Corporate environmental programs are becoming the way of the world. From big companies, such as Apple, buying acres of forestland in Vermont and replacing every tree they use with a new one to the corner grocery store switching from plastic to paper bags, concern for the environment has manifested itself in every part of business. As such, it has become consumer expectation—a “must do” rather than a “nice to do.” One of the largest frontiers for companies pursuing true sustainability is the data center. Data centers across the country are making a concerted effort to increase energy efficiency and make the switch to renewables. This effort is a great start, but we can do better. One major area of digital infrastructure that is at risk of falling behind in sustainability is batteries, the number-one resource consumed by data centers.
The Rise of Data Center Sustainability
Worldwide, governments, nongovernmental organizations (NGOs) and corporate sustainability teams are turning their attention toward the “green Internet.” Why is sustainability increasingly important for data center operators to consider?
First, their customers demand it. Data center customers, as well as consumers, are paying more attention to sustainability in their supply chains. These big, household names want to build or work with data centers that take environmental responsibility seriously. New frameworks and metrics are emerging to not only chart progress toward sustainability but also put pressure on companies that are not acting on their missions of environmental sustainability. For example, Greenpeace has begun releasing an annual “Click Clean Report,” ranking Internet companies on their progress toward full sustainability. According to the report, as data storage grows by 20 percent each year and becomes increasingly integral to business, data centers have a much larger footprint and much larger environmental impact. As further evidence of this trend, several large data center operators have established sustainability positions and organizations.
Sustainable practices, though, are not just a ploy to make the customer feel better; they have serious ramifications for the bottom line. On the tangible scale, media trends in framing poor sustainability performance as a financial risk have driven corporate investors to express concerns about sustainability issues such as energy and water use. As a result, companies such as Apple, Equinix and Google have committed to sourcing 100 percent renewable energy for their data centers.
The industry has made remarkable strides. It’s now time to take a few more steps forward.
Batteries are essential for backup power at data centers. Responsible care of batteries after their useful lives is incredibly important to the sustainability efforts of any data center. Although the vast majority of batteries used in data centers today are lead-acid batteries, some companies are exploring the increased use of lithium-ion batteries. This change comes with great ramifications.
Lithium-ion batteries may take up less space than lead-acid batteries on the data center floor, but they take up a lot more space in a landfill, as they are not recyclable. Rather, spent lithium-ion batteries have a far different path at their end-of-life than spent lead-acid batteries. Lead-acid batteries have four basic ingredients: about 50 percent lead, 40 percent acidic water, 10 percent plastics and about 1 percent separators. By contrast, lithium-ion batteries have hundreds of complex ingredients. These batteries comprise about 3–5 percent lithium, sometimes small percentages of recoverable cobalt and nickel, and 95 percent other materials—mostly fluorinated electrolytes (e.g., hexafluorophosphate), which cannot be recycled. Very small amounts of metal can be recovered from these batteries, and the rest ends up in landfills or is burned off during the recovery process. Spent lithium-ion batteries must be dealt with as a managed waste stream rather than a recoverable and reusable resource. This waste management is not profitable and requires government subsidies to make the economics work. Mining new lithium carbonate is far cheaper and safer than recycling it. The opposite is true for lead, however.
Nearly 100 percent of a lead-acid battery is recyclable. In fact, these batteries are one of the greatest recycling success stories. Not only has lead demand doubled in the last 20 years and is expected to double again in the next 20, lead also has a recycling rate of around 99 percent. Lead-acid-battery recycling is a for-profit business on a global level (about a $22 billion market for recycling and $65 billion market for lead-acid batteries overall). Lead, when handled sustainably, is so recyclable that new lead hardly needs to be mined to feed the battery beast.
But the traditional infrastructure for lead recycling, “smelting,” is one of the top five polluting processes in the world. Smelting releases tons of greenhouse gasses, as well as particulate matter, solid waste and lead dust into the air.
A new technology, AquaRefining, is setting out to make lead recycling a clean process for the first time. This modern hydrometallurgical process replaces the pyrometallurgical process of smelting, which dates back at least to the Bronze Age. It’s a fundamentally nonpolluting, room-temperature, water-based process that makes lead-acid batteries unbeatable in sustainability. The process not only eliminates the off-gassing and toxic waste that has been associated with lead recycling in the past but also produces lead that is even more pure than the day it was mined. This purity opens up opportunities to create even more-advanced lead-acid batteries with higher energy densities, higher cycle rates and lower costs per kilowatt-hour of energy storage. The advent of such technologies makes the value of lead-acid batteries, which data centers already rely on heavily, even more apparent. Thinking ahead about how batteries will be handled after they are no longer usable is vital as data use and the resulting storage needs continue to grow exponentially.
The reality data center operators must face is that no viable recycling process exists for lithium-ion batteries, and innovation in this area is unlikely before today’s lithium-ion batteries need to be recycled—they are right now a waste-management issue. Disposing millions of tons of data-center-generated batteries into landfills is not only extremely detrimental to our environment but also creates industry-wide environmental-stewardship and liability concerns.
Pound for pound, batteries take up the largest percentage of materials consumed by data centers, and lead-acid batteries are the only battery chemistry that can be recycled sustainably and profitably. Although the lifespan of a lithium-ion battery can be relatively long, there is no viable recycling technology in the works, making it a dangerous bet to hedge. Data center operators need to take into consideration not only the environmental impact of the battery types they choose but also the impact the batteries will have on their profitability.
Responsibly Managing Waste, Enabling Recycling
Now is the time to act on creating sustainable stewardship of renewable resources. It’s vital for the data center industry to grow without creating new waste streams. The demand for data will only increase, and waste streams, such as spent lithium-ion batteries, are subject to increasing regulation in the United States. In California, for example, penalties for violating state hazardous-waste laws are becoming more severe, even for nonindustrial companies.
Responsibly and cleanly recycled lead-acid batteries are an important step toward this goal for data centers. Especially owing to new technology for sustainable lead-acid-battery recycling, these batteries present an economically viable, environmentally responsible option for both data centers and their customers. Batteries need not be a sunk cost and an environmental loss.
About the Author
Steve Cotton is the chief commercial officer of Aqua Metals, a company that has developed an innovative, nonpolluting lead-recycling process. Before joining the founding team at Aqua Metals in January 2015, Cotton spent 15 years building his prior company, Data Power Monitoring Corp/IntelliBatt (now Canara), from a garage operation into the largest independent global supplier of data center battery and battery-monitoring systems and solutions, serving over 300 data centers.