Unfortunately, it is not yet in mainstream production due to cost and availability of the required clean (emission-free) renewable energy
BY G. LALCHAND
Globally, the current mantra is for all nations to aim for nett-zero carbon dioxide (CO2) and other greenhouse gases (GHG) emissions by the middle of this century.
These aspirations aim to limit the global temperature rise to below 2oC, and preferably to only 1.5oC to ensure a liveable planet for human beings and all forms of life on this planet.
A significant milestone on this climate challenge journey has been to reduce the global GHG emissions by about 50 per cent from the 2005 levels by 2030 to achieve the target. However, this target seems somewhat insurmountable as many countries did not immediately embark on the measures as rapidly as necessary to meet the very ambitious target.
The chart below from an IRENA 2020 Report “Reaching Zero with Renewables,” shows the limits of “emission targets” needed to constrain the global temperature rise to 1.5oC under different emission reduction policy scenarios. These figures present rather tough challenges for the international community to meet, mainly to satisfy the mid-term target of 50 per cent emission reduction from the 2005 levels by 2030.
A common refrain over the recent decades has been to replace fossil-fuelled (particularly coal-fired) electricity generation with clean, renewable energy (RE) fuelled generation. This transition has been ongoing for at least a couple of decades in many countries with varying degrees of success.
The subsequent most critical fossil fuel use is for the transport sector covering all forms of transport, from a land-based motorised vehicle, shipping and other forms of marine transportation and even air transport.
However, rail transport is an exception. It has become more and more electrified over the years, even for intra-city applications. This is not surprising as electric traction is far more efficient than liquid-fuelled internal combustion engine (ICE) drive trains.
Motorised road transport has traditionally, and even now, predominantly been based on liquid fossil fuels in most parts of the world. Environmental degradation concerns have led to more significant efforts to develop “cleaner” alternatives. Accelerating electrification has been a “game-changer” (albeit a slow-paced one) for road transport to transition to lower emission energy sources.
Development of battery electric vehicles
The Toyota Prius hybrid electric vehicle (HEV), introduced in 1997 in Japan, triggered this transition to improve motorised road vehicles’ energy efficiency performance.
The success of HEVs helped promote the development of battery electric vehicles (BEV,) being fully electric driven and plug-in hybrid electric vehicles (PHEV). PHEVs were intended to use the “cheaper” grid-supplied electricity to keep the batteries fully charged rather than depend on the more costly liquid fuel in HEVs.
Sadly, BEVs have in some cases been touted, mistakenly, as “zero-emission vehicles” when in fact they are simply “elsewhere emission” vehicles. This is because the electricity used to charge their batteries is mostly from fossil-fuelled electricity generation, except some countries generate all their electricity from renewable sources.
A caveat against HFCVs is that the bulk of the hydrogen available for such vehicles is produced from fossil fuel (natural gas) or by using fossil-fuelled energy generation. So, it cannot be called emission-free fuel. Extracts below validate this statement.
Hydrogen fuel cell-powered vehicles (HFCV) were developed parallel with HEVs/BEVs as an alternative and competing technologies for road transport. HFCVs had an advantage over BEVs in their more excellent driving range on a “full tank” of hydrogen versus that of a fully-charged battery system’s range. The initial BEVs had a relatively limited range due to their battery capacity limits (within their battery weight considerations).
Moreover, refilling hydrogen tanks takes much less time than recharging BEV batteries. Although BEVs have overcome this driving range disadvantage, the recharging time (now much reduced with fast-charging options is still a hurdle.
All the same, both technologies currently face a common disadvantage against liquid-fuelled ICE-powered vehicles. And, that is the somewhat limited refilling/recharging outlets for users of these vehicles.
Though costly to produce, hydrogen is a versatile and helpful commodity and has many uses in industrial processes where it may be a significant component or a small but critical component.
Some of the higher capacity uses are the production of hydrochloric acid, production of methanol, hydrogenation of fats and oils and reduction of metallic ores. And in liquid form for cryogenics and study of superconductivity, etc. Under these uses, the cost of hydrogen may not be a hurdle. It may constitute a relatively small portion of the total product cost. However, its use for electricity generation and the transport sector is severely constrained by its production cost, except when it is extracted from natural gas.
Situation likely to go on for a long time
Hence the search for “Green Hydrogen”. It is, unfortunately, not yet in mainstream production due to the cost and availability of the required clean (emission-free) renewable energy to make it economically viable.
This situation is likely to go on for a long time. Maybe even decades, until the growth of RE generated electricity reaches the level of being “surplus to immediate needs” when it is generated. This applies particularly to intermittent (self-despatching) wind power and solar power photovoltaic (PV) generation, which can be used to produce green hydrogen.
A few countries like Denmark, Germany and Iceland had experienced days when their demand was met entirely with RE generated electricity. But that has occurred only in isolated instances, like weekends and holidays.
The surplus green energy from those instances would not be a good or viable source to produce green hydrogen. The box below details some indication of the different forms of hydrogen, “grey, brown, blue”, besides the green hydrogen produced for current use.
So, what are the prospects for green hydrogen to be a significant component for future energy mix scenarios, especially over the next decade?
The chart below shows possible scenarios from the Mitsubishi Heavy Industries Group. Since CCUS (carbon capture, use and sequestration) is still far from being a viable option. Under some limited conditions (such as enhanced oil recovery from depleted oil fields), the “Outlook 2: Long term” option appears to be the more likely to materialise.
Who will benefit most from the production of green hydrogen for its multiple applications? Countries with substantial potential for generating massive amounts of carbon-free electricity, such as wind and solar power (both PV and CSP, or concentrated solar power), can capitalise on early investments in these technologies.
MENA (the Middle East and North African) countries, with their vast, unutilised deserts, with virtually uninterrupted and long sunshine hours, have a massive advantage over most countries in the tropical belt.
The copy of the report on “Saudi Arabia’s bold plan to rule the hydrogen market”, therefore, does exciting reading.
This report brings to mind the Desertec Industrial Initiative (DII) initiated in 2009. It was to generate renewable energy powered electricity in the North African States and the Sahara region and transmit it to Europe.
This massive, ambitious proposition did not materialise as it was initially envisaged. Still, it did encourage the North African countries to develop these resources for their own domestic use.
The Middle East oil-producing countries have the advantage of using their Petro-Dollars to invest in renewable energy generation projects to exploit their climatic advantage.
They can cash in on the valuable future production of green hydrogen. It will be critical in the global efforts to decarbonise energy use from fossil fuels in the “Race to Nett Zero Emissions”. — @green