(1) wattdepot: a software ecosystem for energy data collection, storage, analysis, and visualization...

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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