Overview

WattDepot is an open source, RESTful web service that collects electricity data (such as current power utilization or cumulative power utilization) from meters and stores it in a database. The data can then be retrieved by other tools for visualization and analysis. It is designed to provide infrastructure for experimentation and development of "Smart Grid" applications.

WattDepot provides a unique combination of useful features:

• WattDepot is agnostic about the kinds of meters used to monitor energy production/consumption data, and whether the energy data is utility-scale or personal-scale. WattDepot implements a REST protocol for data transmission that can be used to implement clients for a wide variety of devices; the major constraint is that these devices need to have Internet access. WattDepot clients can be written in any language that supports the HTTP protocol. We provide a high-level client library for Java.

• WattDepot can represent aggregations of power sources. For example, a building might have multiple meters monitoring energy consumption, one per floor. WattDepot can represent the power consumed by individual floors, as well as an aggregate source representing the building as a whole. Aggregations can be nested, so that floors can be aggregated into buildings, buildings into neighborhoods, and neighborhoods into cities.

• WattDepot automatically performs data interpolation when necessary. For example, a meter might provide a snapshot of energy usage once per hour for a given device. Clients can request the power consumed by this device at any time instant, and WattDepot will automatically provide interpolation when the requested time does not match a time for which actual sensor data is available. This becomes particularly important and useful for aggregate power sources. For example, the meters on individual floors of a building will rarely send their data at exactly the same time instant, so providing an aggregate value for power consumed requires combining individual data values obtained at different times.

• WattDepot provides carbon intensity data as well as energy data. To understand the ecological impact of power, it is useful to know the amount of carbon released by a given energy generation source.

• WattDepot is architecturally decoupled from the underlying data storage technology. This supports experimentation with both traditional relational as well as NoSQL technologies, and facilitates scalability.

• Unlike hosted solutions like Google PowerMeter, WattDepot can be installed and run locally. This makes it useful for simulations, experimentation, and what-if scenarios in addition to real-time data collection.

• Also unlike Google PowerMeter, WattDepot is designed to support near-real time (sub-minute) feedback. Google PowerMeter restricts updates to ten minute intervals. Note that WattDepot is not currently designed to support sub-second feedback.

• WattDepot is open source and will remain freely available to the community.

Publications

Selected publications and technical reports regarding WattDepot and the systems built using it are available here.

Associated tools

WattDepot provides the architectural center of an ecosystem of tools for energy data collection, storage, analysis, and presentation. Some associated technology now under development includes:

Public servers

While you can download and run your own instance of WattDepot, the Collaborative Software Development Laboratory in the Department of Computer and Information Sciences at the University of Hawaii supports two public instances of WattDepot, one that collects live data from local meters on campus and in the community, and another that collects simulated data to support development and understanding of the system.

WattDepot server for simulated data. Note: the simulated server and visualizer are turned off for the foreseeable future

WattDepot server for live data. Note: the live data server and visualizer are turned off for the foreseeable future

WattDepot server for Kukui Cup data:

We invite you to become involved with the system. Please peruse our Wiki pages or join our mailing list.