Earlier quoted context omitted.
Kind of buried in the article... but Google is claiming the net of their investments in renewable energy will offset their usage of fossil fuels. That's different than switching to a new energy source.
Does that change the message for you? As I see it the investments are the leading edge of the change over. So a combination of setting up a way to benefit from available clean energy (being a power company and being able to buy directly from the supplier), and investing in companies that produce clean energy or improve efficiency to keep the market moving so that the late adopters have something to adopt.
A Google datacenter near the Columbia River may derive 100% of it's energy from hydro. Google pioneered that practice and many others followed. But their overall real estate footprint relies heavily on local energy suppliers, which may be coal.
Any company making a claim of being 100% renewable, is basically just using offsets.
And offsets are a way the government allows companies to (metaphorically) continue driving down the road in gas-guzzling SUVs, but make investments in renewable energy to offset their footprint.