Koichiro Otaki started taking aerial pictures of photovoltaic power stations in April 2015. At first, it was an innocent desire to capture their sheer scale and aesthetic value that motivated him, he says.

Solar parks, mostly in rural, desolate areas, were also among the few places where he could practice flying a drone without having to worry about hitting people or tall structures, he says.

Weather permitting, the 38-year-old freelance photographer would toss a compact drone into his backpack and venture out to the suburbs of Tokyo or up north to the Tohoku region by motorcycle, snapping away at solar panels neatly lined up along river banks, mountain slopes and even abandoned golf courses.

“I was simply captivated by their geometric beauty,” Otaki said of the panels. “Also, despite a recent boom in solar power generation, few people had seen such facilities firsthand. I just wanted to show people how they really look.”

Until the revised Civil Aeronautics Law came into force exactly a year ago, on Dec. 10, 2015, it was relatively easy for hobbyists to fly drones anywhere in the nation. Now, the use of drones and other unmanned aircraft weighing more than 200 grams are banned in crowded residential areas, at altitudes 150 meters or more above ground, and near airports.

Even with such restrictions, Otaki, who has since obtained a land ministry permit to fly drones, finds aerial photography fascinating, saying that drones have opened a whole new frontier for photographers. As he racked up experience, however, he started having mixed feelings about his subjects, he says.

Because solar parks require large tracts of land, some businesses bought up golf courses in the countryside that were abandoned after the collapse of the bubble economy in the early 1990s and installed panels there. He also heard from owners of other solar parks that, since the state-subsidized project is so lucrative, they wanted to level more mountains to install more.

“I realized that, under the veil of ‘clean energy,’ solar power has proliferated across Japan for reasons that had nothing to do with clean energy,” he says.

The number of solar power stations has surged on the back of a government push to promote renewable energy following the triple core meltdown at the Fukushima No. 1 nuclear power plant in March 2011, the worst nuclear disaster since Chernobyl.

According to the Natural Resources and Energy Agency, some 80 “mega-solar” projects covering power stations with an output of 1,000 kw or more each were completed or underway across Japan as of 2012.

Otaki now has a collection of drone photos he wants to use to show the darker side of solar power. A growing interest in energy issues has also taken him to Fukushima Prefecture, where he has taken shots of black plastic bags containing radioactive soil, rows of which are neatly stacked up along roads, like pyramids.

“I don’t want to be judgmental, and I don’t want to preach something through my photos,” he says.

“I want to deal with themes that are socially important enough, but somehow present them in a graphic way, giving people an opportunity to think about them.”