We have discussed in the previous post how wind turbine effects on wildlife and what we could do to overcome the problem. Now we will discuss the potential effects of solar farms on wildlife and what are the possible mitigation solutions we could take to lessen the effects.
There are many reports of wind farm impacts on wildlife for the past few years. However, unlike the wind farm, solar farm impacts on wildlife have been hardly reported.
There are two main types of solar power, which are photovoltaics (PV) solar power, and concentrated solar power (CSP). PV technology directly converts sunlight into electricity using panels made of semiconductor cells, while CSP technology harnesses the sun’s heat and used it directly or converted into mechanical energy and in turn electricity. These solar powers could be installed individually for homes (usually PV solar power), or at a larger scale where it covers hundreds of acres of land (PV and CSP).
With a recent increase in interest of solar power usage, it could impose direct and indirect environmental effects especially when the development is at a large utility-scale. Theoretically, the indirect impacts to wildlife primarily link to habitat loss and fragmentation, where solar farm requires large tracks of lands (Hernandez et al., 2014; McDonald et al., 2009; Lovich and Ennen, 2011).
The direct impacts of CSP facilities can be seen in Southern California where it has killed 16,200 to 59,400 birds per year mainly caused by solar flux and impact trauma (Walston et al, 2016). When the birds fly through the tower or perch on the mirror panel, the heat could damage the feathers and the soft tissue and hinder the bird’s ability to fly (Kagan et al., 2014). Additionally, the light intensity from the CSP may attract insects even during the daytime and in turn, attracts their predator like birds and bats.
Unfortunately, the direct impacts of PV solar power on wildlife has not yet been monitored. Many taxa like birds and insects use polarized light pattern as orientation cue (Horvath et al, 2009), and the reflected artificial polarized light from smooth surfaces could disrupt their behavior and orientation. PV solar panel has a smooth surface that can reflect polarized light and attracts confused aquatic insects to attempt to lay eggs on the surface instead of water. This behavior could result in mortality and reproductive failure in aquatic insects (Horváth et al., 2010; Blahó et al., 2012). However, this situation might be good and exploited by insectivorous predators such as Wagtails, Sparrow and Great Tit where they have been observed to feed on these polarotactic insects that are trapped on highly polarizing black plastic sheets (Kriska et al., 1998; Bernáth et al., 2008) and vertical glass surfaces (Horváth et al., 2009).
As for common bats species, activity patterns are more likely to be affected indirectly by the habitat change for solar power facilities. Currently, there is limited information on the direct impacts of PV solar power on bats due to no monitoring has been conducted around the facilities. Although Greif and Siemers (2010) did not report any fatality during their study, it is shown that bats perceive horizontal smooth surfaces as water bodies and repeatedly try to drink from it. The smooth panel could affect their foraging activity where they might collide or injure their jaws when attempted to drink from the panels. Similar cases like the birds, the trapped insects on the polarized PV solar panel could lure the insectivorous bats to hunt on them too (Horvath et al., 2010). It is still unknown either this situation is beneficial to bats or brings them harm and injure the bats somehow.
Potential mitigation?
We would like to find ways to minimize the negative effects of solar panel farms on wildlife by identifying viable mitigation method. To reduce the habitat loss because of the solar farm development, unused portions of airport lands can be used to locate some solar facilities, where it can reduce the negative effects on wildlife (DeVault et al., 2012). Another proposed solution by Smith and Dwyer (2016), development of solar farm should avoid the areas that are inhabited by sensitive species or those with conservation concern. Using a partitioned white-gridded solar panel or a matte solar panel with a low level of polarization could reduce aquatic insects’ attraction (Horvath et al, 2009; 2010) compared to a homogenous black solar panel. By reducing the insect’s attraction around the facilities, birds and bats might avoid the area with less prey abundance.
The main point here is to recognize that renewable energy does help to reduce greenhouse gas emissions, but we should also develop them in ways that also minimize their impacts on wildlife, balancing the needs of climate change mitigation and nature conservation. More work is needed to quantify the effects associated with renewable energy which then will allow a more realistic approach and better predictions about how their implementation will affect wildlife.
By: Amira Rahman
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References:
Bernáth, B., Szedenics, G., & Molnár, G. (2001). Visual ecological impact of a peculiar waste oil lake on the avifauna: dual-choice field experiments with water-seeking birds using huge shiny black and white plastic sheets. Arch Nature Conservation Landscape Res. 40: 1–28.
Blahó, M., Egri, Á., Barta, A., Antoni, G., Kriska, G. & Horváth, G. (2012). How can horseflies be captured by solar panels? A new concept of tabanid traps using light polarization and electricity produced by photovoltaics. Veterinary parasitology. 189(2-4): 353–65.
DeVault, T.L., Belant, J.L., & Blackwell, B.F. (2012). Airports offer unrealized potential for alternative energy production. Environmental Management. 49: 517–522.
Greif, S. & Siemers, B.M. (2010). Innate recognition of water bodies in echolocating bats. Nature Communications. Nature Publishing Group, 1, November, p. 107.
Hernandez, R.R. (2014). Environmental impacts of utility-scale solar energy. Renewable & Sustainable Energy Reviews. 29: 766-779.
Horváth, G., Kriska, G., Malik, P. & Robertson, B. (2009). Polarized light pollution: a new kind of ecological photopollution. Frontiers in Ecology and the Environment. Ecological Society of America, 7(6): 317–325.
Horváth, G., Blahó, M., Egri, Á., Kriska, G., Seres, I. & Robertson, B. (2010). Reducing the maladaptive attractiveness of solar panels to polarotactic insects. Conservation Biology. 24(6) pp. 1644–1653.
Kagan, R.A., Viner, T.C., Trail, P.W., & Espinoza E.O. (2014). Avian Mortality at Solar Energy Facilities in Southern California: A Preliminary Analysis. National Fish and Wildlife Forensics Laboratory, Ashland, OR, USA. http://www.ourenergypolicy.org/avian-mortality-at-solar-energyfacilities-in-southern-california-a-preliminary-analysis/
Kriska, G., Horváth, G. & Andrikovics, S. (1998). Why do mayflies lay their eggs en masse on dry asphalt roads? Water-imitating polarized light reflected from asphalt attracts Ephemeroptera. The Journal of Experimental Biology. 201(Pt 15): 2273–86.
Lovich, J.E., & Ennen, J.R. (2011). Wildlife conservation and solar energy development in the desert southwest, United States. Bioscience. 61(2): 982–992.
McDonald, R.I., Fargione, J., Kiesecker, J., Miller, W.M. & Powell, J. (2009). Energy sprawl or energy efficiency: climate policy impacts on natural habitat for the United States of America. PLoS ONE 4, e6802. (Online DOI: 10.1371/journal.pone.0006802).
Smith, J.A, & Dwyer, J.F. (2016). Avian interactions with renewable energy infrastructure: An update. The Condor: Ornithological Applications. 118: 411–423.
Walston, L. J., Rollins, K. E., LaGory, K. E., Smith, K. P. and Meyers, S. A. (2016). A preliminary assessment of avian mortality at utility-scale solar energy facilities in the United States. Renewable Energy, 92, July, pp. 405–414.
