Unfortunately, there is indeed a lot of truth to the statement that it is a PR gimmick.
The problem with wind and solar is that they are intermittent. Therefore, Google's consumption at any particular moment in time cannot be supplied solely by these intermittent sources because their energy output never matches current demand (at least until some big honking batteries are built to level this out, for which the tech currently does not exist AFAIK -- no, Tesla's battery tech isn't even close to operating at this scale, though its a small step in that direction).
Therefore, Google must take power from the grid from non-intermittent sources that can ramp up and down based on demand, such as coal, gas, and nuclear. And this fact will remain true, even if Google had purchased wind and solar contracts for total energy many times greater than their total energy use.
So even though they may be purchasing contracts for wind/solar energy that exceed their own total energy use, they still cannot even approach viable operation without access to non-wind and solar sources, so its definitely misleading by Google to suggest they are running entirely on wind/solar.
Furthermore, the excess energy produced that Google purchased, but did not use because of the intermittency issue, actually reduces the efficiency of fossil and nuclear sources. Because the wind/solar energy is loaded onto the grid intermittently, it forces fossil and nuclear to cycle up and down to compensate. Just like city vs. highway driving, this is vastly less efficient.
I don't agree it is deceptive, if Google paid for 1GW of renewable electricity to be generated and 1GW is contributed to the grid from renewable sources then everything is as it should be. If the EMF that gets to Google's servers happens to be provided by a nearby coal plant they have still caused 1GW to be produced by renewables. This is how the grid works, and how it has always worked, it's just that no one in the past has cared if it was coal, gas, hydro or something else they were getting it from. Organisations are now willing to pay a small premium to use an equal amount of energy as renewables are generated. Storage matters for the long term goal of a zero emissions grid, but is not necessary for the economics to work out and the benefits to be felt.
"using" is a complicated word. If you don't like the usual way "using renewable energy" is used for electricity, by all means campaign against it, but there's nothing special about Google or this press release for this usage... and the New York Times article this discussion is about is quite clear.
That's not the "usual way" it's used. If I want to use solar power for my home, I don't contribute to a fund building solar panels on a different continent and claim I'm "using renewable energy". However, that's exactly what google is doing here.
Some people put solar panels on their home, other people pay someone else to install solar panels elsewhere. It's extremely common for businesses to choose the second, even if homeowners mostly choose the first.
Yeah I'm sorry this is complete nonsense, this is exactly how it works and has always worked. If Google pays for renewables to be produced, uses some energy that happened to be produced at a coal plant but someone else uses the energy from the solar/wind farm, then the benefit of using renewables has been materialised. It's not a hard concept, but somehow people struggle with the idea.
I would bet that the article is inaccurate and the majority of this "renewable energy" is hydro. Google has taken great care to place its datacenters in locations that are close to affordable hydro power, and in many cases owns or has long-term exclusive leases on several power-generation plants within existing hydro dams.
The problem with wind and solar is that they are intermittent. Therefore, Google's consumption at any particular moment in time cannot be supplied solely by these intermittent sources because their energy output never matches current demand (at least until some big honking batteries are built to level this out, for which the tech currently does not exist AFAIK -- no, Tesla's battery tech isn't even close to operating at this scale, though its a small step in that direction).
Therefore, Google must take power from the grid from non-intermittent sources that can ramp up and down based on demand, such as coal, gas, and nuclear. And this fact will remain true, even if Google had purchased wind and solar contracts for total energy many times greater than their total energy use.
So even though they may be purchasing contracts for wind/solar energy that exceed their own total energy use, they still cannot even approach viable operation without access to non-wind and solar sources, so its definitely misleading by Google to suggest they are running entirely on wind/solar.
Furthermore, the excess energy produced that Google purchased, but did not use because of the intermittency issue, actually reduces the efficiency of fossil and nuclear sources. Because the wind/solar energy is loaded onto the grid intermittently, it forces fossil and nuclear to cycle up and down to compensate. Just like city vs. highway driving, this is vastly less efficient.