Renewable Energy

Key Points

Renewable energy currently accounts for about 27% of global electricity generation, but has a lower share in the heating and transport sector, resulting in a share of about 11% in global total energy consumption.
Currently, the largest renewable energy source is hydropower, but its growth is decelerating.
The renewable energy source with the fastest growth is wind power and solar power!

Global Energy Usage

Global primary energy consumption is increasing. If we look at the breakdown of sources of energy during the time period 1965 – 2018, oil consumption rose 2.5% annually on average, continuing to have the largest share (33.6% in 2018). Coal increased by 1.9% annually on average (share of 27.2% in 2018). Natural gas consumption rose at a larger pace than oil or coal, with an annual average of 3.3% (share of 23% in 2020). Nuclear energy and renewable energy had the highest average rate of increase (9.2% and 12.4%, respectively), but their shares are still small (4.4% and 4.0%, respectively), due to large costs. [21]

Major Types of Renewable Energy

Hydropower

Hydropower is currently the largest renewable energy source by capacity and generation, with a total capacity of 1300GW in 2019. It was the earliest form of renewable energy to be commercially used widely and contributed a significant share in primary energy consumption. Hydropower works by using water to drive turbines, and is one of the most cost-effective sources of electricity. Hydropower generation increased at a rate of 2% in 2019, but this growth is rapidly decelerating. The country with the highest capacity is China, accounting for 27% of the world’s hydropower capacity, and has roughly doubled since 2009. In 2017, hydropower accounted for 18% of total power generation in China, 8% in Japan, 7% in the US, and in Norway accounted for approximately 99%! [1][7][18]

Wind Power

Wind power is currently the second largest renewable energy source after hydropower. Wind is generally used to turn turbines for electricity generation, and is known for its efficiency. When generated at a large scale, it can be as cheap as thermal power. There are two types of wind power: onshore and offshore. Total wind power capacity increased by 19% in 2019, reaching a total of 651GW. China accounted for about one third of total wind power, followed by the US and Germany (2019). Onshore wind power increased about 12% in 2019. Offshore wind grew about 30% per year between 2010 and 2018. One fun fact about offshore wind power is that it has the potential to generate annually more than 18 times the current global electricity demand. China and the US each accounted for about 30% of onshore wind power capacity in 2019. Offshore wind power is concentrated in Europe (75% of offshore wind capacity in 2019), bordering the North Sea where weather conditions are especially good, and especially the UK (33% of offshore wind capacity). China is also experiencing growth in offshore wind power, being the country with the biggest capacity growth in 2019. [1][2][4][10][14][15][16]

Solar Power

Solar power is currently the third largest renewable energy source after hydropower and wind power with a total capacity of 580GW, recently overtaking bioenergy. It is one of the fastest growing renewable energy sources, and often one of the cheapest choices of electricity generation. There are two major types of solar power generation. The main one is called solar photovoltaics (PV), which are more widely known as solar cells or solar panels, which converts sunlight into electricity directly. The other one is called concentrating solar power (CSP), which uses mirrors to concentrate sunlight to generate steam to drive a turbine to produce electricity. Solar PV generation and CSP generation increased by 22% and 34% in 2019, respectively. [1][2][9][12][17][20]

Bioenergy

Bioenergy used to be one of the main sources of renewable energy, but was recently overtaken by the rapid growth of wind power and solar power. It used to be the main renewable energy source behind hydropower until about 2010. Bioenergy has long been used and has had a large share within renewable energy with the traditional use of biomass as fuel. Biomass uses the combustion of wood, animal waste and charcoal to make fuel, as well as use the heat energy to drive a steam turbine for electricity generation. Biomass uses organic materials for energy generation, but there are concerns about food prices increasing and deforestation. There have been efforts to produce better, cleaner bioenergy, and these are called modern bioenergy technologies, including biofuels and biogas. In 2019, bioenergy generation increased by about 5%. [1][2][5][19]

Geothermal Energy

Geothermal energy uses the Earth’s heat to drive a turbine for electricity generation, and has a total capacity of 14GW as of 2019. To use the Earth’s heat, generally, a well is dug to a deepness of about 1~3 km, where natural steam can be obtained. Geothermal energy capacity is lower compared to the other renewable energy sources introduced above. There are only limited regions in the European continent where geothermal energy is available (like Italy). The countries with largest geothermal energy generation are the US and Indonesia. One fun fact is that in Kenya and Iceland, geothermal energy accounts for about 47% and 90% of total energy generation, respectively. [1][2][6]

Current Trends

In 2019, renewable energy generation rose by 6%, which is the highest rate among all energy sources, and (excluding traditional use of biomass) accounted for 11% of total final energy consumption. Total final energy consumption can generally be divided into heating and cooling (51%), transport (32%), and power (17%, including electricity). Despite growth of biofuels and electric vehicles, shares of renewable energy are especially low in the transport sector, only accounting for 3%. On the other hand, the largest growth and share was seen in the power/electricity sector, resulting in a share of almost 27% in 2019. This large growth and share has been supported mainly by wind power and solar PV. Wind and solar PV together accounted for 64% of renewable energy generation growth in 2019, and has grown since 1990 at average annual rates of 23.0% and 36.5%, respectively. [3][12][13]

The costs of generating renewable energy have been decreasing as well, especially in Asia (led by China and India) due to its large area compatible with solar and wind power. Compared to 2010, the costs of solar power and onshore wind power has decreased by 77% and 25%, respectively. Renewable energy is expected to grow faster with lower costs and more policies that prioritise the environment. Renewable energy is vital for a less carbon intensive energy system! [1][11]

Sources

[1] Japan Agency for Natural Resources and Energy. (2020). “Trends of Global Energy – Trends of Primary Energy”. https://www.enecho.meti.go.jp/about/whitepaper/2020html/2-2-2.html. Last Accessed: 2020/08/02.

[2] Japan Agency for Natural Resources and Energy. “Renewable Energy”. https://www.enecho.meti.go.jp/category/saving_and_new/saiene/renewable/outline/index.html. Last Accessed: 2020/08/02.

[3] REN 21. (2020). “Key Findings of the Renewables 2020 Global Status Report”. https://www.ren21.net/wp-content/uploads/2019/05/gsr_2020_key_findings_en.pdf. Last Accessed: 2020/08/02.

[4] GWEC. (2020). “Global Wind Report 2019”. https://gwec.net/global-wind-report-2019/. Last Accessed: 2020/08/02.

[5] IRENA. “Bioenergy”. https://www.irena.org/bioenergy. Last Accessed: 2020/08/02.

[6] IRENA. “Geothermal energy”. https://www.irena.org/geothermal. Last Accessed: 2020/08/02.

[7] IRENA. “Hydropower”. https://www.irena.org/hydropower. Last Accessed: 2020/08/02.

[8] IRENA. “Ocean energy”. https://www.irena.org/ocean. Last Accessed: 2020/08/02.

[9] IRENA. “Solar energy”. https://www.irena.org/solar. Last Accessed: 2020/08/02.

[10] IRENA. “Wind energy”. https://www.irena.org/wind. Last Accessed: 2020/08/02.

[11] IEA. (2020). “Renewables”. https://www.iea.org/fuels-and-technologies/renewables. Last Accessed: 2020/08/02.

[12] IEA. (2020). “Renewables Information: Overview”. https://www.iea.org/reports/renewables-information-overview. Last Accessed: 2020/08/02.

[13] IEA. (2020). “Renewable Power”. https://www.iea.org/reports/renewable-power. Last Accessed: 2020/08/02.

[14] IEA. (2020). “Wind”. https://www.iea.org/fuels-and-technologies/wind. Last Accessed: 2020/08/02.

[15] IEA. (2019). “Offshore Wind Outlook 2019”. https://www.iea.org/reports/offshore-wind-outlook-2019. Last Accessed: 2020/08/02.

[16] IEA. (2020). “Onshore Wind”. https://www.iea.org/reports/onshore-wind. Last Accessed: 2020/08/02.

[17] IEA. (2020). “Solar PV”. https://www.iea.org/reports/solar-pv. Last Accessed: 2020/08/02.

[18] IEA. (2020). “Hydropower” https://www.iea.org/reports/hydropower. Last Accessed: 2020/08/02.

[19] IEA. (2020). “Bioenergy Power Generation”. https://www.iea.org/reports/bioenergy-power-generation. Last Accessed: 2020/08/02.

[20] IEA. (2020). “Concentrating Solar Power (CSP)”. https://www.iea.org/reports/concentrating-solar-power-csp. Last Accessed: 2020/08/02.

[21] Japan Agency for Natural Resources and Energy. (2020). “Trends of Global Energy – Overview of Energy Demand and Supply”. https://www.enecho.meti.go.jp/about/whitepaper/2020html/2-2-1.html. Last Accessed: 2020/08/02.

[22][IMAGE] Pombriant, Denis. (2019). “The 21st Century Version of Hydropower”. https://medium.com/@DenisPombriant/the-21st-century-version-of-hydropower-926ac8991d45.

[23][IMAGE] Clark, Evan. (2017). “A Beginners Guide To Concentrated Solar Power (CSP)”. https://medium.com/cleantech-rising/a-beginners-guide-to-concentrated-solar-power-csp-d5e6f9d12cdc.

[24][IMAGE] Hillsdon, Mark. (2019). “What is the future of offshore wind?”. Raconteur. https://www.raconteur.net/sustainability/future-energy-2019/offshore-wind-energy.