Do solar panels kill birds?

You may have heard something about renewable energy technologies like wind power and solar power being bad for birds. Even Donald Trump weighed in at a rally, saying “The wind kills all your birds. All your birds, killed. You know, the environmentalists never talk about that.”

So, is it true? Does solar power kill a lot of birds?

The answer is no. First of all, there are different types of solar power. Solar power installed by residents either on their roof or a ground installation do not harm birds at all. This is true whether the technology is photovoltaic panels or solar thermal collectors. In fact, birds will often nest in the space between your solar panels and the roof, because it provides a nice protected area.

So what’s with the rumor? Well, some types of solar do cause a small number of bird deaths. However, it’s important to compare those numbers against the main causes of bird deaths, including those causes by fossil fuel power sources.

Concentrating solar power and birds

Concentrating solar is a type of solar energy technology that is used in very large utility-scale installations. It’s much different from the kind of solar energy that a homeowner might install on their roof.

Instead of photovolatic panels that directly convert photons into electricity, concentrating solar uses huge fields of mirrors to direct sunlight at a central target. That targets gets very hot, up to hundreds of degrees. That heat energy is collected and then used to turn a steam turbine, which generates electricity.

These installations can be huge. For example, the Ivanpah solar electric plant in the Mohave Desert uses 173,500 mirrors. Altogether, the plant can generate up to 400 megawatts of power.

With a concentraing solar plant, birds can be harmed when they fly too close to the path of the reflected solar energy. If they do, they can basically get cooked by the high energy rays.

The estimate by biologists is that the Ivanpah solar plant kills about 3,500 birds per year this way.

Does photovoltaic solar power kill birds?

Photovoltaic panels, the kind of solar that homeowners install on their roofs, can also kill a smaller number of birds. However, this has really only been documented in large utility scale installations in the desert.

For example, during the construction of the 550 megawatt Desert Sunlight photovoltaic plant located in the Mohave Desert, contractors documented 173 bird deaths over three years.

According to the Audubon Society, these birds deaths are related to large solar photovoltaic installations in the desert, which to waterfowl can appear to look like bodies of water due to the reflectivity of the panels. This results in birds colliding with the surface of the panels.

This seems to be a problem specific to waterfowl and desert installations. Photovoltaic installations in non-desert ecosystems and solar panels on rooftops don’t seem to have the same impact.

In fact, you may find that birds want to nest underneath the solar panels on your roof because they provide a nice sheltered area. There are several companies that manufacture products designed to wrap around the perimeter of solar panels to keep birds and critters out.

What do we know about the human-related causes of bird deaths?

The 3,500 birds deaths per year at Ivanpah still sounds like a lot in absolute numbers. It would be a lot better if avian mortality was zero.

But to put this into perspective, you should understand the bigger picture of what kills birds, and what humans do to impact that.

There have been a number of academic studies that have looked into this issue, and one of the best ones I’ve found is by Environment Canada, the Canadian federal government department responsible for environmental policy.

In 2013, Environment Canada published a study investigating the causes of human-related bird deaths in Canada. While this study was focused on Canada, the numbers are just as useful for understanding this issue for the United States.

You can read the study yourself, but I’ve summarized the key points below.

What are the most common causes of bird deaths?

Cats, both feral and domestic, are the biggest killer of birds by far. In fact, it’s not even close.

According to this study, feral cats were responsible for a median count of 116,000,000 bird deaths annually. Domestic cats were responsible for killing another 80,000,000 birds. That’s a total of 196,00,000 deaths per year caused by our little furry friends. That’s a lot.

The next largest killer are collisions with power lines, which kills 25,600,000 birds a year. Collisions with houses causes 22,400,000 annual bird deaths.

The first energy-related cause of bird deaths that is technology-specific is listed as “Transportation - Chronic ship-source oil”. This refers to oil spills in water ways. Can you picture oil-covered seabirds struggling under a slick black coat of oil? This is what that refers to. It kills 321,900 birds a year.

Wind turbines are the only renewable energy source listed, and it’s estimated to kill 16,700 birds a year in Canada.

How many birds do coal plants kill?

It may seem obvious how the giant spinning blades of a wind turbine can kill birds, but it’s less obvious how fossil fuel plants might do the same or worse.

For numbers related to that, there was this article by the Danish Center of Energy Technologies that estimates that while wind farms may kill about 20,000 birds a year in the United States, fossil fuel generating plants kill about 14,000,000 birds a year.

This study took into account the full lifecycle related to power production, including mining, production, and emissions.

If you want to save birds, you should choose renewable energy

While the spectre of giant spinning propeller blades and massive fields of mirrors beaming searing hot death upon flocks of birds in flight may give you pause when thinking about whether renewable energy is really good for the environment, you should know that if you want to save birds and other wildlife, you should choose renewable power such as solar power.

Coal power plants have less of a dramatic impact on the landspace, but that’s because the real effects are hidden from view. Even if you live only a few miles from a coal plant, you don’t see the impact of mining, and you can’t see the fine particles (PM2.5) of pollution from coal burning that fills the air around your home.

Altogether, it’s estimated that 7,500 and 52,000 people in the United States die prematurely because of air pollution from coal burning. This is due to the fine particulate matter (PM2.5), sulphur dioxide, and nitrous oxides that are released into the atmosphere from coal. While scubbers on power plants can reduce this pollution, many plants today operate without this equipment.

Further reading

• Coal plants without scrubbers account for a majority of U.S. SO2 emissions (EIA)
• Solar Towers Don’t Seem to Be the Bird Destroyers Once Thought (IEEE.org)
• Why Solar Power Is Good for Birds (Audubon Society)
• A Synthesis of Human-related Avian Mortality in Canada (Environment Canada)