Experts said new mandatory fees proposed by DTE Energy would put rooftop solar out of reach for future residential customers.
Hundreds of pages into a 672-page filing with the Michigan Public Service Commission, DTE Energy proposes charging future customers in its residential solar program — called "distributed generation" — a fee based on the three highest 60-minute demands for electricity by the customer over the past year.
Ben Inskeep, a Principal Energy Policy Analyst with EQ-Research, said the proposed charge could easily amount to $100 a month or more.
And he said if DTE keeps its billing documents as they are now, there would be no way for a future customer to know what the charge would be, since peak hours of demand do not appear on bills.
"I certainly can't imagine any customer ever wanting to take service under this proposal," he said. "It would be too draconian and would completely erode any financial benefit one would receive from putting solar on their rooftops."
DTE Energy is also proposing to slash the bill credits that current rooftop solar customers get for exporting their excess solar energy onto the grid.
Inskeep said bill credits could be cut in half under the proposal.
In an email response, DTE Energy spokesperson Peter Ternes said the utility could not yet answer what the average monthly fee would be for new solar customers, nor could the company explain how customers would calculate the fee based on their three highest 60-minute demands for electricity over the past year:
We are at the beginning of the rate making process, so some of your questions cannot be properly addressed until we know the outcome of this rate review. Regarding the proposed rate, as written it would encourage customers to manage their home energy use and use the grid more efficiently. It offers customers the ability to reduce their own bills as they contribute to a reduction in the overall cost of the grid.
The proposed rate would appropriately charge customers based on the peak demand they are placing on the system. If a customer installing a DG system (rooftop solar) and taking service on our DG rate can reduce the peak demand they are placing on the system, then their bill will be rightfully reduced over time as they move to a lower service level. This structure ensures that DG customers are contributing an equitable amount toward system costs based on their usage."
In its filing, DTE Energy said it will voluntarily increase the current 1% cap on the number of customers that can participate in its residential rooftop solar program to 3%, but only if its proposals are approved.
The Michigan Public Service Commission has to approve the changes.
