@Green September/October 2020 - Page 30


@ green | September-October , 2020

A solution to the climate and plastic crises

The hydrogen economy requires government involvement
By Gregers Reimann and Zhi Tao Siew , IEN Consultants


significant transition of the national energy systems is underway , as nations in response to the climate crisis make right on their commitments to urgently decarbonise the economy .
The decarbonisation will mainly be achieved through a concerted push for energy efficiency , as well as a complete shift from fossil fuels to renewable energy . The fluctuating energy production of most renewable energy sources , such as wind and solar power , means that future electric grids must incorporate energy storage systems .
Hydrogen is one of the exciting energy storage technologies , which can be produced from excess renewable electricity production . The hydrogen is produced from electrolysis of water , which is the decomposition of water into oxygen and hydrogen gas by applying an electric current .
Later , the stored hydrogen can be converted into electricity again by reversing the chemical process in a fuel cell . Advantages of hydrogen includes its low energy losses during storage and its clean water vapour emissions when used by fuel cells . develop “ green ” hydrogen produced entirely from renewable energy sources .
At about twice the price , green renewable hydrogen is not yet commercially competitive with the fossil fuel alternative produced from natural gas .
For renewable hydrogen prices to come down and become commercially competitive , hydrogen technologies such as electrolysers need to mature over the next decade or so .
As such , from 2030 onwards , renewable hydrogen technology expected to be deployed on at a large scale . On the short-term , the EU is supporting the installation of a least 6 GW and 40 GW of renewable hydrogen electrolysers by 2024 and 2030 , respectively .
Clean aviation fuel
The rapidly growing transportation sector accounts for 16.5 per cent of the total greenhouse gas emissions . Decarbonising the transport sector has so far proven difficult , though there are promising signs that electric vehicles might someday become mainstream .
However , for the aviation industry , heavy batteries are not a feasible solution , particularly not for long-haul flights . Hydrogen , which contains 236 times more energy per kilogramme than lithium-ion batteries , is looking like a promising option as future aviation fuel .
And with the EU starting to create legislation that forces airlines to use zero-emission fuels , the hydrogen aviation fuel option is being seriously looked at – also by the shipping and truck sectors .
Figure 2 : Energy storage densities plotted per weight along the x-axis and per volume along the y-axis
Figure 1 : Energy storage needed for fluctuating renewable energy sources
In recent years , political commitments and substantial investments have taken place to spur on the hydrogen economy , with countries like South Korea , Japan and Germany leading the way .
The latter recently announced a € 10 billion investment plan with the declared goal of becoming the world leader in the field of hydrogen technologies .
The emerging-market interest for hydrogen is exemplified by the British green hydrogen technology company ITM Power , which has seen its share price increase 15-fold over the last year .
The European Union ( EU ) predicts that 24 per cent of the world ’ s energy will come from hydrogen by 2050 and identifies “ hydrogen [ as ] a vital missing piece of the puzzle to [ achieve ] decarbonisation ”.
In July 2020 , the EU presented a hydrogen strategy for a climate-neutral Europe . The long-term plan is to make hydrogen greener and cheaper .
At the moment , 96 per cent of the hydrogen is “ grey ”, as it is produced from fossil fuels , so EU ’ s priority is to
Hydrogen is a gas and takes up a lot of space . For practical purposes in the aviation industry , hydrogen needs to be compressed , either as a liquid or as compressed gas .
While liquid hydrogen has a very high energy density per weight , it still has a relatively low energy density per volume .
Even when compressed as liquid hydrogen gas , its energy density is still 3.5 times lower than that of gasoline . It is also worth mentioning that compressing hydrogen comes with a 35 per cent energy penalty .
Reuse of all plastics
Despite decades of efforts to recycle plastic , only about 10 per cent of global plastics are recycled , while 80 per cent end up on the landfill or in Nature . One reason is that sorting out the hundreds of different types of plastic is difficult and / or uneconomical .
The pervasive plastic pollution of our environment , including the micro-plastics , ingested / inhaled by all animals and humans alike , is cause for significant concern .
Figure 3 : Plastic waste management since 1960