The Untapped Power of Hydrogen
By Yip Jia Qi
Hydrogen offers the possibility of clean renewable energy use at scale, even in cities that cannot generate their own. Hydrogen is the smallest element in the periodic table, consisting of one proton and one electron. A diatomic molecule at room temperature, it produces water when burnt with oxygen, releasing energy without producing carbon. Energy is required to produce hydrogen as electricity has to be supplied in order to split water into hydrogen and oxygen gas via electrolysis. However, if renewable energy is used for this process, the hydrogen fuel cycle can be completely carbon-free.
Hydrogen could enable electricity generated by renewable means to be stored and traded between incompatible power grids, due to its potential use as a battery (hydrogen fuel cells). This is significant because the intermittency of renewable energy is its Achilles heel.[1] Large countries like the USA with a national infrastructure are able to mitigate this with smart grids, which can quickly move power around to where it is needed. For regions like Southeast Asia where there is no integrated grid, intermittency is a significant challenge as variations in weather do not restrict themselves to national boundaries. Countries where renewable energy supply changes depending on seasons could also trade hydrogen to make up for shortfalls in supply.
In Singapore’s case, liquefied natural gas (LNG) currently accounts for 95% of Singapore’s electricity production, and land scarcity makes renewable energy generation challenging. Importing hydrogen produced by renewable energy may be a cost-effective solution to reducing our carbon footprint. It is also possible to mix hydrogen into natural gas for use in existing plants with limited changes to pipelines in order to reduce carbon dioxide emissions.
Hydrogen fuel cells can be cheaper and more efficient than lithium-ion batteries, especially in heavy vehicles travelling long distances, such as long-haul trucks and inter-city buses. Hydrogen tanks weigh much less than lithium-ion battery packs,[2] and cost less to deploy in a vehicle. Hydrogen tanks also take less time to fill than battery packs take to charge.
Internationally, there is increased investment in hydrogen technologies. China has made plans to turn Wuhan, the capital of Hubei province, into a “hydrogen city” by 2025. It has also designed and deployed hydrogen-powered buses in Chengdu, and ordered 74 hydrogen buses for the 2022 Winter Olympics. Tokyo’s metropolitan government aims to use the 2020 Summer Olympics to establish the use of hydrogen in Japan. The EU has a public-private partnership working on 227 hydrogen-related projects across Europe. Hydrogen has also drawn a total of US$2.5 billion in investment from energy companies like Royal Dutch Shell and Germany’s Uniper in addition to carmakers BMW and Audi.
Infrastructure for trading and transporting hydrogen is starting to emerge. Australia and Japan have worked out safety standards for shipping hydrogen, and Australia started a pilot to supply Japan with liquefied hydrogen produced from brown coal (a non-renewable source), although it could also be from renewable sources. A Norwegian company is also planning to supply Japan with hydrogen from renewable sources. Japan is currently the only country expanding its hydrogen imports, but other countries that are also building hydrogen infrastructure may soon become importers as well.
Countries which have shifted to renewables on a large scale are investigating hydrogen as a solution to the problem of intermittency. An EU-commissioned report benchmarking large-scale storage technologies recommended hydrogen power-to-gas systems over other systems like compressed air, pumped water and lithium-ion batteries because of its high volumetric storage capacity and long storage lifetime. Other studies have shown that hydrogen can be just as efficient as batteries in large-scale energy storage, and the National Renewable Energy Laboratory completed a successful demonstration project integrating wind turbines and photovoltaic arrays with electrolyser systems to produce hydrogen, which can be compressed and stored for later use.
Recent research also suggests that it is possible for an integrated system utilising solar power to conduct desalination and hydrogen production simultaneously. Although the research is still in early stages, if the technology is successful, it could increase Singapore’s self-sufficiency. By producing water and electricity from just solar power and seawater, the technology would reduce the need for the import of these essential resources.
[1] Intermittency is a serious problem for renewables because unlike burning coal, energy production using renewables is at mercy of the weather, creating large spikes and need troughs daily, which stresses the power grid and can be costly to manage at a large scale.
[2] Compressed hydrogen and fuel cells can provide electricity to a vehicle traction motor with weights that are between 8 to 14 times less than current batteries, including lithium-ion batteries.
Yip Jia Qi was Research Assistant atthe Centre for Strategic Futures.
The views expressed in this blog are those of the authors and do not reflect the official position of Centre for Strategic Futures or any agency of the Government of Singapore.
