America’s biggest environmental groups seldom, if ever, talk about the climate-change benefits of nuclear energy. Why not? There’s no money in it.

That’s the finding of a recent paper by Matthew C. Nisbet, a communications professor at Northeastern University. Nisbet examined the climate-change and energy grants given by 19 green-leaning philanthropies — including familiar names like the Hewlett, Kresge and MacArthur foundations. Between 2011 and 2015, the 19 foundations made 2,502 grants totaling nearly $557 million to environmental groups like the Sierra Club (the largest single recipient, with nearly $49 million in grants), Natural Resources Defense Council and Environmental Defense Fund.

Of that $557 million, the big environmental groups received nearly $187 million to promote renewable energy and efficiency. They got another $92.5 million for “climate change-related communication, media and mobilization” and nearly $82 million to oppose hydraulic fracturing and to “promote actions to limit/oppose [the] fossil fuel industry.” But “no grants were focused on promoting nuclear energy, though $175,000 in grants were devoted to opposing nuclear energy for cost and safety reasons.”

To underscore: Over a five-year period, some of America’s biggest foundations doled out more than half a billion dollars to some of America’s biggest environmental groups and not a penny was spent promoting nuclear energy, even though nuclear provides about 20 percent of US electricity and twice as much emissions-free juice as all US solar and wind, combined.

Nisbet’s paper is important because it exposes the anti-nuclear orthodoxy that prevails at some of America’s biggest philanthropic groups. Just as important, it shows that those same philanthropic groups are ignoring the conclusions of the world’s top climate scientists.

In 2013, four scientists, including former NASA climatologist James Hansen, Kerry Emanuel of the Massachusetts Institute of Technology, Tom Wigley of the University of Adelaide in Australia and Ken Caldeira of the Carnegie Institution published an open letter stating renewable-energy sources like wind and solar “cannot scale up fast enough to deliver cheap and reliable power at the scale the global economy requires.”

They continued, “there is no credible path to climate stabilization that does not include a substantial role for nuclear power.” They concluded by saying that if environmental activists have “real concern about risks from climate change,” they should begin “calling for the development and deployment of advanced nuclear energy.”

In 2014, the UN Intergovernmental Panel on Climate Change said achieving deep cuts in greenhouse gas emissions “will require more intensive use of . . . technologies such as renewables [and] nuclear energy.” In 2015, the International Energy Agency called nuclear power “a critical element in limiting greenhouse gas emissions.” It calculated that global nuclear-generation capacity must more than double by 2050 (to about 750 gigawatts) for there to be any hope of limiting temperature increases to the 2-degree scenario that is widely agreed as the acceptable limit.

Yet groups like the Sierra Club use their millions to continue peddling the myth that the United States can run its entire economy solely on solar and wind energy, despite numerous analyses that have demolished that notion. Even worse, Sierra Clubbers are ignoring the landscape- and seascape-destroying energy sprawl — plus the huge number of bird and bat kills — that would accompany an attempt to rely on renewables alone.

Dozens of rural communities from Maine to California are already rejecting the encroachment of Big Wind. Among the most recent rejections: In April, the upstate town of Hopkinton passed a law that effectively bans all wind projects.

The punchline here’s obvious: Nisbet’s paper shows America’s most prominent foundations aren’t helping advance the debate about energy policy and climate change. Instead, by succumbing to the groupthink that prevails on the anti-nuclear left, they’re hindering it.

Robert Bryce is a senior fellow at the Manhattan Institute and the producer of the forthcoming documentary, “Juice: How Electricity Explains the World.”