Microsoft’s Azure cloud has been carbon-neutral since 2012. Half of the energy it uses already comes from 1.2 gigawatts of wind, solar, and hydro-electric sources, which the company expects to make 60 percent by 2020 and 100 percent at some point down the line.
According to Microsoft, renewable energy is only part of what makes Azure a more sustainable way to run workloads like SharePoint, Exchange, and even virtual machines and storage than running them in traditional on-premises data centers. The other part is energy efficiency, some of it coming from the efficiency of its custom Azure hardware, and the bulk of it from operational efficiency and the efficiency of its data center infrastructure.
“It’s about designing cloud services to be more efficient from an operational standpoint, from an equipment standpoint, and an infrastructure standpoint, and mobilizing the world’s largest renewable energy procurement program,” Elizabeth Willmott, Microsoft’s program manager for environmental sustainability, told Data Center Knowledge in an interview.
Efficiency of the Cloud
Microsoft’s new report, The Carbon Benefits of Cloud Computing, compares energy consumption and environmental impact of running applications in Azure versus running them in enterprise data centers. Azure, it turns out, isn’t just more carbon efficient (up to 98 percent better than on-premises), it also uses 22 percent to 93 percent less energy to run the common enterprise workloads, which consume the most energy in Azure.
The study looks at small and large deployments, using both physical and virtual servers. A 10,000-user on-prem Exchange 2016 system spread across two European data centers, for example, used 81 percent more energy than the same deployment in the Microsoft cloud. (It would be 77 percent for a 100,000-user Exchange system and 85 percent for 1,000 users). Deployment size makes an even bigger difference for SharePoint; large and medium deployments are only 22 percent and 40 percent less efficient than Azure, but small, localized SharePoint systems use 93 percent more energy on-premises.
Azure compute is 52 percent more energy efficient than a high-end deployment of virtualized servers in an enterprise data center and 79 percent better than physical servers, according to Microsoft. Azure storage is 71 percent more efficient than dedicated storage and 79 percent more efficient than direct-attached disks. The figures are similar for reductions in carbon emissions.
“Customers aren’t moving [to Azure] explicitly for sustainability but because it’s a marker of a high-performance cloud and a cloud that can be trusted,” Willmott noted. It’s also a hedge against flooding, drought, heat stress, and other climate risks. “Moving from localized servers to cloud is a climate resilience and straight-up resilience strategy.”
Exploring a Utility-Less Future
One way to make Azure data centers even more energy efficient is to get away from piping in utility energy completely. “I want to hyper-simplify and integrate the power supply chain, so we don’t need the grid,” Christian Belady, Microsoft’s general manager for cloud infrastructure strategy and architecture (and the man behind the widely used PUE, or Power Usage Effectiveness, metric), told Data Center Knowledge.
Belady’s team at Microsoft has been exploring the various ways gas-powered fuel cells can be used to make data centers less dependent on utility grids, more efficient, and more resilient. The latest idea being explored is putting fuel cells directly into data center racks.
“When gas generation is being done somewhere remotely, you have all your distribution losses, including down conversion,” Belady said. “Why can’t we just bring it all right next to each other and eliminate everything unnecessary.” That means eliminating the grid but also eliminating things like generators and electrical switchgear, each piece of additional equipment being a potential point of failure. “We can simplify this whole thing by going direct DC from the source; it removes all the things in the supply chain that can fail.”
Natural gas fuel cells are reportedly much more reliable than the grid – six nines or higher, Azure CTO Mark Russinovich said at the recent Build conference – so you can save on the cost of backup generators. By supplying energy directly to servers, avoiding all the lossy conversion steps, they can also be much more energy efficient.
“There's a whole lot of switches and transformers on the way from utility power into the data centers and into the servers,” Russinovich said. Every time you go through one of those devices, you lose a little bit of energy in the transition.” By the time the energy gets to the servers, a significant amount of it has been lost.
Additionally, talking to fuel-cell manufacturers like Bloom Energy Belady realized that using them to provide AC power wasn’t efficient. “You’re looking at a native voltage out of the fuel cell of about 400 volts DC, and we know that in our servers after the first rectification in the back of our power supply it’s about 380 volts DC.” Similarly, he pointed out, wind turbines can provide DC power and remove the need for switchgear.
Fuel cells are expensive, but integrating them directly into the data center power architecture instead of using them alongside grid power and all the traditional infrastructure equipment can bring down the overall cost. “I don't have all that switchgear, that electrical gear in back room, the substations, the grid,” Belady said. “I have to pay for that, and that kills the cost effectiveness of the fuel cell. The big enabler is to just go with fuel cells, a DC bus at 400 volts, and nothing else.”
Microsoft has experimented with putting fuel cells in server racks but its first data center pilot is now running in Seattle with 20 racks of servers and a cluster of (currently) 10 fuel cells. Belady is still testing different sizes of fuel cell from a variety of manufacturers, as well as different fuel technologies, to see how they behave with varying workloads. Production sites would have even larger clusters of fuel cells, and he plans to have a production Azure data center running on fuel cells at scale within the next five years.
One issue is that fuel cell manufacturers are not yet producing cells at large enough scale. “We need to create an ecosystem where if we decide to scale the fuel cells, they can provide them,” he said.
Using natural gas for the fuel cells still produces CO2 and water. “In the long term we want to be 100 percent renewable energy with no fossil fuels,” Belady confirmed, “but we think doubling energy efficiency overnight is a good play in the interim.”
He’s looking at alternative fuels for the cells. (“Some are better for base load and some for different loads.”) A pilot at the Azure data center in Cheyenne, Wyoming, uses biogas from a waste treatment plant to run a container of servers, and Belady is also intrigued by the idea of using flare gas. “It’s gas at some drilling locations that’s too expensive to pipe off as low-quality gas, so it’s burned off. Imagine using fuel cells to build a data center where there’s a lot of flare gas; the energy is free at that point.”
Further in the future, he suggests data centers could even switch to hydrogen. “Think about a future world where we use renewables to do electrolysis with water to provide hydrogen. There’s a lot of research that needs to be done, but that's what fuel cells use, and now the emission is water.”
That would also address energy storage needs. “The problem with wind and with solar is it’s episodic; we have a lot of patents for approaches we’re taking in workload to smooth or follow the production of energy, but if you think about it, electrolysis is actually a battery.”