The price tag for California’s push for 100% renewable resources to generate electricity supplies by 2045 is well above $100 billion, according to an analysis by Moody’s Investors Service.

Reacting to state Senate Bill 100 signed last week by Gov. Jerry Brown, Moody’s Vice President Toby Shea, a senior credit officer, said to reach a carbon-free power grid “will likely mean that the gas capacity will need to be replaced with a massive amount of battery storage, which is still prohibitively costly for long periods.”

Shea estimated the current “all-in” battery storage costs at about $400/kWh, a direct cause of retail electric utility rates skyrocketing, which would put more political, regulatory and financial pressures on distribution utilities.

“The capital cost of having enough batteries to reach the 100% target will be more than $100 billion, assuming installed battery costs decline to $100/kWh of storage capacity,” Shea wrote in his analysis, which was issued on Monday.

The renewable standard goals, according to Moody’s, are inherently credit negative for the predominantly natural gas-fired fleet of utility and merchant operator plants, including Pacific Gas and Electric Co., Southern California Edison Co., San Diego Gas and Electric Co., Los Angeles Department of Water and Power, Calpine Corp. and NRG Energy Inc.

The electricity sector’s need to have supply and demand matched at all times to avoid blackouts and other forms of grid failure makes the goal of carbon-free power far-reaching, according to the analysis.

With the growing dependence on intermittent sources of wind and solar, there is ever-greater pressure to have excess power supplies that currently are supplied by gas-fired peaking plants.

Ironically, the increased reliance on renewables, now estimated at 32% by the California Energy Commission (CEC), points to the need for quick-start gas-fired generation as the technology of choice, even though state policy has ruled out future reliance on using gas for power, the analysis indicated.

In addition, “gas plants are so much in need now that the California Independent System Operator has contracted for about 850 MW of gas capacity to its back-up procedure procurement process to ensure grid reliability.”

However, California is still 27 years away from the 100% renewables goal, and there are “many moderating factors,” including new technology and/or a continuing decline in battery costs, according to the analysis.