MCE will raise its premium slightly for its cleanest energy plan for the first time in 15 years.

As of Oct. 1, the average monthly cost for “deep green” residential customers will increase by $1.11, or 0.6%, to $182.34. Commercial customers will see an average monthly increase of $2.92, to $530.41.

Under the deep green plan, MCE buys wind, solar and geothermal power equal to 100% of each customer’s usage. The electricity is delivered over the infrastructure of Pacific Gas & Electric Co. Monthly electric bills combine charges from both entities.

About 7% of MCE’s 1.5 million customers are enrolled in deep green. Almost everyone else is in its “light green” program, which is 60% renewables. A local solar project has a small number of users.

MCE — formerly known as Marin Clean Energy — is in 38 jurisdictions in Marin, Contra Costa, Napa and Solano counties. That includes Marin’s unincorporated areas and all 11 of its towns or cities.Since 2010, MCE has charged a 1-cent per kilowatt hour premium for deep green participants. In recent months, management has been looking at raising the premium. In 2024, the plan’s administrative costs exceeded revenues by $10 million, said Johnstone Kipyator, a MCE analyst.

In early July, MCE’s executive board rejected a half-cent premium increase. That led management to present two alternatives to its full board on Thursday: a quarter-cent or a half-cent increase. The full board, composed of officials from all the member jurisdictions, voted 17-9 to approve the smaller increase.

Most of Marin voted no. Board members from Belvedere, Corte Madera, Fairfax, Larkspur, Mill Valley and Novato opposed the increase. Ross’ representative supported it. Representatives of San Anselmo, San Rafael, Sausalito and Tiburon were absent.

Most board members from Napa, Solano and Contra Costa counties voted yes.

Marin’s opponents said households, businesses and local governments were facing financial pressures. They noted MCE’s energy plans already were slightly more expensive than PG&E.

“One of my priorities as just one board member is getting and keeping the price of deep green below PG&E,” said Eli Beckman, a board member who is on the Corte Madera Town Council. “I want to see MCE taking market share from dirty energy.”

“I’m going to vote no,” said Max Perrey, who is the MCE executive board chair and a member of the Mill Valley City Council. “Our mission is to clean the grid and I think that deep green is one of the simplest ways we can indicate to customers that we can do that.”

Half of the increase is intended to support MCE’s local rebates and subsidies for electric vehicles, charging stations, heating systems and low-income housing.

“I think we can cover the incremental cost by pulling down what deep green customers are contributing” to these programs, said Kevin Burke a member of the Belvedere City Council.

MCE’s current fiscal year budget anticipates $10.9 million in income after $50.2 million in operating expenses. It projects spending $831 million on power contracts and holding $471 million in reserves.

MCE board members from outside Marin said the revenue from deep green should offset its costs.

“It’s important to me that people pay us for what they are getting,” said Cindy Darling, a member of the Walnut Creek City Council. “It’s higher than it used to be.”

In other business, the board approved a pilot program for municipalities in which MCE would monitor deep green energy sources on an hourly basis to ensure the jurisdictions are receiving 100% renewable energy around the clock.

Currently, the state’s certification of 100% renewable plans requires intermediaries like MCE to match each customer’s usage with the agency’s clean energy purchases on an annual basis. When demand peaks, customers will get whatever is on the grid, which is like a giant reservoir fed by different streams. Starting in 2028, the state will require the hourly tracking and matching of renewables.

The pilot program will be offered to 400 municipal accounts, such as a single firehouse or water plant. It is limited to one-thousandth of the total renewable energy in MCE’s deep green portfolio. MCE estimates increased monthly costs will range from $60 for small municipal accounts to $10,100 for the largest accounts.