As seminal punk band NOFX once sang, “Electricity / All we need to live today / A gift for man to throw away.” The data center industry has a love hate relationship with electricity. It’s obviously a crucial resource that enables the productivity and innovation gains of cloud and large-scale computing, but it comes from polluting power plants, it’s expensive, and it’s delivered from an increasingly unreliable power grid in the United States. Data centers are also using more and more electricity every day.
New developments in electric generation and delivery as well as data center design innovations could help develop the much-hyped smart grid, bringing cost savings, increased reliability, and cleaner power generation. How can data centers and the electric grid work together to create the future of electricity?
The Electric Catch-22
The transformers hooking data centers to the grid might as well be chains. Servers, cooling, storage—infrastructure can’t run without access to grid power. That’s not necessarily a bad thing. Electricity has enabled countless innovations. But the state of the power grid, especially in the United States, is worrisome.
We’ve noted on the blog before that blackouts can be caused by squirrels (a favorite fact of mine). Many components of the grid have reached the end of their lifespan, with original pieces built in the early 1900s and many structures still running after 70 years. Data centers are on the front lines when it comes to negative business impact from the aging grid. Recent natural disasters like Hurricane Sandy may have made this dramatically apparent, but even common brownouts lead to server downtime after UPS batteries die and generators run out of fuel.
In addition to unreliability, grid electricity comes overwhelmingly from polluting power plants that run on coal or natural gas. Renewable energy only contributed about 13% of the total United States power in 2012. A 10 MW data center emits 33,000 – 91,000 metric tons of CO2 even at the relatively low PUE of 1.2. This electric use is attracting attention from the media and activist groups, and while many data centers are striving for efficiency, there’s no escaping the grid.
Finally, energy is simply expensive. Demand spikes, hot days, and the cost of fuel at generation plants can all lead to dramatic increases in costs.
Instead data center managers and researchers at universities across the world are starting to look at ways data centers can turn their energy use into a benefit rather than a necessary evil. Here are three of the ways future data centers can help build more reliable, more efficient “smart grids”.
1) Increasing on-site generation and cleaning up the grid
This is one area where data centers have already taken action. Rooftop solar panels and large solar arrays are relatively common and some lucky data centers are located near hydroelectric or geothermal power generators, allowing them to use entirely renewable energy. If a facility has some on-site generation, there are two primary models to use both that energy and the grid: grid ties and transfer switches.
Grid ties combine on-site electric generation from rooftop solar, hydroelectric turbines, or wind turbines with grid sources. Electricity produced on-site reduces the net draw from the grid, which fills in the blanks when on-site generation can’t cover the entire server and equipment load. When there is excess energy generated, it feeds back into the grid for a net profit.
Transfer switches keep the on-site generated energy separate from the grid entirely. The equipment only receives energy from one source at a time. This falls victim to the same, if not worse, reliability issues as the grid without a very steady source like geothermal or hydroelectric as there is not always a steady source of solar or wind power.
When using renewable energy, data centers must choose between performance and green power. Battery technology is improving but still cannot store enough renewable energy to power a facility during extended periods of low generation. Alternatively, performance adjustments can be made to lower the power draw, but in an enterprise data center this is unlikely to be a real solution due to SLAs and the requirement for constant uptime.
Alternatively, companies can support increased renewable generation by the power companies operating the grid itself. Google and others have made large scale investments into wind farms. Renewable Energy Credits also support the development of renewable generation on the grid.
2) Migrating data center loads cross-country to avoid peak demand
Here is where things start to get crazy with smart grids and data center infrastructure management (DCIM). These new tools can help avoid brownouts or blackouts as well as peak-demand, when energy rates increase dramatically.
Hardware, software, sensors, and controls can be tightly integrated into data center operations and tied to the electric grid with programming and data center automation software. With real-time pricing and energy information from grid providers, this software can migrate entire data center loads geographically according to increasing and decreasing grid loads.
These tools still need development, but experiments have been performed as proof-of-concept. Studied data centers took about eight minutes to move their loads and reduced 10% of their energy use. Another study found energy decreases of up to 46% by moving data center loads.
By dynamically moving workloads, the overall demand is lower and energy cost is less. This improves the grid reliability for everyone, not just data centers. The opportunity is greatest for non-critical loads, which are risky to move. Rescheduling routine backup and storage for off-peak hours is one method of demand reduction that can already be implemented in data centers.
3) Energy storage and micro-grids
Data center technology can give the grid a boost in other ways besides feeding it excess renewable energy or reducing peak demand. Energy storage is developing rapidly, enabling self-healing smart grids within a data center facility itself. These systems store large amounts of energy and constantly monitor the flow of electricity throughout the facility, allowing power to be rerouted during emergencies. Generators are still necessary but their use can be minimized.
Micro grids and backup systems (even current UPS systems) can be combined with DCIM for frequency regulation or boosting power during peak demand. One can even imagine a scenario where data centers are sitting at a low internal load with fully charged battery systems, selling power back to the grid to meet peak demand. Many power utilities pay hourly for frequency regulation, enabling a new (though minor) revenue stream for data centers whose UPS systems and batteries are sitting idle the majority of the time. Of course, this has to be balanced with SLAs to ensure that unexpected outages don't cause downtime.
These solutions may be a ways off from wide scale implementation, but it’s exciting to see how such a major consumer of electricity can actually help improve the generation methods and reliability of the larger grid. Instead of being power hogs, the data center industry can aim to help save electric infrastructure in the United States through innovative power management, onsite generation, and new storage technology.
Posted By: Joe Kozlowicz