Greening IT with quantifiable energy efficiency monitoring

Under the premise that you cannot save money until you know where you are spending it, Telstra, a large UK based IT co-location, private space and managed service provider, wanted to break down their overall electrical energy costs into distinct usage areas with individual measured values. Much like an old fashioned phone bill without the itemised calls, they had overall power consumption information but nothing at a granular level.

Having identified where efficiencies were low and energy was being wasted, the objectives were to assess if both costs and power usage could be reduced, energy efficiency improved and also adherence to the CRC scheme. In particular, they wanted to know whether a more energy efficient solution could provide a fast return on investment (ROI) and demonstrate ‘greener’ operations to its many corporate clients and key stakeholders. Plus recovered energy waste could also be sold on to new clients without the need for substantial investments in new equipment.

The Problem
Cooled supply air from the open floor grilles was freely mixing with the hot air exhaust from the IT servers. This resulted in the return air temperature to the Computer Room Air Conditioning (CRAC) being much lower than the unit was designed for. A CRAC is sized upon its ability to take an amount of heat (kW) out of a space at an agreed return air temperature. With the air mixing this temperature was far lower than it should have been. As a result a 50kW CRAC could only handle 15kW. In reality, more CRAC units than required were operating at full capacity, to keep the space cool.

The Solution
Separation of the inlet and exhaust air was required and a cold aisle containment system was installed.  Schneider Electric StruxureWare energy monitoring software was used to verify the improvements in cooling and subsequent energy efficiency. It also provided the detailed granular data that ultimately enabled cost savings with an ROI in less than two years. This provided the client with an on-going environmental monitoring centre. Recommendations were built on quantifiable statistics with data collated over monthly periods that provided comparisons before, during and after the system implementation. 103 separate temperature and humidity sensors were monitored within the hot and cold aisle as well as the CRAC unit supply and return temperatures plus relative humidity. PowerLogic power metering was used on the DX CRAC units and APC by Schneider Electric in-line meters used on the chilled water CRAC units. Following the system reconfiguration, the granular power consumption data proved system that the system was delivering the same level of service but at a much reduced cost. This formed the basis of a business case for further roll-outs across the site.

Results
For the trial space alone energy savings of over 38% of the initial IT load per annum. After the improvements, stable temperatures and humidity were maintained within the client’s Service Level Agreement (SLA). To achieve this, only six out of the original nine CRAC units were operated, nearly halving the installed base, while retaining N+ 1 system reliability.

Solution
The answer provided by on365 was to not only support improved energy efficiency, but to also provide the data to validate the ROI of the new equipment and installation programme. Once complete, the solution installation provided the client with an ongoing environmental monitoring centre and the complete separation of the cold aisle to prevent the hot and cold air mixing. The ‘before’ results were measured over an 8 day period, as were the ‘after’ results. 103 separate temperature and humidity sensors were monitored within the hot and cold aisle as well as the CRAC unit supply and return temperatures and humidity. PowerLogic power metering was used on the DX CRAC units and APC in-line meters used on the chilled water CRAC units. All were fed back into APC’s InfraStruXure Central product for review, which can be accessed by the customer and on365 teams, in addition to end user corporate customers for specific sections. The installation continues to be monitored using this set-up.

What did we deliver?
Telstra was interested in an approach to monitoring that could help improve data centre efficiency, simplify additional reporting requirements such as CRC EES compliance, and demonstrate the feasibility and business case for increasing the amount of server rack space that could be made available for customer use.

on365 was able to design and implement a service that enabled the customer to meet these needs through surveys, an installation monitoring service and assessments that would demonstrably reduce power consumption and overall costs. After an initial review and design of a tailor made assessment to monitor the current energy consumption and level of efficiency, on365 provided an energy monitoring and server rack reconfiguration that would enable cost savings with an ROI in less than two years. The recommendations were built on quantifiable statistics – accessible by the customer and its corporate clients. Data was collated during a server room infrastructure measurement period of over a month that provides comparisons before, during and after the system implementation. This is the first infrastructure analysis and product ROI of its kind. Following the system reconfiguration, the power consumption data proves system improvement and a business case for extra commercial rack space if required, in addition to support for continued monitoring. The investment in equipment and services for the energy efficiency monitoring and required alterations has delivered ROI in under two years.

Results
Collectively, on365 provided an energy monitoring and server rack reconfiguration that will enable proven savings of over 15 per cent of the initial 151kW IT load per annum and over 15 per cent of the ACU power demand for the same load, expecting a further five to eight per cent in savings next year – savings which are already being seen. This equates to 115 metric tonnes of carbon per annum based on grid electricity supply – the equivalent of two short haul return air flights for 130 people. After the alterations were made, the room still maintains stable temperatures within the client’s existing Service Level Agreement (SLA). ROI will be delivered in less than two years.

On completing the fit-out, the server environment only required the use of six out of the original nine CRAC units to maintain stable air and rack temperatures, a near halving of the installed base, while retaining N 1 system reliability. Overall, the customer now has the ability to closely monitor energy consumption, comply with SLAs in support of client operations, and tackle wider issues such as the CRC.