- Published: 10 May 2023 10 May 2023
A wake-up call from scientists has given rise to agreements between responsible governments to make the effort to prevent a possible catastrophe by setting up plans and standards for emission control and decarbonisation in the form of net-zero target mandates and sustainable energy programmes. Considering the rather short window of time, a crucial question is ‘Is it possible?’
By Ahmad Hemami, McGill University, Montreal, Canada
World energy demand is continuously increasing, as the records show, and the world’s population is also increasing. This implies that even if one day we reach a balance between the population and energy consumption (and the energy demand curve becomes flat), still more energy is necessary because of the population growth. According to the latest figures from bp’s ‘Statistical Review of World Energy’, the total world energy consumption increased by 5.8% in 2021. This is a return to the regular trend after a slowdown due to the pandemic.
‘Net-zero emissions’ implies an overall balance between greenhouse gas produced by all human activities and that taken out of the atmosphere. This definition is subject to misinterpretation and abuse (carbon offsets), especially since currently not much large-scale carbon capture, utilisation and storage (CCUS) facilities exist. While the steps to take can be different for each region/country, in all industrialised countries it involves switching to renewable energy.
World energy consumption in 2021 was 595.15EJ (exajoules: 1018J), of which 102.5EJ (28,406.3TW-h) is in the form of electricity. Of this generated electricity, 62% (63.537EJ) is from fossil fuels, 9.8% (10.043EJ) is nuclear and 28% (28.694EJ) is from all renewable sources (including hydroelectricity). Wind and solar reached a 10.2% share of power generation in 2021, the first time wind and solar power have provided more than 10% of global (electric) power and surpassing the contribution of nuclear energy.
Apart from hydroelectricity, a major part of renewable power comes from wind and solar energy, although the other forms like geothermal, hydrogen fuel, wave and other forms may catch up fast. Any augmentation of renewables, at this time, must be through wind and solar, which currently provide only 1.71% (10.2/595.15) of the world energy need.
Although this calculation can be performed for almost every individual country (and the results are quite different, based on the numbers for each country), here it was done only for the whole world.
Getting back to the original question of whether net-zero emissions is possible, on top of the issues to be considered are technological, economic and social factors. The problem becomes complex because the factors involved are not the same for different countries and different people. The case for a poor country in which some people still use wood for cooking is quite different from that in industrialised countries, where a large part of pollution is from gasoline cars.
From a technological standpoint, replacing fossil fuel with electricity can be at different levels. For instance, we can imagine x% of cars (x can reach 100) are electric. Then comes the question of manufacturing of batteries, and generating electricity, which requires manufacturing of towers, blades, generators, solar panels and so on. Manufacturing by itself needs power, and where should this power come from? Chain-wise, this can go deeper and deeper into all industrial production and manufacturing activities. For instance, an iron smelter of 15 MTPD (metric tonnes per day needs 500MW power. This means that for an all-electric plant, a wind farm with approximately 1,500MW installed capacity is needed. Getting to this stage might be too ambitious at this time. The main action for a target of net-zero emissions, thus, is to consider only:
1. Replacement of fossil fuel to generate electricity (62%, 17,612TWh) with renewables.
2. Providing transportation by electric vehicles
3. Increasing the efficiency of energy usage (at any level, e.g. in buildings).
Next, the economic aspect of the problem. Obviously, any project needs investment, and it needs to be profitable for the investors, otherwise it does not work out. Associated with this aspect are support from government and authorities and the market prices. Whereas government support is more local and based on a country or region, the market price is more global and influenced by more factors. If new technologies or research and development are involved, this translates into a higher cost and, also, more uncertainty. As for wind energy, a forward step is to go farther with offshore floating wind turbines. This is true for the net-zero target, particularly with European Union countries. With the current technology, the cost of operations and maintenance can be up to five times greater than those of the fixed sites, unless new innovations are developed for remote sensing in order to minimise the costly in-person visits to a site.
The social aspect to be considered for attainability of the goal of reducing greenhouse gas emissions is less addressed. Based on an analysis by the National Academies for the USA: ‘Available technologies could allow the United States to achieve net-zero emissions by 2050. This would require rapid and widespread changes in policy and investment across many sectors of society and participation and commitment by government, industry, and individuals.’
It is unfortunate that despite all the recent forest fires, heavy rainfalls and flooding, and increased frequency of tornados, some people still deny global warming and the potential catastrophe that may occur as a result. The harm is more striking when such people become key players in irresponsible companies or incapable governments. What I suggest adding to the list of what is necessary to be done is ‘education’. Educating people on the issue should be a part of government mandates. Many companies follow the policies and guidelines set by governments. A good example of this can be seen in the 1973 oil crisis, which led to the useful result of moving towards alternative energy.
- Wouter Maas, March/April 2023. Financial Viability of Floating Wind, Windtech International 19(2), 20–23.