

  1. It’s daunting to store

Hydrogen energy has not been fully explored, so storage and support infrastructure have not been hugely developed. Hydrogen molecules are minute, which renders hydrogen more susceptible to leakage. This means that it must be stored at high pressure to give it sufficient energy density. In its natural form, hydrogen is volatile and highly flammable, which makes transporting it a lot harder.

  1. It’s relatively expensive

Despite the fact that hydrogen is readily available, the process of extraction such as electrolysis is extremely expensive. The main reason for this is that it’s daunting to separate its basic elements like hydrogen and oxygen. Even though hydrogen fuel cells are increasingly being used in hybrid cars, it’s not quite affordable for everyone. Scientists are working to discover technologies that could make harnessing of hydrogen a lot easier, but until then, the price will continue to remain high.

  1. Still relies on fossils fuels

It’s a fact that hydrogen is a renewable resource and has no impact on the environment. However, the separation of hydrogen components during production process still relies on fossil fuels such as oil, coal and natural gas. Fossil fuels contribute mightily to emission of greenhouse gasses.

  1. It volatile and highly flammable

Hydrogen’s volatility and highly flammable attribute make it challenging to transport to the final consumer. The unique characteristic that makes it hard to store also make its daunting to transport. Hydrogen is majorly transported to the market through pipelines or in tankers. Tanker trucks deliver hydrogen to the marketplace in a liquefied or compressed state. This process leads to hydrogen leaks.

Although hydrogen is not widely used because of its hefty price tag and lack of practicality in terms of lack of infrastructure to support it, researchers project that it will catch up with electricity as an energy carrier. This is because it is derived from renewable energy sources and is almost non-polluting. Its zero-emission property makes it ideal for aircraft fuel, heating homes, and source of fuel for zero emission vehicles.

References: EIA

 

Rinkesh

Rinkesh is passionate about clean and green energy. He is running this site since 2009 and writes on various environmental and renewable energy related topics. He lives a green lifestyle and is often looking for ways to improve the environment around him.