People often ask us how they can incorporate additional gains and effects from bifacial and floating PV arrays. At the moment, there is not a validated mathematical model behind how to simulate gains from bifacial modules, or the effects on production for floating PV arrays, but there are ways to consider these effects in your designs in HelioScope.
Change Soiling Losses
The primary way to incorporate gains from bifacial or increased reflected irradiance from a floating PV array is to edit the soiling losses in your Condition Set. For example, if you expected to see an annual 10% gain in production from these effects, you would reduce your soiling loss for the year by a factor of 10. Negative soiling losses translate to gains in the simulation and you can easily adjust each month independently if the expected gains or losses vary month-to-month. Below is an example of how the soiling loss would change from a default value of 2% after being boosted by 10%
- Default soiling loss: 2.0%
- Soiling with 10% boost: -8.0%
To do so, edit the default condition set or add a new condition set from within the "Conditions" tab in the desired project.
Scroll down to "Soiling" from the menu and enter the monthly values for soiling.
Note: Although albedo, the fraction of light that a surface reflects, is not a visible or an editable option in HelioScope, it is hardcoded into the simulation at 0.2 (20%).
Edit Temperature Coefficients
People can also edit their Condition Set to change the temperature coefficients to change how HelioScope simulates cell temperature for a given ambient temperature and wind speed. HelioScope Condition Sets use default temperature coefficients for standard roof-mounted installations, so these can be modified to address irregular installation conditions.