# Generation¶

## Solar Electric¶

HEScore allows for a single photovoltaic system to be included as of v2016. In HPXML, multiple PVSystem elements can be specified to represent the PV systems on the house. The translator combines multiple systems and generates the appropriate HEScore inputs as follows:

### Capacity Known¶

If each PVSystem has a MaxPowerOutput, this is true. If each PVSystem has a CollectorArea, this is false. Preference is given to known capacity if both are available. Either a MaxPowerOutput must be specified for every PVSystem or CollectorArea must be specified for every PVSystem.

### DC Capacity¶

If each PVSystem has a MaxPowerOutput, the system capacity is known. The system_capacity in HEScore is calculated by summing all the MaxPowerOutput elements in HPXML.

### Number of Panels¶

If MaxPowerOutput is missing from any PVSystem, CollectorArea is required on every PVSystem and the system capacity is not known. The number of panels is calculated by summing all the collector area, dividing by 17.6 sq.ft., and rounding to the nearest whole number.

### Year Installed¶

For each PVSystem the YearInverterManufactured and YearModulesManufactured element values are retrieved, and the greater of the two is assumed to be the year that system was installed. When there are multiple PVSystem elements, a capacity or area-weighted average of the assumed year installed is calculated and used.

### Panel Orientation (Azimuth)¶

For each PVSystem the ArrayAzimuth (degrees clockwise from north) is retrieved. If ArrayAzimuth is not available, ArrayOrientation (north, northwest, etc) is converted into an azimuth. A capacity or area-weighted average azimuth is calculated and converted into the nearest cardinal direction (north, northwest, etc) for submission into the array_azimuth HEScore input (which expects a direction, not a numeric azimuth).