Transcript Data Centre Masterclasses

Data Centre Master Class
Improving Energy Efficiency in the
Data Centre
Saving Money without loss of IT
performance
AGENDA
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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
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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
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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
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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
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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?
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Power path to IT
UPS
PDU’s
Cabling
ATS
Where does it all go?
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Power path to support equipment
Cooling
Lights
Fire
Security
Generator
Switchgear
Some quick fixes
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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
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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%
400kVA
UPS
50% LOAD
EFF. 88%
200kVA
PSU
A
400kVA
UPS
50% LOAD
EFF. 88%
200kVA
PSU
B
2 x 24kW losses
80% LOAD
EFF. 94%
80% LOAD
EFF. 94%
80% LOAD
EFF. 94%
80% LOAD
EFF. 94%
80% LOAD
EFF. 94%
100kVA
UPS
100kVA
UPS
100kVA
UPS
100kVA
UPS
100kVA
UPS
40kVA
LOAD
A
40kVA
LOAD
B A
40kVA
LOAD
B A
40kVA
LOAD
B A
40kVA
LOAD
B A
40kVA
LOAD
B A
40kVA
LOAD
B A
40kVA
LOAD
B A
40kVA
LOAD
B A
40kVA
LOAD
B A
5 x 6kW losses = 30kW
18kW saving or £11,826/annum
B
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
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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
31°C
24°C
32°C
30°C
AIR
AIR
32°C
AIR
∞
29°C
20°C
AIR
Hot Aisle Containment
20°C
14°C
24°C
24°C
24°C
AIR
32°C
AIR
23°C
AIR
23°C
CACS
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• 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
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
•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
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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
Server Inlet
[°C]
Cold Air Supply
[°C]
CW
Return
[°C]
CW Supply
[°C]
Free Cooling
Temp [°C]
Days Possible
100%
HACS
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23
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14
11
210
CACS
24
20
17
11
8
160
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:
Annual saving additional free cooling
£2,563 per annum
£14,500 per annum
Total benefit for HACS over CACS
Considering a life time of 10 years
Savings add up to
£17,063 per annum
£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
DCiE
Data 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
DCiE
Data 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
DCiE
Where 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
Any Questions?