Facebook promised on Tuesday that it would cut its greenhouse gas emissions by 75 percent by the end of 2020 and run on 100 percent renewable energy. Transforming your business into a zero-carbon operation is a laudable goal. We also think Facebook can build on this decision and help lead a transition to powering its operations on 24/7 clean energy. As a practical first step, that means adopting a technology-neutral approach, one that helps preserve all sources of zero-carbon electricity (including nuclear energy) while not locking out future technologies that can help us preserve clean air, water and a healthy environment.
As Ben Geman of Axios pointed out yesterday, Facebook’s data centers use incredible amounts of energy. It's a significant fraction of the 2.46 million megawatt-hours of electricity that the company consumed last year. Those data centers operate 24/7. It also has users who run their desktop computers at all hours and also charge up their smartphones, laptops and tablets at various times. Solar panels produce their electricity mostly at midday, and wind runs more hours of the year than solar, but it, too, is intermittent.
Demand, of course, has never been flat. Depending on latitude and time of year, it peaks on summer afternoons or winter nights.
Facebook, or any other well-meaning company, can buy as many kilowatt-hours from wind and sun as it consumes over the course of a year, but they’re not simultaneous with consumption. Sometimes that energy will run Facebook’s servers. Sometimes Facebook will be buying more than it can use, and the surplus will run somebody else’s air conditioner, microwave or table lamp. Sometimes Facebook will be using electricity from natural gas, which is the common backup for wind and solar when they cannot supply enough energy to meet demand.
For a company with relatively flat demand (i.e., one with data centers), nuclear, which runs 24/7, would be a good carbon-free alternative. That company could buy the output from a new small modular reactor or from a reactor that would otherwise face premature retirement because it (unlike solar panels or wind turbines) doesn’t get paid extra for being carbon-free.
And any company—or government policymaker—could recognize that maintaining existing reactors, and fostering the construction of new ones that will follow load and mesh better with intermittent wind and sun, will minimize fossil fuel burn globally. This requires seeking what you actually want: not just energy from wind and sun, but energy that is emissions-free. The meaningful standard isn’t “renewable energy,” it’s clean energy, 24/7.
The wind-and-sun only approach has a second drawback: It will work (sort of) for individual companies but not for the system as a whole. Grid operators can’t balance the system if everybody insists on only wind and sun. And in the end the atmosphere doesn’t care how the zero-emissions generators were allocated, only how many of them there are.
The smart, long-term approach is to preserve and expand all forms of non-emitting generation, while not taking future zero-carbon options off the table. But for now, we should all celebrate, as Facebook’s announcement is just another step in corporate America’s journey to thinking more broadly about its environmental impacts. It’s certainly a conversation we’d like to be a part of.