Special Focus
On Power Save Mode
Considering the inadequate power availability in the country, a few solutions adopted at both the active and passive infrastructure levels can help organizations address energy woes
By Harshal Kallyanpur
Power is inarguably the most important resource for a data center. As the infrastructure gets into sprawl mode, there is a corresponding increase in the need for highly available and efficient power supply. On the other hand, companies are also hankering for reduction in energy consumption and its costs, while ensuring maximum business uptime. Such a scenario calls for efficient power conditioning solutions. Vendors hence are looking to capitalize on this opportunity by offering some promising power management solutions.
Power hungry
Over the past few years, IT infrastructure in India has grown exponentially. Major companies are setting up their operation centers in the country. This has led to an increase in the number of server farms and data centers.
With the growth in infrastructure comes an increase in demand for power. But despite having the technology to set up a high-quality, next-generation data center, most organizations hit a road block when it comes to powering these data centers. The gap between availability and requirement of the power is fast widening.
“The data center footprint in the country is expected to reach 5.1 million sq ft by 2012. The demand for power is expected to increase specifically in verticals such as BFSI and telecom,” notes Ravichandra GB, Country Sales Director, Enterprise Business, APC.
Feeling powerless
The biggest challenge faced by organizations in India, when setting up their IT infrastructure, is the shortage of power. Several parts of the country do not have power supply. Areas that do receive power supply have to contend with power outages which vary in frequency and duration.
“The power situation in India is grim. Some of the very large data centers, on an average, draw around 10MW of power which is almost as much as the amount consumed by 23,000 urban households or 17,520 cars,” informs Ravichandra of APC.
R Ravichandran, Director, Sales, Intel, South Asia agrees, “In India, grid power is highly limited both in terms of uninterrupted supply, and also in terms of pricing. Power here is priced relatively higher compared to other countries. The availability of power on demand is restricted and the provisioning process is highly cumbersome since the authorities have supply constraints.”
When faced with a situation like lack of uninterrupted power, organizations opt for captive power supply. However, the cost of owning a captive power source poses a major challenge since this requires additional investments. Further, the fuel required to run the generators has monetary as well as environmental implications.
“A 10,000 sq ft data center would require around 2MW of power depending upon its architecture. In an area where a public distribution network is not available, the data center requires its own captive power supply. While the average cost of sourcing power from Electricity Board is around Rs 5 to Rs 6 per unit, the cost of generating the same amount of power is around Rs 11,” explains Venkat Rao, Country Manager, Medium and Large UPS systems, Emerson Network Power.
Saji Thoppil, GM, Platform Practice, Wipro Infotech, mirrors this view. Thoppil explains that depending upon the type of generator used, captive power costs range anywhere between Rs 10 to Rs 25 per unit. Even with the most efficient generator and an outage of around two hours, this generation cost is still around Rs 8 per unit.
Ravichandran of Intel says that while inadequate availability of power necessitates alternate power provisioning (via generators which add to the cost), the ambient temperature across most sites is not favorable and leads to increased cooling requirements.
What compounds the problem are inefficiencies present in data centers built on older design principles. Such data centers do not have any instrumentation to continuously track Power Usage Effectiveness (PUE) and Data Center Efficiency (DCE).
Vendors estimate that almost 50 percent of the total power consumed by a data center is drawn by the actual IT infrastructure, while the remaining amount is used to power the premise and the cooling systems.
If this IT infrastructure is inefficient in terms of performance and energy consumption, the overall data center power consumption and cooling requirements automatically go up resulting in energy wastage and higher energy costs. This situation is further aggravated with the lack of inefficient power supply and cooling systems.
Deepak Sharma, GM, Electrical Group, Saarc and South-East Asia, Eaton, speaks about Eaton’s UPS offerings, which the company claims, offer a smaller UPS footprint, thereby reducing space requirements. Explaining the need for such system, he says, “A UPS system offering a Thermal Harmonic Distortion (THD) range of 3 percent is considerably efficient. A generator with a higher THD range results in higher generator sizing. This also leads to an increase in space requirements.”
On the link between efficient power systems and cooling, Sharma says, “Lower the efficiency of the system, higher is the heat generated. This requires additional cooling to keep the systems running at optimum temperatures. The need for additional cooling in turn leads to an additional increase in power consumption to run these cooling systems.”
Ravichandra of APC further explains, “Traditionally, the approach has been to overprovision resources based on estimations of future requirements. This, in turn, requires oversized power and cooling systems to run this oversized infrastructure. For example, assuming that in six years its power requirements will grow to 20kW, an organization provisions for the corresponding power supply and cooling systems. However, it initially consumes only 2kW while the rest is wasted.”
APC offers a Web-based solution which allows organizations to calculate their IT infrastructure requirements and the precise amount of power required per rack, thereby enabling them to provision for their power requirements accordingly.
The intelligence of power
Having realized the need to save on power, vendors with offerings across all layers of IT infrastructure are working towards creating products and solutions which are highly power efficient. For instance, processor vendors such as Intel and AMD are now offering processors which are not only faster in terms of performance, but also have lower energy consumption and cooling requirements.
Explains Arvind Chandrasekar, GM, Business Development, AMD India, “The processor consumes around 20 to 30 percent of the total power drawn by the infrastructure. The rest is consumed by storage and other components. The design element of a processor matters when trying to bring down this consumption level.”
AMD has developed processors with features that not only minimize inter-processor communication, but also shut down portions of the processor when not in use.
“For operations that require higher memory throughput but lesser compute power, processors can be powered down and for those requiring high compute but less memory, memories can be shut down. We can also throttle cores independently to run only as much in number as required,” adds Chandrasekar.
Intel also offers several power-saving features. For instance, its Xeon 5500 platform features integrated power technologies such as integrated power gates which allow power control of each CPU core—enabling idle cores to go to near zero power independently and reducing latency during transitions between power states. The platform also offers new power management capabilities on memory and I/O.
Vendors offering power management solutions also suggest approaches that can help save power and costs.
“If you look at the ratio of the use of active power to passive power, for every watt saved at the server level, 2.84W of power can be saved at the entire data center level. With virtualization and high density servers, 100kW can be saved for a server farm consuming 1MW. This amounts to a total power savings of 284kW, which is almost 28 percent for a data center,” explains Rao of Emerson.
While Rao is happy about the effort to save power, he believes that these savings can be further maximized with an efficient power supply solution. Solutions such as intelligent racks and servers can be powered down when not in use and this power can be redirected towards cooling or powering other systems.
Emerson offers UPS, active conditioning systems and other power management solutions which the company claims can take efficiency levels up to 97 percent. “Every 1kW of power saved results in savings of $1,000 a year,” estimates Rao.
Companies such as Emerson Network Power, Eaton and APC also offer power supply and management solutions that allow organizations to scale up their power requirements dynamically without any downtime. For example, in the case of blade UPS, if the power requirements increase, another blade can be added, without having to power down the system.
Other systems offer redundant power supplies such as dual bus power wherein the secondary line kicks in as the primary line goes down thus preventing downtime.
Having an efficient IT infrastructure not only reduces power consumption, but also brings down cooling requirements which, in turn, reduce the amount of power needed to cool a data center. But it is also necessary to have an intelligent cooling system which can offer optimum cooling while keeping the power consumption low. Instead of cooling the entire data center, most vendors suggest an approach which involves concentrating on specific areas of the server that generate heat.
One approach includes the hot aisle-cold aisle system in which cold air is blown on to the server and the hot air generated by the server is pulled into a sealed chamber. This hot air is either thrown out or back into the data center as cold air, thereby recycling it.
Another approach includes liquid-based cooling wherein air at normal temperature is blown on to chiller pipes which have cold water flowing through them. This air is then let out on to the servers as cold air, thereby offering maximum cooling and minimum power consumption.
“Conventional approaches include increasing the cooling power of the entire data center just to cool down hotspots created due to blade deployments. Approaches such as hot aisle-cold aisle cooling can replace such methods thereby preventing excessive consumption of cooling and power,” says Thoppil.
He also cites the instance of a data center set up in the northern part of India, that uses geothermal cooling wherein air is used to cool water in chiller pipes.
The future looks green
While companies currently adopt environment-friendly methods to reduce power consumption and ensure optimum cooling for their data center infrastructure, they are also evaluating the viability of using other power generation methods such as solar power energy. However, vendors believe it will take time for such technologies to find massive adoption due to the high cost of solar panels and associated hardware.
Companies have been adopting leaner IT systems based on blades, virtualization and other consolidation technologies. The use of efficient power and cooling systems can not only help companies reduce costs, but also help companies to contribute to the environment. But above all, it can help companies address power issues in a more cost-effective manner than before. |