Facebook is known as a large consumer of electricity that is used to power its data centres around the world. The company had previously committed to procuring 50% renewable power, and had surpassed that goal ahead of schedule last year. Now it’s going for the whole 100%.

The announcement comes amid what has been the busiest year ever for corporate renewables procurements. Companies have purchased nearly 3.86 gGW so far in 2018 across 46 deals, according to the Rocky Mountain Institute’s Business Renewables Center, which tracks such transactions.

This is a trend that is especially popular among Silicon Valley giants.

Google leads with more than 3 GW contracted to cover all of its offices and data centers. Apple also powers all its operations with renewable electricity. Amazong hit 50% renewable for its data centres in January, and Microsoft is working toward 60% clean energy “early in the next decade.”

Facebook requires that the renewable energy it procures come from new projects on the grid where the data center is located.That stipulation of additionality ensures the electrons from Facebook-sponsored generators could possibly end up in its data centers –but this should not be confused with actually running data centres on renewable power. Server farms require constant high-quality electric power. Wind farms and solar farms do not, however.

Because of this, even companies that buy renewable power equal to their annual consumption make use of whatever fossil-fueled plants keep the grid running in areas where they operate.

That practical limitation sets corporate renewables commitments apart from the bill passed in California’s Assembly Tuesday–which would actually ban carbon-emitting power from the state by 2045.