The Google PowerMeter API will allow device manufacturers to build home energy monitoring devices that work with Google PowerMeter. Google PowerMeter allows customers to access their power consumption data through a secure, web-based iGoogle gadget. The data can be published immediately (low latency for the consumer) but is currently limited to uploads at 10 minute intervals.
Google is launching this API to help build the ecosystem of innovative developers working towards making energy information more widely available to consumers. The API provides read and write access to its entities and events through RESTful calls and responses are formatted in XML.