There are two must-know notions in the solar business and every seller, buyer and installer must know what it means, those are Power Density and Specific Weight. But why are they so important?
The power density is the total power generated by a PV module divided by the area of that module with units of watts per square meter (W/m2 ). Higher-density modules are preferred for rooftop solar installations where there are limited surface areas. This measure is suitable for PV module buyers to know what PV module is a better choice for their rooftop.
To put in simple words, if you have a small roof and want to produce as much as possible energy from your solar panels, you must go with the panel with the highest Power Density. This notion should not be misunderstood with the efficiency notion. The efficiency of the PV module is defined as the total power generated per unit area (m2 ) divided by 1,000 W/m2 and multiplied by 100.
The specific weight with units of watts per kilogram may be a more appropriate metric for measuring the load of PV modules mounted on the rooftops of households. Because mounting PV modules on rooftops put excess load on it. Thus, it should be paid more attention to, by both installers and buyers. It is defined as the total generated power of a PV module per unit weight.
For instance, PV-Magazine recently reported that JA Solar’s Jumbo model is the heaviest solar panel on the market. Although the weight of this PV module is more than other modules, it is not a good parameter to judge whether it is suitable or not for rooftop solar installations. If you calculate the specific weight of that solar panel and the PV-magazine proposed solar panel, you will find out that the specific weight of JA Solar’s module is lower than that.
In the case of its power density, the power density of the Jumbo model is lower than the proposed ones. Thus, we can conclude that it is not suitable for rooftop solar installation because of its high weight.
By considering these two notions besides its price, households can conclude which PV module is suitable for them or not. To this end, They should calculate the power density and specific weight of modules.
Did you know? Solar Edition publishes Monthly the most efficient solar Panels list based on Power Density and Efficiency for 60 and 72 cells panels? Click here to learn more …