If countries, including Thailand, want to achieve net-zero targets, they cannot rely completely on renewable energy to produce electricity and fuel economic activities.
They need what Chaiwat Kovavisarach, group chief executive of energy conglomerate Bangchak Corporation, calls "clean molecules", which should be used in tandem with "green electrons", a term which refers to electricity generated by renewables such as sunlight, wind, water and biomass.
The term clean molecules was coined by energy experts to focus on a group of clean fuels, including biofuel for cars and aircraft, and e-fuels.
"Green electrons are a good choice, but they alone cannot serve the global energy demand. We need clean molecules to help us attain net-zero goals," said Mr Chaiwat.
Thailand announced in 2021 at the 26th UN Climate Change Conference in Glasgow that it would be more aggressive in addressing climate change, striving to reach a net-zero target -- a balance between greenhouse gas emissions and absorption -- by 2065.
Mr Chaiwat suggested a path toward the 2065 deadline by using clean molecules during the 13th Greenovative Forum entitled "Regenerative Fuels: Sustainable Mobility", an annual seminar held by Bangchak Group.
In a 15-minute presentation, Mr Chaiwat clarified total energy usage worldwide and described the whole concept of clean molecules for almost 300 participants and roughly 2,700 people viewing the event online.
His keynote speech ended with a visual note, sketched during the seminar to help participants visualise key aspects of his messages.
A visual note outlining the global energy situation and a path toward the net-zero goal through the use of clean molecules.
All countries are driven by a huge amount of energy which still largely comes from fossil fuels despite stronger legal measures and campaigns to reduce carbon dioxide emissions through greater use of renewable energy.
Green electrons, or electricity generated from renewable energy sources, must represent 27% of the global energy supply if the net-zero target is set in 2050, said Mr Chaiwat, citing the International Energy Agency.
The remainder comprises gaseous and liquid fuels, some of which could be generated by clean molecules.
It is highly unlikely that the world could depend heavily on green electrons when global energy demand is taken into consideration.
"The world consumes up to 1.7 exajoules a day. The amount is so huge that it equals the fuel that would be required by an Airbus A320 flying around the world 350,000 times," said Mr Chaiwat.
"In other words, this level of energy usage would be equal to us travelling between the earth and the moon 37,000 times."
To serve this huge level of consumption, up to 80% of energy needs to come from fossil fuels, with the remaining 20% made up of renewables, biomass and nuclear energy.
This volume of fossil fuel can be calculated in relation to oil, which would amount to 220 million barrels a day.
"With the world population currently standing at 8 billion, it means each person requires 4.4 litres of oil per day, which is greater than the daily water consumption requirement of two litres," said Mr Chaiwat.
Oil still plays a key role in the transport sector, although the battery-powered car market is growing rapidly.
"With one kilogramme of oil, a car can run for 15 kilometres, but with a battery weighing one kg, a car runs for less than one km," he said.
"If a battery-powered car wants to run for 15 km, its battery must weigh 20 kg."
E-fuel has the potential to be a fuel of the future.
The development of clean molecules must be promoted as it could be one solution to the huge demand for energy and support global campaigns to curb carbon dioxide emissions, said Mr Chaiwat.
"One type of fuel based on clean molecules is currently sold at Bangchak petrol stations," he said, referring to ethanol, which is mixed with gasoline to make gasohol. This forms part of the efforts to decrease dependence on fossil fuels.
Bangchak is also building a factory to produce sustainable aviation fuel (SAF) using used cooking oil near its oil refinery in Bangkok's Phra Khanong district.
SAF can replace jet fuel because their properties are similar, while the former has a smaller carbon footprint.
This type of biofuel, which can be made from used cooking oil and agricultural waste, produces up to 80% fewer greenhouse gas emissions than conventional jet fuel, according to media reports citing various forecasts.
"SAF production also goes in line with Thailand's BCG scheme," said Mr Chaiwat.
Declared as a national agenda item, bio-, circular and green (BCG) economic development encourages manufacturers to adopt technology to add value to their products and minimise unpleasant effects on the environment.
Making SAF with used cooking oil comes under the bioeconomy concept while upcycling it to make a new type of oil is based on the circular economy, he said, adding that using SAF to reduce carbon dioxide emissions precisely conforms with the concept of green economy.
During the forum, Mr Chaiwat also mentioned electrofuels, also known as e-fuels, which are also a promising source of clean molecules.
One e-fuel development is to use electricity made from renewable energy to separate hydrogen from water in a process called electrolysis. Hydrogen will then bond with carbon captured from carbon dioxide found in the air.
"The final product is hydrocarbon in a liquid form that can be used to fuel cars," said Mr Chaiwat.
Another type of e-fuel is "green ammonia". Using renewable energy and the same process of electrolysis to separate hydrogen from water to capture nitrogen from the air, developers are able to produce green ammonia.
The shipping of ammonia is safe and less expensive than the transport of hydrogen. Because ammonia consists of hydrogen, users can separate the hydrogen to use it as a fuel.
"These technologies can change the world and can help the world deal with global energy demand," said Mr Chaiwat.