IEP MODEL OVERVIEW

The IEP Model defines a rich set of object data models within the solar and energy efficiency domains. It's intent is to provide a "common language" for software applications within these domains so that they may more easily integrate services with one another. It lowers the risk associated with building software integrations, and enables an ecosystem of complementary software applications to work together, lowering cost for the industry as a whole.

XML and JSON

The models are defined using a set of extensible markup language (XML) schema documents. Despite the growing preference of developers to use JavaScript Object Notation (JSON) in their applications, the design team made the conscious decision to take advantage of XML standards for defining schemas, because JSON lacks similar schema definition standardization and associated authoring tools. Despite being defined in XML schemas, the schemas are intended to be used to define JSON structures as well. The design team was careful to structure the XML elements as they would be using JSON, and to avoid use of XML features that are not supported by JSON. Therefore, the structure of all the XML schema elements can be represented in JSON as easily as they are in XML. The model's construction is intended to be modular.

Using the IEP Model

The IEP Model is intended to help software applications within the solar and energy efficiency domains become more standardized in their data definitions. The IEP Model is purely a set of data definitions. The IEP Model does not prescribe specific software functionality nor associated application programming interfaces (APIs).

When building applications, developers can use the IEP Model to inform their application's internal data models. When importing or exporting data from applications, applications can output the data using IEP Model structures. And of course, Software vendors are encouraged to build APIs that leverage IEP Model structured data in request and response payloads.

Growing IEP Model Ecosystem

By "teaching your application to speak IEP" you can more easily participate in the growing ecosystem of software applications transferring data among one another using IEP defined data.

IEP Model objects can be recombined in new vendor specific schemas as needed. Vendors providing services using IEP Model structured data can be listed on the IEP Model website, along with descriptions of their services and links (contact the IEP Model team to be added).

About the Schemas

• Common - A set of basic elements/objects that are used across many other schemas.
• CommonElectrical - A set of electrical elements/objects that are common to multiple types of electrical systems. For example, wire, conduit, circuit connections, basic electrical components (junction boxes, disconnects, circuit breakers, etc).
• CommonSolar - A set of elements/objects that are common to various types of solar energy systems, such as PV modules, inverters, array areas, DC strings, PV arrays, shading, etc.
• PvSystem - A set of elements and detailed structures for defining an entire PV system. Use only the parts of the structure necessary to define the level of PV system description needed for your use case.
• Participant - A set of elements/objects and associated structure for defining an entity that participates in a defined project. Participants may be organizations or individuals. Participants have contacts and role(s) with respect to a project. Examples can be customers, sub-contractors, etc.
• Building - A set of elements/objects and associated structure for defining a building. Most energy projects are associated with buildings and the interface of the defined systems with the building can be very important. 
• UtilityService - A set of elements/objects and associated structure for defining a utility service. Utility services and associated energy consumption are often key attributes for evaluation of energy projects.
• Project - A high level schema that incorporates many objects from schemas across the IEP Model. It incorporates an overall description of an energy project that may include multiple aspects. 
• Other Schemas - The 1.0 version of the IEP Model includes many more schemas that support energy efficiency measures in projects. The DOE SunShot program was instrumental in funding the development of the 2.0 schema, however, its development was limited to support for photovoltaic projects. At this time the other schemas have not been updated to reflect JSON consistency.