new ways of working: linking energy consumption to people
TRANSCRIPT
New Ways of Working: Linking Energy Consumption to People
Ken Dooley World Sustainable Buildings Conference October 2011
Behaviour change
Positive behaviour change:
• Provide comparision with ones peers
• All parties should be compared fairly
• A more just metric than kWh/m2 is required
Compare performance of:
• Buildings
• Departments
• People
Change !?!
World Sustainable Buildings Conference October 2011
Incentive schemes
Residential building example:
• A block of similar 2 bedroom apartments
• Incentive scheme to reduce energy
• Reward given to the lowest energy consumption over a period of time
World Sustainable Buildings Conference October 2011
Building energy breakdown
Directly related to building geometry
• Heating
• Lighting
Directly related to people only
• Equipment electricity
• Ventilation (fresh air)
Directly related to building geometry and people
• Cooling
World Sustainable Buildings Conference October 2011
Relating energy to area
”If you can’t measure it, you can’t manage it”
kWh/m2
• Design phase: good measurement of physical building properties
• Poor insight as to how buildings are used during occupancy phase
• Misleading when evaluating operating costs
World Sustainable Buildings Conference October 2011
An alternative metric
Wh/m2h, annual energy consumption per area per occupied hours
Where:
• kWh1/m2 is the annual energy consumption
• h2 known as total person hours, is the total number of hours that all occupants have spent in the building during the year in question
World Sustainable Buildings Conference October 2011
Occupation density
Energy directly related to people is not considered by area metrics
Average occupation density in UK offices is 11.8m2 per workspace1
• 77% of workspaces between 8m2 & 13m2 per workspace
• Using kWh/m2, 13m2 per ws. will seem more energy efficient than 8m2 per ws.
Productivity and comfort must be considered, however, it does not seem prudent to utilise an energy metric that encourages large amounts of area per person
1: Occupier Density Study Summary Report, British Council for Offices, June 2009
Source: Fooducate.com
World Sustainable Buildings Conference October 2011
Case study
•Simulated case study: office building in Helsinki
• Area: 4650m2
• Hours of occupancy 08:00 – 17:00 (9 hours)
Similar day lengths, different occupation densities
Results
• kWh/m2: case C consumes the least
• kWh/person or Wh/m2h: case A consumes the least
(C consumes 44% more than A)
Case A B C
Population density (m2/person) 8 10 12
Number of occupants 500 400 332
Energy consumption (kWh/m2) 102 99 98
Energy consumption (kWh/person) 951 1150 1368
Energy consumption (Wh/m2h) 0.087 0.105 0.126
World Sustainable Buildings Conference October 2011
Hours of occupation
Not considered by area metrics
• Comparison of two similar healthcare buildings
• Hospital ”A” open 24 hrs / Hospital ”B” open 12 hrs
• kWh/m2 does not provide an allowance for the longer day of ”A”
• Thus ”A” has a higher energy consumption per m2 and seems less energy efficient
By not providing an allowance for the number of hours a day a building is operated kWh/m2 offers a direct benefit to buildings that have shorter working days
World Sustainable Buildings Conference October 2011
Case study
•Simulated case study: office building in Helsinki
• Area: 4650m2
• Population density 10m2 / person
Similar occupation densities, different day lengths
Results
• kWh/m2: case F consumes the least
• kWh/person or Wh/m2h: case D consumes the least
(F consumes 45% more than D)
Case D E F
Working hours per day (h) 12 9 6
Hours of occupancy 08 - 20 08 - 17 09 - 15
Energy consumption (kWh/m2) 115 99 84
Energy consumption (kWh/person) 1330 1150 981
Energy consumption (Wh/m2h) 0.092 0.105 0.134
World Sustainable Buildings Conference October 2011
Monitoring occupancy
Access control system that supports the measurement of total person hours
Employees log in/out of the building via:
• Electronic time clock
• Smart phone
• Personal computer
• Real time location tags
A reporting system that defines location as a set of routines:
• Routine 1: out of the building
• Routine 2: in the building
Building
IN OUT
World Sustainable Buildings Conference October 2011
Concept development
World Sustainable Buildings Conference October 2011
Behaviour Change
Motivation / Incentives
Measure per Person
Technology
Smart Grid
Advanced Controls
Measure Wh/m2h
Advanced Presence Detection
Virtual Energy Prices
Advanced presence detection
Use presence knowledge to control energy consuming systems
Average office utilisation is typically only 45%
• 55% of the desks are empty at any one time Measuring the Benefits of Agility at Work, Regus, May 2011
Define location as a set of routines:
• Routine 1: out of the building
• Routine 2: in the building
• Subroutine A: at workspace (default)
• Subroutine B: in a meeting
• Subroutine C: at lunch
IN OUT
IN
Building
IN OUT OUT
World Sustainable Buildings Conference October 2011
Use presence to control
Use presence knowledge to control:
• Shut down an individual’s workspace if they leave the building
• Set to standby an individual’s workspace if they are in a meeting / at lunch
• Shut down a lighting / ventilation zone if all of the occupants are out of the office
Presence Detected
Desk Lighting ON
Common Lighting ON
Equipment ON
Ventilation 100 %
Heating 21oC
Cooling 25oC
Example zone control modes:
World Sustainable Buildings Conference October 2011
Use presence to control
Use presence knowledge to control:
• Shut down an individual’s workspace if they leave the building
• Set to standby an individual’s workspace if they are in a meeting / at lunch
• Shut down a lighting / ventilation zone if all of the occupants are out of the office
Presence Detected
No presence 15 mins
Desk Lighting ON OFF
Common Lighting ON ON
Equipment ON STAND BY
Ventilation 100 % 100 %
Heating 21oC 21oC
Cooling 25oC 25oC
Example zone control modes:
World Sustainable Buildings Conference October 2011
Use presence to control
Use presence knowledge to control:
• Shut down an individual’s workspace if they leave the building
• Set to standby an individual’s workspace if they are in a meeting / at lunch
• Shut down a lighting / ventilation zone if all of the occupants are out of the office
Presence Detected
No presence 15 mins
No presence 1 hour
Desk Lighting ON OFF OFF
Common Lighting ON ON OFF
Equipment ON STAND BY STAND BY
Ventilation 100 % 100 % 50 %
Heating 21oC 21oC 20oC
Cooling 25oC 25oC 27oC
Example zone control modes:
World Sustainable Buildings Conference October 2011
Use presence to control
Use presence knowledge to control:
• Shut down an individual’s workspace if they leave the building
• Set to standby an individual’s workspace if they are in a meeting / at lunch
• Shut down a lighting / ventilation zone if all of the occupants are out of the office
Presence Detected
No presence 15 mins
No presence 1 hour
No presence 2 hours
Desk Lighting ON OFF OFF OFF
Common Lighting ON ON OFF OFF
Equipment ON STAND BY STAND BY OFF
Ventilation 100 % 100 % 50 % Night time mode
Heating 21oC 21oC 20oC Night time mode
Cooling 25oC 25oC 27oC Night time mode
Example zone control modes:
World Sustainable Buildings Conference October 2011
Next Steps
• Pilot projects
• Today’s innovation and transparency: real time energy is reported
• Tomorrow’s innovation and transparency: Wh/m2h
• An alternative route to measure energy for
• Building regulations
• Energy certificates
• Limitations
• Different building types
• Wh/m2h works best for private buildings when there is a security barrier
World Sustainable Buildings Conference October 2011
Summary
An alternative energy consumption metric:
• Wh/m2h = kWh/m2 ÷ total person hours
• Enabling a fairer comparison of consumption to encourage positive change
• Does not punish buildings for incorporating an efficient occupation density
• Does not punish buildings for incorporating a longer working day
World Sustainable Buildings Conference October 2011
Thank you!
Ken Dooley Sustainability Group Manager Olof Granlund Oy Helsinki Twitter: @sustaingranlund Email: [email protected]
World Sustainable Buildings Conference October 2011