Since 2010, the cost of solar photovoltaic energy has dropped by an astonishing 82%, providing the world with an opportunity to build a zero-emission energy system that may cost less than the fossil fuel system it replaces.The International Energy Agency predicts that if we are to accomplish the dual tasks of reducing global poverty and controlling the temperature rise below 2°C, then by 2040, solar photovoltaic power generation capacity must increase 10 times.
The key challenge remains. Solar energy is “intermittent” because sunlight is different during the day and in different seasons, so energy must be stored when there is no sun. Policies must also be formulated to ensure that solar energy reaches the furthest corners of the world and where it is most needed. Moreover, there will inevitably be trade-offs between solar energy and other uses of the same land, including conservation and biodiversity, agricultural and food systems, and community and indigenous uses.
Now researchers have published the first global list of large-scale solar power generation facilities in the journal Nature. The “large” here refers to a facility that can generate at least 10 kilowatts when the sun is full. A typical small residential rooftop solar installation has a capacity of about 5 kilowatts. Researchers built a machine learning system to detect these facilities in satellite imagery, and then deployed the system on more than 550MB of imagery.
Researchers searched almost half of the land area on the earth, filtered out remote areas far away from humans, and detected a total of 68,661 solar facilities. Using the area of these facilities and controlling the uncertainty of the machine learning system, the researchers obtained an estimate of the global installed capacity of 423 gigawatts at the end of 2018. This is very close to the International Renewable Energy Agency (IRENA) estimate of 420 GW for the same period.
This study shows that between 2016 and 2018, solar photovoltaic power generation capacity has increased significantly by 81%, mainly due to the growth of India (184%), Turkey (143%), China (120%) and Japan (119%). Driven by growth. The scale of the facilities ranges from the endless gigawatt-scale desert installations in Chile, South Africa, India, and northwest China, to commercial and industrial rooftop installations in California and Germany, rural assembly installations in North Carolina and England, and urban assembly installations in South Korea and Japan. The devices vary.