Philip Bartlett, chairman of the Maine Public Utilities Commission, speaks with reporters at the University of Southern Maine in Portland on July 16, 2019. Credit: Troy R. Bennett / BDN

Walmart and other large companies and energy groups are lining up to weigh in on a proposed electricity rate hike that has drawn stiff opposition from political figures including the governor and public advocate.

Central Maine Power Co. is seeking a hefty distribution rate increase from the Maine Public Utilities Commission to pay for reliability improvements. CMP notified the commission in May that it would ask to raise distribution rates to cover a $570 million reliability improvement plan that could create up to 85 new jobs over three years, and filed the request this month.

The decision could have deep impacts on customers who have seen gas and electric rates escalate over the past year, and the large number of interests set to weigh in on the increase includes businesses that use a lot of electricity, some of which plan to expand in Maine.

The rate isn’t the only concern among those who want to join the case, said a lawyer who handles similar cases before the commission. There are many aspects of rate cases, including operations of the utility that may affect climate change or services provided to low-income customers.

“Parties don’t intervene just to say ‘yes’ or ‘no’ to the new rate,” Melissa Horne, a lawyer with Rhode Island-based Higgins, Cavanagh & Cooney, said.

Under CMP’s plan, the average residential customer would pay $10 per month more to be phased in over three years starting in 2023, bringing the average bill for a home using 550 kilowatt hours of electricity to $136 per month in three years. An electricity bill includes two components, electricity supply and delivery. The delivery rate is set by the utilities and the supply rate by a competitive bidding process.

Versant Power, the state’s other dominant electric utility, also asked the commission in August to approve an average $10.50 per month increase in the distribution part of its residential electric bill starting next July. That would raise the average rate for a home using 500 kilowatt hours of electricity to $125.29 per month.

The plans quickly met strong opposition from the governor and public advocate. Gov. Janet Mills said Mainers are already struggling with sky-high costs from record inflation. The Democrat asked CMP and Versant to refrain from asking for the rate hikes, said her energy office would oppose them and called on the utilities commission to reject them.

Former Gov. Paul LePage, the Republican running against Mills in November, issued a statement calling the CMP proposal “frankly unacceptable” with Mainers “already struggling to pay their electric bills.”

The governor’s energy office and Public Advocate William Harwood have signed up to be intervenors in the case, as have the Conservation Law Foundation, Efficiency Maine Trust and Acadia Center. Business interests including Walmart, ChargePoint, Competitive Energy Services and the Industrial Energy Consumer Group also have requested intervenor status.

Walmart’s attorney told the regulator that it has interests in energy efficiency and technology and employees who could provide testimony “that will assist in resolving the issues presented in this case.” The global retailer is a large customer of CMP, owning and operating 17 retail units and a Lewiston distribution center, with more than 7,800 employees statewide. It has participated in earlier commission cases.

ChargePoint, a California electric vehicle charging station company, said it plans to install 2,400 more charging ports around Maine, including for school and transit buses.

The deadline to request status to intervene is Sept. 1, with various hearings held until regulators make a decision on the rate next year.