Last year, the world built more new solar capacity than every other power source combined. Solar is now growing much faster than any other energy technology in history. How fast? Fast enough to completely displace fossil fuels from the entire global economy before 2050, says Andrew Blakers, Professor of Engineering, Australian National University.
Total solar capacity tipped over 1 terawatt (1,000 gigawatts) for the first time last year. The sector is growing at around 20 percent a year, and has been for decades. If this continues, we’ll hit 6 terawatts around 2031. In capacity terms, that would be larger than the combined total of coal, gas, nuclear and hydro.
Fewer and fewer new fossil fuel power stations are now being built. As the rest of the global fleet age, most will retire by mid-century.
By 2050, Earth will have a population of about 10 billion people. To supply everyone with enough electricity to live a good life, Professor Blakers calculates that we will need about 200 billion megawatt-hours per year (equal to 200,000 terawatt-hours per year). So, if solar does the heavy lifting for decarbonisation, completing two-thirds of the task with the remaining one-third left to wind, hydro and everything else put together. Is it possible?
Yes, says Professor Blakers. If sustained, solar’s growth rate of 20 percent per year is easily fast enough to reach 80 terawatts of installed capacity by 2050 - enough to provide 130,000 terawatt-hours per year and (with help from wind) to entirely decarbonise an affluent world.
As well as eliminating most greenhouse emissions, we will also get rid of car exhausts, smokestacks, urban smog, coal mines, ash dumps, oil spills, oil-related warfare and gas fracking. And all enjoy breathing cleaner air.
Most countries have vastly more solar and wind resources than needed to be energy self-sufficient. This, in turn, will boost their resilience in the face of war, pandemics and the changing climate. Solar offers cheap, unlimited energy, available forever with minimal resource, environmental and social constraints.
Wisely, Professor Blakers has only zoomed in on existing technology for his calculations, but it's perfectly possible that a new technology to help power the world - like clean fusion - will ride across the horizon to help us out. After all, Washington-based fusion power startup Helion has just signed the world's first fusion power supply deal, promising to deliver Microsoft at least 50 megawatts of clean fusion power by 2028.
And let's not forget perovskite. This crystalline material in solar panels has quickly shot up the ranks from under 4 percent efficiency in 2009 to over 25 percent by 2021 to rival silicon, and it’s not done yet. When the two materials are forced to work together, they achieve even better results, with efficiencies recently reaching well over 30 percent. No doubt, efficiencies will continue to rise in coming years.
However, Professor Blakers points there's a potential short term fly in the ointment. The world needs to ensure that it is building enough transmission lines - and that we have enough engineers and installers.