The best way to incentivize sustainable energy is to make it affordable.
And the sharp drop in the price of photovoltaic systems has made solar capable of rivaling coal power in China, according to an analysis from researchers published in the journal Proceedings of the National Academy of Sciences of the United States of America.
However, as solar power comes to encompass a greater slice of a national economy's power grid, it becomes harder to achieve a sustainable balance against the fact that solar can only generate power intermittently, potentially exacerbating energy management challenges.
China's solar resources and its people lie on opposite sides of the nation
Once this happens, other issues besides the price become relevant in deciding how much a country should rely on solar energy. These issues aren't identical across all countries, which means building a comprehensive grasp of how solar will affect each nation, which is why the case of China, a rapidly-growing community, is especially enlightening. The recent report found that solar, when combined with storage equipment, could support nearly half of the country's energy needs by roughly 2050.
Similar to other countries, China has noticed the dropping price of solar in the last decade, where, between 2011 and 2018, the cost fell 63%. In reaction to his plummeting price, solar installation has risen to unprecedented levels. As of writing, one-third of the entire world's new solar capacity is being commissioned in China, where installation surpasses the Unites States' solar capacity in 2013, and then Germany in 2015. Now China has 250 GW active, far more than double what it had previously projected by this point. And since China has ambitions to reach net-zero emissions by 2060, it probably won't stop here.
However, most of China's population resides in its southeastern region, on the opposite side of the nation's best solar resources lie, in the northwestern regions where cloudless sunny days are abundant. There aren't a lot of people living there, and this geographic mismatch between supply and demand has created unique solar constraints, since China faces an engineering nightmare of building a reliable grid that transmits the lion's share of its power across vast distances, to the other side of the country. Solar plants stationed in the northwest have frequently gone bust, since the capacity to send this power where it's needed is lacking.
Less reliance by China on coal could save lives
This is why the researchers constructed a model that investigates most of the factors affecting solar performance, according to a report from Ars Technica. The model takes account of economics, changing technology, solar resources, and the projected state of China's power grid from 2020 to 2060. Six years of satellite weather data assisted in an estimation of typical productivity levels throughout the country, in addition to data on existing land use that might mess with present-day solar farm sites.
This model generates what the researchers dubbed the "technical potential", which is the amount of solar energy that might be produced if all accessible sites were put to work to produce it. In 2020, China's technical potential was just under 100 petawatt-hours, or roughly 13 times the entire country's electricity demand. And as technology continues to advance, the researchers think that technical potential could surge to nearly 150 PW-hr by 2060, which would coincide with China's aim to achieve net-zero emissions. It will be interesting to see how China manages its different resources as coal becomes less incentivized than solar, especially because most of the world's materials for renewable power, including wind turbines, batteries, and solar panels, come from China. As a close third, it might also be cool that the reduced pollution from less reliance on coal power will save lives.