The grid, after all, doesn't boast the same uptime guarantees as the data center industry promises its customers. And the grid’s reliance on traditional fossil fuels is increasingly incompatible with the industry’s growing trend to go greener.
For many companies, especially those locating large data centers in more rural areas of the country, the answer isn't blowing in the wind or walking on sunshine.
But it is, potentially, growing on trees.
Biomass — woody residuals from timber, wood-based industries, sawmills, specially grown energy crops, and similar sources — present a reliable, sustainable, and increasingly economical alternative energy source for data centers (Figure 1).
HUNGRY
“Oink” is not a sound a server makes until one starts thinking about all the electricity more than 33 million servers around the world need to keep those cat videos, 99-cent songs, free-shipping offers, and html e-mail newsletters coming.
In a May 28 Wall Street Journal op ed, author and energy analyst Robert Bryce noted that data centers consume 1.3% of the world’s electricity, or about 277 terawatt-hours every year. That’s more than many countries use annually, including Australia and Mexico. It’s not atypical for data centers to need 100 to 200 megawatts (MW) to meet their steady power demand, and DatacenterDynamics forecasts that data center energy consumption will jump 20% this year.
Most other commentators see the same unstoppable trend of increasing data center energy use. Intel forecasts that by 2015 more than 15 billion devices, ranging from smartphones to RFID shipping labels, will pull data from the sky, up from 2.5 billion devices today. A Cisco white paper predicts data center IP traffic growing by 33% annually through 2015, surpassing 4.8 zetabytes per year. That’s more than three times the amount in 2011.
The growing appetite of data centers for electricity is forcing executives to explore alternatives to traditional grid power. At the same time, many companies are striving for a greener approach to business, including in their energy use.
Apple, for example, aims for 100% clean power for some of its facilities. Facebook seeks to source 25% of its data center energy from clean power sources by 2015. Google wants to have a third of its power generated by clean sources this year.
PIE IN THE SKY
The most popular kids on the alternative block, solar and wind, can help “green” the mix for data centers, but those energy sources present a number of problems.
Making wind or solar power at scale requires strong, steady wind or very good solar characteristics. Relatively few places in the country can meet those criteria, and often the places that can, like the Mojave Desert, are not ideal business locations.
Large wind and solar projects require a whole lot of land, too. A highly anticipated Apple plan to use solar to help power a new data center in North Carolina, for example, is estimated to need 6.5 square miles of solar panels.
More important, solar and wind generation only work when the sun shines or the wind blows. For an industry that depends on reliable 24/7 power, intermittent energy sources like wind and solar are flawed resources.
For some data centers, the solution to this conundrum — how to access affordable green power that is also reliable — will be biomass. Biomass provides so-called “base load” power: it runs 24 hours a day, seven days per week. It runs on locally grown fuel that is carbon neutral and generates green power that typically displaces high carbon fossil fuels.
REASONABLE INVESTMENT
Biomass power presents a compelling business case for data centers located within 25 miles of significant fuel resources. Biomass plants themselves are relatively simple in concept. A 15-MW plant requires a footprint of only five or so acres. This includes the key plant components: fuel handling and storage facilities, one or two boilers, one steam turbine, one generator, and appropriate emission control equipment. And the technology is well proven; it has basically been around since James Watt patented an improved version of the steam engine in 1769. Once built, the biomass plant will run for 25 or more years. Fifteen MW may not be enough power to run a reasonably large data center, but it will represent a significant contribution to the data center’s power needs that won’t turn off when grid power is interrupted.
A greenfield 15-MW biomass project will cost about $55 million to develop and, if developed and owned by a third-party developer like Recast Energy, can sell power to a creditworthy data center under a long-term power purchase agreement for an initial price of about $0.12/kWh. EIA Electric Power Monthly reports for September 2012 that typical utility rates for industrial users like data centers vary from a high average of $0.125/kWh in New England to a low average of $0.572/kWh in the West South Central states, with an individual state low of $.0408/kWh in Washington. The rate in each state depends on the applicable utility tariff.
Utility costs will rise over time with the commodity price of natural gas and coal and with environmental compliance and other non-fuel costs. Biomass power prices, in contrast, are uncorrelated to those commodities and provide a significant price hedge against those commodity price risks. Plus, with a renewable biomass power source, a data center would be creating its own carbon offsets and renewable energy credits, which many data centers now buy on the voluntary market.
EFFICIENT, ESPECIALLY IN EMERGENCIES
Biomass bolsters its solid business case with practical benefits, too.
With a biomass facility operating onsite, power is supplied with optimal efficiency — and is available especially in a pinch.
Onsite or near-site power generation is unlikely to go offline simultaneously with a grid outage, giving data center operators a reliable, steady stream of additional and backup power support when mainline electricity supplies flicker.
Last summer, for example, when unexpectedly violent storms ripped through Northern Virginia, popular web services Netflix, Instagram, Pinterest, and others went down because they depend on Amazon’s Elastic Compute Cloud Facility, which is located in the area. Lightning and high winds took out Amazon’s power supply and its backup generators, according to an article in Slate. Soon after, many began to speculate on the risks of cloud computing.
Densely populated and commercial Northern Virginia isn’t ideal for an onsite biomass project (or sizeable wind or solar projects, for that matter), but Amazon’s storm issue underscores the need for an alternative or backup to the grid. Rural and urban areas alike are subject to Mother Nature’s cranky side.
THE POWER TO COOL
Biomass also has a trick up its sleeve that’s a huge plus for data centers.
Biomass facilities can be designed to run in “combined heat and power” mode, or CHP.
CHP is the simultaneous generation of electricity and heat from a single fuel source, such as biomass. It’s an integrated system that efficiently supplies power to a data center’s servers and recycles “waste” heat to run absorption chiller loops that keep servers cool. Absorption chillers use heat instead of electric compressors to turn a refrigerant like Freon to a liquid and begin an evaporation process that removes heat to chill air, which then is used to cool down server rooms.
Hard to argue with cooling as a byproduct of the site’s electricity generation — not to mention greater fuel efficiency and enough heat left over to warm offices and tap water when needed.
CHP upgrades reliability, too. The Green Data Center Alliance cites a report by the EPA’s Combined Heat and Power Partnership. It estimates that a facility with a CHP system and a single connection to utility power can reduce anticipated power outages to 43 minutes per year. A facility running a CHP system with two independent utility connections drops expected outages to seven seconds per year (Figure 2).
COST EFFECTIVE
Biomass power is low risk if situated in the right location where fuel sources are plentiful and easily supplied. Resource maps prepared by the National Renewable Energy Laboratory show the South, Mid-Atlantic, Northeast, and Northwest regions of the country to be especially suitable (Figure 3).
Biomass fuel sources are not subject to the wild price fluctuations common to fossil fuel commodities. Natural gas, for example, may be sitting at record lows these days, but it has a history of spiking. With fossil fuels, what goes down must come up, and it doesn’t take too much upside on the natural gas chart to call many recent power plant investments into question. Biomass, in contrast, has much lower price volatility.
GIVE BIOMASS A CHANCE
Biomass is a clean, renewable, and effective green energy alternative that can be deployed to reduce a data center’s carbon footprint. Its own footprint is easily managed compared to the multiple square miles of real estate that alternatives like solar and wind require. Biomass power operations can be located onsite or in very close proximity to the data center, ensuring a steady, efficient and highly reliable complement to the grid.
And in CHP mode, it tackles other data center essentials, such as cooling and heating. It might even generate additional revenue if, say, an adjacent manufacturer wants to purchase leftover cooling water or steam for their own operations.
Biomass is gaining momentum. Vineyard Data Center Park near Colorado Springs, for example, is a nearly 70-acre development positioned to supplement data center power needs with biomass. Walmart is expected to complete a $107 million, 210,000 sq-ft data center at the park this year.
“In the data center world, we work with strong corporate entities who are also committed to sustainability,” said Vineyard Park developer Vince Colarelli in a local story about the park. “We began with our own commitment to be socially responsible, and then it was really reinforced by the organizations we are dealing with.”
And the big boys continue to set the “go green” tone. Apple’s CFO recently told Reuters, “We haven’t finalized our plans for onsite generation, but any power we need to run our center in Prineville [Oregon] that we get from the grid will be 100% renewable and from locally generated sources.”
The need for greater data storage and greener reliable energy sources will continue to grow. Properly powered data centers will do well in this environment. Biomass is poised to help them succeed.
