The Home Energy Scoring modeling application programming interface calls were developed using software developers and subject matter experts from within Lawrence Berkeley National Laboratory's Environmental Energy Technologies Division. Authorization and access, label generation, and reporting APIs have been updated and expanded by Pacific Northwest National Laboratory. The National Renewable Energy Laboratory assisted by conducting independent accuracy assessments.
The Home Energy Saver API is written in PHP in a Model-View-Controller architecture, except the DOE-2 simulation software written in Fortran. A series of APIs connects the graphical user interface to the back-end infrastructure.
Session data are held in a MySQL database.
The entire HEScore API system is developed and hosted in the Amazon EC2 computing environment.
By hosting the infrastructure in a cloud-computing environment, the code and data are continuously backed up and distributed in a highly disaster-resilient manner. In addition, the databases are backed up to another cloud region, retaining weekly copies for 30 days and the first backup of the month thereafter.