MELS Project Wrap Up

Rich Brown, David Culler, Stephen Dawson-Haggerty, Steven Lanzisera, Jay Taneja

Computer Science Division, University of California, BerkeleyEnvironmental Energy Technologies Division, Lawrence Berkeley National Lab

MELS: Miscellaneous Electric Loads

• Large, rigorous study of miscellaneous electric loads (mostly plugs)– Roughly 1/3 of building energy consumption– Difficult to study due to large number of small

consumers• Test methods to accurately describe

energy use of plug-in devices from individual device to whole building

September 13, 2011 LBNL EETD Seminar Series 2

DOE MELS => Appliance Energy

8/2/2011 CPS-PI-11 3

• 450 plug-load meters• 7 edge routers• 650m data points

Study Phases

Hardware (2009)

• Calibration• Safety

testing

Testing and Setup

• Software validation

Installation

• Device inventory• Stratified sampling

Operation (2011)

• Maintenance and debugging

September 13, 2011 LBNL EETD Seminar Series 4

System Architecture

September 13, 2011 LBNL EETD Seminar Series 5

• IPv6 tunnel from building network to data closet• Data in raw UDP• Configurable metering application

Multipoint Calibration

September 13, 2011 LBNL EETD Seminar Series 6

• Automated 20-point calibration on every meter• Generate a 3-part piecewise calibration

• 90th percentile error is <2 watts across devices

HYDRO Principles

• Maintain multiple next-hop options• Trickelize density-sensitve state propagation• Horizontally scalable with multiple LBRs

September 13, 2011 LBNL EETD Seminar Series 8

Emergent network dynamics

September 13, 2011 LBNL EETD Seminar Series 9

• Verify dynamics results on large scale– Link and device churn are prevalent

• Mean network degree is at least 16, diameter is about 4.5 hops

Exploration is ongoing

September 13, 2011 LBNL EETD Seminar Series 10

• Path length and router degree show clear diurnal and weekly variation

• Exploration of new potential candidate links is a continuous process

• With only “stable” links, diameter increases by factor of 2

ENERGY ANALYSIS

September 13, 2011 LBNL EETD Seminar Series 11

Can we identify when metered devices change over time?

12

From data, found change from older 20” LCD to new 24” LCD

Increase screen area 44%; reduce energy 33%.

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How Common is Computer-Display Power Management?

40 Hour Work Week

PM w/ breaks

Rarely power down monitor

• 83% of monitors use power management

• 15% use it with breaks for days at a time

• 2% do not use it

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What is the Distribution of LCD Computer Display Energy Use?

N=118

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How Common is Desktop Computer Power Management?

40 Hour Work Week

39% rarely powered down

44% managed

How Much of Whole Building is Plugs?

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All Building Electricity

40% of Building Electricity

3 month weekday average:March, April, May

Note: no cooling during these months

Projected based on full inventory and sample weights

All Plugs

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What Makes Up Bldg 90 Plugs Energy?

Computers50% of energy

Displays10% of energy

Task Lighting 7% Networking 6%Other 7%

Imaging10% of energy

Misc. HVAC10% of energy

Timer controlled plug strips?75 MWh/year30% of non-computer plug total 6% of building total

Computer power management?150 MWh/year60% of computer total 12% of building total

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Building 90 Device Inventory & Energy

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Findings and Next Steps

• Bldg 90 network demonstrated large-scale, end-to-end WSN and collected a lot of useful data– IT equipment should be focus of office energy management

programs– Using data for LBNL-wide plug-load management

• Inventory and meter installation are labor-intensive– Exploring using public (homeowner & building occupant)

participation for data collection– Integrate metering & communications into products

• Robust sensor network needs more engineering– ? Evaluate commercial products now available

• Electricity only part of buildings energy problem– Developing low-cost WSN for gas and water metering

QUESTIONS

September 13, 2011 LBNL EETD Seminar Series 20