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Data Centre Master Class. Improving Energy Efficiency in the Data Centre Saving Money without loss of IT performance. AGENDA. Electricity Supply Background Cost to Operate a Typical Data Centre Where does all the energy go? Some quick fixes Right Size. AGENDA. Efficient Design
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Data Centre Master Class Improving Energy Efficiency in the Data Centre Saving Money without loss of IT performance
AGENDA • Electricity Supply Background • Cost to Operate a Typical Data Centre • Where does all the energy go? • Some quick fixes • Right Size
AGENDA • Efficient Design • Cold Aisle v Hot Aisle which is the most efficient? • Free cooling – is it free? • Water or DX? • DCiE • Questions
UK Supply 2007 • 400,159 GWh produced • 31,813 GWh to Energy Industry • 26,401 GWh in transmission losses • 117,733 GWh to Industry • 8,254 GWh to transport • 100,908 GWh to Service Industry • 115,050 GWh to Domestic Users Source Digest of UK Energy Statistics
Data Centre Demand • Estimate that DC’s use 3% in total • Equates to 12,000 GWh • Circa. £1 billion in costs • Excludes desktops and distributed items • Excludes standing charge • Excludes other fees
Data Centre Demand • Electricity costs for an average large user is £0.07/kWh + £0.00456/kWh climate change levy • IBM found that the better performing DC’s were spending 43% of energy costs to supply the actual IT load • 57% to power the support equipment
Data Centre Demand • Example for a 200kW IT load • Support load is 265kW • Total bill circa. £303.5K • £130.5K to IT • £173K to support
Data Centre Demand • Same example for a 200kW IT load at worst • Support load is 466kW with split of 30/70 • Total bill circa. £435K • £130.5K to IT • £304.5K to support
Data Centre Demand • Same example for a 200kW IT load at today’s target of 70/30 • Support load is 85kW • Total bill circa. £186.5K • £130.5K to IT • £56K to support
Data Centre Demand • Saving circa £250K in the worst DC’s • £117K in the better DC’s • £1.25M in 5 years • £600K in 5 years
Data Centre Demand • Recent studies showed that most respondents cannot answer the question . . • How energy efficient is your data centre? • 80% had never conducted an energy audit • 77% had never seen their electricity bill
Gas Guzzler or Tree Hugger? • Where does all the waste go? • Useful energy is consumed by the IT equipment • The rest is used to operate equipment that supports or allows us to use and manage the IT equipment
Where does it all go? • Take this 60W light bulb • What does it do in our Data Centre? • It provides light so that we can see and maintain our assets • It costs a kWh every 16 hours or so • It gives off 60W of heat • All in all it costs £60/year to run
Where does it all go? • £60 is not much • 250m² technical space amounts to £7500 per annum at 30W/m² • Most of us leave the lighting on 24/7 • Fit PIR sensors • Zone the lighting • Very low cost against savings • Little risk to DC
Where does it all go? • Power path to IT • UPS • PDU’s • Cabling • ATS
Where does it all go? • Power path to support equipment • Cooling • Lights • Fire • Security • Generator • Switchgear
Some quick fixes • Close holes in the raised floor • Close holes in the racks • De-clutter the raised floor void • Fit baffles • Hot and cold aisles • Fit air distribution • Can gain 6% savings
Some quick fixes • Raise the ACU set-point • Stop the humidification de-humidification cycle • Remove UPS that are fed by UPS • Have the ACU checked and balanced • Don’t just keep adding ACU
Right Size Equipment • UPS operating at low load percentage? • 150kVA UPS running at 32kW (25%) • Efficiency = 76% • Power draw = 40kW • £5256 per annum to run losses • New UPS = 96% efficiency • £840 per annum to run • 1.28kW heat loss versus 8kW
Efficient Design • UPS for A and B supplies • Two UPS each running at 50% load • Efficiency circa. 88% 2 x 24kW losses
5 x 6kW losses = 30kW 18kW saving or £11,826/annum
Efficient Design • Cooling • Biggest Problem is Air Mixing and bypass (short circuit) • Hot and Cold • Heat Energy Direction • You and the radiator • You and the under-floor heating • You and the space suit
Efficient Design • 35ºC air return = 17.3kW • 32ºC air return = 13.8kW • 29ºC air return = 9.7kW • 26ºC air return = 5.6kW • Mixing and air bypass are very expensive
Efficient Design • Variable speed control fans • Place the ACU and load as close together as possible • Contain hot and cold air and keep them separate
Cold Aisle v Hot Aisle • Which is the most efficient?
Cold Aisle Containment 17°C 11°C AIR AIR 30°C 31°C AIR ∞ 24°C 29°C 32°C 32°C 20°C AIR
Hot Aisle Containment 20°C 14°C AIR 24°C 24°C 24°C AIR 32°C AIR 23°C 23°C
CACS v HACS • 18 x InRow RC • Possible air flow 210,888 m³/h • Required air flow = 108,900 m³/h (52%) • Power draw =7.4 kW • 365 x 24 x 7.4 x 0.075 = £4,862 • 8 x CRAC (Uniflair 4300A) • Possible air flow 192,384 m³/h • Required air flow = 136,125 m³/h (71%) • Power draw =11.3 kW • 365 x 24 x 11.3 x 0.075 = £7,425 • Saving HACS vs. CACS = £2,563 per annum
PLUS other benefits • Reduced usage of free cooling when implementing CACS efficiency ↓ • Extra cost for extra height of raised floor (effect might be minimal, though) PLUS some operational reasons • Predictability of raised floor plenum is critical • No standalone equipment can be placed in CACS room • Warm air volume: CACS: 444 m3 HACS: 113m3 • Cold air volume CACS: 180 m3 HACS: 367m3
More free cooling available with HACS • Facts are: • CW return temperature has to be 3°C colder than supply air temperature • CW supply temperature has to be 3°C warmer than outside air temperature to enable 100% free cooling • Cold air supply of down flow units supporting raised floor cooling have to be 4°C colder than the expected server inlet temperature • Cold air supply of HACS units have to be only 1°C colder than expected server inlet temperature • So, we calculate back from server supply temperature to be 24°C For every day of free cooling we save another £290 on the electrical bill! Savings HACS v CACS (50 days of free cooling more) = £14,500 per annum
Case Study HACS v CACS Summary - Cost Saving Annual saving indoor units: £2,563 per annum Annual saving additional free cooling £14,500 per annum Total benefit for HACS over CACS £17,063 per annum Considering a life time of 10 years Savings add up to £170,630 CAPEX benefit for CACS over HACS £50,000 Break even after 2.9 years
Free Cooling – is it free? • It is the ability to use low external ambient temperature to your advantage • For example at 1ºC external ambient on a chiller you can achieve 100% use of the low ambient and have no mechanical cooling (refrigerant) • Fans and pumps still run
Free Cooling – is it free? • For example at 7ºC external ambient on a chiller you can achieve 50% use of the low ambient and have 50% of mechanical cooling (refrigerant) • In the Midlands, the mean ambient is 9ºC per annum so we can calculate a mix of 40/60 for the whole year • Major savings are experienced
Water or DX? • Water is 35 times more efficient than air • DX plant is generally cheaper • Long distances between CRACS and outside space limits DX installation • Lower running costs for water with free cooling options • Similar maintenance costs • DX = SMALL - Water = HIGH
DCiEData Centre infrastructure Efficiency • DCiE = Main IT Energy Consumption x 100% Total IT Facility Energy Consumption • The higher the figure the more efficient the Data Centre • Follows standard engineering efficiency metrics for other electrical plant • PUE (Power Utilisation Effectiveness) is 1/DCiE
DCiEData Centre infrastructure Efficiency • Difficult to measure • Has to be done over time to allow for equipment cycling, variations in IT workload etc • Does not measure how effective the IT equipment is being used • Is recognised by US Environmental Protection Agency, EU COC and Green Grid
DCiEWhere can you start? • No real industry benchmarks or league tables • You can’t manage what you don’t measure • Much harder to implement with existing installations • Hire expertise and equipment for sampling or longer term assessment • Help with improvement and ROI including timescales
Why look at your DCiE • First stage to securing EU Code of Conduct and implementing COC best practices • Reduce long term operational costs • Market ‘Green Initiatives’ for your business • Mandatory for Government Establishments? • Impending legislation and taxes for climate change levy? • Future energy costs?
In Summary • What’s good for your business is good for our environment • Get the best from what you have • The most efficient Data Centre is the one that does not have to be built • Becoming a Tree Hugger makes good economical sense • Green is definitely LEAN