Arizona has been ground zero for the American Legislative Exchange Council-backed effort to penalize homeowners who build solar panels on their homes.

Last year, the state's main electricity company, ALEC member Arizona Public Service (APS), pushed for a huge new surcharge on families and companies that switch to cheaper (and cleaner) solar energy, which would have had the effect of driving up the costs of rooftop solar and keeping more consumers dependent on the fossil fuel-powered electricity grid.

In November of 2013, the Arizona Corporation Commission -- the agency tasked with regulating utilities -- voted 3-2 against [3] APS' effort to "tax the sun." (The next month, ALEC considered [3] an "updating net metering policies resolution" reflecting APS' push to charge solar users, which fit squarely within ALEC's antagonism [4] towards renewable energy). The Corporation Commission instead passed a smaller tax, allowing APS to charge homeowners around $5 per month for home solar panels rather than the $50-100 solar "deathblow [3]" that the industry had sought.

Many suspect that APS is now secretly seeking revenge.

This year, two seats on the Corporation Commission are open, and a wave of undisclosed dark money has flooded into the races, attacking the candidates that support solar and boosting those that are expected to support the industry. Many suspect that the true source of the funds is APS -- a charge that the utility company has not denied [5], although they have denied donating to similar groups in the past.

Arizona is an overwhelmingly Republican state, and currently every member of the Corporation Commission is a Republican. Yet, the issue of solar energy has not split along party lines. The son of conservative icon Barry Goldwater, for example, is a solar advocate and chairman [6] of the group "Tell Utilities Solar won't be Killed" (known as "TUSK").

The four Republicans vying for the two seats have split into two camps: Vernon Parker and Lucy Mason, who are described as "consistently pro-solar," and Thomas Forese and Doug Little, who are viewed as sympathetic to APS interests.

The Arizona Free Enterprise Club, a nonprofit dark money group, has spent around half-a-million boosting Forese and Little and attacking Parker and Mason. Although it is unprecedented to have this level of spending in a Corporation Commission race, the Club had previously had not even been a major player in any Arizona elections.

"Seemingly overnight, the Arizona Free Enterprise Club has morphed from a low-profile, low-tax advocacy group into the biggest-spending organization of this year's election season," the Arizona Republic noted [7] this month.

Save Our Future Now, another dark money nonprofit that keeps its funders secret, has spent almost $400,000 attacking Parker.

"The candidates supported by APS or the Arizona Free Enterprise Club would pursue utility-friendly regulations at the expense of ratepayers and the solar industry," says Gabe Elsner, Executive Director of the Energy & Policy Institute, a clean energy watchdog.

"When your company attempts to buy and pay for its regulators, you are planting the seeds for an Enron-like moment to happen," Parker and Mason wrote [5] in a July letter addressed to APS' CEO, Don Brandt. "Arizona ratepayers cannot be guaranteed affordable and reliable energy when the largest regulated monopoly handpicks it regulators."

Even national figures on the right are concerned.

“APS is literally attempting to purchase its regulators in the state’s August 26th Republican primary,” wrote [8] Townhall columnist Rachel Alexander. “If successful, the implications are national, especially for fledgling solar power, and crony capitalism will have a new model that will boomerang on the Republican Party.”

The Free Enterprise Club has additionally spent more than half-a-million on the Secretary of State race backing Republican state Rep. Justin Pierce, whose father is on the Corporation Commission and a reliable vote in favor of APS interests. Pierce's opponents have claimed that APS is backing the Corporation Commissioner's son as a "thank you."

If APS is providing the funding for the dark money groups, it wouldn't be the first time.

In 2013, the Koch-backed 60 Plus Association [9] entered the Arizona solar battle, spending $3.7 million on a website [10] and ads [11] claiming that solar amounts to "corporate welfare" helping "out of state billionaires." APS initially denied [6] funding 60 Plus and its anti-solar campaign, but later admitted [12] that it had backed the group.

Notably, APS acknowledged [13] earlier this year that its funding for the 60 Plus campaign was being coordinated by Sean Noble [14], a close associate of the Kochs and president of American Encore [15], formerly known as the Center to Protect Patient Rights. Noble was central to the $11 million "campaign money laundering scheme" in California that resulted in a record $1 million fine.