Kermit the Frog was right – it’s not easy “Bein’ Green.”

The latest example in the struggle of going green is Oncor’s requested monthly minimum charge that the electric utility wants to put on customers who have installed what the company calls residential distributed generation, including rooftop solar panels or micro wind turbines.

The request will be addressed by the Texas Public Utility Commission at a hearing on July 31.

About 10,000 Oncor customers, approximately .00029 percent of the 3.4 million customers Oncor serves in North Texas, have installed solar or wind power at their homes.

Oncor is required to distribute electricity along its 122,500 circuit miles of transmission and distribution lines, and claims that the grid it maintains is designed to meet the peak demand needs of each of its customers – the maximum amount of electricity any one customer may require at any one time.

“Private rooftop solar panels do not reduce residential peak demand, they simply shift that demand to later in the day. Therefore, that residence still needs to be served by Oncor’s system that allows it immediate access to the grid with enough capacity to meet its peak demand,” said Oncor spokesperson Geoff Bailey in a statement to NBC DFW.

“Right now customers with residential distributed generation have reduced their electric delivery charges without reducing the cost to deliver it,” Bailey said.

Oncor claims that the personal savings that solar and wind customers are benefiting from have resulted in an increased cost to the rest of its residential customers, effectively raising rates by as much as $2 million.

With its proposed minimum monthly delivery charge – which might amount to more than $30 a month to many solar and wind customers – Oncor claims it will not increase its revenue.

“[Instead] it will only ensure that those who benefit from electric delivery are paying for it,” Bailey said.

Many proponents of solar power are not buying Oncor’s claims.

“As a solar energy advocate we think that’s a bad idea,” said Larry Howe, a representative of Plano Solar Advocates, a grassroots, volunteer organization of citizens whose mission is to increase awareness and use of solar energy.

Howe acknowledged that Oncor has been “very supportive” with energy efficiency initiatives. For example, Oncor stated it has invested $2 billion to build CREZ lines, which are transmission lines that run to the massive wind turbines in West Texas and the panhandle, in addition to spending $500,000 in energy efficiency credits since 2010 and $62 million in solar incentives.

But Howe said that, with its proposed monthly charge, Oncor is trying to recoup the money it is losing from those customers who, like him, have “gone green.”

“I think the challenge is in any industry where customers don’t need as much as what they’ve sold to you in the past they are going to push back, and that’s exactly what they’re doing,” Howe said.

Howe said he is concerned the proposed monthly minimum charge could be a disincentive for those who are considering adding solar or wind power to their homes.

“Singling out a particular group of customers I would consider it discriminatory,” Howe said. “I mean if you’re going to go after solar people that invested their own money in solar then why wouldn’t you go after the guy who puts in a LED light bulb or installs an energy efficient air conditioner because they’re also using less of your service as well.”

Although solar and wind customers make up a tiny fraction of its North Texas service area, Oncor estimates that as many as 400 to 500 people add those features every month.