White Nose Syndrome has killed around 6 million American bats in the last seven years. Bat populations in Pennsylvania and at least 21 other US states and 5 Canadian provinces have been devastated with a mortality rate of nearly 100 percent. The outlook for bats from this menace is grim.
But the news for bats gets worse.
A new study published in the journal BioScience estimates that more than 600,000 bats died from interactions with wind turbines in the continental United States last year alone – and that estimate is almost surely on the low side.
Can bats survive this double blow?
During my time at Pennsylvania’s Department of Conservation and Natural Resources (DCNR), I started and led the Pennsylvania Wind and Wildlife Collaborative – an effort that involved federal and state wildlife agencies, conservation organizations, and the wind power industry. Over four years of work by PWWC led to a voluntary cooperative agreement between wind companies and the PA Game Commission, and the nation’s first comprehensive siting standards for wind power development. But even that groundbreaking work to find the delicate and elusive balance that preserves the natural world and allows climate-saving technology to be deployed may not be enough in the face of the challenges bats face.
Clearly, we must preserve existing bat habitats - not only caves, but forests. This is critical, to provide conditions that would support population recovery. Voluntary agreements may need to become requirements. But we also need to expand – or at least not dismantle - protections for endangered species. There’s an extraordinarily ill-advised bill moving in Harrisburg that would severely compromise those protections. It would be very bad public policy to weaken protections for endangered species, or limit the state's ability to add species - like more kinds of bats - to the list.
On existing wind farms, we need to move to regulations that stop turbine blades from spinning during predictable, high-risk periods, like when wind speeds are low. That has demonstrated reductions in bat fatalities of up to 93%, with only marginal losses in total annual energy production. And we need to urgently advance R&D for using acoustic deterrents to limit bat/turbine interactions. There have been promising results, but the technology is apparently not yet ready for deployment.
But there’s another reality that needs to be faced. Without these measures – and perhaps more - a renewable energy-dominated future will vastly increase the risk to bats.
The National Renewable Energy Laboratory has concluded that it’s possible to get 80% of America’s energy from renewables by 2050. Wind currently provides about 3.5% of US energy. In NREL’s 80% renewables scenario, wind would provide more than 40% of the nation’s electricity, a more than eleven-fold increase over the next four decades.
That would come on top of an immense amount of landscape industrialization - construction of 110-190 million miles of new transmission and 47-80,000 miles of new intertie capacity. Habitat destruction and fragmentation would be unavoidable and widespread.
Can bats survive White Nose Syndrome and a renewable energy future? We must urgently find ways to answer "yes" for both.