Data centers are a vital cog in our digital world. As data centers become increasingly important, we need to look at the infrastructure behind them: the electric power grid. The grid is aging infrastructure designed in the 20th century well before the advent of digital services like those provided by data centers – and it’s simply not suited to meet the power demands of data centers.
Data centers depend on a reliable supply of electricity in order to perform 24 hours a day, 365 days a year. Today’s electric infrastructure isn’t capable of providing the level of power reliability that data centers require, so these centers spend huge amounts of money on back-up systems in order to protect the facilities from power outages. There is increasing pressure to reduce the costs associated with electric service, however. A recent Gartner report showed that the annual cost to power an 8,000-square-foot data center can hit $1.6 million, and the cost is rising. These costs don’t include expenses associated with building, operating and maintaining back-up systems either.
Data centers also face new pressures to adopt “green” business processes in order to mitigate environmental impacts associated with their operations. As a result, more data centers are evaluating ways to utilize a greater percentage of electricity generated by renewable resources, rather than carbon-emitting fossil fuels.
A modern smart grid would address many of these concerns. An overhaul of the U.S. power grid, however, is likely to take years, if not decades. Regulatory constraints and concerns about how investment returns will be structured are slowing grid modernization programs. However, some data centers are beginning to incorporate new technologies into their on-site electric systems in order to reduce costs, increase energy efficiency, and reduce environmental impacts-all while providing a very high level of electric service reliability. Here are some of the approaches that data centers are adopting.
Eliminate unnecessary system redundancy. Data centers typically have designed additional redundancy into their facilities in order to protect against power outages. The redundancy includes not only electrical lines and equipment but also cooling systems. Chilled water systems, which prevent servers from overheating, typically are not protected by uninterruptible power supplies (UPS) because low-voltage UPS systems aren’t large enough to protect these chillers. As a result, data centers usually have redundant cooling systems to protect servers in the event a power disruption on the utility grid causes the chillers to go offline. This redundancy comes at a considerable cost, however, both in the upfront capital expenditure and in operating costs.
Today, more data centers are investing in UPS technology that provides whole-facility protection, including cooling systems. These systems operate at medium voltage, and can provide back-up power protection for an entire data center. This technology can provide a sizable reduction in the costs associated with providing back-up cooling systems.
Reduce floor space. Data centers can install more of their on-site electrical equipment-like UPS systems-outdoors, which reduces the costs associated with housing equipment indoors in a climate-controlled environment. Not all such equipment is suited for outdoor installation, but this approach gives data center operators another tool to realize additional savings. Other electrical equipment, like switchgear, is available in innovative designs that reduce the total footprint required for the gear itself as well as required operating clearances.
Improve energy efficiency. Data center investments that reduce electricity usage, such as elimination of additional chillers and installation of more equipment outdoors (in turn reducing the electricity needed to air-condition indoor spaces), will clearly reduce carbon-emissions associated with electricity generated by fossil-fuel sources. Modern UPS systems-which are normally offline-also offer efficiency of up to 99%, providing further energy savings.
In the long term, however, a modern, intelligent grid remains the ultimate goal. It would provide major benefits not only for data centers, but for the nation as a whole. The ways in which a smart grid would address data center concerns also highlight how a modern grid can benefit us all:
Improved power reliability. A self-healing smart grid can respond automatically to power disruptions, isolating damaged sections of the utility grid and connecting loads on undamaged parts of the system to alternate power supplies. In this manner, a self-healing grid can reduce the need for data centers to use dual utility sources, because a self-healing grid inherently does this already. Further, with a smart grid providing back-up power sources for data centers, the data centers could reduce use of on-site back-up diesel generators, which are costly and generate additional carbon emissions.
Increased energy efficiency and reduced costs. Smart-grid technologies allow utilities that serve data centers to improve energy efficiency, which can result in lower costs for all served customers, including data centers. Volt/var optimization technology reduces the amount of electricity that is lost in distribution, providing hard cost savings. This technology, along with other smart-grid solutions, like energy storage, can provide further benefit by shaving peak loads, which are by far the most costly for utilities to serve.
Reduced environmental impact. Smart-grid technology that increases energy efficiency and reduces peak loads (which are typically served by less efficient fossil-fuel-fired plants) will reduce the carbon emissions associated with serving a data center. A modern grid can also facilitate greater use of renewable energy resources. Smart-grid technology protects grid reliability against the impact of intermittent renewable energy resources like wind and solar energy, and it can also manage the two-way power flows associated with distributed renewable energy resources. Stored energy resources can also ensure wind and solar energy are available to meet demand..
This electric power infrastructure is in urgent need of an overhaul to better meet the power demands of data centers and our digital economy. Adoption of some smart-grid technologies is growing, but a complete grid overhaul is years away. For data centers, new technologies and design approaches can realize cost savings today while reducing the impact of their operations on the environment. These approaches help provide a stopgap as the U.S. works to revitalize critical electrical infrastructure.
Troy Miller is a Business Development and Marketing Manager in the Power Quality Products Division at S&C Electric Company. He has over 21 years of experience in the Power Engineering industry. Miller has a vast history in the application and implementation of all aspects of power electronics and power quality. Miller is a speaker at industry events for new product introductions and economic benefit analysis. He is currently responsible for Power Quality activities for S&C. These include Energy Storage, VAR compensation and Uninterruptible Power Systems. Miller holds a Bachelor of Science degree in electrical engineering from the Milwaukee School of Engineering.
