RENEWABLE ENERGY -
Our world needs energy and lots of it to survive, yet the energy supply sector is the largest contributor to global greenhouse gas emissions (GHGs) In 2010, the energy supply sector was responsible for about 35% of total anthropogenic GHG emissions.
Renewable energy comes from a source that is naturally occurring and replenishes naturally at a rate that is equal to or faster than the rate at which it is consumed.
We face a dilemna. Do we cut off fossil fuels and lose the boundless benefits afforded by these fuels, or do we use renewables to transition away from fossil fuel usages which contribute the most GHGs? It's a delicate balance to transition to renewables as quickly as possible, yet preserve the useages needed and now unattainable without fossil fuels. Governments face this dilemna constantly and often appear in self-conflict politically. In reality, we're only kidding ourselves if we think we can continue to exploit oil at current evels. Oil and natural gas are expected to completely diminish in the next few decades So, renewables are just about the only option.
"Multiple options exist to reduce energy supply sector GHG emissions (robust evidence, high agreement). These include energy efficiency improvements and fugitive emission reductions in fuel extraction as well as in energy conversion, transmission, and distribution systems; fossil fuel switching; and low-GHG energy supply technologies such as renewable energy (RE), nuclear power, and carbon dioxide capture and storage (CCS)" [RE-1].
Renewables are essential to an energy transition to achieve net zero emissions. The global shift away from carbon emitting fossil fuels begs an understanding of the key role renewables play in the decarbonisation of multiple energy sectors targeting net zero emissions.
Solar PV alone accounts for more than half of all renewable power expansion in 2021, followed by wind and hydropower.
While renewables continued to be recently deployed at a strong pace, they face new opportunities and challenges. On the positive side, the rollout of renewables such as solar and wind has continued at a fast pace, with strong growth set for years to come. On the other hand, it was not fast enough to keep pace with increased energy demand during 2021’s economic rebound and worrying amount of power demand had to be met by dirty coal. The decarbonisation of sectors such as transport and buildings isn’t happening fast enough to reach net-zero goals, and there is insuffient investment in the needed technologies of the future to complete the transition a net-zero future. Governments must move fast to implement policies that can put global emissions into sustained decline in the coming years. This requires data-driven analysis and recommendations for effective energy policy-making ─ and to ensure greater transparency and accountability.
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"By 2026, global renewable electricity capacity is forecast to rise more than 60% from 2020 levels to over 4,800 GW – equivalent to the current total global power capacity of fossil fuels and nuclear combined. Renewables are set to account for almost 95% of the increase in global power capacity through 2026, with solar PV alone providing more than half. The amount of renewable capacity added over the period of 2021 to 2026 is expected to be 50% higher than from 2015 to 2020. This is driven by stronger support from government policies and more ambitious clean energy goals announced before and during the COP26 Climate Change Conference (November 2021).
The growth of renewables is forecast to increase in all regions compared with the 2015-2020 period. China remains the global leader in the volume of capacity additions: it is expected to reach 1200 GW of total wind and solar capacity in 2026 – four years earlier than its current target of 2030. India is set to come top in terms of the rate of growth, doubling new installations compared with 2015-2020. Deployments in Europe and the United States are also on track to speed up significantly from the previous five years. These four markets together account for 80% of renewable capacity expansion worldwide." [RE-2]
However, even this faster deployment would still fall well short of what would be needed in a global pathway to net zero emissions by mid-century. That would require renewable power capacity additions over the period 2021-26 to average almost double the rate of the Renewables 2021 report’s main case. It would also mean growth in biofuels demand averaging four times higher than in the main case, and renewable heat demand almost three times higher.
The levelized cost-of-energy analysis highlights the dramatic decline in solar and wind costs over the decade 2010-2020: wind costs falling by 70 per cent and solar by 90 per cent!
"Perhaps more significantly, the levelized cost of wind and solar — a measure which includes cost to construct and operate power plants — has now reached parity with the
marginal cost of efficient natural gas plants (Figure RE2). This suggests building new renewables is now cheaper than operating existing fossil power plants."[RE-2]
"Despite evidence that renewables are the most affordable energy source to both improve resilience and support decarbonisation, governments across the world continue to resort to fossil fuel subsidies to keep energy bills under control. This growing gap between countries’ ambition and action on the ground is alarming and sends a clear warning that the global energy transition is not happening."[RE-3]
"Worldwide energy demand increased by an estimated 4% in 2021, and was met largely with coal and natural gas leading to record carbon dioxide emissions (up 6%, adding more than 2 billion tonnes). Large sums also continued to be invested in and to subsidize fossil fuels, with the USD 5.9 trillion in subsidies spent in 2020 equivalent to roughly 7% of global gross domestic product. Similar to past years, the highest share of renewable energy use (28%) was in the electricity sector; however, electrical end-uses accounted for only 17% of total final energy consumption (TFEC). The transport sector, meanwhile, accounted for an estimated 32% of TFEC and had the lowest share of renewables (3.7%). The remaining thermal energy uses, which include space and water heating, space cooling, and industrial process heat, represented more than half (51%) of TFEC; of this, renewables supplied 11.2%. As of 2020, modern renewable energy accounted for an estimated 12.6% of TFEC, nearly one percentage point higher than in 2019, as the temporary reduction in energy demand during 2020 favoured higher shares of renewables, while the share of fossil fuels barely changed. The slow progress in energy conservation, energy efficiency and renewables prevents the transition away from fossil fuels that is necessary to meet global energy demand and reduce greenhouse gas emissions. A structural shift in the energy system is increasingly urgent.
Renewable power capacity additions grew 17% in 2021 to reach a new high of more than 314 gigawatts (GW) of added capacity. The total installed renewable power capacity grew 11% to reach around 3,146 GW.
During 2021, China became the first country to exceed 1 terawatt of installed renewable energy capacity. Its total installed capacity of renewables increased 136 GW during the year, accounting for around 43% of global additions, with China leading in all technologies except concentrating solar power (CSP). By year’s end, at least 22 countries had more than 10 GW of non-hydropower renewable capacity, up from 9 countries in 2011. The share of renewables in net power additions continued to increase, reaching a record 84% of newly installed capacity.
Renewables generated 28.3% of global electricity in 2021, similar to 2020 levels (28.5%) and up from 20.4% in 2011. Despite the progress of renewables in the power sector, the surge in global energy demand was met mostly with fossil fuels." [RE-3]
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Although Nuclear Energy isn't strictly a renewable form of energy, it can be considered nearly so in the sense that there is little waste and virtually no GHG emissions compared to other forms of energy. As such it is considered an alternative energy with the capacity to assist weaning ourselves off fossil fuels until renewables are at sufficient levels. The key renewables are hydro, solar, wind, bioenergy, geothermal and tidal.
Hydropower is the largest renewable energy contributor providing about 17% of the world's electricity. Small-scale hydro-power plants are sustainable with little adverse environmental impact. However, massive dam installations for large scale hydro can be disruptive to local human settlements, cultures, and ecosystems, not to mention methane production at the bottom of the reservoir.
Solar energy comes from the continuous nuclear fusion reactions on the Sun of which only a tiny bit of energy reaches Earth. It's use as a renewable varies with the angle of incidence at which sunlight hits the earth and atmospheric obstructions such as clouds and, of course, night-time unavailability. Yet, we are able to utilize heat from solar thermal radiation and electricity.from photovoltaic processes.
Wind energy is related to the energy of the Sun. and the rotation of the Earth. Thermal differences of day and night, as well as atmospheric conditions, set up wind conditions which are suitable to produce wind energy transfers. Ocean waves are a special case of wind energy transfer which can be harnessed.
Bioenergy is used in the form of wood. biomass, and crops (such as sugar cane) typically to produce heat and electricity. Wood and other bioenergy feedstock are potentially sustainable fuel sources if the rate of regrowth exceeds their rate of use. Bioenergy is also used as biofuels for transportation.
Tidal energy is created by the gravitational pull of the moon on the oceans. Turbines can be used to harness this energy; however, are expensive and potentially hazardous to wildlife.
Geothermal energy is derived from extraction of energy from the Earth's core, tyically from hot water circulation and transfer to other forms of heat utilization or electricity.
Figure RE-4
Figure RE 2 Lazard - Levlized Cost of Energy Comparison
Footnotes
RE-2 - Lazard. 2020. Levelized Cost of Energy Analysis, (LCOE 14.0) v14.
RE-3 - https://www.iea.org/reports/renewables-2021/executive-summary
Fig. RE-4 - Renewable Energy Policy Network for the 21st Century, p,37 https://www.ren21.net/wp-content/uploads/2019/05/GSR2022_Full_Report.pdf