Is wind power ready for data centers?
Like photovoltaics, wind power is essentially solar power. Winds are generated through the heating and cooling of the earth. The day night cycle has a lot to do with winds, heating makes the air less dense (low pressure) and cooling more dense (high pressure). The pressure difference causes air to move from high to low pressure areas generating the wind. So if there is little no difference, the winds are light, such as at sunrise and sunset which is why hot air balloons schedule their flights at these times.
Wind can be predictable such as in Buzzard’s Bay (Massachusetts) and Nantucket Sound, ocean areas adjoining Cape Cod, MA, or unpredictable as in those lazy hazy days of summer. And wind power can be controversial which is why many Nantucket and Cape Cod residents are working to block the Cape Wind Project due to the fact the wind turbines will be visible from their beachfront homes. Data Centers using wind generators would likely face similar challenges of intermittent winds and NIMBY neighbors. But the real question is do the economics make sense for data centers?
Certainly intermittent power will mean the data center will need an alternative power source or a connection to the local grid. From a New York Times piece about a New Jersey data center (Link to Source), continuous electrical power use is between 25 MW to 32 MW, enough to power 15,000 US homes. The load could be supplied by 13, 2.5 MW GE 2.5-100 generators with a continuous wind speed of 12 m/s (27 mph or 42 kph), which is quite unrealistic in New Jersey. Link to Souce For reference, the Cape Wind Project puts the Nantucket Sound site at an average of 19.5 mph, well below the 27 mph needed but much higher than New Jersey. With 19.5 mph winds the NJ data center would require 20 wind turbines with a straight extrapolation. However, the output of GE’s 2.5-100 is reduced at the lower wind speed to no more than 2.0 MW, meaning the 32 MW demand would require 16 wind turbines at a steady 19.5 mph, again an unlikely scenario in New Jersey.
One report http://www.electricitylocal.com/states/new-jersey/ puts New Jersey’s average commerical rate at $0.1278/kWh, industrial at $0.1053/kWh. Assuming data centers negotiate among the lowest rates in the state, let’s assume a rate of $0.10/kWh. Assume a 30 MW power need, in one hour a data center would use 30MWh x $0.10/kWh x 1000 kW/MW or $3,000.00 per hour of electricity. If we could get away with the minimum 16, 2.5MW wind turbines at a cost of $2.5 million each, the total cost would be $40 million. At $3,000 per hour, the breakeven period would be 80 weeks. Not bad, total power self sufficiency in a little more a year and a half. Of course the output from 16, 2.5 MW wind turbines will not be enough since there is not enough wind in Newark, for example to meet a steady demand of 19.5 mph. But there may be in another location that has steadier, stronger winds, say rural New York, Pennsylvania or Iowa. Then all we need is a really long extension cord called the grid.
Of course this cursory look at economics ignores costs such as site preparation, installation, operation and maintenance, so even a 19 month payback may not be attractive. And if a data center operator had to directly link a wind turbine array, a wind farm in today’s lexicon, to their data center the cost would be extremely prohibitive. But what about the idea of joining forces with an existing or planned wind farm that is linked to the grid and purchasing grid power at wind farm rates. This is in fact what is going on for some. Wind farms have become big business in rural agricultural states where locating a wind farm along with cash crops can supplement a farmer’s income, help pay for his/her power needs and help the enterprise to become profitable in poor growing years. And rural midwest wind farms are enjoying new respect with major data center players.
Recently Google entered into a 20-year power purchase agreement with NextEra Energy in Illinois to supply 114 MW of electrical power to its Council Bluffs, Iowa data center complex. In an entry into the wind power business, Google is not connected to the wind farm directly but instead the “power goes into the local grid. So Google Energy will sell the power on the regional spot market, where utilities and electricity retailers go to buy power when demand spikes and they have a shortfall. Google will use the revenue from spot market sales to buy renewable energy certificates (RECs) which will offset its greenhouse gas emissions. Many companies buy RECs in an attempt to be carbon neutral, obtaining them from third-party brokers. But by purchasing RECs directly tied to the renewable energy it is also buying, Google is getting a bigger bang for its buck.” Link to Source
Map of Iowa Wind farms (Left: Link to Source) and average wind speeds for the state (Right:
Link to Source) show how rural agricultural areas with strong, steady winds can become green electrical power regions.
Google hopes such agreements will lead to producers building new projects, increasing renewable energy for other applications. And because Google is now an energy seller the company can better protect itself from future price spikes. Google’s subsidiary Google Energy was launched to help the company explore renewable energy sources for future needs and reduce their carbon emissions, a possibly intangible benefit but one that can go a long way in the market place.
With 114 MW of power from NextEra Energy’s Story County, IL wind farm (Left Image), Google’s $1.5 billion, 1,000 acre Council Bluffs, Iowa data center (Right Image) utilizes green, renewable energy. Link to Source
Not every data center player has the resources to experiment with renewable energy at the scale of Google. And not every energy company wants to be in the wind farm business. Even Google lets those with the expertise and capital do that part. But every data center has the ability to purchase renewable energy. If other data centers can find partners like Google’s the market for renewable energy would increase investment and lower costs for wind farm operators. This would translate to lower renewable energy prices with the bragging rights that come from reduced carbon footprint.
For data centers that only care about lowest price per kWh, renewable energy may not fit the bill, the RoI may be too long particularly when compared to fossil fuel sources. Certainly pure play data centers operating on low margins may find the cost extremely prohibitive. But as more companies using hosted sites specify low carbon footprint energy, wind power may fit the bill. At least it’s worth a serious look. And the NIMBY crowd notwithstanding, I love to see modern wind turbines spinning in the wind’ reminds me of multi-masted tall ships sailing on the ocean. But that’s me.