SunMizer Design Support

SunMizer Design Guidelines

How It Works

SunMizer isolates the panel from the string and performs localized maximum power point tracking to extract maximum power from the panel. It independently adjusts the output current and voltage provided to the string to maximize the energy generated by the PV array.

PV System Design

SunMizer is installed below the module so that no additional roof or ground space is required. SunMizer uses MC3 (compatible with locking adapter) connectors so no new wiring is needed. Standard string inverter design practices should be followed including careful assessment of string voltage impacts as a result of shading.

Residential string inverters have a wide MPP voltage range, typically 50% or more of maximum. In addition, typical inverter MPP is robust in support of string-to-string voltage variability. However, when a fraction of the cell area is shaded, the voltage from that bypass diode area can be lost while the current is allowed to bypass the shaded area. SunMizer will help prevent bypass conditions however; string voltage drop as a result of shading should be considered when properly designing the PV system. For areas with extreme shading, requiring more than 30-50% deployment of SunMizer, (see SunMizer Deployment), a separate string inverter for each string is recommended.

SunMizer Deployment

SunMizer is recapturing energy that would have been lost to both the un-shaded panels and the shaded panels as described below. Payback is shortened when SunMizer is deployed on panels shaded for a longer duration and during peak sun-hours.

Deployment of SunMizer on panels shaded during peak sun-hours provides for the shortest payback. These panels are within (less than) the 2:1 ratio of object distance from the panel to object height from the plane of the panel. Early morning and late afternoon east/west horizon shading or minimal shading per California Energy Commission (CEC) guidelines involves multiple panels during non peak sun-hours. Payback is typically significantly longer for this degree of shading.

PV System Energy Production

Un-shaded Panels

Panels that are degraded (shaded) with SunMizer deployed will not impact the performance of the other panels in the string. Therefore, PV system energy production calculations can be based on 100% performance of the panels that are not shaded.

Shaded Panels

Panels with SunMizer deployed will recapture varying amounts of energy depending on the degree of shading, when the shading occurs and the duration of the shading event. As a rule of thumb, the average energy production from a shaded panel, for the duration of the shading event, with SunMizer deployed is typically 50% of what it would have produced un-shaded.