To my four-year-old son, electricity must seem magic—this invisible stuff that comes out of the wall sockets to power the fridge, to light up the TV, or run his favorite toy, an electric piano. He has no personal experience of where it comes from, even if he does see the wires on which it travels.
Many of us never see how electricity is made. This is because most of it is generated in a relatively small number of very large power plants, situated miles away from where we live and work. However as we transition to a zero-carbon economy, wind and solar power is going to get a whole lot more visible. In time, power stations are likely to become as ubiquitous and familiar as gas stations are today.
Wind and photovoltaic systems are modular technologies, composed of many identical panels or turbines. This means, for renewables, bigger is not always better. Whereas conventional round-the-clock coal plants only run efficiently at scales of at least 500 megawatts, large wind and solar projects typically top out in the hundreds of megawatts. So we’ll need a lot more of them to generate the same amount of energy. And because the sun doesn’t always shine and wind doesn’t always blow, each megawatt of capacity produces less electricity than the equivalent amount of coal, gas or nuclear. To replace 500 megawatts of coal power takes around 1,500 megawatts of wind capacity, and about 3,000 megawatts of solar.
Plus, wind and solar capacity take up far more physical space than traditional power plants—7.6 hectares per megawatt for wind and, according to a new analysis published this week by BloombergNEF, 1.7 hectares per megawatt for solar.
As of now, around 650 gigawatts of solar and 644 gigawatts of wind have been commissioned worldwide, accounting for around eight per cent of global electricity generation and covering around 52,000 square kilometers. Onshore wind and solar will supply 48 per cent of global electricity by 2050, according to BNEF’s New Energy Outlook 2019 scenario, which will require an eight- to nine-fold increase in land use, to more than 423,000 square kilometers.
But let’s say all road vehicles and buildings were to go electric. To keep emissions in line with the 2 degrees Celsius warming limit prescribed by the Paris climate agreement, the power sector would have to deploy around 26,000 terawatt hours of wind and solar generation by 2050, which would cover a land area the size of Turkey. The land-use impacts in this scenario differ by country: It would take less than one per cent of land in the U.S., China, and India, but as much as 7.4 per cent in Germany. While the latter is a big number, it’s still much smaller than woodland, which accounts for 30.6 per cent of Germany’s total land area, and agriculture, which covers 51.7 per cent.
Let’s go even further and assume that the entire economy gets to net-zero emissions, including hard-to-abate sectors such as steel-making and aviation. To do that, we’ll probably need another zero-carbon solution. One option is hydrogen. Today, most hydrogen is manufactured from natural gas using a carbon-intensive process, but it’s also possible to make so-called “green hydrogen” by breaking water apart in an electrolyzer powered by renewable energy.
A special report published by BNEF in March concluded that if green hydrogen were to supply 24% of all energy used in 2050, we’d need six terawatts of wind and 6.3 terawatts of solar dedicated to hydrogen production. That would roughly double the amount of installed renewable capacity.
Whether a green hydrogen economy emerges is still far from certain. But the growth of renewables at the expense of large-scale coal, gas, and nuclear means power plants will become much more visible and commonplace. Small-scale solar will come to dominate rooflines in all but the most northern and southern latitudes. Conversations around the dinner table will drift into personal energy tech, from wall-mounted battery units to the latest e-bike or electric vehicle. And whether we take a train or the highway, we’ll pass hundreds of wind turbines and ground-mounted panels.
In this net-zero emissions world, all four-years-olds will have to do is look around them to see where the electricity comes from. Let’s hope they’ll still think it’s a little bit magic.
Seb Henbest is chief economist at BloombergNEF. Regular Sparklines columnist Nathaniel Bullard is on vacation.
© 2020 Bloomberg L.P.