Below the Mandalay Bay Hotel in Las Vegas, they glimmer in the relentless Nevada sun like scales on a monstrous grey dragon. More than 26,000 solar panels cover 113,000 square metres of rooftop. It's the biggest solar array of its kind in America.

"Just look at its physical size," says MGM's chief sustainability officer Cindy Ortega from high atop the Delano hotel which overlooks the arrays. "We have a lot of sunshine here and we want to take advantage of that renewable energy."

The solar panels were installed by MGM to power 25 per cent of the peak energy used by three of its hotels, and generate so much electricity that MGM Hotels can now source all its power from someone other than the Nevada utility.

"At the hottest part of the day, it produces enough power to power 1,350 customers of the Nevada utility," Ortega says.

MGM now plans to obtain some of its energy from its solar installations and other renewable resources, and buy the rest on the wholesale market.

Fantastic, if you're a fan of clean energy. Disaster, if you're privately owned Nevada power utility NV Energy. Seven per cent of its revenue will disappear when the hotel chain pulls the plug, but the utility wouldn't allow that to happen without a fight.

MGM to compensate utility

After a protracted legal battle with NV Energy, MGM has now agreed to cough up $87 million to make up the shortfall.

"What that money goes towards is making sure all the other ratepayers here in southern Nevada aren't harmed or don't have higher power bills because MGM left the grid," says Ortega.

This is what happens when disruptive technology becomes popular: The monopolies fight back. And increasingly, those who are actually being disrupted are the people who have chosen to go solar, like Judi Penna.

"Right here are my solar panels‚" she says, pointing at the panels covering half of her extensive roof in North Las Vegas.

Last year she heard about what she calls "a beautiful plan." It's known as "net metering;" if you install solar panels you can earn credit by sending excess energy back to the power company.

"I jumped on it!" she says. "But that‚" she says, pointing at her roof, "is only half the panels I need."

Net metering scrapped as panels half installed

She had panels installed on the right half of her roof. Then the Nevada power utility suddenly scrapped the deal. With so many people switching to solar, the utility said it was losing revenue and would have to pass the costs off to its non-solar customers. Instead it chose to slash the amount of credit solar customers like Penna got for selling electricity back to the system, effectively cancelling the net metering program. And elected officials did nothing to stop it, she says.

"It's politics at work to help a few keep their money," Penna says.

With that, the consumer solar industry in the country's sunniest state was basically shut down.

As of June of this year, there are approximately 30,000 rooftop solar customers in Nevada, producing more than 265 megawatts of electricity, about three per cent of NV Energy's peak demand.

The impact of the utility's decision to end net metering can be seen at SolarCity, which last year was selling solar panels in Nevada faster than the company could install them.

"So we're here in SolarCity's call centre," says Chandler Sherman, the company's spokeswoman, as she walks down an aisle between dozens and dozens of cubicles. About 200 salespeople are on headsets, some sitting, some standing, some walking, almost all of them trying to convince someone to go solar.

Sales of panels in Nevada dive

"They are selling solar around the country but they can't sell solar to their own neighbours here in Nevada because of the policy decision that made solar unaffordable for Nevadans," Sherman says.

"There were about 1,400 people applying to go solar every month in 2015," she says. "After the new rates went out, it's about 15 per month, in the entire state of Nevada. One-five people. Out of a state of three million."

At a nearby SolarCity warehouse, there's only one worker and one empty truck. Inside are dozens and dozens of solar panels with names taped to them; panels that were destined for Nevada customers who no longer want them.

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