The Arizona Corporation Commission will allow Arizona Public Service to charge customers, who install rooftop solar panels, a fee of 70 cents per kilowatt of power they generate each month.

That means a customer with a typical rooftop solar array will pay APS just under $5 a month.

The fee is meant to offset the cost of electrical grid upkeep that customers with solar panels avoid paying by generating their own power.

APS officials had hoped for a fee that was much larger than what it will be allowed to charge.

“The proposal that was adopted, it falls well short of addressing the cost shift, and it actually pushed the problem down the road,” said Jenna Shaver, APS spokesperson. “It will be much more difficult to solve and harder to address in our next general rate case in 2016.”

The rate change will go into effect the next time the utility has a rate change, which is scheduled for 2015.

APS customers, who already have rooftop solar or those who submit an application before the end of the year will not be charged the fee.