Inspired by plants, Scottish scientists have harnessed the principles of photosynthesis to generate clean energy from hydrogen. The breakthrough, they say, offers a potential solution to the global energy crisis.
Unlike fossil fuels, hydrogen – the most abundant element in the planet – can be burned to produce energy without releasing any emissions into the atmosphere.
The new development is one of the first of its kind: an electrolysis system that is capable of splitting water and releasing hydrogen and oxygen in separate stages – a challenge that scientists have been working on for decades.
When the water is split by sunlight into oxygen and hydrogen, the system captures the hydrogen, which can be stored and used at a later desired date.
“The existing gas infrastructure which brings gas to homes across the country could just as easily carry hydrogen as it currently does methane”, said Professor Lee Cronin, co-author of the study.
“If we were to use renewable power to generate hydrogen using the cheaper, more efficient decoupled process we’ve created, the country could switch to hydrogen to generate our electrical power at home.
“It would also allow us to significantly reduce the country’s carbon footprint.”
Hydrogen is the simplest element. An atom of hydrogen consists of only one proton and one electron. It's also the most plentiful element in the universe. Despite its simplicity and abundance, hydrogen doesn't occur naturally as a gas on the Earth - it's always combined with other elements. Water, for example, is a combination of hydrogen and oxygen (H2O).
Hydrogen is also found in many organic compounds, notably the hydrocarbons that make up many of our fuels, such as gasoline, natural gas, methanol, and propane. Hydrogen can be separated from hydrocarbons through the application of heat - a process known as reforming. Currently, most hydrogen is made this way from natural gas. An electrical current can also be used to separate water into its components of oxygen and hydrogen. This process is known as electrolysis. Some algae and bacteria, using sunlight as their energy source, even give off hydrogen under certain conditions.
NASA uses hydrogen fuel to launch the space shuttles.
A fuel cell combines hydrogen and oxygen to produce electricity, heat, and water. Fuel cells are often compared to batteries. Both convert the energy produced by a chemical reaction into usable electric power. However, the fuel cell will produce electricity as long as fuel (hydrogen) is supplied, never losing its charge.
Fuel cells are a promising technology for use as a source of heat and electricity for buildings, and as an electrical power source for electric motors propelling vehicles. Fuel cells operate best on pure hydrogen. But fuels like natural gas, methanol, or even gasoline can be reformed to produce the hydrogen required for fuel cells. Some fuel cells even can be fueled directly with methanol, without using a reformer.
In the future, hydrogen could also join electricity as an important energy carrier. An energy carrier moves and delivers energy in a usable form to consumers. Renewable energy sources, like the sun and wind, can't produce energy all the time. But they could, for example, produce electric energy and hydrogen, which can be stored until it's needed. Hydrogen can also be transported (like electricity) to locations where it is needed.