September 20, 2013

Google’s wind power bluff

Google has announced it is purchasing the entire energy output of a 240 megawatt Texas wind farm as part of the company’s quest to power its operations with 100 percent renewable energy.

There’s just one problem. None of that wind power will actually be used by Google because wind energy is not reliable enough to power their servers, reports Forbes.

“Due to the current structure of the market, we can’t consume the renewable energy produced by the wind farm directly, but the impact on our overall carbon footprint and the amount of renewable energy on the grid is the same as if we could consume it,” according to Google. “After purchasing the renewable energy, we’ll retire the renewable energy credits (RECs) and sell the energy itself to the wholesale market. We’ll apply any additional RECs produced under this agreement to reduce our carbon footprint elsewhere.”

Google has contracted with companies to get more than 570 megawatts of wind energy, however, this doesn’t mean much in terms of the power they will actually be using to power their servers, writes Tim Worstall in Forbes.

“Google’s server farm is powered by whatever the mix is on the local grid: some coal, some gas, a bit of wind powered no doubt, possibly some nuclear,” writes Worstall. “And the reason that Google has to sell the renewable power to the grid and then buy back the standard mix is because wind power is hugely variable.”

It’s hard to run a wind farm using an energy source that varies throughout the day, when power demands are nonstop. This makes some renewable energy sources a poor choice for powering a server farm.

“Hydro is fine because that is controllable. Solar not so much but at least that’s reasonably predictable… but wind really is something of a problem. It’s variable in output in minutes: your system can be humming along and then there’s a drop in wind speed and you’ve not enough to keep the network going,” Worstall added.

Google’s purchasing of renewable energy credits to offset their carbon footprint is similar to what Apple does — a move which has both companies being hailed as leaders in environmental responsibility.
“You can buy carbon credits from planting trees in Jakarta but when you fly, the aircraft still burns oil,” according to Energy Facts Weekly. “You can buy green credits from waste dumps, wind farms, and solar arrays, but most of the energy actually flowing into data centers and powering everything to do with iPhones, iPads and their increasingly dominant imitators, comes from burning natural gas or uranium, and coal.”

However, it’s not clear that using wind power really lowers carbon dioxide emissions when all things are considered.

“It actually not even certain that the German windmills reduce carbon emissions at all,” Worstall continued. “The combination of having to have spinning reserve and also dumping surplus electricity at times means that it’s a close run thing at least.”


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