Photosynthesis vs. Photovoltaics
When Urban Foresters Meet Wisconsin’s Solar Access Law
Questions about solar access and urban forestry conflicts are becoming increasingly frequent in my renewable energy practice. After going through 20 years with no calls regarding such conflicts, I have encountered five such conflicts since the start of 2011. Conflicts arise because trees and solar energy systems are competing for the same resource – access to the sun. But the needs of trees and solar energy systems can be harmonized if appropriate planning and legal systems are in place.
On January 31, at the 2012 Wisconsin Arborist Association/Wisconsin Department of Natural Resources Annual Conference in Green Bay, I dove further into this subject. My presentation was entitled “Solar Access and Urban Forestry in Wisconsin: Laws, Conflicts and Potential Solutions.” The audience primarily comprised of urban forestry professionals and state and local governmental officials. It included the City Forester for the City of Madison, the City of Milwaukee, the City of Oak Creek, and others. They asked very good questions, and some audience members had encountered these conflicts in their professional experiences.
Competing interests of urban forestry and solar energy development can, on occasion, lead to conflict. Shading of solar energy systems has a different impact on solar photovoltaic (PV) systems than it does on solar thermal (aka, solar hot water) systems. The adverse impact on PV systems is much more severe, but both can be significantly impacted by shading.
Wisconsin’s solar and wind access laws are quite comprehensive and probably the most protective of solar access of any such state laws in the entire country. Some members of the audience were surprised to learn that “vegetative growth that occurs” and impairs solar access to a solar energy system, can be considered a “private nuisance,” even if the growth occurs after the solar energy system is installed. There is no automatic grandfathering for trees that are planted first.
Solar-Tree conflicts can create specific problems that affect the day-to-day job functions of Urban Foresters, including:
– Reconciling their municipality’s mixed policy messages – promoting energy efficiency gained from tree shading while simultaneously promoting renewable energy generation from solar energy systems.
– The difficulty of performing their jobs without making somebody upset – in complying with the solar access law, they may be creating unhappy neighbors who don’t want their favorite local tree to be pruned.
– The difficulty of picking appropriate trees for medians and rights-of-way, knowing that those trees may or may not be someday be adjacent to solar energy systems.
– Knowing what to do if a mature tree that shades an area desirable for solar has to be removed due to disease and replaced by another healthy tree. Does the replacement forfeit any pre-existing “growth rights” that its predecessor may have had?
Don’t despair – Potential solutions exist that can enable sensible urban forestry policy and sensible solar energy promotion to live side-by-side. Potential solutions for mitigating current conflicts include:
– Better-coordinated urban planning
– Using planning software that minimizes solar-tree conflict by providing relevant data reflecting growth and shading
– Community education and local solar advisory committees
– Borrowing from innovative local ordinances in other states
– Possibly making modest changes to the Wisconsin solar access law to better accommodate urban forestry concerns
The best solution will protect investments in both solar energy systems and trees and offer predictability and certainty in the planning process. A copy of the slides from the presentation is available here: WAA Annual Conference Presentation (1-30-12 Final.pdf)
Written on February 6, 2012 at 3:34 pm, by Michael Allen