Model step
IV shading current scale
Electrical shading applied to the array current
Inputs used: Electrical shading effect, Fraction for electrical effect
What it is
Electrical shading is the power lost when a partial shadow limits the current of the strings it touches, beyond the light the shadow removes. The loss diagram counts it as a power loss in its own row. The options set whether the array's current shrinks with that loss. The current enters the loss in the DC cables, the cable voltage drop and every operating point the inverter finds away from the maximum-power point. On strings sized for the window the choice changes the annual energy by a few hundredths of a percent, through the cable loss. On strings that run below the window it can reach a few percent, through the current at the floor. Timesteps without electrical shading are not affected.
Options
- Scale the curve by the electrical shading: the array curve's current scaled by the share of power the electrical shading leaves
- Leave the curve unscaled: the array curve keeps its unshaded current under electrical shading
API
inverter.iv_shading_current_scale = electrical_fraction | off