How many roofs do solar panels need to be installed to supply all of the world's electricity with solar power?

The development of green energy technology to replace fossil fuels is being sought all over the world, and solar power generation is one of them. Installing solar panels on the roof of a building is a common way to generate solar power, but in order for solar power to generate electricity around the world, how many solar panels must be installed on the roof of a building? The researchers have announced their predictions.

High resolution global spatiotemporal assessment of rooftop solar photovoltaics potential for renewable electricity generation | Nature Communications

Solar panels on half the world's roofs could meet its entire electricity demand – new research

The cost of solar power is declining rapidly, 79% cheaper than in 2010. This makes solar power a more viable option for companies and individuals who want to break their reliance on electricity and decarbonize , while all homes and businesses have installed solar panels on their roofs. Will it be able to supply all the electricity needed on earth? There is also the problem.

To address this issue, a research team, including Siddharth Joshi, who studies global energy engineering at the University College Cork, evaluated the rooftop area and sunshine of buildings around the world.

The research team has built a program that integrates data from 130 million square meters of land on almost every surface of the globe and data from 300 million buildings. We investigated how much energy could be produced by a total of 200,000 square kilometers of roofs on land. The figure of 200,000 square kilometers is almost the same as the area of England.

The research team then calculated the power generation potential for each roof from its location. In general, roofs located in high latitudes such as Europe and Canada have large differences in daylight hours between summer and winter, and the amount of electricity generated can fluctuate by as much as 40% depending on the season. On the other hand, the roof located near the equator receives stable sunlight, so there is almost no change in the amount of electricity depending on the season. For this reason, a method of storing electricity is required in places where the potential for electricity generation fluctuates depending on the season, and the electricity bill increases.

As a result of the survey, it was found that 50% of the roofs need to be equipped with solar panels to supply 'the power required by the whole world in one year'. In addition, India and China are said to be able to generate solar power with the best cost performance because the manufacturing cost of solar panels is very low in addition to the good sunlight. Japan, the United Kingdom, and the United States have poor cost performance, and European countries are in the middle.

Using solar panel solar power in urban areas where energy consumption is high can reduce fossil fuel power generation and stop air pollution. In addition, there are often no stable power grids in remote areas, and solar power can be an important source of power. On the other hand, sunlight is only available during the day, so to use electricity during times when sunlight is not available, you need a system to store electricity, which is still expensive. Nevertheless, rooftop solar panel installation is an important way to power, as solar power offers benefits in both urban and remote areas. The research will provide a detailed map of the installation of solar panels on the roof, the researchers said.

in Science, Posted by logq_fa