WattDepot is a software ecosystem developed for the collection, storage, analysis, and visualization of energy data, addressing the need for effective energy use behavior research. It features a flexible architecture that accommodates various sensors and meters, allowing data collection via HTTP and supporting visualization through diverse platforms. The system is open-source and provides capabilities such as data aggregation, interpolation, and real-time monitoring through accessible APIs.

1. WattDepot: A software ecosystem for energy data collection, storage, analysis, and visualization Robert S. Brewer, Philip M. Johnson Collaborative Software Development Laboratory Information and Computer Sciences Dept University of Hawaii at Manoa http://csdl.ics.hawaii.edu/

2. 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

3. Architecture Devices Meters WattDepot Sensors WattDepot Server WattDepot Clients HTTP HTTP

4. 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

5. 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

6. 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

7. Servers: Timestamp Problem Unsynchronized clocks cause problems Naïve data comparison difficult

8. Servers: Data Interpolation Data resampling at arbitrary times Linearly interpolate between data points Solves timestamp problem for virtual sources

9. 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

10. Clients: Heatmap and Gauge

11. Clients: GeoMap

12. System Availability Hosted on Google Code http://wattdepot.googlecode.com/ Open source under New BSD license Discussion list http://groups.google.com/group/wattdepot-users