The state’s Department of Environmental Quality has defined solar panels as impervious surfaces for the purpose of measuring stormwater, which will increase project cost requirements.

Dominion Energy Virginia's Scott Solar facility in Powhatan County.

In March, the Virginia Department of Environmental Quality (DEQ) announced — effective immediately — a change to how it measures water runoff at solar farms. After some pushback, they shifted the start date to 2025.

The DEQ Stormwater page still carries the two memos ( 1 and 2 ) in their ‘Resources’ section. The specific language in the March 29th memo is:

Solar panels are to be considered unconnected impervious areas when performing post-development water quantity calculations using the hydrologic methods specified in the Virginia Stormwater Management Program Regulation.

The change in interpretation, to define solar panels and the land underneath them as impervious areas, can sometimes mean defining the dirt under a solar panel as having the same technical water absorption qualities as asphalt or a building. 

This additional water would thus have to be managed via tools such as a retention pond or drainage infrastructure. First, cost and space that would have been used for solar panels must instead be turned into the aforementioned ponds and infrastructure. The water runoff calculated by the state’s engineers could then be added to tax bills as stormwater fees, depending on each local jurisdiction’s regulations.

One way to mitigate the amount of land that is defined as impervious to water absorption is to store wires above ground in harness systems. This also limits the amount of trenching for said wires that occurs, which disturbs land and is accounted for in water runoff analysis. Some jurisdictions define the impervious area of a solar panel as when it is laid completely flat.

The utility scale solar industry in Virginia recently reached the top five states in terms of capacity installed, and has a nascent medium scale market. But shifting political leadership has recently downshifted the short and medium term trajectory of clean energy in the state.

Other regulatory changes are circulating as well.

For instance, the state legislature introduced House Bill 206 , which says if the DEQ finds a potential “significant adverse impact on wildlife, historic resources, prime agricultural soils, or forest lands”, the solar facility would be required to submit a mitigation plan for public comment. The bill states that disturbing more than 10 acres of prime agricultural land, 50 acres of contiguous forest, and registered forest land automatically requires the mitigation plan.

The law does not define mitigation, but leaves it open to be interpreted by various stakeholders. This law only applies to projects smaller than 150 MW.

This content is protected by copyright and may not be reused. If you want to cooperate with us and would like to reuse some of our content, please contact: editors@pv-magazine.com.

More articles from John Fitzgerald Weaver

This is so stupid. The dirt is just dirt and on tracking solar panels, the dirt underneath will get equally watered over the 24-hour period. On fixed solar panels is just like the area next to a garage or homes roof without gutters and downspouts. This is fossil fuel foolishness to stop renewable energy. The shade from the solar panels will keep the grasses that are growing underneath, greener and more tender for grazing animals longer saving the need for additional livestock feed later in the season. They also provide shade for the herd on hot days. Protection for the herd on rainy or stormy days when the required grounding will protect the animals from lightning.

Please be mindful of our community standards.

Your email address will not be published. Required fields are marked *

Save my name, email, and website in this browser for the next time I comment.

Notify me of follow-up comments by email.

Notify me of new posts by email.

By submitting this form you agree to pv magazine using your data for the purposes of publishing your comment.

Your personal data will only be disclosed or otherwise transmitted to third parties for the purposes of spam filtering or if this is necessary for technical maintenance of the website. Any other transfer to third parties will not take place unless this is justified on the basis of applicable data protection regulations or if pv magazine is legally obliged to do so.

You may revoke this consent at any time with effect for the future, in which case your personal data will be deleted immediately. Otherwise, your data will be deleted if pv magazine has processed your request or the purpose of data storage is fulfilled.

Further information on data privacy can be found in our Data Protection Policy.

Legal Notice Terms and Conditions Privacy Policy © pv magazine 2022

Welcome to pv magazine USA. This site uses cookies. Read our policy. ×

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.