In this blog post we will discuss the unique hydrologic processes at these solar pv facilities and the associated stormwater permitting requirements in various states across the country.
Are solar panels impervious surface.
In 2010 new jersey enacted a similar law exempting solar panels from zoning limitations on impervious cover and anecdotally that law has been embraced in a state that is second in the nation in the total number of homes and businesses which have solar panels installed.
The total solar panel impervious surface for the project z times the panel width times the number of panels.
Solar panels are considered a disconnected impervious surface when water running off a panel is discharged to a pervious surface e g.
Elevated ground mount solar photovoltaic pv facilities present a unique situation for stormwater management because they usually involve an impervious surface elevated above a pervious vegetated surface.
The solar panel with the highest watt is the sunpower e series a commercial solar panel line.
1 roadways gravel surfaces and transformer pads within the solar array are considered effective impervious cover for the purpose s of calculating water quality volume wqv.
In order to determine the total impervious surface area for the project the z dimension should be used.
The top panel in the e series comes out at a whopping 435 watts.
This method will be used to determine the total water quality volume that must be treated for permitting requirements.
The vegetated area receiving runoff must be equal to or greater in length than the disconnected surface e g width of the row of solar panels.
Solar panels usually range in wattage output from around 250 watts to 400 watts but some panels exceed the 400 watt mark.
When non rooftop disconnection is used to treat runoff the following factors should be considered.
The stormwater standards include.
Cost alternative for treating runoff in situations like rows of solar panels.
Turf crop perennial vegetation.
Attenuation of peak rates of runoff caused by land development 310 cmr 10 05 6 k 2 provision of recharge 310 cmr 10 05 6 k 3 control of total suspended solids tss from impervious surfaces excluding solar panels 310 cmr 10 05 6 k 4 and the provision of adequate erosion and sedimentation controls.
In addition to these impervious surfaces all solar panels in the array should also be considered effective impervious cover for the purposes of calculating the wqv.
The mpca allows a volume credit for disconnected impervious surfaces.
