Post on 25-Jun-2015
description
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WattDepot:A software ecosystem for
energy data collection, storage, analysis, and
visualization
Robert S. Brewer, Philip M. JohnsonCollaborative Software Development
Laboratory Information and Computer Sciences Dept
University of Hawaii at Manoahttp://csdl.ics.hawaii.edu/
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Motivation Research on changing energy use behaviors• Need to collect & analyze energy data
Requirements• Collect data from many meters• Sub-minute data collection• Easy to simulate sensor data• Internet-accessible repository• Visualization variety & flexibility• Open source
Could not find an existing solution• Developed WattDepot
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Architecture
Devices MetersWattDepotSensors
WattDepotServer
WattDepotClients
HTTP HTT
P
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Sensors Software to collect data• Interface to specific meters• Store data in server via HTTP
Designed for flexibility• Encapsulates vendor-specific code• Any platform or language• Just needs to output XML over HTTP
Current implementations• TED 5000 home energy meter• Veris power meters• Modbus/TCP meters
Sensors
Server
Clients
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Servers Central data repository• RESTful HTTP API• Pluggable back-end database• Data represented as XML or JSON• Devices represented as Sources
Server-side capabilities• Aggregation of sources (virtual sources)• Data interpolation
Sensors
Server
Clients
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Servers: Virtual Sources Virtual sources combine sub-sources• Maps real-world entities to system• Hierarchy can be multi-level
But meter clocks may not be synchronized
Saunders Hall
Floor 2 North
Saunders Hall
Floor 2 South
Saunders Hall
Floor 2
Saunders Hall
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Servers: Timestamp Problem Unsynchronized clocks cause problems• Naïve data comparison difficult
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Servers: Data Interpolation Data resampling at arbitrary times• Linearly interpolate between data points• Solves timestamp problem for virtual sources
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Clients Data extraction & visualization• Any platform or language• Using REST or Google Visualization APIs
Current implementations• Real-time monitors• Charts• Geographic visualizations• Android mobile application• All independent of data input source
Sensors
Server
Clients
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Clients: Heatmap and Gauge
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Clients: GeoMap
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Related Systems Pachube• Commercial hosted data storage• YouTube for sensor data• Limits on rate of data storage• Arbitrary data means no energy “smarts”
Google PowerMeter• Smart meter data storage & visualization• Data limited to 15 min intervals• Focus on single-family homes
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Our Application Dorm energy competition• 30 floor-level meters• Real-time data
Extensive competition web app• Customized goal-based visualizations
Google Spreadsheet intermediary• High performance “cloud cache”• Build higher-level data abstractions• Easy to prototype visualizations
Simulated energy data critical• Allows progress while meters are installed
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Dorm Energy Visualizations
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Future Directions Privacy• Sources currently public or private• Limited authentication support• All current applications use public data
Data aggregation• Needed when comparing private data
Sensors• Additional meter support
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System Availability Hosted on Google Code• http://code.google.com/p/wattdepot/• Open source under New BSD license
Discussion list• http://groups.google.com/group/wattdepot-users
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Q&A Ask away!
Contact: rbrewer@lava.net, johnson@hawaii.edu